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38 results on '"Aldo Antognini"'

1. Measuring the α-particle charge radius with muonic helium-4 ions

Author

Sandrine Galtier, Julian J. Krauth, Andreas Knecht, Andreas Dax, D. Taqqu, Thomas Graf, Paul Indelicato, Yi-Wei Liu, Karsten Schuhmann, Andreas Voss, F. Mulhauser, Pedro Amaro, Malte Hildebrandt, D. S. Covita, L.M.P. Fernandes, Boris Naar, F. D. Amaro, Theodor W. Hänsch, Marwan Abdou Ahmed, José Paulo Santos, Andrea L. Gouvea, Lucile Julien, Randolf Pohl, Johannes Götzfried, F. Nez, Beatrice Franke, Jorge Machado, Tobias Nebel, C.M.B. Monteiro, J.F.C.A. Veloso, Joaquim M. F. dos Santos, François Biraben, Franz Kottmann, Marc Diepold, Csilla I. Szabo, Jens Hartmann, Jan Vogelsang, Klaus Kirch, Aldo Antognini, Tzu-Ling Chen, Birgit Weichelt, LaserLaB Vrije Universiteit Amsterdam (LaserLaB), Vrije Universiteit Amsterdam [Amsterdam] (VU), Max-Planck-Institute for Quantum Optics, Institut für Physik [Mainz], Johannes Gutenberg - Universität Mainz (JGU), Institute for Particle Physics and Astrophysics [ETH Zürich] (IPA), Department of Physics [ETH Zürich] (D-PHYS), Eidgenössische Technische Hochschule - Swiss Federal Institute of Technology [Zürich] (ETH Zürich)- Eidgenössische Technische Hochschule - Swiss Federal Institute of Technology [Zürich] (ETH Zürich), Paul Scherrer Institute (PSI), Institut für Strahlwerkzeuge, Universität of Stuttgart, Department of Physics [Coimbra], University of Coimbra [Portugal] (UC), Universidade Nova de Lisboa = NOVA University Lisbon (NOVA), Laboratoire Kastler Brossel (LKB [Collège de France]), École normale supérieure - Paris (ENS Paris), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Centre National de la Recherche Scientifique (CNRS)-Fédération de recherche du Département de physique de l'Ecole Normale Supérieure - ENS Paris (FRDPENS), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Centre National de la Recherche Scientifique (CNRS)-Centre National de la Recherche Scientifique (CNRS)-Sorbonne Université (SU)-Collège de France (CdF (institution)), National Tsing Hua University [Hsinchu] (NTHU), Universidade de Aveiro, TRIUMF [Vancouver], Atmosphère, Optique et Spectroscopie (ATMOS), Institut Lumière Matière [Villeurbanne] (ILM), Université Claude Bernard Lyon 1 (UCBL), Université de Lyon-Université de Lyon-Centre National de la Recherche Scientifique (CNRS)-Université Claude Bernard Lyon 1 (UCBL), Université de Lyon-Université de Lyon-Centre National de la Recherche Scientifique (CNRS), Ludwig-Maximilians-Universität München (LMU), Theiss Research, Lund University [Lund], Atoms, Molecules, Lasers, LaserLaB - Physics of Light, DF – Departamento de Física, and LIBPhys-UNL

Subjects
Physics, [PHYS]Physics [physics], Multidisciplinary, Muon, Proton, 010308 nuclear & particles physics, Nuclear structure, Atomic spectroscopy, Electron, 01 natural sciences, 7. Clean energy, Article, Ion, [SPI]Engineering Sciences [physics], Charge radius, 0103 physical sciences, [CHIM]Chemical Sciences, Physics::Atomic Physics, Exotic atoms and molecules, Atomic physics, Experimental nuclear physics, 010306 general physics, Spectroscopy, General
Abstract

The energy levels of hydrogen-like atomic systems can be calculated with great precision. Starting from their quantum mechanical solution, they have been refined over the years to include the electron spin, the relativistic and quantum field effects, and tiny energy shifts related to the complex structure of the nucleus. These energy shifts caused by the nuclear structure are vastly magnified in hydrogen-like systems formed by a negative muon and a nucleus, so spectroscopy of these muonic ions can be used to investigate the nuclear structure with high precision. Here we present the measurement of two 2S–2P transitions in the muonic helium-4 ion that yields a precise determination of the root-mean-square charge radius of the α particle of 1.67824(83) femtometres. This determination from atomic spectroscopy is in excellent agreement with the value from electron scattering1, but a factor of 4.8 more precise, providing a benchmark for few-nucleon theories, lattice quantum chromodynamics and electron scattering. This agreement also constrains several beyond-standard-model theories proposed to explain the proton-radius puzzle2,3,4,5, in line with recent determinations of the proton charge radius6,7,8,9, and establishes spectroscopy of light muonic atoms and ions as a precise tool for studies of nuclear properties., Nature, 589 (7843), ISSN:0028-0836, ISSN:1476-4687

Published
2021

2. Measurement of the quadrupole moment of Re185 and Re187 from the hyperfine structure of muonic X rays

Author

S. Roccia, Thomas Elias Cocolios, Natalia S. Oreshkina, Klaus Kirch, Angela Papa, Frederik Wauters, Andreas Knecht, Paul Indelicato, Rugard Dressler, Aldo Antognini, Randolf Pohl, Klaus-Peter Jungmann, Christoph H. Keitel, Nathal Severijns, Andreas Eggenberger, J. Nuber, E. Rapisarda, A. Ouf, Narongrit Ritjoho, S. M. Vogiatzi, Maxim Pospelov, Lorenz Willmann, Robert Eichler, Nathalie Michel, Niklaus Berger, and A. Skawran

Subjects
Physics, 010308 nuclear & particles physics, chemistry.chemical_element, High resolution, Germanium, Rhenium, 01 natural sciences, 7. Clean energy, chemistry, 0103 physical sciences, Quadrupole, Physics::Atomic Physics, Vacuum polarization, Atomic physics, 010306 general physics, Hyperfine structure
Abstract

The hyperfine splitting of the 5g→4f transitions in muonic Re185,187 has been measured using high resolution high purity germanium detectors and compared to state-of-the-art atomic theoretical predictions. The spectroscopic quadrupole moment has been extracted using modern fitting procedures and compared to the values available in literature obtained from muonic x rays of natural rhenium. The extracted values of the nuclear spectroscopic quadrupole moment are 2.07(5) b and 1.94(5) b, respectively for Re185 and Re187.

Published
2020

3. Demonstration of Muon-Beam Transverse Phase-Space Compression

Author

Andreas Eggenberger, K. S. Khaw, Florian M. Piegsa, Gunther Wichmann, Andreas Knecht, Ryoto Iwai, Narongrit Ritjoho, C. Petitjean, Angela Papa, Thomas J. Phillips, N. J. Ayres, V. Bondar, Klaus Kirch, Aldo Antognini, D. Taqqu, Daniel M. Kaplan, Ivana Belosevic, Alexey Stoykov, and Malte Hildebrandt

Subjects
Physics, Accelerator Physics (physics.acc-ph), Muon, Density gradient, 010308 nuclear & particles physics, Muonium, General Physics and Astronomy, FOS: Physical sciences, 01 natural sciences, Magnetic field, Transverse plane, Compression (functional analysis), Phase space, 0103 physical sciences, Physics::Accelerator Physics, Physics - Accelerator Physics, Atomic physics, 010306 general physics, Beam (structure)
Abstract

We demonstrate efficient transverse compression of a 12.5 MeV/c muon beam stopped in a helium gas target featuring a vertical density gradient and crossed electric and magnetic fields. The muon stop distribution extending vertically over 14 mm was reduced to a 0.25 mm size (rms) within 3.5 μs. The simulation including cross sections for low-energy μ+-He elastic and charge exchange (μ+↔ muonium) collisions describes the measurements well. By combining the transverse compression stage with a previously demonstrated longitudinal compression stage, we can improve the phase space density of a μ+ beam by a factor of 1010 with 10−3 efficiency., Physical Review Letters, 125 (16), ISSN:0031-9007, ISSN:1079-7114

Published
2020

4. muCool: a next step towards efficient muon beam compression

Author

Angela Papa, Alexey Stoykov, Andreas Eggenberger, Thomas J. Phillips, Malte Hildebrandt, Narongrit Ritjoho, Andreas Knecht, Daniel M. Kaplan, Ivana Belosevic, K. S. Khaw, Klaus Kirch, Aldo Antognini, Florian M. Piegsa, Gunther Wichmann, C. Petitjean, Ryoto Iwai, Yu Bao, and D. Taqqu

Subjects
Physics, Accelerator Physics (physics.acc-ph), Muon, Physics and Astronomy (miscellaneous), Physics::Instrumentation and Detectors, FOS: Physical sciences, lcsh:Astrophysics, 01 natural sciences, Magnetic field, Nuclear physics, Phase space, Electric field, lcsh:QB460-466, 0103 physical sciences, Perpendicular, lcsh:QC770-798, Physics::Accelerator Physics, lcsh:Nuclear and particle physics. Atomic energy. Radioactivity, High Energy Physics::Experiment, Physics - Accelerator Physics, Beam emittance, 010306 general physics, Engineering (miscellaneous), Energy (signal processing), Beam (structure)
Abstract

A novel device to compress the phase space of a muon beam by a factor of 1010 with a 10−3 efficiency is under development. A surface muon beam is stopped in a helium gas target consisting of several compression stages, wherein strong electric and magnetic fields are applied. The spatial extent of the stopped muon swarm is decreased by means of these fields until muons with eV energy are extracted into vacuum through a small orifice. It was observed that a 20 cm long muon stop distribution can be compressed in the longitudinal direction to a sub-mm extent within 2 μs. Additionally, a drift perpendicular to the magnetic field of the compressed low-energy muon swarm was successfully demonstrated, paving the way towards extraction from the gas and re-acceleration of the muons., The European Physical Journal C, 79 (5), ISSN:1434-6044, ISSN:1434-6052

Published
2019

5. Theory of the n=2 levels in muonic deuterium

Author

Franz Kottmann, Julian J. Krauth, Aldo Antognini, Marc Diepold, Randolf Pohl, and Beatrice Franke

Subjects
Physics, Nuclear Theory, QED, Atomic Physics (physics.atom-ph), 010308 nuclear & particles physics, FOS: Physical sciences, General Physics and Astronomy, Muonic deuterium, 01 natural sciences, Lamb shift, Physics - Atomic Physics, Nuclear Theory (nucl-th), Deuterium, Charge radius, 0103 physical sciences, Fine structure, Hyperfine structure, Physics::Atomic Physics, Atomic physics, 010306 general physics, Proton radius puzzle
Abstract

The present knowledge of Lamb shift, fine- and hyperfine structure of the $\mathrm{2S}$ and $\mathrm{2P}$ states in muonic deuterium is reviewed in anticipation of the results of a first measurement of several $\mathrm{2S-2P}$ transition frequencies in muonic deuterium ($\mu\mathrm{d}$). A term-by-term comparison of all available sources reveals reliable values and uncertainties of the QED and nuclear structure-dependent contributions to the Lamb shift, which are essential for a determination of the deuteron rms charge radius from $\mu\mathrm{d}$. Apparent discrepancies between different sources are resolved, in particular for the difficult two-photon exchange contributions. Problematic single-sourced terms are identified which require independent recalculation., Comment: 26 pages, add missing feynman diagrams (Fig. 3), renumber items (Tab. IV), correct a sum (column 5, Tab. IV)

Published
2016

6. Temperature dependence of the leak rate and permeability of helium gas through Kapton foils

Author

Andreas Eggenberger, Klaus Kirch, Ivana Belosevic, Aldo Antognini, and Florian M. Piegsa

Subjects
Physics, Nuclear and High Energy Physics, Helium gas, Analytical chemistry, 02 engineering and technology, 021001 nanoscience & nanotechnology, 7. Clean energy, 01 natural sciences, Kapton, Nuclear magnetic resonance, Permeability (electromagnetism), 0103 physical sciences, Barrer, Leak rate, 010306 general physics, 0210 nano-technology, Instrumentation, Order of magnitude
Abstract

The leak rate of helium gas through thin Kapton HN foils was measured for various temperatures between 310 and 150 K and gas pressures ranging from 10 to 300 mbar. From these measurements the permeability constant P(T) and its temperature dependence were determined. At room temperature the permeability constant for Kapton HN is P ( T =296 K ) = ( 2.56 ± 0.31 ) barrer. The temperature dependence of P(T) was verified to drop exponentially with decreasing temperature, causing a change in the permeability by more than two orders of magnitude in the range between 310 and 150 K.

Published
2015

7. Theory of the Lamb Shift and fine structure in muonic 4He ions and the muonic 3He– 4He Isotope Shift

Author

Franz Kottmann, Aldo Antognini, Marc Diepold, Beatrice Franke, Randolf Pohl, and Julian J. Krauth

Subjects
Muonic atoms/ions, Helium, Isotope shift, Nuclear structures, Fine structure, Lamb shift, Muonic atoms, Muonic ions, General Physics and Astronomy, 7. Clean energy, 01 natural sciences, Ion, Charge radius, 0103 physical sciences, Physics::Atomic and Molecular Clusters, Physics::Atomic Physics, Nuclear structure, SDG 7 - Affordable and Clean Energy, 010306 general physics, Exotic atom, Physics, 010308 nuclear & particles physics, Electric form factor, Charge density, Alpha particle, Deuterium, Atomic physics
Abstract

We provide an up to date summary of the theory contributions to the 2S → 2P Lamb shift and the fine structure of the 2P state in the muonic helium ion ( μ 4 He ) + . This summary serves as the basis for the extraction of the alpha particle charge radius from the muonic helium Lamb shift measurements at the Paul Scherrer Institute, Switzerland. Individual theory contributions needed for a charge radius extraction are compared and compiled into a consistent summary. The influence of the alpha particle charge distribution on the elastic two-photon exchange is studied to take into account possible model-dependencies of the energy levels on the electric form factor of the nucleus. We also discuss the theory uncertainty which enters the extraction of the 3He–4He isotope shift from the muonic measurements. The theory uncertainty of the extraction is much smaller than a present discrepancy between previous isotope shift measurements. This work completes our series of n = 2 theory compilations in light muonic atoms which we have performed already for muonic hydrogen, deuterium, and helium-3 ions.

Published
2018

8. The next generation of laser spectroscopy experiments using light muonic atoms

Author

M. Abdou Ahmed, J.F.C.A. Veloso, M. Willig, D. N. Patel, Laura Sinkunaite, Malte Hildebrandt, R. Horn, Jonas Nuber, José Paulo Santos, Li-Bang Wang, Andrzej Adamczak, Klaus Kirch, Stefan E. Schmidt, Miroslaw Marszalek, Jorge Machado, J. Haack, L.M.P. Fernandes, Karsten Schuhmann, Aldo Antognini, Jow-Tsong Shy, François Biraben, P. A. O. C. Silva, Pedro Amaro, Manuel Zeyen, Andreas Knecht, Patrícia Miguel da Silva Carvalho, Yi-Wei Liu, Tzu-Ling Chen, Paul Indelicato, C.M.B. Monteiro, Franz Kottmann, J.M.F. dos Santos, David Taqqu, Thomas Graf, Julian J. Krauth, F. D. Amaro, E. Rapisarda, François Nez, Yi-Jan Huang, Mauro Guerra, Randolf Pohl, Ivo Schulthess, Theodor W. Hänsch, Lucile Julien, Laboratoire Kastler Brossel (LKB [Collège de France]), Fédération de recherche du Département de physique de l'Ecole Normale Supérieure - ENS Paris (FRDPENS), Centre National de la Recherche Scientifique (CNRS)-École normale supérieure - Paris (ENS Paris)-Centre National de la Recherche Scientifique (CNRS)-École normale supérieure - Paris (ENS Paris)-Collège de France (CdF)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS), Atoms, Molecules, Lasers, LaserLaB - Physics of Light, École normale supérieure - Paris (ENS Paris), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Centre National de la Recherche Scientifique (CNRS)-Fédération de recherche du Département de physique de l'Ecole Normale Supérieure - ENS Paris (FRDPENS), Centre National de la Recherche Scientifique (CNRS)-École normale supérieure - Paris (ENS Paris), and Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Centre National de la Recherche Scientifique (CNRS)-Sorbonne Université (SU)-Collège de France (CdF (institution))

Subjects
History, Atomic Physics (physics.atom-ph), measurement methods, chemistry.chemical_element, FOS: Physical sciences, 01 natural sciences, Effective nuclear charge, Education, Lamb shift, Physics - Atomic Physics, hydrogen: muonic atom, 0103 physical sciences, Physics::Atomic and Molecular Clusters, Physics::Atomic Physics, 010306 general physics, Spectroscopy, Helium, Exotic atom, Physics, [PHYS]Physics [physics], 010308 nuclear & particles physics, Precision spectroscopy, helium: muonic atom, nucleus, Nuclear structure, Fundamental interaction, [PHYS.PHYS.PHYS-GEN-PH]Physics [physics]/Physics [physics]/General Physics [physics.gen-ph], Computer Science Applications, laser, chemistry, charge radius, quantum electrodynamics: bound state, spectrometer, Atomic physics, experimental results
Abstract

Precision spectroscopy of light muonic atoms provides unique information about the atomic and nuclear structure of these systems and thus represents a way to access fundamental interactions, properties and constants. One application comprises the determination of absolute nuclear charge radii with unprecedented accuracy from measurements of the 2S - 2P Lamb shift. Here, we review recent results of nuclear charge radii extracted from muonic hydrogen and helium spectroscopy and present experiment proposals to access light muonic atoms with Z ≥ 3. In addition, our approaches towards a precise measurement of the Zemach radii in muonic hydrogen (μp) and helium (μ 3He+) are discussed. These results will provide new tests of bound-state quantum-electrodynamics in hydrogen-like systems and can be used as benchmarks for nuclear structure theories., Journal of Physics: Conference Series, 1138 (1), ISSN:1742-6588, ISSN:1742-6596

Published
2018

9. Nuclear structure with radioactive muonic atoms

Author

Paul Indelicato, Robert Eichler, A. Skawran, Rugard Dressler, S. Roccia, P. Reiter, Angela Papa, Klaus Jungmann, Thomas Elias Cocolios, Andrzej Adamczak, Andreas Eggenberger, E. Rapisarda, Niklaus Berger, Narongrit Ritjoho, Andreas Knecht, Maxim Pospelov, Klaus Kirch, Randolf Pohl, Aldo Antognini, Lorenz Willmann, Nathal Severijns, Frederik Wauters, Precision Frontier, and Koster, U

Subjects
Physics, Radionuclide, Muon, Isotope, Hydrogen, QC1-999, Nuclear structure, chemistry.chemical_element, 01 natural sciences, Effective nuclear charge, 010305 fluids & plasmas, Nuclear physics, chemistry, 0103 physical sciences, Physics::Atomic and Molecular Clusters, Physics::Atomic Physics, 010306 general physics, Spectroscopy, Nuclear Experiment, Exotic atom
Abstract

Muonic atoms have been used to extract the most accurate nuclear charge radii based on the detection of X-rays from the muonic cascades. Most stable and a few unstable isotopes have been investigated with muonic atom spectroscopy techniques. A new research project recently started at the Paul Scherrer Institut aims to extend the highresolution muonic atom spectroscopy for the precise determination of nuclear charge radii and other nuclear structure properties of radioactive isotopes. The challenge to combine the high-energy muon beam with small quantity of stopping mass is being addressed by developing the concept of stopping the muon in a high-density, a high-pressure hydrogen cell and subsequent transfer of the muon to the element of interest. Status and perspectives of the project will be presented., EPJ Web of Conferences

Published
2018

10. Theory of the n = 2 levels in muonic helium-3 ions

Author

Randolf Pohl, Julian J. Krauth, Marc Diepold, Franz Kottmann, Aldo Antognini, and Beatrice Franke

Subjects
Physics, Muon, Nuclear Theory, Atomic Physics (physics.atom-ph), 010308 nuclear & particles physics, Nuclear structure, FOS: Physical sciences, 01 natural sciences, Atomic and Molecular Physics, and Optics, Physics - Atomic Physics, Lamb shift, Nuclear Theory (nucl-th), Nuclear physics, Charge radius, Helium-3, 0103 physical sciences, Atomic Physics, Helion, Physics::Atomic Physics, 010306 general physics, Hyperfine structure, Exotic atom
Abstract

The present knowledge of Lamb shift, fine-, and hyperfine structure of the 2S and 2P states in muonic helium-3 ions is reviewed in anticipation of the results of a first measurement of several 2S → 2P transition frequencies in the muonic helium-3 ion, μ3He+. This ion is the bound state of a single negative muon μ- and a bare helium-3 nucleus (helion), 3He++. A term-by-term comparison of all available sources, including new, updated, and so far unpublished calculations, reveals reliable values and uncertainties of the QED and nuclear structure-dependent contributions to the Lamb shift and the hyperfine splitting. These values are essential for the determination of the helion rms charge radius and the nuclear structure effects to the hyperfine splitting in μ3He+. With this review we continue our series of theory summaries in light muonic atoms [see A. Antognini et al., Ann. Phys. 331, 127 (2013); J.J. Krauth et al., Ann. Phys. 366, 168 (2016); and M. Diepold et al. arXiv:1606.05231 (2016)]., The European Physical Journal D, 71 (12), ISSN:1434-6060, ISSN:1434-6079

Published
2017

11. Statistical uncertainty in quantitative neutron radiography

Author

Klaus Kirch, Aldo Antognini, Florian M. Piegsa, Andreas Eggenberger, Anders Kaestner, and Gunther Wichmann

Subjects
medicine.medical_specialty, Physics - Instrumentation and Detectors, Nuclear engineering, Radiography, Astrophysics::High Energy Astrophysical Phenomena, Nuclear Theory, FOS: Physical sciences, 02 engineering and technology, 01 natural sciences, Neutron flux, Nondestructive testing, 0103 physical sciences, Calibration, medicine, Neutron detection, Neutron, Medical physics, 010306 general physics, Nuclear Experiment, Instrumentation, Physics, business.industry, Neutron imaging, Instrumentation and Detectors (physics.ins-det), 021001 nanoscience & nanotechnology, Condensed Matter Physics, 3. Good health, Electronic, Optical and Magnetic Materials, Industrial radiography, Physics - Data Analysis, Statistics and Probability, Physics::Accelerator Physics, 0210 nano-technology, business, Data Analysis, Statistics and Probability (physics.data-an)
Abstract

We demonstrate a novel procedure to calibrate neutron detection systems commonly used in standard neutron radiography. This calibration allows determining the uncertainties due to Poisson-like neutron counting statistics for each individual pixel of a radiographic image. The obtained statistical errors are necessary in order to perform a correct quantitative analysis. This fast and convenient method is applied to data measured at the cold neutron radiography facility ICON at the Paul Scherrer Institute. Moreover, from the results the effective neutron flux at the beam line is determined.

Published
2017

12. Deuteron charge radius and Rydberg constant from spectroscopy data in atomic deuterium

Author

Randolf Pohl, Thomas Udem, François Nez, Axel Beyer, Julian J. Krauth, François Biraben, Lothar Maisenbacher, Arthur Matveev, Alexey Grinin, Lucile Julien, Theodor W. Hänsch, Aldo Antognini, Franz Kottmann, Hélène Fleurbaey, Atoms, Molecules, Lasers, LaserLaB - Physics of Light, Laboratoire Kastler Brossel (LKB [Collège de France]), Fédération de recherche du Département de physique de l'Ecole Normale Supérieure - ENS Paris (FRDPENS), Centre National de la Recherche Scientifique (CNRS)-École normale supérieure - Paris (ENS Paris)-Centre National de la Recherche Scientifique (CNRS)-École normale supérieure - Paris (ENS Paris)-Collège de France (CdF)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS), École normale supérieure - Paris (ENS Paris), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Centre National de la Recherche Scientifique (CNRS)-Fédération de recherche du Département de physique de l'Ecole Normale Supérieure - ENS Paris (FRDPENS), Centre National de la Recherche Scientifique (CNRS)-École normale supérieure - Paris (ENS Paris), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Centre National de la Recherche Scientifique (CNRS)-Sorbonne Université (SU)-Collège de France (CdF (institution)), Laboratoire Kastler Brossel ( LKB (Lhomond) ), Fédération de recherche du Département de physique de l'Ecole Normale Supérieure - ENS Paris ( FRDPENS ), and Centre National de la Recherche Scientifique ( CNRS ) -École normale supérieure - Paris ( ENS Paris ) -Centre National de la Recherche Scientifique ( CNRS ) -École normale supérieure - Paris ( ENS Paris ) -Université Pierre et Marie Curie - Paris 6 ( UPMC ) -Centre National de la Recherche Scientifique ( CNRS )

Subjects
Hydrogen, Proton, Atomic Physics (physics.atom-ph), Physical constant, FOS: Physical sciences, chemistry.chemical_element, [PHYS.NEXP]Physics [physics]/Nuclear Experiment [nucl-ex], 01 natural sciences, 7. Clean energy, Physics - Atomic Physics, Rydberg constant, Charge radius, 0103 physical sciences, [ PHYS.PHYS.PHYS-GEN-PH ] Physics [physics]/Physics [physics]/General Physics [physics.gen-ph], Physics::Atomic Physics, [ PHYS.NEXP ] Physics [physics]/Nuclear Experiment [nucl-ex], Nuclear Experiment (nucl-ex), 010306 general physics, Spectroscopy, Nuclear Experiment, Physics, proton radius, 010308 nuclear & particles physics, deuteron radius, General Engineering, Charge (physics), [PHYS.PHYS.PHYS-GEN-PH]Physics [physics]/Physics [physics]/General Physics [physics.gen-ph], 3. Good health, chemistry, Deuterium, Atomic physics
Abstract

We give a pedagogical description of the method to extract the charge radii and Rydberg constant from laser spectroscopy in regular hydrogen (H) and deuterium (D) atoms, that is part of the CODATA least-squares adjustment (LSA) of the fundamental physical constants. We give a deuteron charge radius Rd from D spectroscopy alone of 2.1415(45) fm. This value is independent of the measurements that lead to the proton charge radius, and five times more accurate than the value found in the CODATA Adjustment 10. The improvement is due to the use of a value for the 1S->2S transition in atomic deuterium which can be inferred from published data or found in a PhD thesis., 9 pages, 7 Tables and 3 Figures. Values of the Rydberg constant and discussion of the deuteron structure radius added

Published
2017

13. Laser spectroscopy of muonic hydrogen

Author

F. Mulhauser, F. D. Amaro, David Taqqu, Lucile Julien, Theodor W. Hänsch, Thomas Graf, Lukas A. Schaller, Randolf Pohl, Karsten Schuhmann, Joaquim M. F. dos Santos, Yi-Wei Liu, Andrea L. Gouvea, Aldo Antognini, Catherine Schwob, F. Biraben, Franz Kottmann, Cheng-Yang Kao, J. A. M. Lopes, D. S. Covita, Eric-Olivier Le Bigot, Tobias Nebel, Paul Indelicato, Livia Ludhova, J.F.C.A. Veloso, Satish Dhawan, João Cardoso, Marc Diepold, Jan Vogelsang, François Nez, Paul Rabinowitz, Adolf Giesen, Paul E. Knowles, C.M.B. Monteiro, Andreas Dax, and L.M.P. Fernandes

Subjects
Physics, General Physics and Astronomy, Laser, 01 natural sciences, 3. Good health, 010305 fluids & plasmas, law.invention, Lamb shift, Rydberg constant, Charge radius, law, 0103 physical sciences, Atomic physics, 010306 general physics, Spectroscopy, Hyperfine structure, Exotic atom
Abstract

We present here a discussion about the physics motivations and the experimental feasibility of our recent experimental proposal “Spectroscopy of Muonic Hydrogen” presented to the Dec. 1991 meeting of the PSI Benutzervesammlung (proposal R-9206–1).

Published
2013

14. Theory of the 2S–2P Lamb shift and 2S hyperfine splitting in muonic hydrogen

Author

Randolf Pohl, Aldo Antognini, François Nez, François Biraben, Franz Kottmann, and Paul Indelicato

Subjects
Physics, Proton, Hydrogen, Atomic Physics (physics.atom-ph), 010308 nuclear & particles physics, FOS: Physical sciences, General Physics and Astronomy, chemistry.chemical_element, Charge (physics), 01 natural sciences, Physics - Atomic Physics, Lamb shift, chemistry, Charge radius, 0103 physical sciences, Physics::Atomic Physics, Atomic physics, 010306 general physics, Spectroscopy, Hyperfine structure, Exotic atom
Abstract

The 7 standard deviations between the proton rms charge radius from muonic hydrogen and the CODATA-10 value from hydrogen spectroscopy and electron-scattering has caused considerable discussions. Here, we review the theory of the 2S-2P Lamb shift and 2S hyperfine splitting in muonic hydrogen combining the published contributions and theoretical approaches. The prediction of these quantities is necessary for the determination of both proton charge and Zemach radii from the two 2S-2P transition frequencies measured in muonic hydrogen., Comment: 20 pages with 3 Tables summarising the contributions to the muonic hydrogen Lamb shift and hyperfine splitting

Published
2013

15. Novel concept for neutron detection: proportional counter filled with

Author

J.M.F. dos Santos, F. D. Amaro, C.M.B. Monteiro, and Aldo Antognini

Subjects
inorganic chemicals, Materials science, Astrophysics::High Energy Astrophysical Phenomena, Nuclear Theory, Proportional counter, Characterization and analytical techniques, 01 natural sciences, Radiation Portal Monitor, Particle detector, Article, Techniques and instrumentation, 0103 physical sciences, Neutron detection, Neutron, 010306 general physics, Nuclear Experiment, Multidisciplinary, integumentary system, 010308 nuclear & particles physics, technology, industry, and agriculture, Corrigenda, Neutron temperature, Aerosol, Computational physics, Volume (thermodynamics), biological sciences, lipids (amino acids, peptides, and proteins)
Abstract

The high neutron detection efficiency, good gamma-ray discrimination and non-toxicity of 3He made of proportional counters filled with this gas the obvious choice for neutron detection, particularly in radiation portal monitors (RPM), used to control the illicit transport of nuclear material, of which neutron detectors are key components. 3He is very rare and during the last decade this gas has become increasingly difficult to acquire. With the exception of BF3, which is toxic, no other gas can be used for neutron detection in proportional counters. We present an alternative where the 3He atoms are replaced by nanoparticles made of another neutron sensitive material, 10B. The particles are dispersed in a gaseous volume, forming an aerosol with neutron sensitive properties. A proportional counter filled with such aerosol was exposed to a thermal neutron beam and the recorded response indicates that the neutrons have interacted with the particles in the aerosol. This original technique, which transforms a standard proportional gas mixture into a neutron sensitive aerosol, is a breakthrough in the field of radiation detection and has the potential to become an alternative to the use of 3He in proportional counters., Scientific Reports, 7, ISSN:2045-2322

Published
2016

16. Spatial confinement of muonium atoms

Author

Zaher Salman, Laszlo Liszkay, K. S. Khaw, Paolo Crivelli, Thomas Prokscha, Klaus Kirch, Aldo Antognini, Institut de Recherches sur les lois Fondamentales de l'Univers (IRFU), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Paris-Saclay, Institut de Recherches sur les lois Fondamentales de l'Univers ( IRFU ), and Commissariat à l'énergie atomique et aux énergies alternatives ( CEA ) -Université Paris-Saclay

Subjects
Atomic Physics (physics.atom-ph), measurement methods, Muonium, FOS: Physical sciences, Electron, 01 natural sciences, 7. Clean energy, 010305 fluids & plasmas, Physics - Atomic Physics, High Energy Physics - Experiment, High Energy Physics - Experiment (hep-ex), [ PHYS.HEXP ] Physics [physics]/High Energy Physics - Experiment [hep-ex], 0103 physical sciences, Bound state, [PHYS.HEXP]Physics [physics]/High Energy Physics - Experiment [hep-ex], [ PHYS.PHYS.PHYS-GEN-PH ] Physics [physics]/Physics [physics]/General Physics [physics.gen-ph], [PHYS.PHYS.PHYS-INS-DET]Physics [physics]/Physics [physics]/Instrumentation and Detectors [physics.ins-det], Physics::Atomic Physics, 010306 general physics, Spectroscopy, [ PHYS.PHYS.PHYS-INS-DET ] Physics [physics]/Physics [physics]/Instrumentation and Detectors [physics.ins-det], Physics, muonium, Muon, Mesoporous silica, [PHYS.PHYS.PHYS-GEN-PH]Physics [physics]/Physics [physics]/General Physics [physics.gen-ph], laser, Reflection (mathematics), confinement, spectrometer, silicon: oxygen, atom: excited state, Atomic physics, Law of cosines
Abstract

We report the achievement of spatial confinement of muonium atoms (the bound state of a positive muon and an electron). Muonium emitted into vacuum from mesoporous silica reflects between two SiO$_2$ confining surfaces separated by 1 mm. From the data, one can extract that the reflection probability on the confining surfaces kept at 100 K is about 90% and the reflection process is well described by a cosine law. This technique enables new experiments with this exotic atomic system and is a very important step towards a measurement of the 1S-2S transition frequency using continuous wave laser spectroscopy., 5 pages, 6 figures

Published
2016

17. Experiments towards resolving the proton charge radius puzzle

Author

A. Knecht, José Paulo Santos, David Taqqu, Andreas Dax, Theodor W. Hänsch, Thomas Graf, Jorge Machado, Randolf Pohl, L.M.P. Fernandes, Marc Diepold, Françoise Mulhauser, F. D. Amaro, B. Franke, Malte Hildebrandt, Karsten Schuhmann, A. L. Gouvea, Pedro Amaro, Paul Indelicato, Yi-Wei Liu, Julian J. Krauth, C.M.B. Monteiro, S. Galtier, M. Abdou-Ahmed, L. Julien, D. S. Covita, Klaus Kirch, Aldo Antognini, J.F.C.A. Veloso, Csilla I. Szabo, Birgit Weichelt, J.M.F. dos Santos, Andreas Voss, Tzu-Ling Chen, François Nez, Franz Kottmann, François Biraben, Johannes Götzfried, Atoms, Molecules, Lasers, LaserLaB - Physics of Light, Elster, Charlotte, Phillips, Daniel R., Roberts, Craig, LIBPhys-UNL, and DF – Departamento de Física

Subjects
Hydrogen, Proton, POLARIZABILITY CONTRIBUTION, Atomic Physics (physics.atom-ph), QC1-999, chemistry.chemical_element, FOS: Physical sciences, MUONIC-HYDROGEN, Physics and Astronomy(all), FREQUENCY, 01 natural sciences, CHIRAL PERTURBATION-THEORY, HYDROGEN LAMB SHIFT, Physics - Atomic Physics, ATOMS, Charge radius, 0103 physical sciences, Physics::Atomic Physics, SDG 7 - Affordable and Clean Energy, 010306 general physics, Spectroscopy, Exotic atom, Physics, 010308 nuclear & particles physics, Scattering, METROLOGY, chemistry, ELASTIC-SCATTERING, Atomic physics, TRANSITION
Abstract

We review the status of the proton charge radius puzzle. Emphasis is given to the various experiments initiated to resolve the conflict between the muonic hydrogen results and the results from scattering and regular hydrogen spectroscopy., EPJ Web of Conferences, 113, ISSN:2100-014X, ISSN:2101-6275

Published
2016

18. Laser Spectroscopy of Muonic Atoms and Ions

Author

C.M.B. Monteiro, Andreas Dax, F. D. Amaro, Julian J. Krauth, Catherine Schwob, Andrea L. Gouvea, Jose A. Matias Lopes, Malte Hildebrandt, Marwan Abdou Ahmed, François Nez, Yi-Wei Liu, Jorge Machado, Eric-Olivier Le Bigot, José Paulo Santos, Lucile Julien, Paul Indelicato, David Taqqu, Beatrice Franke, L.M.P. Fernandes, João Cardoso, Pedro Amaro, Andreas Knecht, Lukas A. Schaller, Joaquim M. F. dos Santos, Paul E. Knowles, Sandrine Galtier, Johannes Götzfried, Csilla I. Szabo, Thomas Graf, Karsten Schuhmann, Franz Kottmann, D. S. Covita, Adolf Giesen, Theodor W. Hänsch, Birgit Weichelt, Paul Rabinowitz, Livia Ludhova, Tobias Nebel, Marc Diepold, Françoise Mulhauser, Randolf Pohl, François Biraben, Klaus Kirch, Aldo Antognini, J.F.C.A. Veloso, Satish Dhawan, Andreas Voss, Laboratoire Kastler Brossel (LKB [Collège de France]), École normale supérieure - Paris (ENS Paris), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Centre National de la Recherche Scientifique (CNRS)-Fédération de recherche du Département de physique de l'Ecole Normale Supérieure - ENS Paris (FRDPENS), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Centre National de la Recherche Scientifique (CNRS)-Centre National de la Recherche Scientifique (CNRS)-Sorbonne Université (SU)-Collège de France (CdF (institution)), Fédération de recherche du Département de physique de l'Ecole Normale Supérieure - ENS Paris (FRDPENS), Centre National de la Recherche Scientifique (CNRS)-École normale supérieure - Paris (ENS Paris)-Centre National de la Recherche Scientifique (CNRS)-École normale supérieure - Paris (ENS Paris)-Collège de France (CdF)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS), Laboratoire Kastler Brossel ( LKB (Lhomond) ), Fédération de recherche du Département de physique de l'Ecole Normale Supérieure - ENS Paris ( FRDPENS ), and Centre National de la Recherche Scientifique ( CNRS ) -École normale supérieure - Paris ( ENS Paris ) -Centre National de la Recherche Scientifique ( CNRS ) -École normale supérieure - Paris ( ENS Paris ) -Université Pierre et Marie Curie - Paris 6 ( UPMC ) -Centre National de la Recherche Scientifique ( CNRS )

Subjects
deuteron, Proton, [PHYS.NUCL]Physics [physics]/Nuclear Theory [nucl-th], Atomic Physics (physics.atom-ph), muonic atoms, hyperfine structure, Nuclear Theory, FOS: Physical sciences, Molecular physics, 01 natural sciences, 7. Clean energy, 010305 fluids & plasmas, Ion, Physics - Atomic Physics, Lamb shift, Charge radius, Atom, 0103 physical sciences, Physics::Atomic and Molecular Clusters, [ PHYS.PHYS.PHYS-GEN-PH ] Physics [physics]/Physics [physics]/General Physics [physics.gen-ph], Physics::Atomic Physics, 010306 general physics, Spectroscopy, Nuclear Experiment, Hyperfine structure, [ PHYS.NUCL ] Physics [physics]/Nuclear Theory [nucl-th], Exotic atom, Physics, [PHYS]Physics [physics], Muon, [ PHYS ] Physics [physics], 010308 nuclear & particles physics, muonic atom, [PHYS.PHYS.PHYS-GEN-PH]Physics [physics]/Physics [physics]/General Physics [physics.gen-ph], laser, Deuterium, charge radius, laser spectroscopy, spectrometer, Atomic physics, proton
Abstract

Laser spectroscopy of the Lamb shift (2S-2P energy difference) in light muonic atoms or ions, in which one negative muon $\mu^-$ is bound to a nucleus, has been performed. The measurements yield significantly improved values of the root-mean-square charge radii of the nuclei, owing to the large muon mass, which results in a vastly increased muon wave function overlap with the nucleus. The values of the proton and deuteron radii are 10 and 3 times more accurate than the respective CODATA values, but 7 standard deviations smaller. Data on muonic helium-3 and -4 ions is being analyzed and will give new insights. In future, the (magnetic) Zemach radii of the proton and the helium-3 nuclei will be determined from laser spectroscopy of the 1S hyperfine splittings, and the Lamb shifts of muonic Li, Be and B can be used to improve the respective charge radii., Comment: Contribution to LEAP 2016 in Kanazawa, Japan

Published
2016

19. Laser spectroscopy of muonic deuterium

Author

Thomas Graf, L.M.P. Fernandes, Catherine Schwob, Lukas A. Schaller, Lucile Julien, David Taqqu, Paul Indelicato, F. D. Amaro, Franz Kottmann, Yi-Wei Liu, Joaquim M. F. dos Santos, François Nez, João Cardoso, F. Biraben, J.F.C.A. Veloso, Satish Dhawan, J. A. M. Lopes, Paul E. Knowles, Randolf Pohl, Tobias Nebel, D. S. Covita, Andrea L. Gouvea, F. Mulhauser, Karsten Schuhmann, Aldo Antognini, C.M.B. Monteiro, Andreas Dax, Paul Rabinowitz, Adolf Giesen, Eric-Olivier Le Bigot, Theodor W. Hänsch, Marc Diepold, Livia Ludhova, Laboratoire Kastler Brossel (LKB [Collège de France]), Fédération de recherche du Département de physique de l'Ecole Normale Supérieure - ENS Paris (FRDPENS), Centre National de la Recherche Scientifique (CNRS)-École normale supérieure - Paris (ENS Paris)-Centre National de la Recherche Scientifique (CNRS)-École normale supérieure - Paris (ENS Paris)-Collège de France (CdF)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS), CREMA, École normale supérieure - Paris (ENS Paris), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Centre National de la Recherche Scientifique (CNRS)-Fédération de recherche du Département de physique de l'Ecole Normale Supérieure - ENS Paris (FRDPENS), and Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Centre National de la Recherche Scientifique (CNRS)-Centre National de la Recherche Scientifique (CNRS)-Sorbonne Université (SU)-Collège de France (CdF (institution))

Subjects
deuteron, atom: exotic, Proton, Nuclear Theory, 01 natural sciences, benchmark, hydrogen: muonic atom, Charge radius, muon, 0103 physical sciences, Neutron, Physics::Atomic Physics, 010306 general physics, Nuclear Experiment, deuterium, Exotic atom, Multidisciplinary, Muon, 010308 nuclear & particles physics, Chemistry, nuclear force, nucleus, transition, Radius, polarizability, [PHYS.PHYS.PHYS-GEN-PH]Physics [physics]/Physics [physics]/General Physics [physics.gen-ph], laser, Atomic radius, Deuterium, charge radius, Atomic physics
Abstract

The deuteron is too small, too The radius of the proton has remained a point of debate ever since the spectroscopy of muonic hydrogen indicated a large discrepancy from the previously accepted value. Pohl et al. add an important clue for solving this so-called proton radius puzzle. They determined the charge radius of the deuteron, a nucleus consisting of a proton and a neutron, from the transition frequencies in muonic deuterium. Mirroring the proton radius puzzle, the radius of the deuteron was several standard deviations smaller than the value inferred from previous spectroscopic measurements of electronic deuterium. This independent discrepancy points to experimental or theoretical error or even to physics beyond the standard model. Science , this issue p. 669

Published
2016

20. Laser spectroscopy of muonic deuterium: New contribution to the proton puzzle

Author

Theodor W. Hänsch, E.-O. Le Bigot, J. A. M. Lopes, Marc Diepold, Françoise Mulhauser, D. S. Covita, L.M.P. Fernandes, Th. Graf, João Cardoso, Franz Kottmann, Y. Wei Liu, Tobias Nebel, Lukas A. Schaller, Adolf Giesen, F. D. Amaro, Catherine Schwob, J.F.C.A. Veloso, F. Nez, Satish Dhawan, Livia Ludhova, David Taqqu, François Biraben, Karsten Schuhmann, Aldo Antognini, Paul Rabinowitz, Andrea L. Gouvea, J.M.F. dos Santos, Randolf Pohl, Lucile Julien, Paul E. Knowles, Paul Indelicato, C.M.B. Monteiro, and Andreas Dax

Subjects
Physics, Proton, Nuclear structure, 02 engineering and technology, 01 natural sciences, Lamb shift, Nuclear physics, 020210 optoelectronics & photonics, Rydberg constant, Deuterium, Charge radius, 0103 physical sciences, 0202 electrical engineering, electronic engineering, information engineering, Atomic physics, 010306 general physics, Spectroscopy, Exotic atom
Abstract

We report the first laser spectroscopy of muonic deuterium. At the Paul Scherrer Institute, we have measured the frequency of the 2S-2P Lamb shift in muonic deuterium. As in the case of the muonic hydrogen, the observed lines are shifted from the theoretical predictions. Thanks to improved new QED and nuclear structure calculations, an accurate determination of the deuteron radius can be extracted from our study. This determination will give a new and important input to the proton size puzzle.

Published
2016
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21. The Lamb shift in muonic hydrogenThis paper was presented at the International Conference on Precision Physics of Simple Atomic Systems, held at École de Physique, les Houches, France, 30 May – 4 June, 2010

Author

Randolf Pohl, Aldo Antognini, François Nez, Fernando D. Amaro, François Biraben, João M.R. Cardoso, Daniel S. Covita, Andreas Dax, Satish Dhawan, Luis M.P. Fernandes, Adolf Giesen, Thomas Graf, Theodor W. Hänsch, Paul Indelicato, Lucile Julien, Cheng-Yang Kao, Paul Knowles, Eric-Olivier Le Bigot, Yi-Wei Liu, José A.M. Lopes, Livia Ludhova, Cristina M.B. Monteiro, Françoise Mulhauser, Tobias Nebel, Paul Rabinowitz, Joaquim M.F. dos Santos, Lukas A. Schaller, Karsten Schuhmann, Catherine Schwob, David Taqqu, João F.C.A. Veloso, and Franz Kottmann

Subjects
Physics, Hydrogen, 010308 nuclear & particles physics, General Physics and Astronomy, chemistry.chemical_element, Spectral shift, 01 natural sciences, Lamb shift, chemistry, 0103 physical sciences, Atomic physics, 010306 general physics, Spectroscopy, Exotic atom
Abstract

The long quest for a measurement of the Lamb shift in muonic hydrogen is over. Last year we measured the 2S 1/2F=1 –2P 3/2F=2 energy splitting (Pohl et al., Nature, 466, 213 (2010)) in μp with an experimental accuracy of 15 ppm, twice better than our proposed goal. Using current QED calculations of the fine, hyperfine, QED, and finite size contributions, we obtain a root-mean-square proton charge radius of rp = 0.841 84 (67) fm. This value is 10 times more precise, but 5 standard deviations smaller, than the 2006 CODATA value of rp. The origin of this discrepancy is not known. Our measurement, together with precise measurements of the 1S–2S transition in regular hydrogen and deuterium, gives improved values of the Rydberg constant, R∞ = 10 973 731.568 160 (16) m–1 and the rms charge radius of the deuteron rd = 2.128 09 (31) fm.

Published
2011

22. Illuminating the proton radius conundrum: the μHe+ Lamb shiftThis paper was presented at the International Conference on Precision Physics of Simple Atomic Systems, held at École de Physique, les Houches, France, 30 May – 4 June, 2010

Author

J.M.F. dos Santos, L. Julien, A. Voss, F. Nez, Andreas Dax, Theodor W. Hänsch, Paul Indelicato, João Cardoso, François Biraben, L.M.P. Fernandes, F. Mulhauser, Andrea L. Gouvea, J.F.C.A. Veloso, Randolf Pohl, K. Schuhmann, Yi-Wei Liu, Klaus Kirch, Tobias Nebel, Aldo Antognini, Malte Hildebrandt, D. S. Covita, Th. Graf, D. Taqqu, F. Kottmann, and C.M.B. Monteiro

Subjects
Physics, 010308 nuclear & particles physics, Ab initio, General Physics and Astronomy, Radius, Polarization (waves), 7. Clean energy, 01 natural sciences, Charged particle, Lamb shift, Nuclear physics, Charge radius, 0103 physical sciences, Atomic physics, 010306 general physics, Spectroscopy, Hyperfine structure
Abstract

We plan to measure several 2S–2P transition frequencies in μ4He+ and μ3He+ by means of laser spectroscopy with an accuracy of 50 ppm. This will lead to a determination of the corresponding nuclear rms charge radii with a relative accuracy of 3 × 10−4, limited by the uncertainty of the nuclear polarization contribution. First, these measurements will help to solve the proton radius puzzle. Second, these very precise nuclear radii are benchmarks for ab initio few-nucleon theories and potentials. Finally when combined with an ongoing measurement of the 1S–2S transition in He+, these measurements will lead to an enhanced bound-state QED test of the 1S Lamb shift in He+.

Published
2011

23. Thin-Disk Yb:YAG Oscillator-Amplifier Laser, ASE, and Effective Yb:YAG Lifetime

Author

Livia Ludhova, N. Moschuring, Paul E. Knowles, David Taqqu, Lucile Julien, F. D. Amaro, K. Schuhmann, Françoise Mulhauser, Yi-Wei Liu, Paul Rabinowitz, Andreas Dax, E.-O. Le Bigot, Randolf Pohl, Aldo Antognini, Theodor W. Hänsch, Adolf Giesen, Tobias Nebel, François Biraben, Cheng-Yang Kao, Paul Indelicato, Franz Kottmann, Catherine Schwob, Thomas Graf, François Nez, Max-Planck-Institut für Quantenoptik (MPQ), Max-Planck-Gesellschaft, Dausinger & Giesen GmbH, Departamento de Física [Coimbra] (DFC), Universidade de Coimbra [Coimbra], Laboratoire Kastler Brossel (LKB (Jussieu)), Université Pierre et Marie Curie - Paris 6 (UPMC)-Fédération de recherche du Département de physique de l'Ecole Normale Supérieure - ENS Paris (FRDPENS), École normale supérieure - Paris (ENS Paris), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Centre National de la Recherche Scientifique (CNRS)-École normale supérieure - Paris (ENS Paris), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Centre National de la Recherche Scientifique (CNRS)-Centre National de la Recherche Scientifique (CNRS), Physics Department, Yale University [New Haven], Technol Gesell Strahlwerkzeuge, Universität Stuttgart [Stuttgart], Institut für Strahwerkzeuge (IFSW), Stuttgart University, National Tsing Hua University [Hsinchu] (NTHU), Institut fur Teilchenphysik [Zürich], Eidgenössische Technische Hochschule - Swiss Federal Institute of Technology [Zürich] (ETH Zürich), departement de physique, Albert-Ludwigs-Universität Freiburg, Department of Chemistry, Princeton University, Institut des Nanosciences de Paris (INSP), Université Pierre et Marie Curie - Paris 6 (UPMC)-Centre National de la Recherche Scientifique (CNRS), Paul Scherrer Institute (PSI), Fédération de recherche du Département de physique de l'Ecole Normale Supérieure - ENS Paris (FRDPENS), École normale supérieure - Paris (ENS-PSL), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Centre National de la Recherche Scientifique (CNRS)-École normale supérieure - Paris (ENS-PSL), and Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Centre National de la Recherche Scientifique (CNRS)-Université Pierre et Marie Curie - Paris 6 (UPMC)-Centre National de la Recherche Scientifique (CNRS)

Subjects
Ytterbium, Amplified spontaneous emission, Materials science, chemistry.chemical_element, thin-disk laser, 01 natural sciences, law.invention, 010309 optics, Optical pumping, Optics, law, Amplified spontaneous emission (ASE), Collins integral, oscillator, 0103 physical sciences, Electrical and Electronic Engineering, 010306 general physics, ComputingMilieux_MISCELLANEOUS, [PHYS.PHYS.PHYS-OPTICS]Physics [physics]/Physics [physics]/Optics [physics.optics], business.industry, Amplifier, diode-pumped laser, effective Yb:YAG lifetime, prelasing, Superradiance, Condensed Matter Physics, Laser, Q-switching, Atomic and Molecular Physics, and Optics, Thin disk, chemistry, thermal lens, multipass amplifier, business
Abstract

We report on a thin-disk Yb:YAG laser made from a Q-switched oscillator and a multipass amplifier delivering pulses of 48 mJ at 1030 nm. The peculiar requirements for this laser are the short delay time (< 500 ns) between electronic trigger and optical output pulse and the time randomness with which these triggers occur (with trigger to next trigger delay ges 1.5 ms). Details concerning the oscillator dynamics (-switching cycle, intensity stabilization), and the peculiar amplifier layout are given. Simulations of the beam propagation in the amplifier based on the Collins integral and the measured aspherical components of the disk reproduce well the measured beam intensity profiles (with higher order intensity moments) and gains. Measurements of the thermal lens and ASE effects of the disk are also presented. A novel method to deduce the effective Yb:YAG upper state lifetime (under real laser operation and including ASE effects) is presented. That knowledge is necessary to determine gain and stored energy in the active medium and to understand the limiting factors for energy scaling of thin-disk lasers.

Published
2009

24. Quantum interference effects in laser spectroscopy of muonic hydrogen, deuterium, and helium-3

Author

Pedro Amaro, Paul Indelicato, Franz Kottmann, Randolf Pohl, F. Fratini, Marc Diepold, L. Safari, Aldo Antognini, Jorge Machado, José Paulo Santos, Beatrice Franke, Julian J. Krauth, LIBPhys-UNL, DF – Departamento de Física, Atoms, Molecules, Lasers, and LaserLaB - Physics of Light

Subjects
IONS, Photon, Atomic Physics (physics.atom-ph), FOS: Physical sciences, LINE, FREQUENCY, PROTON, 7. Clean energy, 01 natural sciences, 010305 fluids & plasmas, Physics - Atomic Physics, Laser linewidth, LAMB-SHIFT, Helium-3, 0103 physical sciences, Physics::Atomic Physics, 010306 general physics, Spectroscopy, Hyperfine structure, NONRESONANT CORRECTIONS, Exotic atom, Physics, Atomic and Molecular Physics, and Optics, 3. Good health, Lamb shift, Deuterium, Atomic physics, 1S-2S TRANSITION
Abstract

Quantum interference between energetically close states is theoretically investigated, with the state structure being observed via laser spectroscopy. In this work, we focus on hyperfine states of selected hydrogenic muonic isotopes, and on how quantum interference affects the measured Lamb shift. The process of photon excitation and subsequent photon decay is implemented within the framework of nonrelativistic second-order perturbation theory. Due to its experimental interest, calculations are performed for muonic hydrogen, deuterium, and helium-3. We restrict our analysis to the case of photon scattering by incident linear polarized photons and the polarization of the scattered photons not being observed. We conclude that while quantum interference effects can be safely neglected in muonic hydrogen and helium-3, in the case of muonic deuterium there are resonances with close proximity, where quantum interference effects can induce shifts up to a few percent of the linewidth, assuming a pointlike detector. However, by taking into account the geometry of the setup used by the CREMA collaboration, this effect is reduced to less than 0.2% of the linewidth in all possible cases, which makes it irrelevant at the present level of accuracy., 8 pages, 4 Figs. Shorter version as recommended by the referee. More details can be found in v1

Published
2015

25. Geant4 simulation of the PSI LEM beam line: energy loss and muonium formation in thin foils and the impact of unmoderated muons on the $\mu$SR spectrometer

Author

K. S. Khaw, Klaus Kirch, Aldo Antognini, Elvezio Morenzoni, Zaher Salman, Thomas Prokscha, Andreas Suter, and Paolo Crivelli

Subjects
Materials science, Muon, Physics - Instrumentation and Detectors, Spectrometer, 010308 nuclear & particles physics, Physics::Instrumentation and Detectors, Cyclotron, Muonium, FOS: Physical sciences, Instrumentation and Detectors (physics.ins-det), Muon spin spectroscopy, Kinetic energy, 01 natural sciences, law.invention, Nuclear physics, law, 0103 physical sciences, Physics::Accelerator Physics, High Energy Physics::Experiment, 010306 general physics, Instrumentation, Mathematical Physics, Beam (structure), Lepton
Abstract

The PSI low-energy $��$SR spectrometer is an instrument dedicated to muon spin rotation and relaxation measurements. Knowledge of the muon beam parameters such as spatial, kinetic energy and arrival-time distributions at the sample position are important ingredients to analyze the $��$SR spectra. We present here the measured energy losses in the thin carbon foil of the muon start detector deduced from time-of-flight measurements. Muonium formation in the thin carbon foil (10 nm thickness) of the muon start detector also affect the measurable decay asymmetry and therefore need to be accounted for. Muonium formation and energy losses in the start detector, whose relevance increase with decreasing muon implantation energy ($, Paper submitted to JINST for review on 15th Jun 2015

Published
2015

26. Observation of positronium annihilation in the 2S state: towards a new measurement of the 1S-2S transition frequency

Author

André Rubbia, Paolo Crivelli, V. Vrankovic, B. Brown, T. W. Haensch, S. Friedreich, D. A. Cooke, A. Gabard, Klaus Kirch, Aldo Antognini, and Janis Alnis

Subjects
Nuclear and High Energy Physics, Photon, Atomic Physics (physics.atom-ph), FOS: Physical sciences, Electron, Positronium, Bound state QED, 01 natural sciences, Physics - Atomic Physics, High Energy Physics - Experiment, High Energy Physics - Experiment (hep-ex), Positron, 0103 physical sciences, Physical and Theoretical Chemistry, 010306 general physics, Wave function, Spectroscopy, Physics, Annihilation, 010308 nuclear & particles physics, Condensed Matter Physics, Atomic and Molecular Physics, and Optics, Excited state, Atomic physics, Ground state
Abstract

We report the first observation of the annihilation of positronium from the 2S state. Positronium (Ps) is excited with a two-photon transition from the 1S to the 2S state where its lifetime is increased by a factor of eight compared to the ground state due to the decrease in the overlap of the positron electron wave-function. The yield of delayed annihilation photons detected as a function of laser frequency is used as a new method of detecting laser-excited Ps in the 2S state. This can be considered the first step towards a new high precision measurement of the 1S–2S Ps line., Hyperfine Interactions, 233 (1), ISSN:0304-3843, ISSN:0304-3834, ISSN:1572-9540, Proceedings of the International Conference on Exotic Atoms and Related Topics (EXA 2014)

Published
2015
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27. Behaviour of large-area avalanche photodiodes under intense magnetic fields for VUV- visible- and X-ray photon detection

Author

Franz Kottmann, C.A.N. Conde, David Taqqu, F. Mulhauser, J.M.F. dos Santos, L.M.P. Fernandes, Lukas A. Schaller, Randolf Pohl, Paul E. Knowles, O. Huot, Aldo Antognini, J.F.C.A. Veloso, Livia Ludhova, and M. Boucher

Subjects
X-ray detection, Nuclear and High Energy Physics, Physics::Instrumentation and Detectors, Photon detectors, 01 natural sciences, law.invention, Optics, law, 0103 physical sciences, 010306 general physics, Instrumentation, Physics, Avalanche photodiodes, 010308 nuclear & particles physics, business.industry, Detector, Resolution (electron density), X-ray, Avalanche photodiode, Photodiode, Magnetic field, Pulse-amplitude modulation, Optoelectronics, business, Visible spectrum
Abstract

The behaviour of large-area avalanche photodiodes for X-rays, visible and vacuum-ultra-violet (VUV) light detection in magnetic fields up to 5 T is described. For X-rays and visible light detection, the photodiode pulse amplitude and energy resolution were unaffected from 0 to 5 T, demonstrating the insensitivity of this type of detector to strong magnetic fields. For VUV light detection, however, the photodiode relative pulse amplitude decreases with increasing magnetic field intensity reaching a reduction of about 24% at 5 T, and the energy resolution degrades noticeably with increasing magnetic field. http://www.sciencedirect.com/science/article/B6TJM-47K21KV-1/1/9eb7bcce781352042c63344265f8da97

Published
2003

28. Lifetime and population of the 2S state in muonic hydrogen and deuterium

Author

Marc Diepold, Jan Vogelsang, Paul E. Knowles, François Nez, Catherine Schwob, C.M.B. Monteiro, Andreas Dax, K. Schuhmann, David Taqqu, João Cardoso, Livia Ludhova, Eric-Olivier Le Bigot, Lucile Julien, Franz Kottmann, Paul Rabinowitz, Theodor W. Hänsch, Randolf Pohl, François Biraben, Joaquim M. F. dos Santos, L.M.P. Fernandes, Yi-Wei Liu, J. A. M. Lopes, Thomas Graf, D. S. Covita, Paul Indelicato, J.F.C.A. Veloso, Adolf Giesen, Satish Dhawan, Tobias Nebel, F. D. Amaro, Lukas A. Schaller, Cheng-Yang Kao, F. Mulhauser, Aldo Antognini, and Andrea L. Gouvea

Subjects
Physics, education.field_of_study, Muon, 010308 nuclear & particles physics, Population, State (functional analysis), 01 natural sciences, Atomic and Molecular Physics, and Optics, Deuterium, Excited state, Metastability, 0103 physical sciences, Molecule, Atomic physics, 010306 general physics, education, muonic hydrogen, deuterium, Exotic atom
Abstract

Radiative deexcitation (RD) of the metastable 2S state of muonic protium and deuterium atoms has been observed. In muonic protium, we improve the precision on lifetime and population (formation probability) values for the short-lived {\mu}p(2S) component, and give an upper limit for RD of long-lived {\mu}p(2S) atoms. In muonic deuterium at 1 hPa, 3.1 +-0.3 % of all stopped muons form {\mu}d(2S) atoms. The short-lived 2S component has a population of 1.35 +0.57 -0.33 % and a lifetime of {\tau}_short({\mu}d) = 138 +32 -34 ns. We see evidence for RD of long-lived {\mu}d(2S) with a lifetime of {\tau}_long({\mu}d) = 1.15 +0.75 -0.53 {\mu}s. This is interpreted as formation and decay of excited muonic molecules.

Published
2013

29. Proton Structure from the Measurement of 2S-2P Transition Frequencies of Muonic Hydrogen

Author

Marc Diepold, J.F.C.A. Veloso, Jan Vogelsang, Françoise Mulhauser, Franz Kottmann, D. S. Covita, Satish Dhawan, C.M.B. Monteiro, Andreas Dax, Theodor W. Hänsch, Livia Ludhova, J. A. M. Lopes, Lukas A. Schaller, Yi-Wei Liu, David Taqqu, François Nez, Paul Rabinowitz, Eric-Olivier Le Bigot, Andrea L. Gouvea, João Cardoso, Tobias Nebel, Cheng-Yang Kao, F. D. Amaro, Karsten Schuhmann, Lucile Julien, Paul E. Knowles, Adolf Giesen, Catherine Schwob, Joaquim M. F. dos Santos, Paul Indelicato, Thomas Graf, L.M.P. Fernandes, Randolf Pohl, Aldo Antognini, and François Biraben

Subjects
Femtometer, Multidisciplinary, Muon, Proton, 010308 nuclear & particles physics, Chemistry, Radius, 01 natural sciences, Muonic Hydrogen, Nuclear physics, Proton Structure, Charge radius, 0103 physical sciences, Atomic physics, 010306 general physics, Spectroscopy, GeneralLiterature_REFERENCE(e.g.,dictionaries,encyclopedias,glossaries), Order of magnitude, Exotic atom
Abstract

Proton Still Too Small Despite a proton's tiny size, it is possible to measure its radius based on its charge or magnetization distributions. Traditional measurements of proton radius were based on the scattering between protons and electrons. Recently, a precision measurement of a line in the spectrum of muonium—an atom consisting of a proton and a muon, instead of an electron—revealed a radius inconsistent with that deduced from scattering studies. Antognini et al. (p. 417 ; see the Perspective by Margolis ) examined a different spectral line of muonium, with results less dependent on theoretical analyses, yet still inconsistent with the scattering result; in fact, the discrepancy increased.

Published
2013

30. Muonium Emission into Vacuum from Mesoporous Thin Films at Cryogenic Temperatures

Author

K. S. Khaw, Bernardo Barbiellini, K. Kwuida, Laszlo Liszkay, Paolo Crivelli, Thomas Prokscha, Zaher Salman, Klaus Kirch, Aldo Antognini, Elvezio Morenzoni, Florian M. Piegsa, and Andreas Suter

Subjects
Physics, Atomic Physics (physics.atom-ph), 010308 nuclear & particles physics, Muonium, FOS: Physical sciences, General Physics and Astronomy, 01 natural sciences, Physics - Atomic Physics, High Energy Physics - Experiment, 3. Good health, High Energy Physics - Experiment (hep-ex), 0103 physical sciences, Thin film, Atomic physics, 010306 general physics, Energy (signal processing)
Abstract

We report on Muonium (Mu) emission into vacuum following {\mu}+ implantation in mesoporous thin SiO2 films. We obtain a yield of Mu into vacuum of (38\pm4)% at 250 K temperature and (20\pm4)% at 100 K for 5 keV {\mu}+ implantation energy. From the implantation energy dependence of the Mu vacuum yield we determine the Mu diffusion constants in these films: D250KMu = (1.6 \pm 0.1) \times 10-4 cm2/s and D100KMu = (4.2\pm0.5)\times10-5 cm2/s. Describing the diffusion process as quantum mechanical tunneling from pore-to-pore, we reproduce the measured temperature dependence T^3/2 of the diffusion constant. We extract a potential barrier of (-0.3 \pm 0.1) eV which is consistent with our computed Mu work-function in SiO2 of [-0.3,-0.9] eV. The high Mu vacuum yield even at low temperatures represents an important step towards next generation Mu spectroscopy experiments., Comment: 5 pages, 5 Figures

Published
2012

31. The proton radius puzzle

Author

Paul Indelicato, J.F.C.A. Veloso, T. Graf, Satish Dhawan, Randolf Pohl, Aldo Antognini, L.M.P. Fernandes, João Cardoso, F. D. Amaro, C.M.B. Monteiro, Tobias Nebel, K. Schuhmann, Françoise Mulhauser, Lukas A. Schaller, Livia Ludhova, François Nez, Adolf Giesen, Yi-Wei Liu, E.-O. Le Bigot, Cheng-Yang Kao, Andreas Dax, Theodor W. Hänsch, Paul E. Knowles, L. Julien, F. Biraben, J. A. M. Lopes, Paul Rabinowitz, D. S. Covita, Franz Kottmann, J.M.F. dos Santos, Catherine Schwob, David Taqqu, Max-Planck-Institut für Quantenoptik (MPQ), Max-Planck-Gesellschaft, Institut f¨ur Particle Physics, Departamento de Física [Coimbra] (DFC), Universidade de Coimbra [Coimbra], Laboratoire Kastler Brossel (LKB (Jussieu)), Fédération de recherche du Département de physique de l'Ecole Normale Supérieure - ENS Paris (FRDPENS), École normale supérieure - Paris (ENS-PSL), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Centre National de la Recherche Scientifique (CNRS)-École normale supérieure - Paris (ENS-PSL), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Centre National de la Recherche Scientifique (CNRS)-Université Pierre et Marie Curie - Paris 6 (UPMC)-Centre National de la Recherche Scientifique (CNRS), Departamento de Fisica [Aveiro], Universidade de Aveiro, Physics Department, Yale University [New Haven], Dausinger & Giesen Gmbh, Dausinger & Giesen GmbH, Institut für Strahwerkzeuge (IFSW), Universität Stuttgart [Stuttgart], National Tsing Hua University [Hsinchu] (NTHU), departement de physique, Albert-Ludwigs-Universität Freiburg, Department of Chemistry, Princeton University, Paul Scherrer Institute (PSI), Université Pierre et Marie Curie - Paris 6 (UPMC)-Fédération de recherche du Département de physique de l'Ecole Normale Supérieure - ENS Paris (FRDPENS), École normale supérieure - Paris (ENS Paris), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Centre National de la Recherche Scientifique (CNRS)-École normale supérieure - Paris (ENS Paris), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Centre National de la Recherche Scientifique (CNRS)-Centre National de la Recherche Scientifique (CNRS), and Stuttgart University

Subjects
Physics, History, Muon, Proton, [PHYS.PHYS.PHYS-ATOM-PH]Physics [physics]/Physics [physics]/Atomic Physics [physics.atom-ph], 010308 nuclear & particles physics, Scattering, Hadron, Elementary particle, Radius, 01 natural sciences, Computer Science Applications, Education, 0103 physical sciences, Atomic physics, 010306 general physics, Nucleon, Lepton
Abstract

International audience; By means of pulsed laser spectroscopy applied to muonic hydrogen (mu(-)p) we have measured the 2S(1/2)(F=1) - 2P(3/2)(F=2) transition frequency to be 49881.88(76) GHz [1]. By comparing this measurement with its theoretical prediction [2, 3, 4, 5, 6, 7] based on bound-state QED we have determined a proton radius value of r(p) = 0.84184(67) fm. This new value differs by 5.0 standard deviations from the CODATA value of 0.8768(69) fm [8], and 3 standard deviation from the e-p scattering results of 0.897(18) fm [9]. The observed discrepancy may arise from a computational mistake of the energy levels in mu p or H, or a fundamental problem in bound-state QED, an unknown effect related to the proton or the muon, or an experimental error.

Published
2012

32. Is the proton radius a player in the redefinition of the International System of Units

Author

François Biraben, Andreas Dax, Theodor W. Hänsch, Françoise Mulhauser, Randolf Pohl, Lukas A. Schaller, Tobias Nebel, François Nez, Paul E. Knowles, L. Julien, Yi-Wei Liu, C.M.B. Monteiro, Paul Rabinowitz, E.-O. Le Bigot, Franz Kottmann, Adolf Giesen, D. S. Covita, K. Schuhmann, L.M.P. Fernandes, Livia Ludhova, Cheng-Yang Kao, João Cardoso, J. A. M. Lopes, Th. Graf, Paul Indelicato, J.M.F. dos Santos, David Taqqu, Aldo Antognini, F. D. Amaro, Catherine Schwob, J.F.C.A. Veloso, Satish Dhawan, Laboratoire Kastler Brossel (LKB (Jussieu)), Université Pierre et Marie Curie - Paris 6 (UPMC)-Fédération de recherche du Département de physique de l'Ecole Normale Supérieure - ENS Paris (FRDPENS), École normale supérieure - Paris (ENS Paris), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Centre National de la Recherche Scientifique (CNRS)-École normale supérieure - Paris (ENS Paris), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Centre National de la Recherche Scientifique (CNRS)-Centre National de la Recherche Scientifique (CNRS), Max-Planck-Institut für Quantenoptik (MPQ), Max-Planck-Gesellschaft, Departamento de Física [Coimbra] (DFC), Universidade de Coimbra [Coimbra], Physics Department, Yale University [New Haven], Technol Gesell Strahlwerkzeuge, Universität Stuttgart [Stuttgart], Institut für Strahwerkzeuge (IFSW), Stuttgart University, National Tsing Hua University [Hsinchu] (NTHU), departement de physique, Albert-Ludwigs-Universität Freiburg, Department of Chemistry, Princeton University, Paul Scherrer Institute (PSI), Institut fur Teilchenphysik [Zürich], Eidgenössische Technische Hochschule - Swiss Federal Institute of Technology [Zürich] (ETH Zürich), Fédération de recherche du Département de physique de l'Ecole Normale Supérieure - ENS Paris (FRDPENS), École normale supérieure - Paris (ENS-PSL), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Centre National de la Recherche Scientifique (CNRS)-École normale supérieure - Paris (ENS-PSL), and Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Centre National de la Recherche Scientifique (CNRS)-Université Pierre et Marie Curie - Paris 6 (UPMC)-Centre National de la Recherche Scientifique (CNRS)

Subjects
Physics, Proton radius, [PHYS.PHYS.PHYS-ATOM-PH]Physics [physics]/Physics [physics]/Atomic Physics [physics.atom-ph], Proton, 010308 nuclear & particles physics, General Mathematics, Rydberg constant, General Engineering, General Physics and Astronomy, Fine-structure constant, Planck constant, 01 natural sciences, Electron magnetic dipole moment, symbols.namesake, Charge radius, Avogadro constant, Quantum mechanics, 0103 physical sciences, symbols, 010306 general physics, Constant (mathematics), muonic hydrogen
Abstract

It is now recognized that the International System of Units (SI units) will be redefined in terms of fundamental constants, even if the date when this will occur is still under debate. Actually, the best estimate of fundamental constant values is given by a least-squares adjustment, carried out under the auspices of the Committee on Data for Science and Technology (CODATA) Task Group on Fundamental Constants. This adjustment provides a significant measure of the correctness and overall consistency of the basic theories and experimental methods of physics using the values of the constants obtained from widely differing experiments. The physical theories that underlie this adjustment are assumed to be valid, such as quantum electrodynamics (QED). Testing QED, one of the most precise theories is the aim of many accurate experiments. The calculations and the corresponding experiments can be carried out either on a boundless system, such as the electron magnetic moment anomaly, or on a bound system, such as atomic hydrogen. The value of fundamental constants can be deduced from the comparison of theory and experiment. For example, using QED calculations, the value of the fine structure constant given by the CODATA is mainly inferred from the measurement of the electron magnetic moment anomaly carried out by Gabrielse's group. (Hanneke et al. 2008 Phys. Rev. Lett. 100 , 120801) The value of the Rydberg constant is known from two-photon spectroscopy of hydrogen combined with accurate theoretical quantities. The Rydberg constant, determined by the comparison of theory and experiment using atomic hydrogen, is known with a relative uncertainty of 6.6×10 −12 . It is one of the most accurate fundamental constants to date. A careful analysis shows that knowledge of the electrical size of the proton is nowadays a limitation in this comparison. The aim of muonic hydrogen spectroscopy was to obtain an accurate value of the proton charge radius. However, the value deduced from this experiment contradicts other less accurate determinations. This problem is known as the proton radius puzzle. This new determination of the proton radius may affect the value of the Rydberg constant . This constant is related to many fundamental constants; in particular, links the two possible ways proposed for the redefinition of the kilogram, the Avogadro constant N A and the Planck constant h . However, the current relative uncertainty on the experimental determinations of N A or h is three orders of magnitude larger than the ‘possible’ shift of the Rydberg constant, which may be shown by the new value of the size of the proton radius determined from muonic hydrogen. The proton radius puzzle will not interfere in the redefinition of the kilogram. After a short introduction to the properties of the proton, we will describe the muonic hydrogen experiment. There is intense theoretical activity as a result of our observation. A brief summary of possible theoretical explanations at the date of writing of the paper will be given. The contribution of the proton radius puzzle to the redefinition of SI-based units will then be examined.

Published
2012

33. The size of the proton and the deuteron

Author

J.F.C.A. Veloso, Satish Dhawan, Livia Ludhova, François Nez, Lucile Julien, Catherine Schwob, Yi-Wei Liu, Randolf Pohl, Paul Indelicato, Joaquim M. F. dos Santos, João Cardoso, Franz Kottmann, D. S. Covita, L.M.P. Fernandes, David Taqqu, C.M.B. Monteiro, Andreas Dax, J. A. M. Lopes, Paul E. Knowles, F. D. Amaro, Aldo Antognini, Thomas Graf, Karsten Schuhmann, Lukas A. Schaller, Eric-Olivier Le Bigot, Tobias Nebel, Françoise Mulhauser, Cheng-Yang Kao, Paul Rabinowitz, Adolf Giesen, Theodor W. Hänsch, François Biraben, Technische Universität Dresden = Dresden University of Technology (TU Dresden), Universidade do Estado do Rio de Janeiro [Rio de Janeiro] (UERJ), Max-Planck-Institut für Quantenoptik (MPQ), Max-Planck-Gesellschaft, Université Paris 06, Faculdade de Engenharia da Universidade do Porto (FEUP), Universidade do Porto, Departamento de Fisica [Aveiro], Universidade de Aveiro, Ecole Polytechnique Fédérale de Lausanne (EPFL), Physics Department, Yale University [New Haven], Departamento de Física, University of Coimbra [Portugal] (UC), Institut für Strahwerkzeuge (IFSW), Stuttgart University, Laboratoire d'Economie et de Gestion (LEG), Université de Bourgogne (UB)-Centre National de la Recherche Scientifique (CNRS), National Tsing Hua University [Hsinchu] (NTHU), Laboratoire Kastler Brossel (LKB (Jussieu)), Université Pierre et Marie Curie - Paris 6 (UPMC)-Fédération de recherche du Département de physique de l'Ecole Normale Supérieure - ENS Paris (FRDPENS), Centre National de la Recherche Scientifique (CNRS)-École normale supérieure - Paris (ENS Paris), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Centre National de la Recherche Scientifique (CNRS)-École normale supérieure - Paris (ENS Paris), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Centre National de la Recherche Scientifique (CNRS), Institut d'Électronique et des Technologies du numéRique (IETR), Nantes Université (NU)-Université de Rennes 1 (UR1), Université de Rennes (UNIV-RENNES)-Université de Rennes (UNIV-RENNES)-Institut National des Sciences Appliquées - Rennes (INSA Rennes), Institut National des Sciences Appliquées (INSA)-Université de Rennes (UNIV-RENNES)-Institut National des Sciences Appliquées (INSA)-CentraleSupélec-Centre National de la Recherche Scientifique (CNRS), Centro de Quimica Estrutural (CQE), Instituto Superior Técnico, Universidade Técnica de Lisboa (IST), Département de Physique (dpuf), Albert-Ludwigs-Universität Freiburg, Department of Chemistry, Princeton University, Institut des Nanosciences de Paris (INSP), Université Pierre et Marie Curie - Paris 6 (UPMC)-Centre National de la Recherche Scientifique (CNRS), Paul Scherrer Institute (PSI), Institut fur Teilchenphysik [Zürich], Eidgenössische Technische Hochschule - Swiss Federal Institute of Technology [Zürich] (ETH Zürich), Technische Universität Dresden ( TUD ), Universidade do Estado do Rio de Janeiro, UERJ, Max-Planck-Institut für Quantenoptik ( MPQ ), Max-Planck-Institut, Faculdade de Engenharia [Porto] ( FEUP ), Universidade do Porto [Porto], Ecole Polytechnique Fédérale de Lausanne ( EPFL ), Université Yale - New Haven, University of Coimbra [Portugal] ( UC ), Institut für Strahwerkzeuge ( IFSW ), Laboratoire d'Economie et de Gestion ( LEG ), Université de Bourgogne ( UB ) -Centre National de la Recherche Scientifique ( CNRS ), CEMAGREF Antony, CEMAGREF, Laboratoire Kastler Brossel ( LKB (Jussieu) ), Fédération de recherche du Département de physique de l'Ecole Normale Supérieure - ENS Paris ( FRDPENS ), École normale supérieure - Paris ( ENS Paris ) -Centre National de la Recherche Scientifique ( CNRS ) -École normale supérieure - Paris ( ENS Paris ) -Centre National de la Recherche Scientifique ( CNRS ) -Université Pierre et Marie Curie - Paris 6 ( UPMC ) -Centre National de la Recherche Scientifique ( CNRS ), Institut d'Electronique et de Télécommunications de Rennes ( IETR ), Université de Nantes ( UN ) -Université de Rennes 1 ( UR1 ), Université de Rennes ( UNIV-RENNES ) -Université de Rennes ( UNIV-RENNES ) -Institut National des Sciences Appliquées - Rennes ( INSA Rennes ) -CentraleSupélec-Centre National de la Recherche Scientifique ( CNRS ), Centro de Química Estrutural, Instituto Superior Técnico, Universidade de Lisboa, Lisboa, Département de Physique ( dpuf ), Institut des Nanosciences de Paris ( INSP ), Université Pierre et Marie Curie - Paris 6 ( UPMC ) -Centre National de la Recherche Scientifique ( CNRS ), Paul Scherrer Institute ( PSI ), Institut fur Teilchenphysik, Swiss Federal Institute of Technology in Zürich ( ETH Zürich ), Universidade do Porto = University of Porto, Universität Stuttgart [Stuttgart], Fédération de recherche du Département de physique de l'Ecole Normale Supérieure - ENS Paris (FRDPENS), École normale supérieure - Paris (ENS-PSL), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Centre National de la Recherche Scientifique (CNRS)-École normale supérieure - Paris (ENS-PSL), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Centre National de la Recherche Scientifique (CNRS)-Université Pierre et Marie Curie - Paris 6 (UPMC)-Centre National de la Recherche Scientifique (CNRS), Université de Nantes (UN)-Université de Rennes (UR)-Institut National des Sciences Appliquées - Rennes (INSA Rennes), Institut National des Sciences Appliquées (INSA)-Institut National des Sciences Appliquées (INSA)-CentraleSupélec-Centre National de la Recherche Scientifique (CNRS), and Université de Nantes (UN)-Université de Rennes 1 (UR1)

Subjects
Physics, History, Proton, [PHYS.PHYS.PHYS-ATOM-PH]Physics [physics]/Physics [physics]/Atomic Physics [physics.atom-ph], [ PHYS.PHYS.PHYS-ATOM-PH ] Physics [physics]/Physics [physics]/Atomic Physics [physics.atom-ph], Hydrogen atom, 01 natural sciences, 010305 fluids & plasmas, Computer Science Applications, Education, Nuclear physics, Rydberg constant, Deuterium, Charge radius, 0103 physical sciences, Atom, Physics::Atomic Physics, Atomic physics, 010306 general physics, Hyperfine structure, Exotic atom
Abstract

We have recently measured the 2S1/2⁼¹ − 2P3/2 ⁼ ² energy splitting in the muonic hydrogen atom μp to be 49881.88 (76) GHz. Using recent QED calculations of the fine-, hyperfine, QED and finite size contributions we obtain a root-mean-square proton charge radius of rp = 0.84184 (67) fm. This value is ten times more precise, but 5 standard deviations smaller, than the 2006 CODATA value of rp = 0.8768 (69) fm. The source of this discrepancy is unknown. Using the precise measurements of the 1S-2S transition in regular hydrogen and deuterium and our value of rp we obtain improved values of the Rydberg constant, R∞ = 10973731.568160 (16) m⁻¹and the rms charge radius of the deuteron rd = 2.12809 (31) fm.

Published
2011

34. The size of the proton

Author

Eric-Olivier Le Bigot, J.F.C.A. Veloso, Satish Dhawan, Livia Ludhova, F. D. Amaro, C.M.B. Monteiro, Andreas Dax, Randolf Pohl, Tobias Nebel, Yi-Wei Liu, François Nez, Theodor W. Hänsch, Aldo Antognini, Lukas A. Schaller, Lucile Julien, L.M.P. Fernandes, João Cardoso, Paul E. Knowles, Franz Kottmann, Joaquim M. F. dos Santos, D. S. Covita, F. Biraben, Karsten Schuhmann, J. A. M. Lopes, Paul Rabinowitz, Catherine Schwob, Cheng-Yang Kao, Adolf Giesen, Françoise Mulhauser, Paul Indelicato, David Taqqu, Thomas Graf, Max-Planck-Institut für Quantenoptik (MPQ), Max-Planck-Gesellschaft, Laboratoire Kastler Brossel (LKB (Jussieu)), Fédération de recherche du Département de physique de l'Ecole Normale Supérieure - ENS Paris (FRDPENS), École normale supérieure - Paris (ENS-PSL), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Centre National de la Recherche Scientifique (CNRS)-École normale supérieure - Paris (ENS-PSL), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Centre National de la Recherche Scientifique (CNRS)-Université Pierre et Marie Curie - Paris 6 (UPMC)-Centre National de la Recherche Scientifique (CNRS), Departamento de Física, University of Coimbra [Portugal] (UC), Physics Department, Yale University [New Haven], Technol Gesell Strahlwerkzeuge, Universität Stuttgart [Stuttgart], Institut für Strahwerkzeuge (IFSW), Sektion Physik, Ludwig-Maximilians-Universität München (LMU), National Tsing Hua University [Hsinchu] (NTHU), Département de Physique (dpuf), Albert-Ludwigs-Universität Freiburg, Departamento de Física [Coimbra] (DFC), Universidade de Coimbra [Coimbra], departement de physique, Department of Chemistry, Princeton University, Paul Scherrer Institute (PSI), Université Pierre et Marie Curie - Paris 6 (UPMC)-Fédération de recherche du Département de physique de l'Ecole Normale Supérieure - ENS Paris (FRDPENS), École normale supérieure - Paris (ENS Paris), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Centre National de la Recherche Scientifique (CNRS)-École normale supérieure - Paris (ENS Paris), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Centre National de la Recherche Scientifique (CNRS)-Centre National de la Recherche Scientifique (CNRS), and Stuttgart University

Subjects
Physics, Multidisciplinary, Muon, proton radius, Proton, Anomalous magnetic dipole moment, [PHYS.PHYS.PHYS-ATOM-PH]Physics [physics]/Physics [physics]/Atomic Physics [physics.atom-ph], 010308 nuclear & particles physics, Electron, 01 natural sciences, 7. Clean energy, Lamb shift, Rydberg constant, Charge radius, 0103 physical sciences, Physics::Atomic Physics, Atomic physics, 010306 general physics, proton size, muonic hydrogen, Bohr radius, ComputingMilieux_MISCELLANEOUS
Abstract

Considering that the proton is a basic subatomic component of all ordinary matter — as well as being ubiquitous in its solo role as the hydrogen ion H+ — there are some surprising gaps in our knowledge of its structure and behaviour. A collaborative project to determine the root-mean-square charge radius of the proton to better than the 1% accuracy of the current 'best' value suggests that those knowledge gaps may be greater than was thought. The new determination comes from a technically challenging spectroscopic experiment — the measurement of the Lamb shift (the energy difference between a specific pair of energy states) in 'muonic hydrogen', an exotic atom in which the electron is replaced by its heavier twin, the muon. The result is unexpected: a charge radius about 4% smaller than the previous value. The discrepancy remains unexplained. Possible implications are that the value of the most accurately determined fundamental constant, the Rydberg constant, will need to be revised — or that the validity of quantum electrodynamics theory is called into question. Here, a technically challenging spectroscopic experiment is described: the measurement of the muonic Lamb shift. The results lead to a new determination of the charge radius of the proton. The new value is 5.0 standard deviations smaller than the previous world average, a large discrepancy that remains unexplained. Possible implications of the new finding are that the value of the Rydberg constant will need to be revised, or that the validity of quantum electrodynamics theory is called into question. The proton is the primary building block of the visible Universe, but many of its properties—such as its charge radius and its anomalous magnetic moment—are not well understood. The root-mean-square charge radius, rp, has been determined with an accuracy of 2 per cent (at best) by electron–proton scattering experiments1,2. The present most accurate value of rp (with an uncertainty of 1 per cent) is given by the CODATA compilation of physical constants3. This value is based mainly on precision spectroscopy of atomic hydrogen4,5,6,7 and calculations of bound-state quantum electrodynamics (QED; refs 8, 9). The accuracy of rp as deduced from electron–proton scattering limits the testing of bound-state QED in atomic hydrogen as well as the determination of the Rydberg constant (currently the most accurately measured fundamental physical constant3). An attractive means to improve the accuracy in the measurement of rp is provided by muonic hydrogen (a proton orbited by a negative muon); its much smaller Bohr radius compared to ordinary atomic hydrogen causes enhancement of effects related to the finite size of the proton. In particular, the Lamb shift10 (the energy difference between the 2S1/2 and 2P1/2 states) is affected by as much as 2 per cent. Here we use pulsed laser spectroscopy to measure a muonic Lamb shift of 49,881.88(76) GHz. On the basis of present calculations11,12,13,14,15 of fine and hyperfine splittings and QED terms, we find rp = 0.84184(67) fm, which differs by 5.0 standard deviations from the CODATA value3 of 0.8768(69) fm. Our result implies that either the Rydberg constant has to be shifted by −110 kHz/c (4.9 standard deviations), or the calculations of the QED effects in atomic hydrogen or muonic hydrogen atoms are insufficient.

Published
2010

35. Muonic hydrogen cascade time and lifetime of the short-lived $2S$ state

Author

C.M.B. Monteiro, Aldo Antognini, David Taqqu, Lukas A. Schaller, J. A. M. Lopes, Yi-Wei Liu, J.F.C.A. Veloso, L.M.P. Fernandes, Satish Dhawan, Françoise Mulhauser, João Cardoso, Lucile Julien, V. W. Hughes, Andreas Dax, Paul E. Knowles, Paul Rabinowitz, Livia Ludhova, Theodor W. Hänsch, F. D. Amaro, François Biraben, Randolf Pohl, J.M.F. dos Santos, Paul Indelicato, François Nez, Catherine Schwob, Franz Kottmann, C.A.N. Conde, Paul Scherrer Institute (PSI), Département de Physique (dpuf), Albert-Ludwigs-Universität Freiburg, Departamento de Física, University of Coimbra [Portugal] (UC), Max-Planck-Institut für Quantenoptik (MPQ), Max-Planck-Gesellschaft, Laboratoire Kastler Brossel (LKB (Jussieu)), Fédération de recherche du Département de physique de l'Ecole Normale Supérieure - ENS Paris (FRDPENS), École normale supérieure - Paris (ENS-PSL), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Centre National de la Recherche Scientifique (CNRS)-École normale supérieure - Paris (ENS-PSL), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Centre National de la Recherche Scientifique (CNRS)-Université Pierre et Marie Curie - Paris 6 (UPMC)-Centre National de la Recherche Scientifique (CNRS), Physics Department, Yale University [New Haven], Institut für Teilchenphysik, Eidgenössische Technische Hochschule - Swiss Federal Institute of Technology [Zürich] (ETH Zürich), National Tsing Hua University [Hsinchu] (NTHU), Department of Chemistry, Princeton University, Université Pierre et Marie Curie - Paris 6 (UPMC)-Fédération de recherche du Département de physique de l'Ecole Normale Supérieure - ENS Paris (FRDPENS), École normale supérieure - Paris (ENS Paris), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Centre National de la Recherche Scientifique (CNRS)-École normale supérieure - Paris (ENS Paris), and Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Centre National de la Recherche Scientifique (CNRS)-Centre National de la Recherche Scientifique (CNRS)

Subjects
Physics, education.field_of_study, [PHYS.PHYS.PHYS-ATOM-PH]Physics [physics]/Physics [physics]/Atomic Physics [physics.atom-ph], Atomic Physics (physics.atom-ph), 010308 nuclear & particles physics, muonic atoms, Population, FOS: Physical sciences, State (functional analysis), Kinetic energy, 01 natural sciences, 7. Clean energy, Atomic and Molecular Physics, and Optics, Physics - Atomic Physics, Gas pressure, 0103 physical sciences, Atom, metastable states, Physics::Atomic Physics, Atomic physics, 36.10.Dr, 34.50.Fa, 010306 general physics, education, Energy (signal processing), Exotic atom
Abstract

Metastable ${2S}$ muonic-hydrogen atoms undergo collisional ${2S}$-quenching, with rates which depend strongly on whether the $\mu p$ kinetic energy is above or below the ${2S}\to {2P}$ energy threshold. Above threshold, collisional ${2S} \to {2P}$ excitation followed by fast radiative ${2P} \to {1S}$ deexcitation is allowed. The corresponding short-lived $\mu p ({2S})$ component was measured at 0.6 hPa $\mathrm{H}_2$ room temperature gas pressure, with lifetime $\tau_{2S}^\mathrm{short} = 165 ^{+38}_{-29}$ ns (i.e., $\lambda_{2S}^\mathrm{quench} = 7.9 ^{+1.8}_{-1.6} \times 10^{12} \mathrm{s}^{-1}$ at liquid-hydrogen density) and population $\epsilon_{2S}^\mathrm{short} = 1.70^{+0.80}_{-0.56}$ % (per $\mu p$ atom). In addition, a value of the $\mu p$ cascade time, $T_\mathrm{cas}^{\mu p} = (37\pm5)$ ns, was found., Comment: 4 pages, 3 figures

Published
2006

36. Powerful fast triggerable 6 μm laser for the muonic hydrogen 2S-Lamb shift experiment

Author

Catherine Schwob, J.F.C.A. Veloso, Randolf Pohl, Satish Dhawan, F. D. Amaro, Aldo Antognini, V. W. Hughes, Françoise Mulhauser, L.M.P. Fernandes, Yi-Wei Liu, J. A. M. Lopes, O. Huot, Theodor W. Hänsch, C.M.B. Monteiro, François Nez, Paul Indelicato, C.A.N. Conde, J.M.F. dos Santos, Livia Ludhova, B. N. Perry, João Cardoso, L. Julien, Franz Kottmann, David Taqqu, D. S. Covita, François Biraben, Paul E. Knowles, A. Dax, Paul Rabinowitz, and Lukas A. Schaller

Subjects
Materials science, Dye laser, business.industry, Laser pumping, Laser, 01 natural sciences, Atomic and Molecular Physics, and Optics, Electronic, Optical and Magnetic Materials, law.invention, Lamb shift, 010309 optics, Wavelength, symbols.namesake, Optics, law, 0103 physical sciences, symbols, Electrical and Electronic Engineering, Physical and Theoretical Chemistry, 010306 general physics, Spectroscopy, Raman spectroscopy, business, Ultrashort pulse
Abstract

Laser spectroscopy of the 2S-Lamb shift in muonic hydrogen (μ−p) is being performed at the Paul Scherrer Institute, Switzerland, to determine the root-mean-square (rms) proton charge radius with 10−3 precision. A multistage laser system has been developed which provides 0.2 mJ pulse energy tunable at 6 μm wavelength. An excimer pumped dye laser is used to drive a titanium sapphire (Ti:Sa) system whose wavelength is then shifted to 6 μm using a multipass Raman cell filled with hydrogen. The short cavity length of the Ti:Sa oscillator (7 cm) guarantees a pulse width of 7 ns and a pulse energy of 1.2 mJ at 708 nm, a wavelength controlled by a mono-mode cw-Ti:Sa laser. The laser is triggered at a maximum 60 s−1 repetition rate by muons entering the apparatus at random times. A new type of multipass cavity has been developed to provide a homogeneously illuminated volume (25 × 7 × 170 mm³).

Published
2005

37. Planar LAAPDs: temperature dependence, performance, and application in low-energy X-ray spectroscopy

Author

Livia Ludhova, Theodor W. Hänsch, François Biraben, Franz Kottmann, D. S. Covita, A. Dax, François Nez, J.M.F. dos Santos, Yi-Wei Liu, Paul E. Knowles, Aldo Antognini, João Cardoso, Françoise Mulhauser, Randolf Pohl, Paul Rabinowitz, O. Huot, David Taqqu, C.M.B. Monteiro, J. A. M. Lopes, Lucile Julien, Lukas A. Schaller, J.F.C.A. Veloso, Satish Dhawan, Paul Indelicato, F. D. Amaro, L.M.P. Fernandes, V. W. Hughes, C.A.N. Conde, Paul Scherrer Institute (PSI), Département de Physique (dpuf), Albert-Ludwigs-Universität Freiburg, Departamento de Física, University of Coimbra [Portugal] (UC), Max-Planck-Institut für Quantenoptik (MPQ), Max-Planck-Gesellschaft, Laboratoire Kastler Brossel (LKB (Jussieu)), Université Pierre et Marie Curie - Paris 6 (UPMC)-Fédération de recherche du Département de physique de l'Ecole Normale Supérieure - ENS Paris (FRDPENS), École normale supérieure - Paris (ENS Paris), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Centre National de la Recherche Scientifique (CNRS)-École normale supérieure - Paris (ENS Paris), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Centre National de la Recherche Scientifique (CNRS)-Centre National de la Recherche Scientifique (CNRS), Laboratoire de Spectroscopie Hertzienne de l'ENS (LSH-ENS), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Centre National de la Recherche Scientifique (CNRS), Departamento de Física [Coimbra] (DFC), Universidade de Coimbra [Coimbra], Physics Department, Yale University [New Haven], Sektion Physik (SEKTION PHYSIK), Ludwig-Maximilians-Universität München (LMU), Sektion Physik, Institut für Teilchenphysik, Eidgenössische Technische Hochschule - Swiss Federal Institute of Technology [Zürich] (ETH Zürich), National Tsing Hua University [Hsinchu] (NTHU), Department of Chemistry, Princeton University, Fédération de recherche du Département de physique de l'Ecole Normale Supérieure - ENS Paris (FRDPENS), École normale supérieure - Paris (ENS-PSL), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Centre National de la Recherche Scientifique (CNRS)-École normale supérieure - Paris (ENS-PSL), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Centre National de la Recherche Scientifique (CNRS)-Université Pierre et Marie Curie - Paris 6 (UPMC)-Centre National de la Recherche Scientifique (CNRS), and Biraben, François

Subjects
Nuclear and High Energy Physics, Physics - Instrumentation and Detectors, Physics::Instrumentation and Detectors, FOS: Physical sciences, Noise figure, 01 natural sciences, 7. Clean energy, Noise (electronics), law.invention, Response to [alpha] particles, Optics, law, 0103 physical sciences, Low-energy X-ray spectroscopy, [PHYS.PHYS.PHYS-INS-DET]Physics [physics]/Physics [physics]/Instrumentation and Detectors [physics.ins-det], Physics::Atomic Physics, 010306 general physics, Spectroscopy, Instrumentation, Physics, 010308 nuclear & particles physics, business.industry, Detector, Instrumentation and Detectors (physics.ins-det), Large Area Avalanche Photodiodes performance, Avalanche photodiode, Photodiode, Lamb shift, [PHYS.PHYS.PHYS-INS-DET] Physics [physics]/Physics [physics]/Instrumentation and Detectors [physics.ins-det], Temperature dependence, business, Dark current
Abstract

An experiment measuring the 2S Lamb shift in muonic hydrogen mup is being performed at the Paul Scherrer Institute, Switzerland. It requires small and compact detectors for 1.9 keV x rays (2P-1S transition) with an energy resolution around 25% at 2 keV, a time resolution better than 100 ns, a large solid angle coverage, and insensitivity to a 5 T magnetic field. We have chosen Large Area Avalanche Photodiodes (LAAPDs) from Radiation Monitoring Devices as x-ray detectors, and they were used during the last data taking period in 2003. For x-ray spectroscopy applications, these LAAPDs have to be cooled in order to suppress the dark current noise, hence, a series of tests were performed to choose the optimal operation temperature. Specifically, the temperature dependence of gain, energy resolution, dark current, excess noise factor, and detector response linearity was studied. Finally, details of the LAAPDs application in the muonic hydrogen experiment as well as their response to alpha particles are presented., 20 pages, 19 figures, submitted to Nucl. Instr. and Methods A

Published
2005

38. The Lamb shift in muonic hydrogen and the proton radius

Author

Catherine Schwob, David Taqqu, Paul Indelicato, A. Voss, J.F.C.A. Veloso, Klaus Kirch, Satish Dhawan, Livia Ludhova, J.M.F. dos Santos, Tobias Nebel, Franz Kottmann, Paul E. Knowles, F. D. Amaro, Aldo Antognini, J. A. M. Lopes, Yi-Wei Liu, C.M.B. Monteiro, Andreas Dax, D. S. Covita, François Nez, Th. Graf, L.M.P. Fernandes, K. Schuhmann, Lukas A. Schaller, L. Julien, François Biraben, Françoise Mulhauser, T.W. Ḧansch, João Cardoso, Cheng-Yang Kao, Randolf Pohl, Malte Hildebrandt, E.-O. Le Bigot, Andrea L. Gouvea, Adolf Giesen, Paul Rabinowitz, Max-Planck-Institut für Quantenoptik (MPQ), Max-Planck-Gesellschaft, Institut fur Teilchenphysik [Zürich], Eidgenössische Technische Hochschule - Swiss Federal Institute of Technology [Zürich] (ETH Zürich), Departamento de Física [Coimbra] (DFC), Universidade de Coimbra [Coimbra], Laboratoire Kastler Brossel (LKB (Jussieu)), Fédération de recherche du Département de physique de l'Ecole Normale Supérieure - ENS Paris (FRDPENS), École normale supérieure - Paris (ENS-PSL), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Centre National de la Recherche Scientifique (CNRS)-École normale supérieure - Paris (ENS-PSL), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Centre National de la Recherche Scientifique (CNRS)-Université Pierre et Marie Curie - Paris 6 (UPMC)-Centre National de la Recherche Scientifique (CNRS), Physics Department, Yale University [New Haven], Technol Gesell Strahlwerkzeuge, Universität Stuttgart [Stuttgart], Institut für Strahwerkzeuge (IFSW), Paul Scherrer Institute (PSI), National Tsing Hua University [Hsinchu] (NTHU), departement de physique, Albert-Ludwigs-Universität Freiburg, Department of Chemistry, Princeton University, Dausinger & Giesen GmbH, Université Pierre et Marie Curie - Paris 6 (UPMC)-Fédération de recherche du Département de physique de l'Ecole Normale Supérieure - ENS Paris (FRDPENS), École normale supérieure - Paris (ENS Paris), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Centre National de la Recherche Scientifique (CNRS)-École normale supérieure - Paris (ENS Paris), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Centre National de la Recherche Scientifique (CNRS)-Centre National de la Recherche Scientifique (CNRS), and Stuttgart University

Subjects
Physics, Muon, proton radius, Proton, [PHYS.PHYS.PHYS-ATOM-PH]Physics [physics]/Physics [physics]/Atomic Physics [physics.atom-ph], 010308 nuclear & particles physics, Radius, Physics and Astronomy(all), bound-state QED, 01 natural sciences, hydrogen-like, Lamb shift, Nuclear physics, Deuterium, Charge radius, muon, 0103 physical sciences, Atomic physics, few-nucleon, 010306 general physics, Spectroscopy, Exotic atom
Abstract

International audience; By means of pulsed laser spectroscopy applied to muonic hydrogen (mu(-) p) we have measured the 2S(1/2)(F=1) - 2P(3/2)(F=2) transition frequency to be 49881.88(76) GHz. By comparing this measurement with its theoretical prediction based on bound-state QED we have determined a proton radius value of r(p) = 0.84184 (67) fm. This new value is an order of magnitude preciser than previous results but disagrees by 5 standard deviations from the CODATA and the electron-proton scattering values. An overview of the present effort attempting to solve the observed discrepancy is given. Using the measured isotope shift of the 1S-2S transition in regular hydrogen and deuterium also the rms charge radius of the deuteron r(d) = 2.12809 (31) fm has been determined. Moreover we present here the motivations for the measurements of the mu(4)He(+) and mu(3)He(+) 2S-2P splittings. The alpha and triton charge radii are extracted from these measurements with relative accuracies of few 10(-4). Measurements could help to solve the observed discrepancy, lead to the best test of hydrogen-like energy levels and provide crucial tests for few-nucleon ab-initio theories and potentials.

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