Search

Your search keyword '"Malte Hildebrandt"' showing total 110 results
Start Over Author "Malte Hildebrandt"
110 results on '"Malte Hildebrandt"'

1. The Search for μ+ → e+γ with 10–14 Sensitivity: The Upgrade of the MEG Experiment

Author

Alessandro M. Baldini, Vladimir Baranov, Michele Biasotti, Gianluigi Boca, Paolo W. Cattaneo, Gianluca Cavoto, Fabrizio Cei, Marco Chiappini, Gianluigi Chiarello, Alessandro Corvaglia, Federica Cuna, Giovanni dal Maso, Antonio de Bari, Matteo De Gerone, Marco Francesconi, Luca Galli, Giovanni Gallucci, Flavio Gatti, Francesco Grancagnolo, Marco Grassi, Dmitry N. Grigoriev, Malte Hildebrandt, Kei Ieki, Fedor Ignatov, Toshiyuki Iwamoto, Peter-Raymond Kettle, Nikolay Khomutov, Satoru Kobayashi, Alexander Kolesnikov, Nikolay Kravchuk, Victor Krylov, Nikolay Kuchinskiy, William Kyle, Terence Libeiro, Vladimir Malyshev, Manuel Meucci, Satoshi Mihara, William Molzon, Toshinori Mori, Alexander Mtchedlishvili, Mitsutaka Nakao, Donato Nicolò, Hajime Nishiguchi, Shinji Ogawa, Rina Onda, Wataru Ootani, Atsushi Oya, Dylan Palo, Marco Panareo, Angela Papa, Valerio Pettinacci, Alexander Popov, Francesco Renga, Stefan Ritt, Massimo Rossella, Aleksander Rozhdestvensky, Patrick Schwendimann, Kohei Shimada, Giovanni Signorelli, Alexey Stoykov, Giovanni F. Tassielli, Kazuki Toyoda, Yusuke Uchiyama, Masashi Usami, Cecilia Voena, Kosuke Yanai, Kensuke Yamamoto, Taku Yonemoto, and Yury V. Yudin

Subjects
lepton flavor violation, rare muon decay, high intensity experiment, particle detector, physics beyond the Standard Model, Mathematics, QA1-939
Abstract

The MEG experiment took data at the Paul Scherrer Institute in the years 2009–2013 to test the violation of the lepton flavor conservation law, which originates from an accidental symmetry that the Standard Model of elementary particle physics has, and published the most stringent limit on the charged lepton flavor violating decay μ+→e+γ: BR(μ+→e+γ) <4.2×10−13 at 90% confidence level. The MEG detector has been upgraded in order to reach a sensitivity of 6×10−14. The basic principle of MEG II is to achieve the highest possible sensitivity using the full muon beam intensity at the Paul Scherrer Institute (7×107 muons/s) with an upgraded detector. The main improvements are better rate capability of all sub-detectors and improved resolutions while keeping the same detector concept. In this paper, we present the current status of the preparation, integration and commissioning of the MEG II detector in the recent engineering runs.

Published
2021
Full Text
View/download PDF

2. Search for lepton flavour violating muon decay mediated by a new light particle in the MEG experiment

Author

A. Stoykov, Valerio Pettinacci, Andrey Popov, S. Ogawa, Toshinori Mori, Stefan Ritt, K. Ieki, G. F. Tassielli, N. P. Kravchuk, Satoru Kobayashi, M. Panareo, M. De Gerone, P. Schwendimann, Malte Hildebrandt, Flavio Gatti, A. Papa, G. Pizzigoni, M. Francesconi, William Kyle, T. Libeiro, M. Usami, W. R. Molzon, Michele Biasotti, Yusuke Uchiyama, M. Chiappini, Satoshi Mihara, D. Nicolò, R. Onda, Dylan Palo, P.-R. Kettle, G. M. A. Lim, N. V. Khomutov, L. Galli, M. Nakao, Vladimir Malyshev, M. Nishimura, F. Ignatov, A. Kolesnikov, C. Chiri, Gianluigi Boca, F. Renga, Atsushi Oya, Ryu Sawada, G. Signorelli, A. de Bari, F. Grancagnolo, G. Cavoto, P. W. Cattaneo, H. Natori, Z. Hodge, R. Iwai, Yu.V. Yudin, Fabrizio Cei, F. Berg, Kazuki Toyoda, T. Iwamoto, M. Rossella, K. Yanai, Marco Grassi, Wataru Ootani, C. Voena, A. Corvaglia, A. M. Baldini, Nikolay Kuchinskiy, Aleksander Rozhdestvensky, Hajime Nishiguchi, Manuel Meucci, G. Chiarello, D. N. Grigoriev, A. Mtchedilishvili, Nobuo Matsuzawa, Baldini, A. M., Berg, F., Biasotti, M., Boca, G., Cattaneo, P. W., Cavoto, G., Cei, F., Chiappini, M., Chiarello, G., Chiri, C., Corvaglia, A., de Bari, A., De Gerone, M., Francesconi, M., Galli, L., Gatti, F., Grancagnolo, F., Grassi, M., Grigoriev, D. N., Hildebrandt, M., Hodge, Z., Ieki, K., Ignatov, F., Iwai, R., Iwamoto, T., Kobayashi, S., Kettle, P. -R., Kyle, W., Khomutov, N., Kolesnikov, A., Kravchuk, N., Kuchinskiy, N., Libeiro, T., Lim, G. M. A., Malyshev, V., Matsuzawa, N., Meucci, M., Mihara, S., Molzon, W., Mori, Toshinori, Mtchedilishvili, A., Nakao, M., Natori, H., Nicolò, D., Nishiguchi, H., Nishimura, M., Ogawa, S., Onda, R., Ootani, W., Oya, A., Palo, D., Panareo, M., Papa, A., Pettinacci, V., Pizzigoni, G., Popov, A., Renga, F., Ritt, S., Rozhdestvensky, A., Rossella, M., Sawada, R., Schwendimann, P., Signorelli, G., Stoykov, A., Tassielli, G. F., Toyoda, K., Uchiyama, Y., Usami, M., Voena, C., Yanai, K., and Yudin, Yu. V.

Subjects
Particle physics, Physics and Astronomy (miscellaneous), Flavour, Light particle, FOS: Physical sciences, lcsh:Astrophysics, MEG experiment, lepton flavour violation, muon decay, 01 natural sciences, High Energy Physics - Experiment, High Energy Physics - Experiment (hep-ex), 0103 physical sciences, lcsh:QB460-466, Direct search, lcsh:Nuclear and particle physics. Atomic energy. Radioactivity, Lepton Flavour Violation, MEG experiment, 010306 general physics, Engineering (miscellaneous), Physics, Muon, 010308 nuclear & particles physics, Branching fraction, lcsh:QC770-798, High Energy Physics::Experiment, Lepton Flavour Violation, Lepton
Abstract

We present the first direct search for lepton flavour violating muon decay mediated by a new light particle X, $$\upmu ^+ \rightarrow \mathrm {e}^+\mathrm {X}, \mathrm {X} \rightarrow \upgamma \upgamma \ $$ μ + → e + X , X → γ γ . This search uses a dataset resulting from $$7.5\times 10^{14}$$ 7.5 × 10 14 stopped muons collected by the MEG experiment at the Paul Scherrer Institut in the period 2009–2013. No significant excess is found in the mass region 20–45 MeV/c$$^2$$ 2 for lifetimes below 40 ps, and we set the most stringent branching ratio upper limits in the mass region of 20–40 MeV/c$$^2$$ 2 , down to $${\mathcal {O}}(10^{-11})$$ O ( 10 - 11 ) at 90% confidence level.

Published
2020

3. MuCap: Muon Capture on the Proton

Author

Malte Hildebrandt and C. Petitjean

Subjects
Physics, Nuclear physics, Proton, Muon capture
Abstract

The singlet muon capture rate \Lambda_SΛS on the proton \mu^-\ p \to \nu_\mu~nμ−p→νμn is determined in a high precision lifetime measurement. The main apparatus consists of a new hydrogen time projection chamber as muon detector, developed by PSI, surrounded by cylindrical wire chambers and a plastic scintillator hodoscope as electron detectors. The parameter \Lambda_SΛS is evaluated as the difference between the inverse \mu\,pμp lifetime and that of the free \mu^+μ+. The result \Lambda_S^\text{MuCap} = (715.6 \pm 5.4^\text{stat} \pm 5.1^\text{sys})\,\text{s}^{-1}ΛSMuCap=(715.6±5.4stat±5.1sys)s−1 is in excellent agreement with the prediction of chiral perturbation theory \Lambda_S^{\chi\text{PT}} = (715.4 \pm 6.9)\,\text{s}^{-1}ΛSχPT=(715.4±6.9)s−1. From \Lambda_S^\text{MuCap}ΛSMuCap a recent analysis derives for the induced pseudoscalar coupling g^\text{MuCap}_p = 8.23 \pm 0.83gpMuCap=8.23±0.83 whereas \bar{g}^{\chi\text{PT}}_p = 8.25 \pm 0.25g‾pχPT=8.25±0.25.

Published
2021

4. 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

5. Development of next generation muon beams at the Paul Scherrer Institute

Author

Stefan Ritt, N. J. Ayres, C. Petitjean, Jonas Nuber, Malte Hildebrandt, Thomas J. Phillips, Florian M. Piegsa, Andreas Eggenberger, Daniel M. Kaplan, Ivana Belosevic, Gunther Wichmann, Klaus Kirch, Aldo Antognini, David Taqqu, Yu Bao, Ryoto Iwai, Alexey Stoykov, V. Bondar, Andreas Knecht, P.-R. Kettle, and Angela Papa

Subjects
Physics, Orders of magnitude (power), Nuclear physics, Muon, Phase space, Physics::Accelerator Physics, Development (differential geometry), Accelerators and Storage Rings, Intensity (heat transfer), Energy (signal processing), Order of magnitude, Beam (structure)
Abstract

The Paul Scherrer Institute (PSI) provides the world's highest intensity muon beam of Ó(108)μ+/s at 28MeV/c. The HiMB project aims to improve this rate by two orders of magnitude. Meanwhile, the muCool collaboration is developing a device which converts a standard surface μ+ beam of cm-size and MeV-energy into a beam of 1mm-size and 1eV energy spread by achieving a compression of 6-dimensional phase space by 10 orders of magnitude with an efficiency of 10−3., PoS: Proceedings of Science, 369, ISSN:1824-8039, Proceedings of the 21st international workshop on neutrinos from accelerators

Published
2020

6. 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

7. Evaluation of ZnS:6LiF and ZnO:6LiF Scintillation Neutron Detectors Readout With SiPMs

Author

Malte Hildebrandt, J.-B. Mosset, and Alexey Stoykov

Subjects
Nuclear and High Energy Physics, Scintillation, Materials science, Physics::Instrumentation and Detectors, 010308 nuclear & particles physics, business.industry, Detector, Scintillator, 01 natural sciences, Signal, Afterglow, Condensed Matter::Materials Science, Nuclear Energy and Engineering, 0103 physical sciences, Neutron detection, Optoelectronics, Neutron, Electrical and Electronic Engineering, Photonics, 010306 general physics, business
Abstract

It is generally accepted that the count rate capability of ZnS:6LiF neutron detectors is strongly limited due to the long afterglow of the scintillator. However, realized as an array of individual sensitive elements (pixels) with independent signal readout and processing, such detectors can be operated with blocking times down to 1 $\mu \text{s}$ and promising counting rates up to 100 kHz/pixel. In this paper, we investigate how the long emission of the ZnS scintillator influences the detector performance apart from requiring a finite blocking time to suppress the probability of multiple counts. We also study the potential of the ZnO:6LiF scintillator with lower afterglow as a possible replacement of ZnS:6LiF.

Published
2018

8. Characterization of Cryogenic SiPM Down to 6.5 K

Author

Andreas Knecht, Angela Papa, Ryoto Iwai, Mikio Sakurai, Klaus Kirch, Aldo Antognini, Ivana Belosevic, Alexey Stoykov, and Malte Hildebrandt

Subjects
Silicon photomultiplier, Materials science, business.industry, Optoelectronics, business, Characterization (materials science)
Published
2019

9. 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

10. Publisher Correction: Measuring the α-particle charge radius with muonic helium-4 ions

Author

F. Mulhauser, Franz Kottmann, Birgit Weichelt, J.F.C.A. Veloso, Jens Hartmann, Thomas Graf, José Paulo Santos, Tzu-Ling Chen, Julian J. Krauth, Paul Indelicato, D. S. Covita, Marwan Abdou Ahmed, Beatrice Franke, Randolf Pohl, Malte Hildebrandt, L.M.P. Fernandes, Csilla I. Szabo, Johannes Götzfried, C.M.B. Monteiro, François Biraben, Theodor W. Hänsch, Sandrine Galtier, Pedro Amaro, Klaus Kirch, Aldo Antognini, Andrea L. Gouvea, Andreas Dax, Andreas Knecht, Boris Naar, Marc Diepold, Yi-Wei Liu, Jan Vogelsang, F. D. Amaro, Andreas Voss, F. Nez, Lucile Julien, Jorge Machado, Karsten Schuhmann, Joaquim M. F. dos Santos, Tobias Nebel, and D. Taqqu

Subjects
Multidisciplinary, Computer science, Published Erratum, Creative commons, Publisher Correction, SDG 17 - Partnerships for the Goals, Helium-4, Charge radius, Exotic atoms and molecules, Experimental nuclear physics, α particles, License, Mathematical economics
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 scattering

Published
2021

11. Trigger Efficiency of a ZnS:6LiF Scintillation Neutron Detector Readout With a SiPM

Author

Malte Hildebrandt, J.-B. Mosset, and Alexey Stoykov

Subjects
Physics, Nuclear and High Energy Physics, Scintillation, Physics::Instrumentation and Detectors, 010308 nuclear & particles physics, business.industry, Detector, Dead time, Scintillator, 01 natural sciences, Neutron capture, Silicon photomultiplier, Optics, Nuclear Energy and Engineering, 0103 physical sciences, Neutron detection, Neutron, Electrical and Electronic Engineering, 010306 general physics, business
Abstract

The efficiency of detecting signals from neutron absorption events (trigger efficiency) in detectors using ZnS scintillators loaded with neutron absorbers (6Li, 10B) is prone to be limited to values well below 100%: the non-transparency of the scintillator results in a wide dynamic range of the detected signals with some fraction always falling under the detection threshold set to satisfy the requirements on the gamma sensitivity, multi-count ratio, and the background count rate of the detector. The question of the limited trigger efficiency of such detectors is very seldom discussed in publications, yet it is very important as the product of the trigger efficiency and the probability of neutron absorption in the detector defines its overall efficiency. Available data indicate that the trigger efficiency of PMT-based detectors used in neutron diffraction experiments can be as low as $\sim 50$ %. In this work we evaluate the trigger efficiency of a SiPM-based ZnS:6LiF scintillation neutron detector developed to replace a 3He-detector of the POLDI time-of-flight diffractometer at the Paul Scherrer Institut in Switzerland. Requiring the gamma sensitivity with a 60Co source $\le 10^{-7}$ , the multi-count ratio $\le 10^{-3}$ with the detector dead time set to $10~\mu \text {s}$ , and the background count rate $\le 10^{-3}$ Hz we obtain the maximum possible trigger efficiency of $\sim 85$ % with the main restriction coming from the gamma sensitivity condition. Considering the neutron absorption probability of $\sim 80$ % at 1°A, the detector efficiency at this wavelength amounts to $\sim 70$ %, which is comparable to that of the current 3He-detector of the POLDI instrument.

Published
2016

12. 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

13. The design of the MEG II experiment: MEG II Collaboration

Author

G. Cavoto, Stefan Ritt, P. W. Cattaneo, A. D’Onofrio, F. Morsani, Yu.V. Yudin, C. Voena, Masatoshi Maki, K. Ieki, S. Nakaura, Flavio Gatti, T. Libeiro, A. S. Korenchenko, F. Berg, Marco Francesconi, Ryu Sawada, G. F. Tassielli, A. Mtchedilishvili, F. Ignatov, D. Nicolò, C. Bemporad, G. Chiarello, Fabrizio Cei, A. Papa, D. N. Grigoriev, G. Signorelli, Nobuo Matsuzawa, M. Usami, Marco Grassi, Toshinori Mori, M. Simonetta, Andrey Popov, L. Galli, M. Nakao, P.-R. Kettle, A. Pepino, N. P. Kravchuk, Hajime Nishiguchi, A. de Bari, B.I. Khazin, Yusuke Uchiyama, F. Raffaelli, T. Iwamoto, W. R. Molzon, N. V. Khomutov, E. Baracchini, Satoshi Mihara, M. Panareo, D. Kaneko, Y. Zhang, S. Ogawa, A. Corvaglia, Kayo Yoshida, Malte Hildebrandt, G. Piredda, A. M. Baldini, M. Milgie, Wataru Ootani, M. De Gerone, C. Chiri, M. Rossella, Z. Hodge, R. Iwai, Yuki Fujii, Katsuyu Kasami, M. Venturini, M. Nishimura, Gianluigi Boca, F. Grancagnolo, F. Renga, Michele Biasotti, M. Chiappini, G. Rutar, E. Ripiccini, G. Cocciolo, Baldini, A. M., Baracchini, E., Bemporad, C., Berg, F., Biasotti, M., Boca, G., Cattaneo, P. W., Cavoto, G., Cei, F., Chiappini, M., Chiarello, G., Chiri, C., Cocciolo, G., Corvaglia, A., de Bari, A., De Gerone, M., D’Onofrio, A., Francesconi, M., Fujii, Y., Galli, L., Gatti, F., Grancagnolo, F., Grassi, M., Grigoriev, D. N., Hildebrandt, M., Hodge, Z., Ieki, K., Ignatov, F., Iwai, R., Iwamoto, T., Kaneko, D., Kasami, K., Kettle, P. -R., Khazin, B. I., Khomutov, N., Korenchenko, A., Kravchuk, N., Libeiro, T., Maki, M., Matsuzawa, N., Mihara, S., Milgie, M., Molzon, W., Mori, Toshinori, Morsani, F., Mtchedilishvili, A., Nakao, M., Nakaura, S., Nicolò, D., Nishiguchi, H., Nishimura, M., Ogawa, S., Ootani, W., Panareo, M., Papa, A., Pepino, A., Piredda, G., Popov, A., Raffaelli, F., Renga, F., Ripiccini, E., Ritt, S., Rossella, M., Rutar, G., Sawada, R., Signorelli, G., Simonetta, M., Tassielli, G. F., Uchiyama, Y., Usami, M., Venturini, M., Voena, C., Yoshida, K., Yudin, Yu. V., and Zhang, Y.

Subjects
SUSY SO(10), Physics and Astronomy (miscellaneous), High Energy Pysics, muons, charged lepton flavor violation, particles detectors, LEPTON-FLAVOR VIOLATION, SUPERSYMMETRIC STANDARD MODEL, SCINTILLATION-COUNTERS, PLASTIC SCINTILLATOR, UNIFIED THEORIES, TIME RESOLUTION, NEUTRINO-MASS, HIGGS-BOSON, 50 PS, 01 natural sciences, Muon Decay Violating Decay, Nuclear physics, 0103 physical sciences, Sensitivity (control systems), Engineering (miscellaneous), 010306 general physics, Physics, 010308 nuclear & particles physics, Branching fraction, Detector, Gamma ray, Upgrade, Order of magnitude
Abstract

The MEG experiment, designed to search for the μ+→e+γ decay, completed data-taking in 2013 reaching a sensitivity level of 5.3×10^−13 for the branching ratio. In order to increase the sensitivity reach of the experiment by an order of magnitude to the level of 6×10^−14, a total upgrade, involving substantial changes to the experiment, has been undertaken, known as MEG II. We present both the motivation for the upgrade and a detailed overview of the design of the experiment and of the expected detector performance

Published
2018

14. Fundamentals of Charged Particle Transport in Gases and Condensed Matter

Author

Robert Robson, Ronald White, Malte Hildebrandt, Robert Robson, Ronald White, and Malte Hildebrandt

Subjects
Kinetic theory of gases, Transport theory, Fluid dynamics, Condensed matter
Abstract

This book offers a comprehensive and cohesive overview of transport processes associated with all kinds of charged particles, including electrons, ions, positrons, and muons, in both gases and condensed matter. The emphasis is on fundamental physics, linking experiment, theory and applications. In particular, the authors discuss: The kinetic theory of gases, from the traditional Boltzmann equation to modern generalizations A complementary approach: Maxwell's equations of change and fluid modeling Calculation of ion-atom scattering cross sections Extension to soft condensed matter, amorphous materials Applications: drift tube experiments, including the Franck-Hertz experiment, modeling plasma processing devices, muon catalysed fusion, positron emission tomography, gaseous radiation detectors Straightforward, physically-based arguments are used wherever possible to complement mathematical rigor.Robert Robson has held professorial positions in Japan, the USA and Australia, and was an Alexander von Humboldt Fellow at several universities in Germany. He is a Fellow of the American Physical Society.Ronald White is Professor of Physics and Head of Physical Sciences at James Cook University, Australia.Malte Hildebrandt is Head of the Detector Group in the Laboratory of Particle Physics at the Paul Scherrer Institut, Switzerland.

Published
2017

17. Concluding Remarks

Author

Robert E. Robson, Ronald D. White, and Malte Hildebrandt

Published
2017

26. Introduction

Author

Robert E. Robson, Ronald D. White, and Malte Hildebrandt

Published
2017

29. The Franck–Hertz Experiment

Author

Robert Robson, Ronald D. White, and Malte Hildebrandt

Subjects
Physics, Quantum mechanics, Franck–Hertz experiment
Published
2017

31. Temporal Non-Locality

Author

Robert Robson, Malte Hildebrandt, and Ronald D. White

Subjects
Geography, Cartography
Published
2017

34. New approaches for a 2D neutron detector based on ZnS:6LiF scintillator read out with WLS-fibers and SiPMs

Author

Alexey Stoykov, Malte Hildebrandt, and J.-B. Mosset

Subjects
Signal processing, Materials science, Physics::Instrumentation and Detectors, 010308 nuclear & particles physics, business.industry, 010401 analytical chemistry, Detector, STRIPS, Scintillator, 01 natural sciences, 0104 chemical sciences, law.invention, law, 0103 physical sciences, Neutron detection, Optoelectronics, Neutron, Spallation, Absorption (electromagnetic radiation), business
Abstract

Recently we reported on a high efficiency, low gamma-sensitivity, high count rate capable 1D neutron detector consisting of ZnS:6LiF scintillator readout with WLS-fibers coupled to SiPMs which showed a performance comparable with a 3He-based detector. In this work we discuss a possible extension of the developed technology to large area 2D detectors with high count rate capability suitable, for example, for the new generation of neutron powder diffraction instruments planned at the European Spallation Source.

Published
2016

35. A new concept of 2D scintillation detector for thermal neutrons based on a light sharing approach

Author

Malte Hildebrandt, J.-B. Mosset, and Alexey Stoykov

Subjects
Physics, Transverse plane, Optics, Physics::Instrumentation and Detectors, business.industry, Bar (music), Attenuation, Detector, Ranging, Scintillator, Neutron radiation, Photonics, business
Abstract

In this new concept of 2-dimensional scintillation detector, the detector consists of an almost gapless assembly of individual and optically isolated ZnS/6LiF bars with embedded and uniformly distributed WLS fibers running from one end of the bar to the other. The longitudinal position is determined from the left-right asymmetry of the number of photons detected on both sides of the fibers while the transverse position is simply given by the transverse position of the bar. Special Y11(400)M WLS fibers with different attenuation lengths ranging from 13 cm to 30 cm have been developed by Kuraray for this specific application. Two different detection units have been built. Their performance in a neutron beam are presented and compared with simulation results.

Published
2016

36. Muon polarization in the MEG experiment: predictions and measurements

Author

A. M. Baldini, Akira Yamamoto, Z. You, M. De Gerone, W. R. Molzon, Malte Hildebrandt, Z. Hodge, B.I. Khazin, Marco Grassi, G. Chiarello, D. N. Grigoriev, Yu Bao, A. Mtchedlishvili, K. Ieki, S. Nakaura, A. Pepino, G. F. Tassielli, G. Cavoto, A. de Bari, T. I. Kang, P. W. Cattaneo, Hajime Nishiguchi, F. Berg, F. Renga, E. Baracchini, Flavio Gatti, A. Papa, Yuki Fujii, Yusuke Uchiyama, T. Haruyama, S. Ogawa, T. Iwamoto, M. Rossella, Andrey Popov, Michele Biasotti, G. M. A. Lim, L. Galli, S. Dussoni, A. S. Korenchenko, G. Pizzigoni, P.-R. Kettle, G. Rutar, E. Ripiccini, F. Grancagnolo, A. D’Onofrio, N. V. Khomutov, Wataru Ootani, Stefan Ritt, N. P. Kravchuk, D. Nicolò, C. Voena, A. Graziosi, F. Ignatov, K. Yoshida, M. Venturini, D. Kaneko, Ryu Sawada, F. Tenchini, G. Piredda, Satoshi Mihara, G. Signorelli, Yu.V. Yudin, M. Nishimura, F. Sergiampietri, Gianluigi Boca, Fabrizio Cei, C. Chiri, M. Panareo, C. Bemporad, and Toshinori Mori

Subjects
Physics, Particle physics, Muon, Physics and Astronomy (miscellaneous), 010308 nuclear & particles physics, High Energy Physics::Phenomenology, Order (ring theory), 7. Clean energy, 01 natural sciences, Standard Model, Massless particle, 0103 physical sciences, Physics::Accelerator Physics, High Energy Physics::Experiment, Production (computer science), Neutrino, 010306 general physics, Engineering (miscellaneous), Energy (signal processing), Lepton
Abstract

The MEG experiment makes use of one of the world's most intense low energy muon beams, in order to search for the lepton flavour violating process $\mu^{+} \rightarrow {\rm e}^{+} \gamma$. We determined the residual beam polarization at the thin stopping target, by measuring the asymmetry of the angular distribution of Michel decay positrons as a function of energy. The initial muon beam polarization at the production is predicted to be $P_{\mu} = -1$ by the Standard Model (SM) with massless neutrinos. We estimated our residual muon polarization to be $P_{\mu} = -0.85 \pm 0.03 ~ {\rm (stat)} ~ { }^{+ 0.04}_{-0.05} ~ {\rm (syst)}$ at the stopping target, which is consistent with the SM predictions when the depolarizing effects occurring during the muon production, propagation and moderation in the target are taken into account. The knowledge of beam polarization is of fundamental importance in order to model the background of our ${\megsign}$ search induced by the muon radiative decay: $\mu^{+} \rightarrow {\rm e}^{+} \bar{\nu}_{\mu} \nu_{\rm e} \gamma$.

Published
2016

37. 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

38. 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

39. Calibration and monitoring of the MEG experiment by a proton beam from a Cockcroft–Walton accelerator

Author

D.N. Grigoriev, M. Rossella, P.-R. Kettle, Luca Galli, A. M. Baldini, Marco Grassi, Flavio Gatti, A. de Bari, Tomiyoshi Haruyama, R. Pazzi, J. Adam, Stefan Ritt, N. P. Kravchuk, M. Panareo, W. R. Molzon, H. Natori, M. Corbo, Donato Nicolo, G. Gallucci, E. Baracchini, D. Mzavia, Fedor Ignatov, Satoshi Mihara, Hajime Nishiguchi, Gianluigi Boca, Tadayoshi Doke, T. Iwamoto, P. W. Cattaneo, M. De Gerone, C. Topchyan, C. Voena, B. Golden, K. Fratini, J. Egger, X. Bai, A. Maki, Malte Hildebrandt, Yu.V. Yudin, N. Curalli, Angela Papa, Yasuhiro Nishimura, C. Cerri, O. Kiselev, A. S. Korenchenko, Wataru Ootani, R. Valle, B.I. Khazin, Akira Yamamoto, Ryu Sawada, Fabrizio Cei, C. Bemporad, F. Renga, A.S. Popov, Giovanni Signorelli, F. Sergiampietri, Yuki Fujii, G. Cavoto, F. Tenchini, G. Piredda, D. Zanello, F. Xiao, Takehiko Mori, Yusuke Uchiyama, and S. Dussoni

Subjects
Physics, Nuclear reaction, Nuclear and High Energy Physics, Muon, Spectrometer, Proton, Branching fraction, Particle accelerator, law.invention, Calorimeter, γrays, Beam monitoring, Calibration, CockcroftWalton accelerator, Instrumentation, Nuclear physics, law, Nucleon
Abstract

The MEG experiment at PSI searches for the decay μ → e γ at a level of ≈ 10 − 13 on the branching ratio BR ( μ → e γ / μ → tot ), well beyond the present experimental limit ( BR ≤ 1.2 × 10 − 11 ) and is sensitive to the predictions of SUSY-GUT theories. To reach this goal the experiment uses one of the most intense continuous surface muon beams available ( ≈ 10 8 μ / s ) and relies on advanced technology (LXe calorimetry, a gradient-field superconducting spectrometer as well as flexible and powerful trigger and acquisition systems). In order to maintain the highest possible energy, time and spatial resolutions for such detector, frequent calibration and monitoring, using a Cockcroft–Walton proton accelerator, are required. The proton beam is brought to the centre of MEG by a special bellows insertion system and travels in a direction opposite to the one of the normal μ ‐ beam . Protons interact with a lithium tetraborate (Li2B4O7) nuclear target and produce one γ (17.6 MeV) from the reaction Li ( p , γ ) 3 7 Be 4 8 or two coincident γ s (11.67 and 4.4 MeV) from the reaction B ( p , γ 1 ) 5 11 C ⁎ 6 12 . The 17.6 MeV γ is used for calibrating and monitoring the LXe calorimeter ( σ E γ / E γ = 3.85 ± 0.15 % at 17.6 MeV) while the coincident 11.67 and 4.4 MeV γ s are used to measure the relative timing of the calorimeter and the spectrometer timing counters ( σ Δ t = 0.450 ± 0.015 ns ).

Published
2011

40. The 10bar hydrogen time projection chamber of the MuCap experiment

Author

Malte Hildebrandt, Johny Egger, and C. Petitjean

Subjects
Physics, Nuclear and High Energy Physics, Time projection chamber, Muon, Hydrogen, Proton, Physics::Instrumentation and Detectors, Detector, chemistry.chemical_element, Muon capture, Nuclear physics, chemistry, Measuring principle, High Energy Physics::Experiment, Nuclear Experiment, Instrumentation, Bar (unit)
Abstract

The experimental goal of the MuCap experiment at the Paul Scherrer Institute (PSI) is a high-precision measurement of the singlet capture rate of the nuclear muon capture on the free proton in the reaction μ − + p → n + ν μ . The measuring principle is a lifetime measurement whereas the experimental approach is based on a specially developed Time Projection Chamber (TPC) operating with ultra-pure and deuterium-depleted hydrogen gas at a pressure of 10 bar. The TPC acts as an active muon stop detector and the 10 bar hydrogen operates as target and detector. Design, construction and operation of the Time Projection Chamber are presented.

Published
2011

41. 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

42. Local Transients of Flooding and Current in Channel and Land Areas of a Polymer Electrolyte Fuel Cell

Author

Alexander Wokaun, Ingo A. Schneider, Günther G. Scherer, Steffen Von Dahlen, Malte Hildebrandt, Eberhard Lehmann, Pierre Boillat, Pierre Oberholzer, and Michael H. Bayer

Subjects
chemistry.chemical_classification, Materials science, Analytical chemistry, chemistry.chemical_element, Polymer, Electrolyte, Thermal diffusivity, Oxygen, Cathode, Surfaces, Coatings and Films, Electronic, Optical and Magnetic Materials, law.invention, General Energy, chemistry, law, Electrode, Physical and Theoretical Chemistry, Composite material, Current (fluid), Voltage
Abstract

Submillimeter resolved current density distribution measurements and in-plane neutron radiography were used simultaneously in voltage step experiments for the local investigation of flooding and cell performance in cathode channel and land areas of a polymer electrolyte fuel cell. Our results demonstrate that oxygen depletion leads to a strong performance loss under the ribs already before the onset of a notable liquid water accumulation. Here, the detrimental effect of liquid water accumulation on cell current is more likely associated with a loss of electrode performance rather than the result of a decreasing effective diffusivity for oxygen in the gas diffusion layer.

Published
2010

43. Deeply virtual Compton scattering and its beam charge asymmetry in e±p collisions at HERA

Author

K. H. Hiller, R. C. W. Henderson, Pavel Murin, Judith Katzy, Calin Alexa, V. Tchoulakov, R.N. Shaw-West, T. Toll, A. D.R. Vargas Trevino, Laurent Favart, S. Habib, S. Ghazaryan, B. Olivier, R. Kogler, E. E. Elsen, Ivan Smiljanic, Emmanuelle Perez, Stephen Maxfield, S. M. Piec, I. R. Kenyon, H. U. Martyn, J-P. Meyer, K. Lipka, T. N. Trinh, R. Zus, J. G. Contreras, Paul Laycock, E. Malinovski, Emmanuel Sauvan, C. Wissing, Ilias Panagoulias, G. Grindhammer, K. Krüger, B. R. Grell, B. Pokorny, J. Žáček, D. Wegener, A. Raspiareza, M. Sauter, Andrew Mehta, N. Gogitidze, A. Specka, M. Kapichine, M. Nozicka, B. Delcourt, Max Klein, B. Stella, Stefan Schmitt, U. Straumann, V. Lubimov, P. E. Reimer, Th. Naumann, F. Tomasz, A. W. Jung, A. Dubak, Fabian Zomer, K. Urban, David M. South, V. Efremenko, P. Sopicki, Tomas Hreus, G. Leibenguth, A. M. Fomenko, Maxime Gouzevitch, A. Knutsson, J. Zálešák, V. Lendermann, V. Spaskov, G. Herrera, S. Shushkevich, Murrough Landon, Sakar Osman, Vladimir Palichik, Paul Richard Newman, Grzegorz Nowak, Mila Pandurovic, A. Falkiewicz, G. Cozzika, N. Loktionova, S. Mikocki, A. Eliseev, A. Nikiforov, L. N. Shtarkov, K. Alimujiang, Hannes Jung, Alexander Zhokin, O. Pejchal, E. Gabathuler, A. Dossanov, R. Pla akyt, T. J. Sloan, V. Andreev, A.S. Belousov, A. Petrukhin, A. Baghdasaryan, A. Rostovtsev, Ll. Marti, I. Bozovic-Jelisavcic, J. Cvach, Th D. Papadopoulou, Sergey Rusakov, P. Truöl, Pierre Marage, C. Vallée, M. Herbst, M. Deak, V. Cerny, G. Thompson, K. Nowak, P. Van Mechelen, K. Krastev, T.H. Tran, Benno List, John A Coughlan, J. Bracinik, H-C. Schultz-Coulon, G. La tovi ka-Medin, E. Wünsch, T. Kluge, Z. Staykova, M. E. Janssen, A. B. Meyer, Christian Helebrant, A. Makankine, G. Buschhorn, Gabriel Stoicea, D. Ozerov, Wolfgang Lange, Gerhard Brandt, K. Daum, J. Gayler, Karel Cerny, V. Michels, V. Volchinski, D.K. Nikitin, Dirk L. Hoffmann, J. B. Dainton, Leif J. Jönsson, Roland Horisberger, D. J. Fischer, A. Valkárová, Krzysztof Kutak, Y. Vazdik, P.D. Thompson, H. Henschel, J.C. Bizot, A. Glazov, M. Brinkmann, C. Niebuhr, Benoit Roland, S. Egli, J. Delvax, M. Aldaya Martin, V. Brisson, K. Müller, Xavier Janssen, I. Picuric, Zhen Zhang, I. Glushkov, Guenter Eckerlin, André Schöning, Peter Robmann, Ricardo Lopez-Fernandez, Matthias Ulrich Mozer, Y. Soloviev, Dusan Bruncko, A. Fedotov, K. B. Cantun Avila, C. Kiesling, T. Zimmermann, E. Barrelet, F. Moreau, Gang Li, M. Steder, T. Greenshaw, A. J. Campbell, E. Hennekemper, M. von den Driesch, G. D. Patel, M. Jacquet, S. Backovic, J. E. Ruiz Tabasco, E. A. De Wolf, Voica Radescu, Zuzana Rurikova, Christoph Grab, R. Roosen, H. Meyer, Biljana Antunović, S. Levonian, D. álek, Y. de Boer, S. Vinokurova, J. Ferencei, I. Milcewicz-Mika, L. Bystritskaya, J. E. Olsson, W. Bartel, Malte Hildebrandt, P. Kostka, T. Sykora, T. Ravdandorj, Claus Kleinwort, M. Kraemer, J. Turnau, H. Zohrabyan, K. Begzsuren, Richard Polifka, Natasa Raicevic, M. Mudrinic, I. Tsakov, V. Chekelian, F. D. Aaron, J. Feltesse, J. V. Morris, Jenny List, Vincent Boudry, A. N. Morozov, M. Fleischer, A.J. Rahmat, A. Bunyatyan, Marina Rotaru, D. Sunar, C. Pascaud, A. Cholewa, Bogdan Povh, F. Sefkow, A. Lebedev, Cristinel Diaconu, Daniel Pitzl, D. Traynor, D. Haidt, Jan Kretzschmar, Andrej Liptaj, Eram Rizvi, V. Dodonov, Laurent Schoeffel, B. Tseepeldorj, D. P. C. Sankey, Anna Kropivnitskaya, R. Felst, M. Del Degan, and L. Goerlich

Subjects
Physics, Nuclear and High Energy Physics, Particle physics, Photon, 010308 nuclear & particles physics, media_common.quotation_subject, Momentum transfer, Compton scattering, Parton, HERA, 01 natural sciences, Asymmetry, Nuclear physics, Dipole, 0103 physical sciences, High Energy Physics::Experiment, 010306 general physics, P system, media_common
Abstract

A measurement of elastic deeply virtual Compton scattering gamma*p --> gamma p using e(+) p and e(-) p collision data recorded with the HI detector at HERA is presented. The analysed data sample corresponds to an integrated luminosity of 306 pb(-1), almost equally shared between both beam charges. The cross section is measured as a function of the virtuality Q(2) of the exchanged photon and the centre-of-mass energy W of the gamma*p system in the kinematic domain 6.5 < Q(2) < 80 GeV2, 30 < W < 140 GeV and |t| < 1 GeV2, where t denotes the squared momentum transfer at the proton vertex. The cross section is determined differentially in t for different Q(2) and W values and exponential t-slope parameters are derived. Using e(+) p and e(-) p data samples, a beam charge asymmetry is extracted for the first time in the low Biorken x kinematic domain. The observed asymmetry is attributed to the interference between Bethe-Heitler and deeply virtual Compton scattering processes. Experimental results are discussed in the context of two different models, one based on generalised parton distributions and one based on the dipole approach. (C) 2009 Elsevier B.V. All rights reserved.

Published
2009

44. Inclusive photoproduction of ρ0, K∗0 and ϕ mesons at HERA

Author

J. V. Morris, Jenny List, A.J. Rahmat, A. Bunyatyan, Marina Rotaru, Katerina Lipka, V. Tchoulakov, G. Laštovička-Medin, R.N. Shaw-West, F. Moreau, S. J. Aplin, C. Niebuhr, G. Leibenguth, A. D.R. Vargas Trevino, A. Astvatsatourov, Mila Pandurovic, S. Egli, Y. Soloviev, K. H. Hiller, K. Daum, R. C. W. Henderson, A. Specka, Matthias Ulrich Mozer, A. Fedotov, M. Kraemer, M. Gouzevitch, R. Kogler, J. Žáček, U. Straumann, Magnus Hansson, Voica Radescu, Christoph Grab, Richard Polifka, A. Knutsson, M. Deak, K. B. Cantun Avila, E. Wünsch, T. Toll, S. Shushkevich, Sakar Osman, V. Chekelian, M. Del Degan, B. R. Grell, V. Lendermann, F. D. Aaron, Judith Katzy, C. Wissing, A. Eliseev, C. Kiesling, Pavel Murin, Tim Greenshaw, J-P. Meyer, V. Jemanov, D. Wegener, J. Delvax, A. J. Campbell, G. Thompson, Paul Laycock, E. Malinovski, Emmanuel Sauvan, M. von den Driesch, Wolfgang Lange, G. D. Patel, Biljana Antunović, F. Tomasz, A. Raspiareza, Stephen Maxfield, David M. South, P. E. Reimer, Z. Staykova, J. Bracinik, I. R. Kenyon, Karel Cerny, Th. D. Papadopoulou, B. Stella, J. Gayler, T. Sykora, M. Sauter, A. Baghdasaryan, A. Rostovtsev, A. Schöning, Tomas Hreus, Stefan Schmitt, G. Grindhammer, T. H. Tran, I. Sheviakov, V. Efremenko, L. Goerlich, M. E. Janssen, Roland Horisberger, T. Kluge, A. Lebedev, J. Ferencei, A. Valkárová, Laurent Schoeffel, Andrew Mehta, N. Gogitidze, H. Henschel, Laurent Favart, D. Haidt, A. De Roeck, A. Nikiforov, K. Krastev, A. Glazov, J.C. Bizot, S. Mikocki, Fabian Zomer, Vladimir Andreev, Peter Robmann, K. Urban, Eram Rizvi, Calin Alexa, Gabriel Stoicea, H. U. Martyn, Matthias Klein, Murrough Landon, V. Korbel, J. Zálešák, A. Makankine, A. Dubak, V. Dodonov, V. Spaskov, S. Ghazaryan, G. Buschhorn, D. Ozerov, Vladimir Palichik, Ll. Marti, G. Cozzika, I. Picuric, C. Pascaud, T. Zimmermann, A. B. Meyer, V. Cerny, D. J. Fischer, B. Olivier, A. W. Jung, Zhen Zhang, Ricardo Lopez-Fernandez, S. Backovic, I. Bozovic-Jelisavcic, M. Herbst, Y. Vazdik, Zuzana Rurikova, E. E. Elsen, S. Vinokurova, M. Jacquet, Guenter Eckerlin, Nicolas Berger, I. Panagoulias, G. Herrera, P.D. Thompson, V. Michels, P. Van Mechelen, J. B. Dainton, B. Tseepeldorj, M. Steder, D. Hoffmann, P. Kostka, Ivan Smiljanic, C. Schmitz, Dusan Bruncko, Hannes Jung, B. Naroska, D. P. C. Sankey, J. Turnau, Alexander Zhokin, S. Levonian, John A Coughlan, J. E. Olsson, C. Vallée, D. Salek, E. Hennekemper, K. Begzsuren, M. Mudrinic, I. Tsakov, L. Bystritskaya, W. Bartel, Th. Naumann, Christian Helebrant, T. Ravdandorj, Claus Kleinwort, Leif J. Jönsson, Benoit Roland, Malte Hildebrandt, Anna Kropivnitskaya, Gang Li, Gerhard Brandt, V. Volchinski, M. Kapichine, M. Nozicka, R. Felst, Emmanuelle Perez, J. G. Contreras, H. Meyer, H. Zohrabyan, B. Delcourt, Xavier Janssen, I. Milcewicz-Mika, S. M. Piec, E. Gabathuler, T. N. Trinh, M. Fleischer, Natasa Raicevic, J. Feltesse, J. Cvach, Vincent Boudry, O. Pejchal, A. N. Morozov, Bogdan Povh, F. Sefkow, Benno List, R. Plačakytė, P. Sopicki, A. M. Fomenko, K. Nowak, H-C. Schultz-Coulon, M. Brinkmann, Krzysztof Kutak, T. J. Sloan, P.J.W. Faulkner, A.S. Belousov, Sergey Rusakov, P. Truöl, K. Müller, N. Loktionova, T. Preda, E. Barrelet, J. E. Ruiz Tabasco, E. A. De Wolf, Karlheinz Meier, R. Roosen, Y. de Boer, Paul Richard Newman, Grzegorz Nowak, A. Dossanov, A. Petrukhin, S. Habib, V. Brisson, A. Falkiewicz, K. Krüger, V. Lubimov, L. N. Shtarkov, Daniel Pitzl, D. Traynor, A. Asmone, F. Cassol-Brunner, Jan Kretzschmar, Andrej Liptaj, Pierre Marage, I. Glushkov, O. Behnke, D. Sunar, A. Cholewa, L. Lytkin, and Cristinel Diaconu

Subjects
Physics, Nuclear and High Energy Physics, Particle physics, Meson, 010308 nuclear & particles physics, High Energy Physics::Phenomenology, HERA, 01 natural sciences, 0103 physical sciences, Transverse momentum, High Energy Physics::Experiment, Rapidity, Nuclear Experiment, 010306 general physics
Abstract

Inclusive non-diffractive photoproduction of rho(770)(0), K*(892)(0) and phi(1020) mesons is investigated with the H1 detector in ep collisions at HERA. The corresponding average gamma p centre-of-mass energy is 210 GeV. The mesons are measured in the transverse momentum range 0.5 < p(T) < 7 GeV and the rapidity range vertical bar y(lab)vertical bar < 1. Differential cross sections are presented as a function of transverse momentum and rapidity, and are compared to the predictions of hadroproduction models. (C) 2009 Elsevier B.V. All rights reserved.

Published
2009

45. Measurement of diffractive scattering of photons with large momentum transfer at HERA

Author

J. Feltesse, David M. South, H. Peng, Leif J. Jönsson, Benoit Roland, A. Baghdasaryan, A. Rostovtsev, K. H. Hiller, R. C. W. Henderson, Matthias Ulrich Mozer, T. Klimkovich, A. Fedotov, S. Vinokurova, K. B. Cantun Avila, M. E. Janssen, P. Kostka, Paul Laycock, J. Turnau, E. Malinovski, Emmanuel Sauvan, Stephen Maxfield, V. Lubimov, P. A. Smirnov, C. Kiesling, E. Tzamariudaki, A. J. Campbell, K. Nankov, L. N. Shtarkov, E. E. Elsen, G. Grindhammer, E. Wünsch, A. Specka, K. Begzsuren, T. H. Tran, Dave Sankey, S. Habib, A. Falkiewicz, I. R. Kenyon, J. E. Olsson, Laurent Schoeffel, M. Mudrinic, J. Delvax, K. Krüger, Peter Robmann, Alessandro Bacchetta, I. Tsakov, W. Bartel, Pierre Marage, Emmanuelle Perez, L. Bystritskaya, Matthew Beckingham, Andrew Mehta, C. Niebuhr, N. Gogitidze, P. E. Reimer, Th. Naumann, Malte Hildebrandt, K. Urban, Murrough Landon, G. D. Patel, Biljana Antunović, B. Stella, Anna Kropivnitskaya, Roland Horisberger, J. Žáček, G. Leibenguth, H. U. Martyn, Matthias Klein, I. Glushkov, A. Valkárová, S. Egli, R. Felst, Stefan Schmitt, H. Zohrabyan, Katerina Lipka, T. Sykora, V. Tchoulakov, R.N. Shaw-West, Zhiqing Zhang, T. Zimmermann, Natasa Raicevic, Y. Soloviev, E. Gabathuler, V. Michels, J. B. Dainton, D. Wegener, M. Fleischer, S. M. Piec, M. Gouzevitch, Hans-Christian Schultz-Coulon, Vincent Boudry, A. N. Morozov, V. Yeganov, P. Van Mechelen, G. Laštovička-Medin, Gerhard Brandt, Voica Radescu, A. Lebedev, F. Salvaire, D. Haidt, B. R. Grell, A. De Roeck, Eram Rizvi, M. Kapichine, M. Nozicka, A. Nikiforov, O. Behnke, I. Sheviakov, S. Backovic, Daniel Pitzl, U. Straumann, Ll. Marti, Vladimir Palichik, Bogdan Povh, F. Sefkow, Gang Li, B. Delcourt, V. Lendermann, F. Moreau, S. J. Aplin, I. Bozovic-Jelisavcic, Christoph Grab, D. Traynor, A. Asmone, F. Tomasz, C. Wissing, L. Finke, R. Plačakytė, V. Dodonov, S. Shushkevich, Sakar Osman, A.-I. Lucaci-Timoce, V. Volchinski, Zuzana Rurikova, J. Zálešák, F. Cassol-Brunner, H. Meyer, Judith Katzy, Y.C. Zhu, K. Daum, A. Eliseev, V. Efremenko, Wolfgang Lange, V. Spaskov, P. Sopicki, A. M. Fomenko, B. Tseepeldorj, T. Kluge, Benno List, N. Loktionova, M. Brinkmann, A. Hovhannisyan, T. Preda, I. Tsurin, I. Milcewicz-Mika, O. Pejchal, I. Picuric, P. Baranov, M. Goettlich, J. Gayler, K. Krastev, Ricardo Lopez-Fernandez, I. Panagoulias, M. Steder, D. Hoffmann, S. Essenov, Fabian Zomer, G. Cozzika, C. Schmitz, A. Astvatsatourov, Mila Pandurovic, Jan Kretzschmar, Andrej Liptaj, A. D.R. Vargas Trevino, D. Sunar, R. Kogler, Karel Cerny, J. Bracinik, A. Schöning, A. Knutsson, A. Makankine, G. Buschhorn, D. Ozerov, J. V. Morris, Jenny List, Calin Alexa, A.J. Rahmat, A. Bunyatyan, Marina Rotaru, S. Ghazaryan, Tomas Hreus, V. Jemanov, A. Raspiareza, M. Sauter, A. B. Meyer, A. Dubak, Dusan Bruncko, B. Naroska, Y. Vazdik, P.D. Thompson, T. Greenshaw, Xavier Janssen, T. N. Trinh, J-P. Meyer, T. Toll, S. Mikocki, C. Pascaud, Guenter Eckerlin, T. J. Sloan, P.J.W. Faulkner, V. Cerny, Hannes Jung, Alexander Zhokin, C. Vallée, M. Deak, M.-O. Boenig, D. Johnson, A. Glazov, V. Korbel, J. Ferencei, B. Olivier, Nicolas Berger, A.S. Belousov, Sergey Rusakov, P. Truöl, S. Levonian, G. Thompson, A. Zhelezov, Z. Staykova, V. Andreev, John A Coughlan, A. Cholewa, H. Henschel, Magnus Hansson, M. Jacquet, J.C. Bizot, T. Ravdandorj, Claus Kleinwort, M. Kraemer, M. Del Degan, L. Lytkin, Christian Helebrant, Richard Polifka, Cristinel Diaconu, L. Goerlich, S. Schmidt, V. Chekelian, F. D. Aaron, E. Barrelet, A. W. Jung, G. Herrera, J. E. Ruiz Tabasco, E. A. De Wolf, Krzysztof Kutak, Karlheinz Meier, R. Roosen, Y. de Boer, K. Müller, Paul Richard Newman, Grzegorz Nowak, A. Dossanov, A. Petrukhin, J. Cvach, K. Nowak, Michael R. Wessels, V. Brisson, Ivan Smiljanic, D. Salek, J. G. Contreras, Pavel Murin, Th. D. Papadopoulou, Laurent Favart, Laboratoire de Physique Nucléaire et de Hautes Énergies (LPNHE), Université Pierre et Marie Curie - Paris 6 (UPMC)-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Université Paris Diderot - Paris 7 (UPD7)-Centre National de la Recherche Scientifique (CNRS), Laboratoire de l'Accélérateur Linéaire (LAL), Université Paris-Sud - Paris 11 (UP11)-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Centre National de la Recherche Scientifique (CNRS), Laboratoire Leprince-Ringuet (LLR), Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-École polytechnique (X)-Centre National de la Recherche Scientifique (CNRS), Centre de Physique des Particules de Marseille (CPPM), Aix Marseille Université (AMU)-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Centre National de la Recherche Scientifique (CNRS), Institut de Recherches sur les lois Fondamentales de l'Univers (IRFU), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Paris-Saclay, H1, (ukupan broj autora: 274), H1 Collaboration, Centre National de la Recherche Scientifique (CNRS)-Université Paris Diderot - Paris 7 (UPD7)-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Université Pierre et Marie Curie - Paris 6 (UPMC), Centre National de la Recherche Scientifique (CNRS)-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Université Paris-Sud - Paris 11 (UP11), and Centre National de la Recherche Scientifique (CNRS)-École polytechnique (X)-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)

Subjects
Diffraction, Particle physics, Nuclear and High Energy Physics, Photon, FOS: Physical sciences, Physics::Optics, 01 natural sciences, 7. Clean energy, High Energy Physics - Experiment, Nuclear physics, High Energy Physics - Experiment (hep-ex), 0103 physical sciences, [PHYS.HEXP]Physics [physics]/High Energy Physics - Experiment [hep-ex], ddc:530, Vector meson, Nuclear Experiment, 010306 general physics, Physics, 010308 nuclear & particles physics, Scattering, Momentum transfer, Perturbative QCD, HERA, Vertex (geometry), Physique des particules élémentaires, High Energy Physics::Experiment
Abstract

The first measurement of diffractive scattering of quasi-real photons with large momentum transfer γ p → γ Y, where Y is the proton dissociative system, is made using the H1 detector at HERA. The measurement is performed for initial photon virtualities Q 2 < 0.01 GeV 2. Single differential cross sections are measured as a function of W, the incident photon-proton centre of mass energy, and t, the square of the four-momentum transferred at the proton vertex, in the range 175 < W < 247 GeV and 4 <, 0, SCOPUS: ar.j, info:eu-repo/semantics/published

Published
2009
Full Text
View/download PDF

46. Measurement of the proton structure function FL(x,Q2) at low x

Author

L. Finke, Roland Horisberger, H. Peng, Y.C. Zhu, K. Daum, A. Valkárová, K. H. Hiller, R. C. W. Henderson, Matthias Ulrich Mozer, B. R. Grell, A. Fedotov, K. B. Cantun Avila, Calin Alexa, F. Tomasz, S. Vinokurova, T. Kluge, David M. South, S. Shushkevich, Sakar Osman, A. Eliseev, E. E. Elsen, J. Bracinik, P. Kostka, A. Specka, I. Sheviakov, J. Ferencei, Laurent Schoeffel, Judith Katzy, P. E. Reimer, E. Wuensch, C. Kiesling, E. Tzamariudaki, A. J. Campbell, J. Turnau, K. Begzsuren, M. Mudrinic, Alessandro Bacchetta, I. Tsakov, I. Picuric, C. Pascaud, A. Makankine, Pavel Murin, J. Zálešák, K. Urban, Murrough Landon, K. Krastev, V. Spaskov, G. Li, S. Ghazaryan, G. Buschhorn, D. Ozerov, Th. D. Papadopoulou, Paul Laycock, Emmanuelle Perez, Tim Greenshaw, V. Jemanov, Guenter Eckerlin, E. Malinovski, V. Yeganov, A. B. Meyer, Emmanuel Sauvan, M. Beckingharn, V. Michels, C. Wissing, A. Baghdasaryan, A. Rostovtsev, M. Kraemer, Leif J. Jönsson, Dave Sankey, Benoit Roland, J. Delvax, J. B. Dainton, G. Grindhammer, F. Moreau, S. J. Aplin, Ricardo Lopez-Fernandez, T. Klimkovich, Richard Polifka, S. M. Piec, A. Raspiareza, S. Schmidt, V. Chekelian, F. D. Aaron, Laurent Favart, A. Nikiforov, Karel Cerny, I. Panagoulias, M. Steder, M. Kapichine, M. Nozicka, D. Hoffmann, S. Habib, Th. Naumann, Ll. Marti, P. Van Mechelen, I. Bozovic-Jelisavcic, S. Essenov, M. Sauter, G. D. Patel, Wolfgang Lange, M. Goettlich, Biljana Antunović, Dusan Bruncko, O. Pejchal, J. Gayler, A. Falkiewicz, Krzysztof Kutak, B. Naroska, M. E. Janssen, E. Gabathuler, T. H. Tran, D.P. Johnson, J. E. Olsson, W. Bartel, T. Sykora, Malte Hildebrandt, B. Delcourt, G. Laštovička-Medin, A. Glazov, I. R. Kenyon, G. Leibenguth, T. Ravdandorj, Claus Kleinwort, E. Barrelet, A. D.R. Vargas Trevino, V. Lubimov, P. Baranov, M. Jacquet, Natasa Raicevic, Vincent Boudry, C. Niebuhr, Benno List, A. N. Morozov, R. Placakyte, J. E. Ruiz Tabasco, E. A. De Wolf, A. Knutsson, Karlheinz Meier, R. Roosen, M. Gouzevitch, J. V. Morris, Jenny List, R. Kogler, T. J. Sloan, P.J.W. Faulkner, Peter Robmann, I. Milcewicz-Mika, T. Zimmermann, A.S. Belousov, S. Egli, Sergey Rusakov, M. Fleischer, Zhiqing Zhang, K. Nankov, L. N. Shtarkov, J. Feltesse, J. Cvach, A. Dubak, Gerhard Brandt, A. Schoening, Y. de Boer, A.J. Rahmat, A. Bunyatyan, D. Salek, Marina Rotaru, S. Backovic, U. Straumann, Y. Soloviev, K. Nowak, Bogdan Povh, V. Volchinski, Zuzana Rurikova, N. Loktionova, F. Sefkow, H. Meyer, Y. Vazdik, A. Hovhannisyan, Stephen Maxfield, P.D. Thompson, M. Deak, T. Preda, K. Krueger, V. Korbel, Andrew Mehta, N. Gogitidze, J. Zacek, P. A. Smirnov, I. Tsurin, M. Brinkmann, Katerina Lipka, Xavier Janssen, Paul Richard Newman, Grzegorz Nowak, V. Tchoulakov, A. Dossanov, P. Sopicki, R.N. Shaw-West, Mila Pandurovic, A. M. Fomenko, A. Petrukhin, A. W. Jung, Voica Radescu, Christoph Grab, J. G. Contreras, T. N. Trinh, M.-O. Boenig, Vladimir Andreev, H. U. Martyn, Matthias Klein, G. Thompson, Z. Staykova, A. Lebedev, G. Herrera, Michael R. Wessels, Magnus Hansson, M. Del Degan, V. Brisson, F. Salvaire, Nicolas Berger, L. Goerlich, D. Haidt, A. De Roeck, H. Henschel, J.C. Bizot, B. Tseepeldorj, Eram Rizvi, S. Levonian, A. Zhelezov, V. Dodonov, G. Cozzika, Anna Kropivnitskaya, R. Felst, J-P. Meyer, I. Smijanic, V. Lendermann, C. Schmitz, Hannes Jung, Alexander Zhokin, C. Vallée, A.-I. Lucaci-Timoce, K. Mueller, L. Bystritskaya, H. Zohrabyan, D. Wegener, T. Toll, Hans-Christian Schultz-Coulon, V. Efremenko, Tomas Hreus, S. Mikocki, V. Cerny, B. Olivier, B. Stella, F. Zomer, Stefan Schmitt, Christian Helebrant, Vladimir Palichik, A. Astvatsatourov, John A Coughlan, Pierre Marage, I. Glushkov, O. Behnke, P. Truoel, D. Sunar, A. Cholewa, L. Lytkin, Cristinel Diaconu, Daniel Pitzl, D. Traynor, A. Asmone, F. Cassol-Brunner, Jan Kretzschmar, and Andrej Liptaj

Subjects
Quantum chromodynamics, Physics, Nuclear and High Energy Physics, Range (particle radiation), Particle physics, Proton, 010308 nuclear & particles physics, Parton, HERA, 01 natural sciences, law.invention, Nuclear physics, Cross section (physics), law, 0103 physical sciences, Physics::Accelerator Physics, High Energy Physics::Experiment, Nuclear Experiment, 010306 general physics, Collider, Beam (structure)
Abstract

A first measurement is reported of the longitudinal proton structure function FL(X, Q(2)) at the ep collider HERA. It is based on inclusive deep inelastic e(+)p scattering cross section measurements with a positron beam energy of 27.5 GeV and proton beam energies of 920, 575 and 460 GeV. Employing the energy dependence of the cross section, FL is measured in a range of squared four-momentum transfers 12

Published
2008

47. Measurement of inclusive jet production in deep-inelastic scattering at high and determination of the strong coupling

Author

E. Wünsch, G. Tsipolitis, M. Deak, Dave Sankey, Daniel Pitzl, J. Delvax, Wolfgang Lange, M. Goettlich, A. M. Fomenko, G. Thompson, Pavel Murin, D. Traynor, Z. Staykova, A. Asmone, J. E. Olsson, G. D. Patel, V. Lubimov, W. Bartel, T. Kluge, I. Picuric, Guenter Eckerlin, J. Gayler, Leif J. Jönsson, Benoit Roland, Malte Hildebrandt, Biljana Antunović, D.P. Johnson, Paul Richard Newman, Grzegorz Nowak, F. Cassol-Brunner, F. Eisele, T. Sykora, K. Müller, F. W. Büsser, C. Niebuhr, Th. Papadopoulou, M. Fleischer, R. Oganezov, A. Petrukhin, H. Henschel, J.C. Bizot, Bogdan Povh, F. Sefkow, Laurent Favart, T. Anthonis, S. Egli, M. Kraemer, T. Klimkovich, Natasa Raicevic, J. Feltesse, K. Nankov, Y. Soloviev, M. Kapichine, R. Plaakyt, L. N. Shtarkov, J. V. Morris, Jan Kretzschmar, Richard Polifka, S. Schmidt, C. Risler, V. Cerny, Vincent Boudry, B. Olivier, Jenny List, P. E. Reimer, K. H. Hiller, M. Nozicka, Peter Robmann, A.J. Rahmat, A. Bunyatyan, R. C. W. Henderson, N. Loktionova, Andrej Liptaj, A. N. Morozov, D. Perez-Astudillo, V. Chekelian, D. Sunar, Paul Laycock, E. Malinovski, Emmanuel Sauvan, G. Grindhammer, R. Weber, J. Cvach, A. Hovhannisyan, T. Preda, L. Finke, J. Zacek, C. Wissing, T. Toll, Ivan Smiljanic, B. Delcourt, Voica Radescu, Christoph Grab, Michael R. Wessels, V. Brisson, B. R. Grell, F. Tomasz, K. Nowak, Stephen Maxfield, T. N. Trinh, T. Zimmermann, J. Stiewe, I. Tsurin, V. Andreev, Katerina Lipka, David M. South, Sakar Osman, I. R. Kenyon, C. Pascaud, J. Záleák, A. Astvatsatourov, Mila Pandurovic, A. Cholewa, Andrew Mehta, J. Bracinik, V. Tchoulakov, N. Gogitidze, A. Lebedev, A. Eliseev, E. Barrelet, J. G. Contreras, A. Mohamed, S. Backovic, Zuzana Rurikova, A. W. Jung, P. Baranov, A. Baghdasaryan, A. Rostovtsev, Y.C. Zhu, P. Prideaux, F. Salvaire, D. Haidt, T. J. Sloan, K. Daum, Christian Helebrant, R.N. Shaw-West, I. Sheviakov, Eram Rizvi, G. Heinzelmann, Judith Katzy, E. A. De Wolf, Karlheinz Meier, R. Roosen, K. Krastev, L. Lytkin, Cristinel Diaconu, G. Latovika-Medin, Pierre Marage, A. Dubak, S. Levonian, V. Dodonov, G. Herrera, R. Wolf, M. E. Janssen, Fabian Zomer, Ll. Marti, Dirk L. Hoffmann, I. Bozovic-Jelisavcic, G. Franke, A. Specka, Y. de Boer, L. Lindfeld, S. Habib, P.J.W. Faulkner, John A Coughlan, A.S. Belousov, Sergey Rusakov, D. Utkin, P. Truöl, Hans-Christian Schultz-Coulon, V. Jemanov, I. Glushkov, V. Spaskov, Gang Li, G. Cozzika, E. E. Elsen, Roland Horisberger, A. Valkárová, Y. Vazdik, B. Stella, Stefan Schmitt, A. D.R. Vargas Trevino, Zhen Zhang, M. Jacquet, Ricardo Lopez-Fernandez, H. U. Martyn, A. Falkiewicz, P.D. Thompson, M. Sauter, D. Wegener, Emmanuelle Perez, K. Krüger, A. B. Meyer, C. Schmitz, M. Steder, Hannes Jung, Alexander Zhokin, C. Vallée, Stefania Xella, Tomas Hreus, R. Eichler, V. Yeganov, T. Frisson, S. M. Piec, O. Behrendt, H. Peng, S. Vinokurova, Vladimir Palichik, A. Aktas, I. Milcewicz-Mika, P. Kostka, V. Efremenko, Matthias Ulrich Mozer, F. Moreau, S. J. Aplin, S. Mikocki, O. Behnke, J. Turnau, Calin Alexa, A. Fedotov, Dusan Bruncko, B. Naroska, K. B. Cantun Avila, K. Begzsuren, S. Ginzburgskaya, C. Kiesling, A. De Roeck, E. Tzamariudaki, I. Tsakov, A. J. Campbell, S. Ghazaryan, Th. Naumann, K. Urban, G. Leibenguth, Murrough Landon, W. Yan, T. Greenshaw, E. Gabathuler, I. Panagoulias, A. Schöning, S. Gorbounov, J. Ferencei, M. Martisikova, V. Michels, S. Essenov, J. B. Dainton, M.-O. Boenig, T. Ravdandorj, Claus Kleinwort, A. Knutsson, Nicolas Berger, A. Makankine, P. Van Mechelen, Max Klein, G. Buschhorn, D. Ozerov, A. Zhelezov, S. Baudrand, T.H. Tran, Adrian Perieanu, P. A. Smirnov, Gerhard Brandt, V. Volchinski, H. Meyer, Xavier Janssen, A. Nikiforov, J-P. Meyer, Maxime Gouzevitch, Benno List, M. Brinkmann, V. Korbel, V. Lendermann, Magnus Hansson, M. Del Degan, A.-I. Lucaci-Timoce, C. Werner, L. Goerlich, L. Bystritskaya, G. Weber, H. Zohrabyan, U. Straumann, Laurent Schoeffel, B. Tseepeldorj, Karel Cerny, Matthew Beckingham, Anna Kropivnitskaya, R. Felst, and A. Glazov

Subjects
Physics, Nuclear and High Energy Physics, Particle physics, Jet (fluid), Neutral current, 010308 nuclear & particles physics, Scattering, High Energy Physics::Phenomenology, Four-momentum, Perturbative QCD, HERA, Deep inelastic scattering, 01 natural sciences, 7. Clean energy, Nuclear physics, Cross section (physics), 0103 physical sciences, High Energy Physics::Experiment, 010306 general physics
Abstract

Inclusive jet production is studied in neutral current deep-inelastic positron-proton scattering at large four momentum transfer squared Q^2>150 GeV^2 with the H1 detector at HERA. Single and double differential inclusive jet cross sections are measured as a function of Q^2 and of the transverse energy E_T of the jets in the Breit frame. The measurements are found to be well described by calculations at next-to-leading order in perturbative QCD. The running of the strong coupling is demonstrated and the value of alpha_s(M_Z) is determined. The ratio of the inclusive jet cross section to the inclusive neutral current cross section is also measured and used to extract a precise value for alpha_s(M_Z)=0.1193+/-0.0014(exp.)^{+0.0047}_{-0.0030}(th.)+/-0.0016(pdf).

Published
2007

48. Diffractive open charm production in deep-inelastic scattering and photoproduction at HERA

Author

S. Hussain, C. Grab, G. Thompson, H. Henschel, J.C. Bizot, G. Tsipolitis, Paul Laycock, E. Malinovski, Emmanuel Sauvan, G. Grindhammer, Judith Katzy, G. Cozzika, C. Schmitz, Hannes Jung, Alexander Zhokin, C. Vallée, W. Yan, Peter Robmann, A. M. Fomenko, E. Gabathuler, N. Loktionova, V. Jemanov, A. Hovhannisyan, Gero Flucke, M. Kapichine, M. Nozicka, H. Peng, I. Tsurin, G. Laštovička-Medin, B. Delcourt, D. Mladenov, Matthias Ulrich Mozer, Søren Schmidt, A. Baghdasaryan, A. Rostovtsev, A. Lebedev, A. Fedotov, Dusan Bruncko, M. Gouzevitch, K. B. Cantun Avila, S. Ginzburgskaya, C. Kiesling, A. De Roeck, F. Salvaire, E. Tzamariudaki, A. J. Campbell, D. Haidt, J. Feltesse, K. H. Hiller, R. C. W. Henderson, Laurent Schoeffel, Paul Newman, T. Zimmermann, A. Aktas, P. Baranov, B. Naroska, J. Cvach, M. Goettlich, D. Utkin, R.N. Shaw-West, A. Rimmer, C. Risler, C. Niebuhr, M. Fleischer, T. J. Sloan, Eram Rizvi, A. Dubak, P.J.W. Faulkner, G. Heinzelmann, A. Knutsson, Pavel Murin, K. Nowak, A.S. Belousov, T. Greenshaw, Sergey Rusakov, P. Truöl, Magnus Hansson, S. Egli, Y. Vazdik, B. List, M. Del Degan, V. Dodonov, Stefania Xella, S. Backovic, Th. D. Papadopoulou, M. Ibbotson, Y. Soloviev, Max Klein, G. Weber, C. Gwilliam, E. E. Elsen, U. Straumann, Thomas Naumann, Bogdan Povh, F. Sefkow, A. D.R. Vargas Trevino, J. Ferencei, Zuzana Rurikova, A. Astvatsatourov, Mila Pandurovic, K. Urban, M. Martisikova, Murrough Landon, A. Makankine, Erika Garutti, D. Wegener, Katerina Lipka, S. Ghazaryan, H. Lueders, G. Buschhorn, D. Ozerov, V. Tchoulakov, L. Goerlich, C. Wissing, Wolfgang Lange, V. Korbel, A. Specka, M. Sauter, E. Wünsch, R. Weber, Claus Kleinwort, P. A. Smirnov, M. Kraemer, Dave Sankey, S. M. Piec, Laurent Favart, M. Brinkmann, H. U. Martyn, J. Gayler, T. Anthonis, V. Efremenko, K. Müller, G. D. Patel, Matthew Beckingham, S. Gorbounov, T. Kluge, Stephen Maxfield, S. Mikocki, Biljana Antunović, G. Leibenguth, D.P. Johnson, T. Sykora, J. Stiewe, V. Chekelian, Anna Kropivnitskaya, E. Perez, Andrew Mehta, J. Bracinik, N. Gogitidze, R. Felst, I. Picuric, C. Pascaud, C. Werner, Guenter Eckerlin, André Schöning, J. V. Morris, Jenny List, A. W. Jung, M. Wessels, I. Sheviakov, P. E. Reimer, G. Herrera, Bradley Cox, A.J. Rahmat, A. Bunyatyan, A. Nikiforov, M. Jacquet, K. Krüger, R. Wolf, T. Frisson, Karel Cerny, J. Zálešák, P. Van Mechelen, L. Bystritskaya, V. Spaskov, S. Baudrand, K. Wacker, Ivan Smiljanic, I. Milcewicz-Mika, Anton Babaev, J. G. Contreras, A. Mohamed, P. Prideaux, A. Glazov, P. D. Thompson, V. Yeganov, H. Zohrabyan, A. Stoilov, Ll. Marti, I. Bozovic-Jelisavcic, L. Finke, R. Marshall, F. Moreau, S. J. Aplin, R. Plačakytė, Y.C. Zhu, S. Essenov, F. Zomer, K. Daum, V. Michels, J. B. Dainton, V. Andreev, V. Lendermann, A.-I. Lucaci-Timoce, G. Knies, Christian Helebrant, G. Franke, J. Žáček, Leif J. Jönsson, Benoit Roland, Hans-Christian Schultz-Coulon, T. Klimkovich, A. Falkewicz, Tomas Hreus, R. Eichler, F. Eisele, R. Oganezov, V. Cerny, B. Olivier, John A Coughlan, Grzegorz Nowak, A. Petrukhin, V. Brisson, E. Barrelet, T. Toll, E. A. De Wolf, Karlheinz Meier, R. Roosen, Y. de Boer, B. Stella, Stefan Schmitt, Vladimir Palichik, V. Lubimov, K. Nankov, L. N. Shtarkov, M.-O. Boenig, Zhen Zhang, Ricardo Lopez-Fernandez, S. Levonian, I. Panagoulias, M. Steder, S. Habib, Sakar Osman, D. Hoffmann, Andreas Meyer, Nicolas Berger, David South, A. Usik, J. Zimmermann, A. Eliseev, J. E. Olsson, A. Zhelezov, W. Bartel, J-P. Meyer, Malte Hildebrandt, F. W. Büsser, I. R. Kenyon, Natasa Raicevic, O. Behrendt, Vincent Boudry, S. Vinokurova, A. N. Morozov, P. Kostka, D. Perez-Astudillo, M. Gregori, J. Turnau, Adrian Perieanu, B. R. Grell, Gerhard Brandt, V. Volchinski, K. Begzsuren, H. Meyer, F. Tomasz, Xavier Janssen, I. Tsakov, T. N. Trinh, Roland Horisberger, A. Valkárová, K. Krastev, L. Lindfeld, D. Sunar, L. Lytkin, Cristinel Diaconu, Daniel Pitzl, D. Traynor, A. Asmone, F. Cassol-Brunner, M. Urban, Jan Kretzschmar, Andrej Liptaj, Pierre Marage, I. Glushkov, O. Behnke, Laboratoire de Physique Nucléaire et de Hautes Énergies (LPNHE), Université Pierre et Marie Curie - Paris 6 (UPMC)-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Université Paris Diderot - Paris 7 (UPD7)-Centre National de la Recherche Scientifique (CNRS), Laboratoire de l'Accélérateur Linéaire (LAL), Université Paris-Sud - Paris 11 (UP11)-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Centre National de la Recherche Scientifique (CNRS), Laboratoire Leprince-Ringuet (LLR), Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-École polytechnique (X)-Centre National de la Recherche Scientifique (CNRS), Centre de Physique des Particules de Marseille (CPPM), Aix Marseille Université (AMU)-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Centre National de la Recherche Scientifique (CNRS), Département d'Astrophysique, de physique des Particules, de physique Nucléaire et de l'Instrumentation Associée (DAPNIA), Commissariat à l'énergie atomique et aux énergies alternatives (CEA), H1, (ukupan broj autora: 294), Centre National de la Recherche Scientifique (CNRS)-Université Paris Diderot - Paris 7 (UPD7)-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Université Pierre et Marie Curie - Paris 6 (UPMC), Centre National de la Recherche Scientifique (CNRS)-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Université Paris-Sud - Paris 11 (UP11), and Centre National de la Recherche Scientifique (CNRS)-École polytechnique (X)-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)

Subjects
Physics, Quantum chromodynamics, Particle physics, Physics and Astronomy (miscellaneous), Meson, 010308 nuclear & particles physics, High Energy Physics::Phenomenology, Hadron, FOS: Physical sciences, Parton, HERA, Deep inelastic scattering, 01 natural sciences, High Energy Physics - Experiment, Charm quark, Nuclear physics, High Energy Physics - Experiment (hep-ex), 0103 physical sciences, [PHYS.HEXP]Physics [physics]/High Energy Physics - Experiment [hep-ex], ddc:530, High Energy Physics::Experiment, Rapidity, Nuclear Experiment, 010306 general physics, Engineering (miscellaneous)
Abstract

Measurements are presented of diffractive open charm production at HERA. The event topology is given by ep -> eX Y where the system X contains at least one charmed hadron and is well separated by a large rapidity gap from a leading low-mass proton remnant system Y. Two analysis techniques are used for the cross section measurements. In the first, the charm quark is tagged by the reconstruction of a D*(2010) meson. This technique is used in deep-inelastic scattering (DIS) and photoproduction. In the second, a method based on the displacement of tracks from the primary vertex is used to measure the open charm contribution to the inclusive diffractive cross section in DIS. The measurements are compared with next-to-leading order QCD predictions based on diffractive parton density functions previously obtained from a QCD analysis of the inclusive diffractive cross section at H1. A good agreement is observed in the full kinematic regime, which supports the validity of QCD factorization for open charm production in diffractive DIS and photoproduction., 39 pages, 13 figures, 8 tables

Published
2007

49. Improved x-ray detection and particle identification with avalanche photodiodes

Author

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

Subjects
Physics - Instrumentation and Detectors, Materials science, Physics::Instrumentation and Detectors, business.industry, Resolution (electron density), Detector, X-ray, FOS: Physical sciences, Instrumentation and Detectors (physics.ins-det), Electron, Avalanche photodiode, Particle identification, Optics, SDG 7 - Affordable and Clean Energy, business, Absorption (electromagnetic radiation), Photodiodes, Instrumentation, Energy (signal processing)
Abstract

Avalanche photodiodes are commonly used as detectors for low energy x-rays. In this work we report on a fitting technique used to account for different detector responses resulting from photo absorption in the various APD layers. The use of this technique results in an improvement of the energy resolution at 8.2 keV by up to a factor of 2, and corrects the timing information by up to 25 ns to account for space dependent electron drift time. In addition, this waveform analysis is used for particle identification, e.g. to distinguish between x-rays and MeV electrons in our experiment., 6 pages, 6 figures

Published
2015

50. Measurement of the Formation Rate of Muonic Hydrogen Molecules

Author

A. A. Vasilyev, K. R. Lynch, Jules Deutsch, An.A. Vorobyov, T. P. Gorringe, J. Egger, D. W. Hertzog, R. M. Carey, Malte Hildebrandt, O. Maev, P. Kammel, V.A. Ganzha, B. Kiburg, Stuart J. Freedman, Françoise Mulhauser, M. Vznuzdaev, P. Winter, René Prieels, T. I. Banks, V. A. Andreev, G. G. Semenchuk, Kenneth M. Crowe, T. Case, A. G. Krivshich, G. N. Schapkin, V. Tishchenko, M. A. Soroka, C. Petitjean, Bernhard Lauss, P. Kravtsov, E. M. Maev, S. Knaack, S. M. Clayton, G. E. Petrov, F. Gray, and UCL - SST/IRMP - Institut de recherche en mathématique et physique

Subjects
Physics, Nuclear and High Energy Physics, Muon, Physics - Instrumentation and Detectors, Proton, 010308 nuclear & particles physics, FOS: Physical sciences, Instrumentation and Detectors (physics.ins-det), Lambda, Coupling (probability), 01 natural sciences, High Energy Physics - Experiment, Pseudoscalar, High Energy Physics - Experiment (hep-ex), 0103 physical sciences, Atom, Molecule, Nuclear Experiment (nucl-ex), Atomic physics, 010306 general physics, Nuclear Experiment, Exotic atom
Abstract

Background: The rate \lambda_pp\mu\ characterizes the formation of pp\mu\ molecules in collisions of muonic p\mu\ atoms with hydrogen. In measurements of the basic weak muon capture reaction on the proton to determine the pseudoscalar coupling g_P, capture occurs from both atomic and molecular states. Thus knowledge of \lambda_pp\mu\ is required for a correct interpretation of these experiments. Purpose: Recently the MuCap experiment has measured the capture rate \Lambda_S from the singlet p\mu\ atom, employing a low density active target to suppress pp\mu\ formation (PRL 110, 12504 (2013)). Nevertheless, given the unprecedented precision of this experiment, the existing experimental knowledge in \lambda_pp\mu\ had to be improved. Method: The MuCap experiment derived the weak capture rate from the muon disappearance rate in ultra-pure hydrogen. By doping the hydrogen with 20 ppm of argon, a competing process to pp\mu\ formation was introduced, which allowed the extraction of \lambda_pp\mu\ from the observed time distribution of decay electrons. Results: The pp\mu\ formation rate was measured as \lambda_pp\mu = (2.01 +- 0.06(stat) +- 0.03(sys)) 10^6 s^-1. This result updates the \lambda_pp\mu\ value used in the above mentioned MuCap publication. Conclusions: The 2.5x higher precision compared to earlier experiments and the fact that the measurement was performed at nearly identical conditions to the main data taking, reduces the uncertainty induced by \lambda_pp\mu\ to a minor contribution to the overall uncertainty of \Lambda_S and g_P, as determined in MuCap. Our final value for \lambda_pp\mu\ shifts \Lambda_S and g_P by less than one tenth of their respective uncertainties compared to our results published earlier., Comment: 12 pages, 6 figures, to be submitted to Phys. Rev. C

Published
2015

Catalog

Books, media, physical & digital resources
See catalog results