Search

Your search keyword '"C. Palatchi"' showing total 10 results
Start Over Author "C. Palatchi" Language english
10 results on '"C. Palatchi"'

1. First Measurement of the $Q^2$ Dependence of the Beam-Normal Single Spin Asymmetry for Elastic Scattering off Carbon

Author

P. Herrmann, Concettina Sfienti, S. Širca, K. Aulenbacher, M. Dehn, B. S. Schlimme, Ivica Friščić, F. E. Maas, J. Müller, J. Beričič, D. Bosnar, S. Štajner, M. Hoek, B. Spruck, U. Müller, Michaela Thiel, Kent Paschke, H. Fonvieille, A. Weber, S. Baunack, S. Kegel, M. O. Distler, J. Pochodzalla, T. Kolar, M. Mihovilovic, V. Tioukine, H. J. Kreidel, Y. Kohl, C. Palatchi, Mikhail Gorchtein, Anselm Esser, A. Tyukin, L. Correa, Patrick Achenbach, M. Schoth, Harald Merkel, S. Heidrich, F. Schulz, F. Nillius, Laboratoire de Physique de Clermont (LPC), Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Université Clermont Auvergne (UCA)-Centre National de la Recherche Scientifique (CNRS), Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Université Clermont Auvergne [2017-2020] (UCA [2017-2020])-Centre National de la Recherche Scientifique (CNRS), and Centre National de la Recherche Scientifique (CNRS)-Université Clermont Auvergne [2017-2020] (UCA [2017-2020])-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)

Subjects
carbon: target, electron: polarized beam, media_common.quotation_subject, General Physics and Astronomy, Electron, [PHYS.NEXP]Physics [physics]/Nuclear Experiment [nucl-ex], momentum transfer dependence, 01 natural sciences, Asymmetry, Mainz Linac, 0103 physical sciences, gallium: arsenic, polarization: transverse, elektronsko raspršenje, 010306 general physics, Nuclear Experiment, Spin-½, media_common, Physics, Elastic scattering, form factor: ratio, form factor: charge, exchange: two-photon, 010308 nuclear & particles physics, nucleus: target, izmjena dva fotona, electron nucleus: elastic scattering, Charge (physics), amplitude analysis, NATURAL SCIENCES. Physics, PRIRODNE ZNANOSTI. Fizika, spin: asymmetry: measured, Elektronsko raspršenje, izmjena dva fotona, Amplitude, Cover (topology), High Energy Physics::Experiment, Atomic physics, radiation: laser, Beam (structure), photoelectron, experimental results
Abstract

We report on the first Q^{2}-dependent measurement of the beam-normal single spin asymmetry A_{n} in the elastic scattering of 570 MeV vertically polarized electrons off ^{12}C. We cover the Q^{2} range between 0.02 and 0.05 GeV^{2}/c^{2} and determine A_{n} at four different Q^{2} values. The experimental results are compared to a theoretical calculation that relates A_{n} to the imaginary part of the two-photon exchange amplitude. The result emphasizes that the Q^{2} behavior of A_{n} given by the ratio of the Compton to charge form factors cannot be treated independently of the target nucleus.

Published
2018
Full Text
View/download PDF

2. Novel Measurement of the Neutron Magnetic Form Factor from A=3 Mirror Nuclei.

Author

Santiesteban SN, Li S, Abrams D, Alsalmi S, Androic D, Aniol K, Arrington J, Averett T, Ayerbe Gayoso C, Bane J, Barcus S, Barrow J, Beck A, Bellini V, Bhatt H, Bhetuwal D, Biswas D, Camsonne A, Castellanos J, Chen J, Chen JP, Chrisman D, Christy ME, Clarke C, Covrig S, Cruz-Torres R, Day D, Dutta D, Fuchey E, Gal C, Garibaldi F, Gautam TN, Gogami T, Gomez J, Guèye P, Hague TJ, Hansen JO, Hauenstein F, Henry W, Higinbotham DW, Holt RJ, Hyde C, Itabashi K, Kaneta M, Karki A, Katramatou AT, Keppel CE, King PM, Kurbany L, Kutz T, Lashley-Colthirst N, Li WB, Liu H, Liyanage N, Long E, Lovato A, Mammei J, Markowitz P, McClellan RE, Meddi F, Meekins D, Michaels R, Mihovilovič M, Moyer A, Nagao S, Nguyen D, Nycz M, Olson M, Ou L, Owen V, Palatchi C, Pandey B, Papadopoulou A, Park S, Petkovic T, Premathilake S, Punjabi V, Ransome RD, Reimer PE, Reinhold J, Riordan S, Rocco N, Rodriguez VM, Schmidt A, Schmookler B, Segarra EP, Shahinyan A, Širca S, Slifer K, Solvignon P, Su T, Suleiman R, Tang L, Tian Y, Tireman W, Tortorici F, Toyama Y, Uehara K, Urciuoli GM, Votaw D, Williamson J, Wojtsekhowski B, Wood S, Ye ZH, Zhang J, and Zheng X

Abstract

The electromagnetic form factors of the proton and neutron encode information on the spatial structure of their charge and magnetization distributions. While measurements of the proton are relatively straightforward, the lack of a free neutron target makes measurements of the neutron's electromagnetic structure more challenging and more sensitive to experimental or model-dependent uncertainties. Various experiments have attempted to extract the neutron form factors from scattering from the neutron in deuterium, with different techniques providing different, and sometimes large, systematic uncertainties. We present results from a novel measurement of the neutron magnetic form factor using quasielastic scattering from the mirror nuclei ^{3}H and ^{3}He, where the nuclear effects are larger than for deuterium but expected to largely cancel in the cross-section ratios. We extracted values of the neutron magnetic form factor for low-to-modest momentum transfer, 0.6

Published
2024
Full Text
View/download PDF

3. Revealing the short-range structure of the mirror nuclei 3 H and 3 He.

Author

Li S, Cruz-Torres R, Santiesteban N, Ye ZH, Abrams D, Alsalmi S, Androic D, Aniol K, Arrington J, Averett T, Gayoso CA, Bane J, Barcus S, Barrow J, Beck A, Bellini V, Bhatt H, Bhetuwal D, Biswas D, Bulumulla D, Camsonne A, Castellanos J, Chen J, Chen JP, Chrisman D, Christy ME, Clarke C, Covrig S, Craycraft K, Day D, Dutta D, Fuchey E, Gal C, Garibaldi F, Gautam TN, Gogami T, Gomez J, Guèye P, Habarakada A, Hague TJ, Hansen JO, Hauenstein F, Henry W, Higinbotham DW, Holt RJ, Hyde C, Itabashi T, Kaneta M, Karki A, Katramatou AT, Keppel CE, Khachatryan M, Khachatryan V, King PM, Korover I, Kurbany L, Kutz T, Lashley-Colthirst N, Li WB, Liu H, Liyanage N, Long E, Mammei J, Markowitz P, McClellan RE, Meddi F, Meekins D, Beck SM, Michaels R, Mihovilovič M, Moyer A, Nagao S, Nelyubin V, Nguyen D, Nycz M, Olson M, Ou L, Owen V, Palatchi C, Pandey B, Papadopoulou A, Park S, Paul S, Petkovic T, Pomatsalyuk R, Premathilake S, Punjabi V, Ransome RD, Reimer PE, Reinhold J, Riordan S, Roche J, Rodriguez VM, Schmidt A, Schmookler B, Segarra EP, Shahinyan A, Slifer K, Solvignon P, Širca S, Su T, Suleiman R, Szumila-Vance H, Tang L, Tian Y, Tireman W, Tortorici F, Toyama Y, Uehara K, Urciuoli GM, Votaw D, Williamson J, Wojtsekhowski B, Wood S, Zhang J, and Zheng X

Abstract

When protons and neutrons (nucleons) are bound into atomic nuclei, they are close enough to feel significant attraction, or repulsion, from the strong, short-distance part of the nucleon-nucleon interaction. These strong interactions lead to hard collisions between nucleons, generating pairs of highly energetic nucleons referred to as short-range correlations (SRCs). SRCs are an important but relatively poorly understood part of nuclear structure 1-3 , and mapping out the strength and the isospin structure (neutron-proton (np) versus proton-proton (pp) pairs) of these virtual excitations is thus critical input for modelling a range of nuclear, particle and astrophysics measurements 3-5 . Two-nucleon knockout or 'triple coincidence' reactions have been used to measure the relative contribution of np-SRCs and pp-SRCs by knocking out a proton from the SRC and detecting its partner nucleon (proton or neutron). These measurements 6-8 have shown that SRCs are almost exclusively np pairs, but they had limited statistics and required large model-dependent final-state interaction corrections. Here we report on measurements using inclusive scattering from the mirror nuclei hydrogen-3 and helium-3 to extract the np/pp ratio of SRCs in systems with a mass number of three. We obtain a measure of the np/pp SRC ratio that is an order of magnitude more precise than previous experiments, and find a marked deviation from the near-total np dominance observed in heavy nuclei. This result implies an unexpected structure in the high-momentum wavefunction for hydrogen-3 and helium-3. Understanding these results will improve our understanding of the short-range part of the nucleon-nucleon interaction., (© 2022. The Author(s), under exclusive licence to Springer Nature Limited.)

Published
2022
Full Text
View/download PDF

4. Precision Determination of the Neutral Weak Form Factor of ^{48}Ca.

Author

Adhikari D, Albataineh H, Androic D, Aniol KA, Armstrong DS, Averett T, Ayerbe Gayoso C, Barcus SK, Bellini V, Beminiwattha RS, Benesch JF, Bhatt H, Bhatta Pathak D, Bhetuwal D, Blaikie B, Boyd J, Campagna Q, Camsonne A, Cates GD, Chen Y, Clarke C, Cornejo JC, Covrig Dusa S, Dalton MM, Datta P, Deshpande A, Dutta D, Feldman C, Fuchey E, Gal C, Gaskell D, Gautam T, Gericke M, Ghosh C, Halilovic I, Hansen JO, Hassan O, Hauenstein F, Henry W, Horowitz CJ, Jantzi C, Jian S, Johnston S, Jones DC, Kakkar S, Katugampola S, Keppel C, King PM, King DE, Kumar KS, Kutz T, Lashley-Colthirst N, Leverick G, Liu H, Liyanage N, Mammei J, Mammei R, McCaughan M, McNulty D, Meekins D, Metts C, Michaels R, Mihovilovic M, Mondal MM, Napolitano J, Narayan A, Nikolaev D, Owen V, Palatchi C, Pan J, Pandey B, Park S, Paschke KD, Petrusky M, Pitt ML, Premathilake S, Quinn B, Radloff R, Rahman S, Rashad MNH, Rathnayake A, Reed BT, Reimer PE, Richards R, Riordan S, Roblin YR, Seeds S, Shahinyan A, Souder P, Thiel M, Tian Y, Urciuoli GM, Wertz EW, Wojtsekhowski B, Yale B, Ye T, Yoon A, Xiong W, Zec A, Zhang W, Zhang J, and Zheng X

Abstract

We report a precise measurement of the parity-violating (PV) asymmetry A_{PV} in the elastic scattering of longitudinally polarized electrons from ^{48}Ca. We measure A_{PV}=2668±106(stat)±40(syst) parts per billion, leading to an extraction of the neutral weak form factor F_{W}(q=0.8733  fm^{-1})=0.1304±0.0052(stat)±0.0020(syst) and the charge minus the weak form factor F_{ch}-F_{W}=0.0277±0.0055. The resulting neutron skin thickness R_{n}-R_{p}=0.121±0.026(exp)±0.024(model)  fm is relatively thin yet consistent with many model calculations. The combined CREX and PREX results will have implications for future energy density functional calculations and on the density dependence of the symmetry energy of nuclear matter.

Published
2022
Full Text
View/download PDF

5. Deeply Virtual Compton Scattering Cross Section at High Bjorken x_{B}.

Author

Georges F, Rashad MNH, Stefanko A, Dlamini M, Karki B, Ali SF, Lin PJ, Ko HS, Israel N, Adikaram D, Ahmed Z, Albataineh H, Aljawrneh B, Allada K, Allison S, Alsalmi S, Androic D, Aniol K, Annand J, Atac H, Averett T, Ayerbe Gayoso C, Bai X, Bane J, Barcus S, Bartlett K, Bellini V, Beminiwattha R, Bericic J, Biswas D, Brash E, Bulumulla D, Campbell J, Camsonne A, Carmignotto M, Castellano J, Chen C, Chen JP, Chetry T, Christy ME, Cisbani E, Clary B, Cohen E, Compton N, Cornejo JC, Covrig Dusa S, Crowe B, Danagoulian S, Danley T, De Persio F, Deconinck W, Defurne M, Desnault C, Di D, Duer M, Duran B, Ent R, Fanelli C, Franklin G, Fuchey E, Gal C, Gaskell D, Gautam T, Glamazdin O, Gnanvo K, Gray VM, Gu C, Hague T, Hamad G, Hamilton D, Hamilton K, Hansen O, Hauenstein F, Henry W, Higinbotham DW, Holmstrom T, Horn T, Huang Y, Huber GM, Hyde CE, Ibrahim H, Jen CM, Jin K, Jones M, Kabir A, Keppel C, Khachatryan V, King PM, Li S, Li WB, Liu J, Liu H, Liyanage A, Magee J, Malace S, Mammei J, Markowitz P, McClellan E, Mazouz M, Meddi F, Meekins D, Mesik K, Michaels R, Mkrtchyan A, Montgomery R, Muñoz Camacho C, Myers LS, Nadel-Turonski P, Nazeer SJ, Nelyubin V, Nguyen D, Nuruzzaman N, Nycz M, Obretch OF, Ou L, Palatchi C, Pandey B, Park S, Park K, Peng C, Pomatsalyuk R, Pooser E, Puckett AJR, Punjabi V, Quinn B, Rahman S, Reimer PE, Roche J, Sapkota I, Sarty A, Sawatzky B, Saylor NH, Schmookler B, Shabestari MH, Shahinyan A, Sirca S, Smith GR, Sooriyaarachchilage S, Sparveris N, Spies R, Su T, Subedi A, Sulkosky V, Sun A, Thorne L, Tian Y, Ton N, Tortorici F, Trotta R, Urciuoli GM, Voutier E, Waidyawansa B, Wang Y, Wojtsekhowski B, Wood S, Yan X, Ye L, Ye Z, Yero C, Zhang J, Zhao Y, and Zhu P

Abstract

We report high-precision measurements of the deeply virtual Compton scattering (DVCS) cross section at high values of the Bjorken variable x_{B}. DVCS is sensitive to the generalized parton distributions of the nucleon, which provide a three-dimensional description of its internal constituents. Using the exact analytic expression of the DVCS cross section for all possible polarization states of the initial and final electron and nucleon, and final state photon, we present the first experimental extraction of all four helicity-conserving Compton form factors (CFFs) of the nucleon as a function of x_{B}, while systematically including helicity flip amplitudes. In particular, the high accuracy of the present data demonstrates sensitivity to some very poorly known CFFs.

Published
2022
Full Text
View/download PDF

6. New Measurements of the Beam-Normal Single Spin Asymmetry in Elastic Electron Scattering over a Range of Spin-0 Nuclei.

Author

Adhikari D, Albataineh H, Androic D, Aniol K, Armstrong DS, Averett T, Ayerbe Gayoso C, Barcus S, Bellini V, Beminiwattha RS, Benesch JF, Bhatt H, Bhatta Pathak D, Bhetuwal D, Blaikie B, Boyd J, Campagna Q, Camsonne A, Cates GD, Chen Y, Clarke C, Cornejo JC, Covrig Dusa S, Dalton MM, Datta P, Deshpande A, Dutta D, Feldman C, Fuchey E, Gal C, Gaskell D, Gautam T, Gericke M, Ghosh C, Halilovic I, Hansen JO, Hauenstein F, Henry W, Horowitz CJ, Jantzi C, Jian S, Johnston S, Jones DC, Karki B, Kakkar S, Katugampola S, Keppel CE, King PM, King DE, Knauss M, Kumar KS, Kutz T, Lashley-Colthirst N, Leverick G, Liu H, Liyange N, Malace S, Mammei J, Mammei R, McCaughan M, McNulty D, Meekins D, Metts C, Michaels R, Mihovilovic M, Mondal MM, Napolitano J, Nikolaev D, Rashad MNH, Owen V, Palatchi C, Pan J, Pandey B, Park S, Paschke KD, Petrusky M, Pitt ML, Premathilake S, Puckett AJR, Quinn B, Radloff R, Rahman S, Rathnayake A, Reed BT, Reimer PE, Richards R, Riordan S, Roblin Y, Seeds S, Shahinyan A, Souder PA, Tang L, Thiel M, Tian Y, Urciuoli GM, Wertz EW, Wojtsekhowski B, Xiong W, Yale B, Ye T, Zec A, Zhang W, Zhang J, and Zheng X

Abstract

We report precision determinations of the beam-normal single spin asymmetries (A_{n}) in the elastic scattering of 0.95 and 2.18 GeV electrons off ^{12}C, ^{40}Ca, ^{48}Ca, and ^{208}Pb at very forward angles where the most detailed theoretical calculations have been performed. The first measurements of A_{n} for ^{40}Ca and ^{48}Ca are found to be similar to that of ^{12}C, consistent with expectations and thus demonstrating the validity of theoretical calculations for nuclei with Z≤20. We also report A_{n} for ^{208}Pb at two new momentum transfers (Q^{2}) extending the previous measurement. Our new data confirm the surprising result previously reported, with all three data points showing significant disagreement with the results from the Z≤20 nuclei. These data confirm our basic understanding of the underlying dynamics that govern A_{n} for nuclei containing ≲50 nucleons, but point to the need for further investigation to understand the unusual A_{n} behavior discovered for scattering off ^{208}Pb.

Published
2022
Full Text
View/download PDF

7. Form Factors and Two-Photon Exchange in High-Energy Elastic Electron-Proton Scattering.

Author

Christy ME, Gautam T, Ou L, Schmookler B, Wang Y, Adikaram D, Ahmed Z, Albataineh H, Ali SF, Aljawrneh B, Allada K, Allison SL, Alsalmi S, Androic D, Aniol K, Annand J, Arrington J, Atac H, Averett T, Ayerbe Gayoso C, Bai X, Bane J, Barcus S, Bartlett K, Bellini V, Beminiwattha R, Bericic J, Bhatt H, Bhetuwal D, Biswas D, Brash E, Bulumulla D, Camacho CM, Campbell J, Camsonne A, Carmignotto M, Castellanos J, Chen C, Chen JP, Chetry T, Cisbani E, Clary B, Cohen E, Compton N, Cornejo JC, Covrig Dusa S, Crowe B, Danagoulian S, Danley T, Deconinck W, Defurne M, Desnault C, Di D, Dlamini M, Duer M, Duran B, Ent R, Fanelli C, Fuchey E, Gal C, Gaskell D, Georges F, Gilad S, Glamazdin O, Gnanvo K, Gramolin AV, Gray VM, Gu C, Habarakada A, Hague T, Hamad G, Hamilton D, Hamilton K, Hansen O, Hauenstein F, Hernandez AV, Henry W, Higinbotham DW, Holmstrom T, Horn T, Huang Y, Huber GM, Hyde C, Ibrahim H, Israel N, Jen CM, Jin K, Jones M, Kabir A, Karki B, Keppel C, Khachatryan V, King PM, Li S, Li W, Liu H, Liu J, Liyanage AH, Mack D, Magee J, Malace S, Mammei J, Markowitz P, Mayilyan S, McClellan E, Meddi F, Meekins D, Mesick K, Michaels R, Mkrtchyan A, Moffit B, Montgomery R, Myers LS, Nadel-Turonski P, Nazeer SJ, Nelyubin V, Nguyen D, Nuruzzaman N, Nycz M, Obrecht RF, Ohanyan K, Palatchi C, Pandey B, Park K, Park S, Peng C, Persio FD, Pomatsalyuk R, Pooser E, Puckett AJR, Punjabi V, Quinn B, Rahman S, Rashad MNH, Reimer PE, Riordan S, Roche J, Sapkota I, Sarty A, Sawatzky B, Saylor NH, Shabestari MH, Shahinyan A, Širca S, Smith GR, Sooriyaarachchilage S, Sparveris N, Spies R, Stefanko A, Su T, Subedi A, Sulkosky V, Sun A, Tan Y, Thorne L, Ton N, Tortorici F, Trotta R, Uniyal R, Urciuoli GM, Voutier E, Waidyawansa B, Wojtsekhowski B, Wood S, Yan X, Ye L, Ye ZH, Yero C, Zhang J, Zhao YX, and Zhu P

Abstract

We present new precision measurements of the elastic electron-proton scattering cross section for momentum transfer (Q^{2}) up to 15.75  (GeV/c)^{2}. Combined with existing data, these provide an improved extraction of the proton magnetic form factor at high Q^{2} and double the range over which a longitudinal or transverse separation of the cross section can be performed. The difference between our results and polarization data agrees with that observed at lower Q^{2} and attributed to hard two-photon exchange (TPE) effects, extending to 8  (GeV/c)^{2} the range of Q^{2} for which a discrepancy is established at >95% confidence. We use the discrepancy to quantify the size of TPE contributions needed to explain the cross section at high Q^{2}.

Published
2022
Full Text
View/download PDF

8. Deep Exclusive Electroproduction of π^{0} at High Q^{2} in the Quark Valence Regime.

Author

Dlamini M, Karki B, Ali SF, Lin PJ, Georges F, Ko HS, Israel N, Rashad MNH, Stefanko A, Adikaram D, Ahmed Z, Albataineh H, Aljawrneh B, Allada K, Allison S, Alsalmi S, Androic D, Aniol K, Annand J, Atac H, Averett T, Ayerbe Gayoso C, Bai X, Bane J, Barcus S, Bartlett K, Bellini V, Beminiwattha R, Bericic J, Biswas D, Brash E, Bulumulla D, Campbell J, Camsonne A, Carmignotto M, Castellano J, Chen C, Chen JP, Chetry T, Christy ME, Cisbani E, Clary B, Cohen E, Compton N, Cornejo JC, Covrig Dusa S, Crowe B, Danagoulian S, Danley T, De Persio F, Deconinck W, Defurne M, Desnault C, Di D, Duer M, Duran B, Ent R, Fanelli C, Franklin G, Fuchey E, Gal C, Gaskell D, Gautam T, Glamazdin O, Gnanvo K, Gray VM, Gu C, Hague T, Hamad G, Hamilton D, Hamilton K, Hansen O, Hauenstein F, Henry W, Higinbotham DW, Holmstrom T, Horn T, Huang Y, Huber GM, Hyde C, Ibrahim H, Jen CM, Jin K, Jones M, Kabir A, Keppel C, Khachatryan V, King PM, Li S, Li W, Liu J, Liu H, Liyanage A, Magee J, Malace S, Mammei J, Markowitz P, McClellan E, Meddi F, Meekins D, Mesik K, Michaels R, Mkrtchyan A, Montgomery R, Muñoz Camacho C, Myers LS, Nadel-Turonski P, Nazeer SJ, Nelyubin V, Nguyen D, Nuruzzaman N, Nycz M, Obretch OF, Ou L, Palatchi C, Pandey B, Park S, Park K, Peng C, Pomatsalyuk R, Pooser E, Puckett AJR, Punjabi V, Quinn B, Rahman S, Reimer PE, Roche J, Sapkota I, Sarty A, Sawatzky B, Saylor NH, Schmookler B, Shabestari MH, Shahinyan A, Sirca S, Smith GR, Sooriyaarachchilage S, Sparveris N, Spies R, Su T, Subedi A, Sulkosky V, Sun A, Thorne L, Tian Y, Ton N, Tortorici F, Trotta R, Urciuoli GM, Voutier E, Waidyawansa B, Wang Y, Wojtsekhowski B, Wood S, Yan X, Ye L, Ye Z, Yero C, Zhang J, Zhao Y, and Zhu P

Abstract

We report measurements of the exclusive neutral pion electroproduction cross section off protons at large values of x_{B} (0.36, 0.48, and 0.60) and Q^{2} (3.1 to 8.4  GeV^{2}) obtained from Jefferson Lab Hall A experiment E12-06-014. The corresponding structure functions dσ_{T}/dt+εdσ_{L}/dt, dσ_{TT}/dt, dσ_{LT}/dt, and dσ_{LT^{'}}/dt are extracted as a function of the proton momentum transfer t-t_{min}. The results suggest the amplitude for transversely polarized virtual photons continues to dominate the cross section throughout this kinematic range. The data are well described by calculations based on transversity generalized parton distributions coupled to a helicity flip distribution amplitude of the pion, thus providing a unique way to probe the structure of the nucleon.

Published
2021
Full Text
View/download PDF

9. Accurate Determination of the Neutron Skin Thickness of ^{208}Pb through Parity-Violation in Electron Scattering.

Author

Adhikari D, Albataineh H, Androic D, Aniol K, Armstrong DS, Averett T, Ayerbe Gayoso C, Barcus S, Bellini V, Beminiwattha RS, Benesch JF, Bhatt H, Bhatta Pathak D, Bhetuwal D, Blaikie B, Campagna Q, Camsonne A, Cates GD, Chen Y, Clarke C, Cornejo JC, Covrig Dusa S, Datta P, Deshpande A, Dutta D, Feldman C, Fuchey E, Gal C, Gaskell D, Gautam T, Gericke M, Ghosh C, Halilovic I, Hansen JO, Hauenstein F, Henry W, Horowitz CJ, Jantzi C, Jian S, Johnston S, Jones DC, Karki B, Katugampola S, Keppel C, King PM, King DE, Knauss M, Kumar KS, Kutz T, Lashley-Colthirst N, Leverick G, Liu H, Liyange N, Malace S, Mammei R, Mammei J, McCaughan M, McNulty D, Meekins D, Metts C, Michaels R, Mondal MM, Napolitano J, Narayan A, Nikolaev D, Rashad MNH, Owen V, Palatchi C, Pan J, Pandey B, Park S, Paschke KD, Petrusky M, Pitt ML, Premathilake S, Puckett AJR, Quinn B, Radloff R, Rahman S, Rathnayake A, Reed BT, Reimer PE, Richards R, Riordan S, Roblin Y, Seeds S, Shahinyan A, Souder P, Tang L, Thiel M, Tian Y, Urciuoli GM, Wertz EW, Wojtsekhowski B, Yale B, Ye T, Yoon A, Zec A, Zhang W, Zhang J, and Zheng X

Abstract

We report a precision measurement of the parity-violating asymmetry A_{PV} in the elastic scattering of longitudinally polarized electrons from ^{208}Pb. We measure A_{PV}=550±16(stat)±8(syst) parts per billion, leading to an extraction of the neutral weak form factor F_{W}(Q^{2}=0.00616  GeV^{2})=0.368±0.013. Combined with our previous measurement, the extracted neutron skin thickness is R_{n}-R_{p}=0.283±0.071  fm. The result also yields the first significant direct measurement of the interior weak density of ^{208}Pb: ρ_{W}^{0}=-0.0796±0.0036(exp)±0.0013(theo)  fm^{-3} leading to the interior baryon density ρ_{b}^{0}=0.1480±0.0036(exp)±0.0013(theo)  fm^{-3}. The measurement accurately constrains the density dependence of the symmetry energy of nuclear matter near saturation density, with implications for the size and composition of neutron stars.

Published
2021
Full Text
View/download PDF

10. First Measurement of the Q^{2} Dependence of the Beam-Normal Single Spin Asymmetry for Elastic Scattering off Carbon.

Author

Esser A, Thiel M, Achenbach P, Aulenbacher K, Baunack S, Beričič J, Bosnar D, Correa L, Dehn M, Distler MO, Fonvieille H, Friščić I, Gorchtein M, Heidrich S, Herrmann P, Hoek M, Kegel S, Kohl Y, Kolar T, Kreidel HJ, Maas FE, Merkel H, Mihovilovič M, Müller J, Müller U, Nillius F, Palatchi C, Paschke KD, Pochodzalla J, Schlimme BS, Schoth M, Schulz F, Širca S, Spruck B, Štajner S, Tioukine V, Tyukin A, Weber A, and Sfienti C

Abstract

We report on the first Q^{2}-dependent measurement of the beam-normal single spin asymmetry A_{n} in the elastic scattering of 570 MeV vertically polarized electrons off ^{12}C. We cover the Q^{2} range between 0.02 and 0.05  GeV^{2}/c^{2} and determine A_{n} at four different Q^{2} values. The experimental results are compared to a theoretical calculation that relates A_{n} to the imaginary part of the two-photon exchange amplitude. The result emphasizes that the Q^{2} behavior of A_{n} given by the ratio of the Compton to charge form factors cannot be treated independently of the target nucleus.

Published
2018
Full Text
View/download PDF

Catalog

Books, media, physical & digital resources
See catalog results