skip to main content
OSTI.GOV title logo U.S. Department of Energy
Office of Scientific and Technical Information

Title: Polarization transfer observables in elastic electron-proton scattering at Q 2 = 2.5 , 5.2, 6.8, and 8.5   GeV 2

Abstract

In this paper, interest in the behavior of nucleon electromagnetic form factors at large momentum transfers has steadily increased since the discovery, using polarization observables, of the rapid decrease of the ratio G p E/G p M of the proton's electric and magnetic form factors for momentum transfers Q 2 ≳ 1 GeV 2, in strong disagreement with previous extractions of this ratio using the traditional Rosenbluth separation technique.

Authors:
 [1];  [2];  [3];  [4];  [5];  [3];  [5];  [6];  [6];  [7];  [8];  [9];  [10];  [11];  [12];  [13];  [14];  [15];  [16];  [3] more »;  [17];  [18];  [19];  [20];  [9];  [13];  [10];  [3];  [8];  [21];  [22];  [13];  [17];  [23];  [3];  [23];  [3];  [13];  [23];  [3];  [15];  [24];  [22];  [11];  [25];  [3];  [6];  [3];  [4];  [15];  [18];  [26];  [9];  [6];  [21];  [20];  [9];  [22];  [27];  [9];  [13];  [28];  [19];  [22];  [13];  [29];  [3];  [22];  [30];  [12];  [12];  [15];  [31];  [13];  [32];  [33];  [23];  [34];  [19];  [20];  [19];  [27];  [20];  [11];  [17];  [13];  [13];  [12];  [22];  [35];  [20];  [20];  [3];  [22];  [11];  [13];  [36];  [22];  [19];  [3];  [3];  [9];  [20];  [4];  [4];  [13];  [15] « less
  1. Univ. of Connecticut, Storrs, CT (United States)
  2. Christopher Newport Univ., Newport News, VA (United States); Thomas Jefferson National Accelerator Facility (TJNAF), Newport News, VA (United States)
  3. Thomas Jefferson National Accelerator Facility (TJNAF), Newport News, VA (United States)
  4. Lanzhou Univ., Gansu (People's Republic of China)
  5. College of William and Mary, Williamsburg, VA (United States)
  6. Norfolk State Univ., Norfolk, VA (United States)
  7. George Washington Univ., Washington, DC (United States)
  8. North Carolina A&T State Univ., Greensboro, NC (United States)
  9. Hampton Univ., Hampton, VA (United States)
  10. California State Univ. Los Angeles, Los Angeles, CA (United States)
  11. Argonne National Lab. (ANL), Argonne, IL (United States)
  12. Yerevan Physics Inst. (YerPhI), Yerevan (Armenia)
  13. Univ. of Virginia, Charlottesville, VA (United States)
  14. Duquesne Univ., Pittsburgh, PA (United States)
  15. Massachusetts Inst. of Technology (MIT), Cambridge, MA (United States)
  16. CNRS/IN2P3 and Univ. Paris-Sud (France)
  17. Florida Intl Univ., Miami, FL (United States)
  18. Univ. of Regina, Regina, SK (Canada)
  19. Christopher Newport Univ., Newport News, VA (United States)
  20. JINR-LHE, Moscow Region (Russia)
  21. Ohio Univ., Athens, OH (United States)
  22. IHEP, Moscow Region (Russia)
  23. Sezione Sanita and Istituto Superiore di Sanita, Rome (Italy)
  24. Thomas Jefferson National Accelerator Facility (TJNAF), Newport News, VA (United States); Rutgers Univ., Piscataway, NJ (United States)
  25. Univ. of Glasgow, Scotland (United Kingdom)
  26. Christopher Newport Univ. Newport News, VA (United States)
  27. Rutgers Univ., Piscataway, NJ (United States)
  28. California State Univ Los Angeles, Los Angeles, CA (United States)
  29. Univ. of Witwatersrand, Johannesburg (South Africa)
  30. Univ. of Maryland, College Park, MD (United States)
  31. SLAC National Accelerator Lab., Menlo Park, CA (United States)
  32. Mississippi State Univ., Mississippi State, MS (United States)
  33. Univ. of Chemical Technology and Metallurgy, Sofia (Bulgaria)
  34. Univ. of Tel Aviv, Tel Aviv (Israel)
  35. Univ. of Ljubljana, Ljubljana (Slovenia); Jozef Stefan Institute, Ljubljana (Slovenia)
  36. CNRS/IN2P3 and Univ. Paris-Sud (France); DSM, IRFU, SPhN, Gif-sur-Yvette (France)
Publication Date:
Research Org.:
Univ. of Connecticut, Storrs, CT (United States); Thomas Jefferson National Accelerator Facility, Newport News, VA (United States); SLAC National Accelerator Lab., Menlo Park, CA (United States); Argonne National Lab. (ANL), Argonne, IL (United States)
Sponsoring Org.:
USDOE Office of Science (SC), Nuclear Physics (NP) (SC-26); National Science Foundation (NSF); Centre National de la Recherche Scientifique (CNRS); Natural Science and Engineering Research Council of Canada
OSTI Identifier:
1406995
Report Number(s):
JLAB-PHY-17-2533; DOE/OR/23177-4207; arXiv:1707.08587
Journal ID: ISSN 2469-9985; PRVCAN; TRN: US1703268
Grant/Contract Number:
SC0014230; AC02-06CH11357; AC05-06OR23177; AC02-76SF00515
Resource Type:
Journal Article: Accepted Manuscript
Journal Name:
Physical Review C
Additional Journal Information:
Journal Volume: 96; Journal Issue: 5; Journal ID: ISSN 2469-9985
Publisher:
American Physical Society (APS)
Country of Publication:
United States
Language:
English
Subject:
73 NUCLEAR PHYSICS AND RADIATION PHYSICS; Proton form factors

Citation Formats

Puckett, Andrew J. R., Brash, E. J., Jones, M. K., Luo, W., Meziane, M., Pentchev, L., Perdrisat, C. F., Punjabi, V., Wesselmann, F. R., Afanasev, A., Ahmidouch, A., Albayrak, I., Aniol, K. A., Arrington, J., Asaturyan, A., Baghdasaryan, H., Benmokhtar, F., Bertozzi, W., Bimbot, L., Bosted, P., Boeglin, W., Butuceanu, C., Carter, P., Chernenko, S., Christy, M. E., Commisso, M., Cornejo, J. C., Covrig, S., Danagoulian, S., Daniel, A., Davidenko, A., Day, D., Dhamija, S., Dutta, D., Ent, R., Frullani, S., Fenker, H., Frlez, E., Garibaldi, F., Gaskell, D., Gilad, S., Gilman, R., Goncharenko, Y., Hafidi, K., Hamilton, D., Higinbotham, D. W., Hinton, W., Horn, T., Hu, B., Huang, J., Huber, G. M., Jensen, E., Keppel, C., Khandaker, M., King, P., Kirillov, D., Kohl, M., Kravtsov, V., Kumbartzki, G., Li, Y., Mamyan, V., Margaziotis, D. J., Marsh, A., Matulenko, Y., Maxwell, J., Mbianda, G., Meekins, D., Melnik, Y., Miller, J., Mkrtchyan, A., Mkrtchyan, H., Moffit, B., Moreno, O., Mulholland, J., Narayan, A., Nedev, S., Nuruzzaman, ., Piasetzky, E., Pierce, W., Piskunov, N. M., Prok, Y., Ransome, R. D., Razin, D. S., Reimer, P., Reinhold, J., Rondon, O., Shabestari, M., Shahinyan, A., Shestermanov, K., Sirca, S., Sitnik, I., Smykov, L., Smith, G., Solovyev, L., Solvignon, P., Subedi, R., Tomasi-Gustafsson, E., Vasiliev, A., Veilleux, M., Wojtsekhowski, B. B., Wood, S., Ye, Z., Zanevsky, Y., Zhang, X., Zhang, Y., Zheng, X., and Zhu, L. Polarization transfer observables in elastic electron-proton scattering at Q2=2.5, 5.2, 6.8, and 8.5 GeV2. United States: N. p., 2017. Web. doi:10.1103/PhysRevC.96.055203.
Puckett, Andrew J. R., Brash, E. J., Jones, M. K., Luo, W., Meziane, M., Pentchev, L., Perdrisat, C. F., Punjabi, V., Wesselmann, F. R., Afanasev, A., Ahmidouch, A., Albayrak, I., Aniol, K. A., Arrington, J., Asaturyan, A., Baghdasaryan, H., Benmokhtar, F., Bertozzi, W., Bimbot, L., Bosted, P., Boeglin, W., Butuceanu, C., Carter, P., Chernenko, S., Christy, M. E., Commisso, M., Cornejo, J. C., Covrig, S., Danagoulian, S., Daniel, A., Davidenko, A., Day, D., Dhamija, S., Dutta, D., Ent, R., Frullani, S., Fenker, H., Frlez, E., Garibaldi, F., Gaskell, D., Gilad, S., Gilman, R., Goncharenko, Y., Hafidi, K., Hamilton, D., Higinbotham, D. W., Hinton, W., Horn, T., Hu, B., Huang, J., Huber, G. M., Jensen, E., Keppel, C., Khandaker, M., King, P., Kirillov, D., Kohl, M., Kravtsov, V., Kumbartzki, G., Li, Y., Mamyan, V., Margaziotis, D. J., Marsh, A., Matulenko, Y., Maxwell, J., Mbianda, G., Meekins, D., Melnik, Y., Miller, J., Mkrtchyan, A., Mkrtchyan, H., Moffit, B., Moreno, O., Mulholland, J., Narayan, A., Nedev, S., Nuruzzaman, ., Piasetzky, E., Pierce, W., Piskunov, N. M., Prok, Y., Ransome, R. D., Razin, D. S., Reimer, P., Reinhold, J., Rondon, O., Shabestari, M., Shahinyan, A., Shestermanov, K., Sirca, S., Sitnik, I., Smykov, L., Smith, G., Solovyev, L., Solvignon, P., Subedi, R., Tomasi-Gustafsson, E., Vasiliev, A., Veilleux, M., Wojtsekhowski, B. B., Wood, S., Ye, Z., Zanevsky, Y., Zhang, X., Zhang, Y., Zheng, X., & Zhu, L. Polarization transfer observables in elastic electron-proton scattering at Q2=2.5, 5.2, 6.8, and 8.5 GeV2. United States. doi:10.1103/PhysRevC.96.055203.
Puckett, Andrew J. R., Brash, E. J., Jones, M. K., Luo, W., Meziane, M., Pentchev, L., Perdrisat, C. F., Punjabi, V., Wesselmann, F. R., Afanasev, A., Ahmidouch, A., Albayrak, I., Aniol, K. A., Arrington, J., Asaturyan, A., Baghdasaryan, H., Benmokhtar, F., Bertozzi, W., Bimbot, L., Bosted, P., Boeglin, W., Butuceanu, C., Carter, P., Chernenko, S., Christy, M. E., Commisso, M., Cornejo, J. C., Covrig, S., Danagoulian, S., Daniel, A., Davidenko, A., Day, D., Dhamija, S., Dutta, D., Ent, R., Frullani, S., Fenker, H., Frlez, E., Garibaldi, F., Gaskell, D., Gilad, S., Gilman, R., Goncharenko, Y., Hafidi, K., Hamilton, D., Higinbotham, D. W., Hinton, W., Horn, T., Hu, B., Huang, J., Huber, G. M., Jensen, E., Keppel, C., Khandaker, M., King, P., Kirillov, D., Kohl, M., Kravtsov, V., Kumbartzki, G., Li, Y., Mamyan, V., Margaziotis, D. J., Marsh, A., Matulenko, Y., Maxwell, J., Mbianda, G., Meekins, D., Melnik, Y., Miller, J., Mkrtchyan, A., Mkrtchyan, H., Moffit, B., Moreno, O., Mulholland, J., Narayan, A., Nedev, S., Nuruzzaman, ., Piasetzky, E., Pierce, W., Piskunov, N. M., Prok, Y., Ransome, R. D., Razin, D. S., Reimer, P., Reinhold, J., Rondon, O., Shabestari, M., Shahinyan, A., Shestermanov, K., Sirca, S., Sitnik, I., Smykov, L., Smith, G., Solovyev, L., Solvignon, P., Subedi, R., Tomasi-Gustafsson, E., Vasiliev, A., Veilleux, M., Wojtsekhowski, B. B., Wood, S., Ye, Z., Zanevsky, Y., Zhang, X., Zhang, Y., Zheng, X., and Zhu, L. 2017. "Polarization transfer observables in elastic electron-proton scattering at Q2=2.5, 5.2, 6.8, and 8.5 GeV2". United States. doi:10.1103/PhysRevC.96.055203.
@article{osti_1406995,
title = {Polarization transfer observables in elastic electron-proton scattering at Q2=2.5, 5.2, 6.8, and 8.5 GeV2},
author = {Puckett, Andrew J. R. and Brash, E. J. and Jones, M. K. and Luo, W. and Meziane, M. and Pentchev, L. and Perdrisat, C. F. and Punjabi, V. and Wesselmann, F. R. and Afanasev, A. and Ahmidouch, A. and Albayrak, I. and Aniol, K. A. and Arrington, J. and Asaturyan, A. and Baghdasaryan, H. and Benmokhtar, F. and Bertozzi, W. and Bimbot, L. and Bosted, P. and Boeglin, W. and Butuceanu, C. and Carter, P. and Chernenko, S. and Christy, M. E. and Commisso, M. and Cornejo, J. C. and Covrig, S. and Danagoulian, S. and Daniel, A. and Davidenko, A. and Day, D. and Dhamija, S. and Dutta, D. and Ent, R. and Frullani, S. and Fenker, H. and Frlez, E. and Garibaldi, F. and Gaskell, D. and Gilad, S. and Gilman, R. and Goncharenko, Y. and Hafidi, K. and Hamilton, D. and Higinbotham, D. W. and Hinton, W. and Horn, T. and Hu, B. and Huang, J. and Huber, G. M. and Jensen, E. and Keppel, C. and Khandaker, M. and King, P. and Kirillov, D. and Kohl, M. and Kravtsov, V. and Kumbartzki, G. and Li, Y. and Mamyan, V. and Margaziotis, D. J. and Marsh, A. and Matulenko, Y. and Maxwell, J. and Mbianda, G. and Meekins, D. and Melnik, Y. and Miller, J. and Mkrtchyan, A. and Mkrtchyan, H. and Moffit, B. and Moreno, O. and Mulholland, J. and Narayan, A. and Nedev, S. and Nuruzzaman, . and Piasetzky, E. and Pierce, W. and Piskunov, N. M. and Prok, Y. and Ransome, R. D. and Razin, D. S. and Reimer, P. and Reinhold, J. and Rondon, O. and Shabestari, M. and Shahinyan, A. and Shestermanov, K. and Sirca, S. and Sitnik, I. and Smykov, L. and Smith, G. and Solovyev, L. and Solvignon, P. and Subedi, R. and Tomasi-Gustafsson, E. and Vasiliev, A. and Veilleux, M. and Wojtsekhowski, B. B. and Wood, S. and Ye, Z. and Zanevsky, Y. and Zhang, X. and Zhang, Y. and Zheng, X. and Zhu, L.},
abstractNote = {In this paper, interest in the behavior of nucleon electromagnetic form factors at large momentum transfers has steadily increased since the discovery, using polarization observables, of the rapid decrease of the ratio GpE/GpM of the proton's electric and magnetic form factors for momentum transfers Q2 ≳ 1 GeV2, in strong disagreement with previous extractions of this ratio using the traditional Rosenbluth separation technique.},
doi = {10.1103/PhysRevC.96.055203},
journal = {Physical Review C},
number = 5,
volume = 96,
place = {United States},
year = 2017,
month =
}

Journal Article:
Free Publicly Available Full Text
This content will become publicly available on November 6, 2018
Publisher's Version of Record

Save / Share:
  • The GEp-III and GEp-2more » $$\gamma$$ experiments were carried out in Jefferson Lab's (JLab's) Hall C from 2007-2008, to extend the knowledge of $$G_E^p/G_M^p$$ to the highest practically achievable $Q^2$ and to search for effects beyond the Born approximation in polarization transfer observables of elastic $$\vec{e}p$$ scattering. This article reports an expanded description of the common experimental apparatus and data analysis procedure, and the results of a final reanalysis of the data from both experiments, including the previously unpublished results of the full-acceptance data of the GEp-2$$\gamma$$ experiment. The Hall C High Momentum Spectrometer detected and measured the polarization of protons recoiling elastically from collisions of JLab's polarized electron beam with a liquid hydrogen target. A large-acceptance electromagnetic calorimeter detected the elastically scattered electrons in coincidence to suppress inelastic backgrounds. The final GEp-III data are largely unchanged relative to the originally published results. The statistical uncertainties of the final GEp-2$$\gamma$$ data are significantly reduced at $$\epsilon = 0.632$$ and $0.783$ relative to the original publication. The decrease with $Q^2$ of $$G_E^p/G_M^p$$ continues to $Q^2 = 8.5$ GeV$^2$, but at a slowing rate relative to the approximately linear decrease observed in earlier Hall A measurements. At $Q^2 = 2.5$ GeV$^2$, the proton form factor ratio $$G_E^p/G_M^p$$ shows no statistically significant $$\epsilon$$-dependence, as expected in the Born approximation. The ratio $$P_\ell/P_\ell^{Born}$$ of the longitudinal polarization transfer component to its Born value shows an enhancement of roughly 1.7\% at $$\epsilon = 0.783$$ relative to $$\epsilon = 0.149$$, with $$\approx 2.2\sigma$$ significance based on the total uncertainty, implying a similar effect in the transverse component $$P_t$$ that cancels in the ratio $R$.« less
  • In this paper, interest in the behavior of nucleon electromagnetic form factors at large momentum transfers has steadily increased since the discovery, using polarization observables, of the rapid decrease of the ratio G p E/G p M of the proton's electric and magnetic form factors for momentum transfers Q 2 ≳ 1 GeV 2, in strong disagreement with previous extractions of this ratio using the traditional Rosenbluth separation technique.
  • Background: Interest in the behavior of nucleon electromagnetic form factors at large momentum transfers has steadily increased since the discovery, using polarization observables, of the rapid decrease of the ratio G(E)(p)/G(M)(p) of the proton's electric and magnetic form factors for momentum transfers Q(2) greater than or similar to 1 GeV2, in strong disagreement with previous extractions of this ratio using the traditional Rosenbluth separation technique. Purpose: The GEp-III and GEp-2 gamma experiments were carried out in Jefferson Laboratory's ( JLab's) Hall C from 2007 to 2008, to extend the knowledge of G(E)(p) /G(M)(p) to the highest practically achievable Q(2) givenmore » the maximum beam energy of 6 GeV and to search for effects beyond the Born approximation in polarization transfer observables of elastic (e) over right arrowp scattering. This article provides an expanded description of the common experimental apparatus and data analysis procedures, and reports the results of a final reanalysis of the data from both experiments, including the previously unpublished results of the full-acceptance dataset of the GEp-2 gamma experiment. Methods: Polarization transfer observables in elastic (e) over right arrowp -> e (p) over right arrow scattering were measured at central Q(2) values of 2.5, 5.2, 6.8, and 8.54 GeV2. At Q 2 = 2.5 GeV2, data were obtained for central values of the virtual photon polarization parameter is an element of of 0.149, 0.632, and 0.783. The Hall C High Momentum Spectrometer detected and measured the polarization of protons recoiling elastically from collisions of JLab's polarized electron beam with a liquid hydrogen target. A large-acceptance electromagnetic calorimeter detected the elastically scattered electrons in coincidence to suppress inelastic backgrounds. Results: The final GEp-III data are largely unchanged relative to the originally published results. The statistical uncertainties of the final GEp-2 gamma data are significantly reduced at is an element of = 0.632 and 0.783 relative to the original publication. Conclusions: The final GEp-III results show that the decrease with Q(2) of G(E)(p)/G(M)(p) continues to Q(2) = 8.5 GeV2, but at a slowing rate relative to the approximately linear decrease observed in earlier Hall A measurements. At Q(2) = 8.5 GeV2, G(E)(p)/G(M)(p) remains positive but is consistent with zero. At Q(2) = 2.5 GeV2, G(E)(p)/G(M)(p) derived from the polarization component ratio R alpha P-t/P-l shows no statistically significant is an element of dependence, as expected in the Born approximation. On the other hand, the ratio P-l/P-l(Born) of the longitudinal polarization transfer component to its Born value shows an enhancement of roughly 1.7% at is an element of = 0.783 relative to is an element of = 0.149, with approximate to 2.2 sigma significance based on the total uncertainty, implying a similar effect in the transverse component Pt that cancels in the ratio R« less
  • Charge asymmetry in the processes e +e → μ +μ γ and e +e → π +π γ is measured using 232 fb –1 of data collected with the BABAR detector at e +e center-of-mass energies near 10.58 GeV. An observable is introduced and shown to be very robust against detector asymmetries while keeping a large sensitivity to the physical charge asymmetry that results from the interference between initial- and final-state radiation (FSR). The asymmetry is determined as a function of the invariant mass of the final-state tracks from production threshold to a few GeV/c 2. Itmore » is compared to the expectation from QED for e +e → μ +μ γ, and from theoretical models for e +e → π +π γ. A clear interference pattern is observed in e +e → π +π γ, particularly in the vicinity of the f 2(1270) resonance. As a result, the inferred rate of lowest-order FSR production is consistent with the QED expectation for e +e → μ +μ γ, and is negligibly small for e +e → π +π γ.« less