Exploring the Structure of the Bound Proton With Deeply Virtual Compton Scattering

Authors

M. Hattawy, Old Dominion UniversityFollow
N. A. Baltzell, Old Dominion UniversityFollow
R. Dupré
S. Bültmann, Old Dominion UniversityFollow
B. Torayev, Old Dominion UniversityFollow
G. Gavalian, Old Dominion University
F. Hauenstein, Old Dominion UniversityFollow
S. E. Kuhn, Old Dominion UniversityFollow
M. Khachatryan, Old Dominion UniversityFollow
M. Mayer, Old Dominion UniversityFollow
J. Poudel, Old Dominion UniversityFollow
Y. Prok, Old Dominion UniversityFollow
L. B. Weinstein, Old Dominion UniversityFollow
J. Zhang, Old Dominion University
Z. W. Zhao
CLAS Collaboration

Document Type

Article

Publication Date

2019

DOI

10.1103/PhysRevLett.123.032502

Publication Title

Physical Review Letters

Volume

123

Issue

3

Pages

032502 (1-7)

Abstract

In the past two decades, deeply virtual Compton scattering of electrons has been successfully used to advance our knowledge of the partonic structure of the free proton and investigate correlations between the transverse position and the longitudinal momentum of quarks inside the nucleon. Meanwhile, the structure of bound nucleons in nuclei has been studied in inclusive deep-inelastic lepton scattering experiments off nuclear targets, showing a significant difference in longitudinal momentum distribution of quarks inside the bound nucleon, known as the EMC effect. In this Letter, we report the first beam spin asymmetry (BSA) measurement of exclusive deeply virtual Compton scattering off a proton bound in ⁴He. The data used here were accumulated using a 6 GeV longitudinally polarized electron beam incident on a pressurized ⁴He gaseous target placed within the CLAS spectrometer in Hall-B at the Thomas Jefferson National Accelerator Facility. The azimuthal angle (ϕ) dependence of the BSA was studied in a wide range of virtual photon and scattered proton kinematics. The Q², x_B, and t dependencies of the BSA on the bound proton are compared with those on the free proton. In the whole kinematical region of our measurements, the BSA on the bound proton is smaller by 20% to 40%, indicating possible medium modification of its partonic structure.

Comments

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Original Publication Citation

CLAS Collaboration, Hattawy, M., Baltzell, N. A., Dupré, R., Bültmann, S., De Vita, R., ... Zhao, Z. W. (2019). Exploring the structure of the bound proton with deeply virtual Compton scattering. Physical Review Letters, 123(3), 032502. doi:10.1103/PhysRevLett.123.032502

ORCID

0000-0003-2243-6836 (Kuhn), 0000-0001-5416-2900 (Weinstein)

Repository Citation

Hattawy, M.; Baltzell, N. A.; Dupré, R.; Bültmann, S.; Torayev, B.; Gavalian, G.; Hauenstein, F.; Kuhn, S. E.; Khachatryan, M.; Mayer, M.; Poudel, J.; Prok, Y.; Weinstein, L. B.; Zhang, J.; Zhao, Z. W.; and CLAS Collaboration, "Exploring the Structure of the Bound Proton With Deeply Virtual Compton Scattering" (2019). Physics Faculty Publications. 391.
https://digitalcommons.odu.edu/physics_fac_pubs/391