Exploring the Structure of the Bound Proton with Deeply Virtual Compton Scattering
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 work, we report the first beam spin asymmetry (BSA) measurement of exclusive deeply virtual Compton scattering (DVCS) off a proton bound in He. The data used here were accumulated using a GeV longitudinally polarized electron beam incident on a pressurized He gaseous target placed within the CLAS spectrometer in Hall-B at the Thomas Jefferson National Accelerator Facility. The azimuthal angle () dependence of the BSA was studied in a wide range of virtual photon and scattered proton kinematics. The , , 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.
Cite
@article{arxiv.1812.07628,
title = {Exploring the Structure of the Bound Proton with Deeply Virtual Compton Scattering},
author = {M. Hattawy and N. A. Baltzell and R. Dupré and S. Bültmann and R. De Vita and A. El Alaoui and L. El Fassi and H. Egiyan and F. X. Girod and M. Guidal and K. Hafidi and D. Jenkins and S. Liuti and Y. Perrin and S. Stepanyan and B. Torayev and E. Voutier and S. Adhikari and Giovanni Angelini and C. Ayerbe Gayoso and L. Barion and M. Battaglieri and I. Bedlinskiy and A. S. Biselli and F. Bossù and W. Brooks and F. Cao and D. S. Carman and A. Celentano and P. Chatagnon and T. Chetry and G. Ciullo and L. Clark and P. L. Cole and M. Contalbrigo and V. Crede and A. D'Angelo and N. Dashyan and E. De Sanctis and M. Defurne and A. Deur and S. Diehl and C. Djalali and M. Ehrhart and P. Eugenio and S. Fegan and A. Filippi and T. A. Forest and A. Fradi and M. Garçon and G. Gavalian and N. Gevorgyan and G. P. Gilfoyle and K. L. Giovanetti and E. Golovatch and R. W. Gothe and K. A. Griffioen and N. Harrison and F. Hauenstein and T. B. Hayward and D. Heddle and K. Hicks and M. Holtrop and Y. Ilieva and D. G. Ireland and E. L. Isupov and S. Johnston and D. Keller and G. Khachatryan and M. Khachatryan and A. Khanal and M. Khandaker and C. W. Kim and W. Kim and F. J. Klein and V. Kubarovsky and S. E. Kuhn and L. Lanza and M. L. Kabir and P. Lenisa and K. Livingston and I. J. D. MacGregor and D. Marchand and N. Markov and M. Mayer and B. McKinnon and Z. E. Meziani and T. Mineeva and M. Mirazita and R. A. Montgomery and C. Munoz Camacho and P. Nadel-Turonski and S. Niccolai and A. I. Ostrovidov and L. L. Pappalardo and R. Paremuzyan and E. Pasyuk and O. Pogorelko and J. Poudel and Y. Prok and D. Protopopescu and M. Ripani and D. Riser and A. Rizzo and G. Rosner and P. Rossi and F. Sabatié and C. Salgado and R. A. Schumacher and Y. G. Sharabian and Iu. Skorodumina and D. Sokhan and O. Soto and N. Sparveris and S. Strauch and M. Taiuti and J. A. Tan and N. Tyler and M. Ungaro and H. Voskanyan and R. Wang and D. P. Watts and X. Wei and L. B. Weinstein and M. H. Wood and N. Zachariou and J. Zhang and Z. W. Zhao},
journal= {arXiv preprint arXiv:1812.07628},
year = {2019}
}