@article{89aefe5ce8734c89b93000d145bf83fc,
title = "Measurement of deeply virtual Compton scattering off He 4 with the CEBAF Large Acceptance Spectrometer at Jefferson Lab",
abstract = "We report on the measurement of the beam spin asymmetry in the deeply virtual Compton scattering off He4 using the CEBAF Large Acceptance Spectrometer (CLAS) at Jefferson Lab using a 6 GeV longitudinally polarized electron beam incident on a pressurized He4 gaseous target. We detail the method used to ensure the exclusivity of the measured reactions, in particular the upgrade of CLAS with a radial time projection chamber to detect the low-energy recoiling He4 nuclei and an inner calorimeter to extend the photon detection acceptance at forward angles. Our results confirm the theoretically predicted enhancement of the coherent (eHe4→e′He4′γ′) beam spin asymmetries compared to those observed on the free proton, while the incoherent (eHe4→e′p′γ′X′) asymmetries exhibit a 30% suppression. From the coherent data, we were able to extract, in a model-independent way, the real and imaginary parts of the only He4 Compton form factor, HA, leading the way toward 3D imaging of the partonic structure of nuclei.",
author = "{CLAS Collaboration} and R. Dupr{\'e} and M. Hattawy and Baltzell, {N. A.} and S. B{\"u}ltmann and {De Vita}, R. and {El Alaoui}, A. and {El Fassi}, L. and H. Egiyan and Girod, {F. X.} 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 Amaryan, {M. J.} and Armstrong, {W. R.} and H. Atac and {Ayerbe Gayoso}, C. and L. Barion and M. Battaglieri and I. Bedlinskiy and F. Benmokhtar and A. Bianconi and Biselli, {A. S.} and M. Bondi and F. Boss{\`u} and S. Boiarinov and Briscoe, {W. J.} and D. Bulumulla and V. Burkert and Carman, {D. S.} and Carvajal, {J. C.} and M. Caudron and A. Celentano and P. Chatagnon and V. Chesnokov and T. Chetry and G. Ciullo and Clary, {B. A.} and Cole, {P. L.} and M. Contalbrigo and G. Costantini and V. Crede and A. D'Angelo and N. Dashyan and M. Defurne and Jo, {H. S.}",
note = "Publisher Copyright: {\textcopyright} 2021 American Physical Society.",
year = "2021",
month = aug,
doi = "10.1103/PhysRevC.104.025203",
language = "English",
volume = "104",
journal = "Physical Review C",
issn = "2469-9985",
publisher = "American Physical Society",
number = "2",
}