Measurement of azimuthal asymmetries associated with deeply virtual Compton scattering on a longitudinally polarized deuterium target
Abstract
Azimuthal asymmetries in exclusive electroproduction of a real photon from a longitudinally polarized deuterium target are measured with respect to target polarization alone and with respect to target polarization combined with beam helicity and/or beam charge. The asymmetries appear in the distribution of the real photons in the azimuthal angle around the virtual photon direction, relative to the lepton scattering plane. The asymmetries arise from the deeply virtual Compton scattering process and its interference with the Bethe-Heitler process. The results for the beam-charge and beam-helicity asymmetries from a tensor polarized deuterium target with vanishing vector polarization are shown to be compatible with those from an unpolarized deuterium target, which is expected for incoherent scattering dominant at larger momentum transfer. Furthermore, the results for the single target-spin asymmetry and for the double-spin asymmetry are found to be compatible with the corresponding asymmetries previously measured on a hydrogen target. For coherent scattering on the deuteron at small momentum transfer to the target, these findings imply that the tensor contribution to the cross section is small. Furthermore, the tensor asymmetry is found to be compatible with zero.
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Cite
@article{arxiv.1008.3996,
title = {Measurement of azimuthal asymmetries associated with deeply virtual Compton scattering on a longitudinally polarized deuterium target},
author = {The HERMES Collaboration and A. Airapetian and N. Akopov and Z. Akopov and E. C. Aschenauer and W. Augustyniak and R. Avakian and A. Avetissian and E. Avetisyan and S. Belostotski and N. Bianchi and H. P. Blok and A. Borissov and J. Bowles and I. Brodski and V. Bryzgalov and J. Burns and M. Capiluppi and G. P. Capitani and E. Cisbani and G. Ciullo and M. Contalbrigo and P. F. Dalpiaz and W. Deconinck and R. De Leo and L. De Nardo and E. De Sanctis and M. Diefenthaler and P. Di Nezza and M. Dueren and M. Ehrenfried and G. Elbakian and F. Ellinghaus and A. Fantoni and L. Felawka and S. Frullani and D. Gabbert and G. Gapienko and V. Gapienko and F. Garibaldi and G. Gavrilov and V. Gharibyan and F. Giordano and S. Gliske and M. Golembiovskaya and C. Hadjidakis and M. Hartig and D. Hasch and G. Hill and A. Hillenbrand and M. Hoek and Y. Holler and I. Hristova and Y. Imazu and A. Ivanilov and H. E. Jackson and A. Jgoun and H. S. Jo and S. Joosten and R. Kaiser and G. Karyan and T. Keri and E. Kinney and A. Kisselev and N. Kobayashi and V. Korotkov and V. Kozlov and B. Krauss and P. Kravchenko and V. G. Krivokhijine and L. Lagamba and R. Lamb and L. Lapikas and I. Lehmann and P. Lenisa and L. A. Linden-Levy and A. Lopez Ruiz and W. Lorenzon and X. -G. Lu and X. -R. Lu and B. -Q. Ma and D. Mahon and N. C. R. Makins and S. I. Manaenkov and L. Manfre and Y. Mao and B. Marianski and A. Martinez de la Ossa and H. Marukyan and C. A. Miller and A. Movsisyan and V. Muccifora and M. Murray and D. Mueller and A. Mussgiller and E. Nappi and Y. Naryshkin and A. Nass and M. Negodaev and W. -D. Nowak and L. L. Pappalardo and R. Perez-Benito and N. Pickert and M. Raithel and P. E. Reimer and A. R. Reolon and C. Riedl and K. Rith and G. Rosner and A. Rostomyan and J. Rubin and D. Ryckbosch and Y. Salomatin and F. Sanftl and A. Schaefer and G. Schnell and K. P. Schueler and B. Seitz and T. -A. Shibata and V. Shutov and M. Stancari and M. Statera and E. Steffens and J. J. M. Steijger and H. Stenzel and J. Stewart and F. Stinzing and S. Taroian and A. Terkulov and A. Trzcinski and M. Tytgat and A. Vandenbroucke and P. B. Van der Nat and Y. Van Haarlem and C. Van Hulse and D. Veretennikov and V. Vikhrov and I. Vilardi and C. Vogel and S. Wang and S. Yaschenko and Z. Ye and S. Yen and W. Yu and D. Zeiler and B. Zihlmann and P. Zupranski},
journal= {arXiv preprint arXiv:1008.3996},
year = {2011}
}
Comments
33 pages, 7 figures, 7 tables; minor textual changes on pages 5 and 27, additional Table 2 added on page 10