Photoproduction of Λ(1520) with liquid hydrogen and deuterium targets was examined at photon energies below 2.4 GeV in the SPring-8 LEPS experiment. For the first time, the differential cross sections were measured at low energies and with a deuterium target. A large asymmetry of the production cross sections from protons and neutrons was observed at backward K+/0 angles. This suggests the importance of the contact term, which coexists with t-channel K exchange under gauge invariance. This interpretation was compatible with the differential cross sections, decay asymmetry, and photon beam asymmetry measured in the production from protons at forward K+ angles.
@article{arxiv.0904.2034,
title = {Near-threshold photoproduction of $\Lambda(1520)$ from protons and deuterons},
author = {LEPS Collaboration and N. Muramatsu and J. Y. Chen and W. C. Chang and D. S. Ahn and J. K. Ahn and H. Akimune and Y. Asano and S. Daté and H. Ejiri and H. Fujimura and M. Fujiwara and S. Fukui and S. Hasegawa and K. Hicks and K. Horie and T. Hotta and K. Imai and T. Ishikawa and T. Iwata and Y. Kato and H. Kawai and K. Kino and H. Kohri and N. Kumagai and S. Makino and T. Matsuda and T. Matsumura and N. Matsuoka and T. Mibe and M. Miyabe and M. Miyachi and T. Nakano and M. Niiyama and M. Nomachi and Y. Ohashi and H. Ohkuma and T. Ooba and D. S. Oshuev and C. Rangacharyulu and A. Sakaguchi and P. M. Shagin and Y. Shiino and H. Shimizu and Y. Sugaya and M. Sumihama and Y. Toi and H. Toyokawa and A. Wakai and C. W. Wang and S. C. Wang and K. Yonehara and T. Yorita and M. Yoshimura and M. Yosoi and R. G. T. Zegers},
journal= {arXiv preprint arXiv:0904.2034},
year = {2009}
}