Measurement of spin-density matrix elements for φ-meson photoproduction from protons and deuterons near threshold

W. C. Chang, D. S. Ahn, J. K. Ahn, H. Akimune, Y. Asano, S. Daté, H. Ejiri, H. Fujimura, M. Fujiwara, S. Fukui, S. Hasegawa, K. Hicks, K. Horie, T. Hotta, K. Imai, T. Ishikawa, T. Iwata, Y. Kato, H. Kawai, K. KinoH. Kohri, N. Kumagai, P. J. Lin, S. Makino, T. Matsuda, T. Matsumura, N. Matsuoka, T. Mibe, M. Miyabe, Y. Miyachi, N. Muramatsu, T. Nakano, M. Niiyama, M. Nomachi, Y. Ohashi, H. Ohkuma, T. Ooba, D. S. Oshuev, C. Rangacharyulu, A. Sakaguchi, P. M. Shagin, Y. Shiino, H. Shimizu, Y. Sugaya, M. Sumihama, Y. Toi, H. Toyokawa, M. Uchida, A. Wakai, C. W. Wang, S. C. Wang, K. Yonehara, T. Yorita, M. Yoshimura, M. Yosoi, R. G.T. Zegers

Research output: Contribution to journalArticlepeer-review

24 Citations (Scopus)


The LEPS/SPring-8 experiment made a comprehensive measurement of the spin-density matrix elements for γp→p, γd→pn, and γd→d at forward production angles. A linearly polarized photon beam at Eγ=1.6-2.4 GeV was used for the production of mesons. The natural-parity Pomeron exchange processes remain dominant near threshold. The unnatural-parity processes of pseudoscalar exchange is visible in the production from the nucleons but is greatly reduced in the coherent production from deuterons. There is no strong Eγ dependence, but there is some dependence on momentum transfer. A small but finite value of the spin-density matrix elements reflecting helicity-nonconserving amplitudes in the t-channel is observed.

Original languageEnglish
Article number015205
JournalPhysical Review C - Nuclear Physics
Issue number1
Publication statusPublished - 2010 Jul 23
Externally publishedYes

ASJC Scopus subject areas

  • Nuclear and High Energy Physics


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