@article{0e9d26d3037a4aeebd9bea362a84ce6a,
title = "First measurement of coherent φ -meson photoproduction from He 4 near threshold",
abstract = "The differential cross sections and decay angular distributions for coherent φ-meson photoproduction from helium-4 are measured for the first time at forward angles with linearly polarized photons in the energy range Eγ=1.685-2.385GeV. Thanks to the target with spin-parity JP=0+, unnatural-parity exchanges are absent, and thus natural-parity exchanges can be investigated clearly. The decay asymmetry with respect to photon polarization is shown to be very close to the maximal value. This ensures the strong dominance (>94%) of natural-parity exchanges in this reaction. To evaluate the contribution from natural-parity exchanges to the forward cross section (θ=0{\^a}) for the γp→φp reaction near threshold, the energy dependence of the forward cross section (θ=0{\^a}) for the γHe4→φHe4 reaction is analyzed. The comparison to γp→φp data suggests that enhancement of the forward cross section arising from natural-parity exchanges and/or destructive interference between natural-parity and unnatural-parity exchanges is needed in the γp→φp reaction near threshold.",
author = "{LEPS Collaboration} and T. Hiraiwa and M. Yosoi and M. Niiyama and Y. Morino and Y. Nakatsugawa and M. Sumihama and Ahn, {D. S.} and Ahn, {J. K.} and Chang, {W. C.} and Chen, {J. Y.} and S. Dat{\'e} and H. Fujimura and S. Fukui and K. Hicks and T. Hotta and Hwang, {S. H.} and T. Ishikawa and Y. Kato and H. Kawai and H. Kohri and Y. Kon and Lin, {P. J.} and Y. Maeda and M. Miyabe and K. Mizutani and N. Muramatsu and T. Nakano and Y. Nozawa and Y. Ohashi and T. Ohta and M. Oka and C. Rangacharyulu and Ryu, {S. Y.} and T. Saito and T. Sawada and H. Shimizu and Strokovsky, {E. A.} and Y. Sugaya and K. Suzuki and Tokiyasu, {A. O.} and T. Tomioka and T. Tsunemi and M. Uchida and T. Yorita",
note = "Funding Information: The authors thank the staff at SPring-8 for supporting the LEPS experiment. We thank A. I. Titov, A. Hosaka, and H. Nagahiro for fruitful discussions. The experiment was performed at the BL33LEP of SPring-8 with the approval of the Japan Synchrotron Radiation Research Institute (JASRI) as a contract beamline (Proposal No. BL33LEP/6001). This work was supported in part by the Ministry of Education, Science, Sports and Culture of Japan, the National Science Council of the Republic of China (Taiwan), the National Science Foundation (USA), and the National Research Foundation (Korea). Publisher Copyright: {\textcopyright} 2018 American Physical Society.",
year = "2018",
month = mar,
day = "27",
doi = "10.1103/PhysRevC.97.035208",
language = "English",
volume = "97",
journal = "Physical Review C",
issn = "2469-9985",
publisher = "American Physical Society",
number = "3",
}