Interference Effect between ϕ and Λ(1520) Production Channels in the γp→K^{+}K^{-}p Reaction near Threshold

S Y Ryu; J K Ahn; T Nakano; D S Ahn; S Ajimura; H Akimune; Y Asano; W C Chang; J Y Chen; S Daté; H Ejiri; H Fujimura; M Fujiwara; S Fukui; S Hasegawa; K Hicks; K Horie; T Hotta; S H Hwang; K Imai; T Ishikawa; T Iwata; Y Kato; H Kawai; K Kino; H Kohri; Y Kon; N Kumagai; P J Lin; Y Maeda; S Makino; T Matsuda; N Matsuoka; T Mibe; M Miyabe; M Miyachi; Y Morino; N Muramatsu; R Murayama; Y Nakatsugawa; S I Nam; M Niiyama; M Nomachi; Y Ohashi; H Ohkuma; T Ohta; T Ooba; D S Oshuev; J D Parker; C Rangacharyulu; A Sakaguchi; T Sawada; P M Shagin; Y Shiino; H Shimizu; E A Strokovsky; Y Sugaya; M Sumihama; A O Tokiyasu; Y Toi; H Toyokawa; T Tsunemi; M Uchida; M Ungaro; A Wakai; C W Wang; S C Wang; K Yonehara; T Yorita; M Yoshimura; M Yosoi; R G T Zegers; LEPS Collaboration

doi:10.1103/PhysRevLett.116.232001

Interference Effect between ϕ and Λ(1520) Production Channels in the γp→K^{+}K^{-}p Reaction near Threshold

Phys Rev Lett. 2016 Jun 10;116(23):232001. doi: 10.1103/PhysRevLett.116.232001. Epub 2016 Jun 7.

Authors

S Y Ryu¹, J K Ahn², T Nakano¹, D S Ahn³, S Ajimura¹, H Akimune⁴, Y Asano⁵, W C Chang⁶, J Y Chen⁷, S Daté⁸, H Ejiri¹, H Fujimura⁹, M Fujiwara¹, S Fukui¹, S Hasegawa¹, K Hicks¹⁰, K Horie¹¹, T Hotta¹, S H Hwang¹², K Imai¹³, T Ishikawa¹⁴, T Iwata¹⁵, Y Kato¹⁶, H Kawai¹⁷, K Kino¹, H Kohri¹, Y Kon¹, N Kumagai⁸, P J Lin⁶, Y Maeda¹⁸, S Makino⁹, T Matsuda¹⁹, N Matsuoka¹, T Mibe²⁰, M Miyabe¹⁴, M Miyachi²¹, Y Morino²⁰, N Muramatsu¹⁴, R Murayama¹¹, Y Nakatsugawa²⁰, S I Nam²², M Niiyama²³, M Nomachi¹, Y Ohashi⁸, H Ohkuma⁸, T Ohta¹, T Ooba¹⁷, D S Oshuev⁶, J D Parker²³, C Rangacharyulu²⁴, A Sakaguchi¹¹, T Sawada⁶, P M Shagin²⁵, Y Shiino¹⁷, H Shimizu¹⁴, E A Strokovsky²⁶, Y Sugaya¹, M Sumihama²⁷, A O Tokiyasu¹⁴, Y Toi¹⁹, H Toyokawa⁸, T Tsunemi²³, M Uchida²¹, M Ungaro²⁸, A Wakai²⁹, C W Wang⁶, S C Wang⁶, K Yonehara⁴, T Yorita¹, M Yoshimura³⁰, M Yosoi¹, R G T Zegers³¹; LEPS Collaboration

Affiliations

¹ Research Center for Nuclear Physics, Osaka University, Ibaraki, Osaka 567-0047, Japan.
² Department of Physics, Korea University, Seoul 02841, Republic of Korea.
³ RIKEN, The Institute of Physical and Chemical Research, Wako, Saitama 351-0198, Japan.
⁴ Department of Physics, Konan University, Kobe, Hyogo 658-8501, Japan.
⁵ XFEL Project Head Office, RIKEN, Sayo, Hyogo 679-5143, Japan.
⁶ Institute of Physics, Academia Sinica, Taipei 11529, Taiwan.
⁷ Light Source Division, National Synchrotron Radiation Research Center, Hsinchu 30076, Taiwan.
⁸ Japan Synchrotron Radiation Research Institute, Sayo, Hyogo 679-5143, Japan.
⁹ Wakayama Medical College, Wakayama 641-8509, Japan.
¹⁰ Department of Physics and Astronomy, Ohio University, Athens, Ohio 45701, USA.
¹¹ Department of Physics, Osaka University, Toyonaka, Osaka 560-0043, Japan.
¹² Korea Research Institute of Standards and Science (KRISS), Daejeon 34113, Republic of Korea.
¹³ Advanced Science Research Center, Japan Atomic Energy Agency, Tokai, Ibaraki 319-1195, Japan.
¹⁴ Research Center for Electron Photon Science, Tohoku University, Sendai, Miyagi 982-0826, Japan.
¹⁵ Department of Physics, Yamagata University, Yamagata 990-8560, Japan.
¹⁶ Kobayashi-Maskawa Institute, Nagoya University, Nagoya, Aichi 464-8602, Japan.
¹⁷ Department of Physics, Chiba University, Chiba 263-8522, Japan.
¹⁸ Proton Therapy Center, Fukui Prefectural Hospital, Fukui 910-8526, Japan.
¹⁹ Department of Applied Physics, Miyazaki University, Miyazaki 889-2192, Japan.
²⁰ High Energy Accelerator Organization (KEK), Tsukuba, Ibaraki 305-0801, Japan.
²¹ Department of Physics, Tokyo Institute of Technology, Tokyo 152-8551, Japan.
²² Department of Physics, Pukyong National University, Busan 48513, Republic of Korea.
²³ Department of Physics, Kyoto University, Kyoto 606-8502, Japan.
²⁴ Department of Physics and Engineering Physics, University of Saskatchewan, Saskatoon, Saskatchewan S7N 5E2, Canada.
²⁵ School of Physics and Astronomy, University of Minnesota, Minneapolis, Minnesota 55455, USA.
²⁶ Joint Institute for Nuclear Research, Dubna, Moscow Region, 142281, Russia.
²⁷ Department of Education, Gifu University, Gifu 501-1193, Japan.
²⁸ Department of Physics, University of Connecticut, Storrs, Connecticut 06269-3046, USA.
²⁹ Akita Research Institute of Brain and Blood Vessels, Akita 010-0874, Japan.
³⁰ Institute for Protein Research, Osaka University, Suita, Osaka 565-0871, Japan.
³¹ National Superconducting Cyclotron Laboratory, Michigan State University, East Lansing, Michigan 48824, USA.

PMID: 27341225
DOI: 10.1103/PhysRevLett.116.232001

Abstract

The ϕ-Λ(1520) interference effect in the γp→K^{+}K^{-}p reaction has been measured for the first time in the energy range from 1.673 to 2.173 GeV. The relative phases between ϕ and Λ(1520) production amplitudes were obtained in the kinematic region where the two resonances overlap. The measurement results support strong constructive interference when K^{+}K^{-} pairs are observed at forward angles but destructive interference for proton emission at forward angles. Furthermore, the observed interference effect does not account for the sqrt[s]=2.1 GeV bump structure in forward differential cross sections for ϕ photoproduction. This fact suggests possible exotic structures such as a hidden-strangeness pentaquark state, a new Pomeron exchange, or rescattering processes via other hyperon states.