Near-threshold photoproduction of Lambda(1520) from protons and deuterons

• Published in: Physical review letters Vol. 103; no. 1; p. 012001
• Main Authors: Muramatsu, N, Chen, J Y, Chang, W C, Ahn, D S, Ahn, J K, Akimune, H, Asano, Y, Daté, S, Ejiri, H, Fujimura, H, Fujiwara, M, Fukui, S, Hasegawa, S, Hicks, K, Horie, K, Hotta, T, Imai, K, Ishikawa, T, Iwata, T, Kato, Y, Kawai, H, Kino, K, Kohri, H, Kumagai, N, Makino, S, Matsuda, T, Matsumura, T, Matsuoka, N, Mibe, T, Miyabe, M, Miyachi, M, Nakano, T, Niiyama, M, Nomachi, M, Ohashi, Y, Ohkuma, H, Ooba, T, Oshuev, D S, Rangacharyulu, C, Sakaguchi, A, Shagin, P M, Shiino, Y, Shimizu, H, Sugaya, Y, Sumihama, M, Toi, Y, Toyokawa, H, Wakai, A, Wang, C W, Wang, S C, Yonehara, K, Yorita, T, Yoshimura, M, Yosoi, M, Zegers, R G T
• Format: Journal Article
• Language: English
• Published: United States 03-07-2009
• Subjects: ASYMMETRY; BARYONS; BASIC INTERACTIONS; BEAMS; BOSONS; CHARGED PARTICLES; CROSS SECTIONS; DECAY; DEUTERIUM TARGET; DEUTERONS; DIFFERENTIAL CROSS SECTIONS; ELECTROMAGNETIC INTERACTIONS; ELEMENTARY PARTICLES; ENERGY RANGE; FERMIONS; GAUGE INVARIANCE; GEV RANGE; GEV RANGE 01-10; HADRONS; HYPERONS; INTERACTIONS; INVARIANCE PRINCIPLES; KAONS; KAONS NEUTRAL; KAONS PLUS; LAMBDA BARYONS; LAMBDA-1520 BARYONS; MASSLESS PARTICLES; MESONS; NEUTRONS; NUCLEONS; PARTICLE DECAY; PARTICLE INTERACTIONS; PARTICLE PRODUCTION; PHOTON BEAMS; PHOTONS; PHOTOPRODUCTION; PHYSICS OF ELEMENTARY PARTICLES AND FIELDS; PROTONS; PSEUDOSCALAR MESONS; STRANGE MESONS; STRANGE PARTICLES; T CHANNEL; TARGETS
• ISSN: 0031-9007; 1079-7114
• DOI: 10.1103/PhysRevLett.103.012001

Photoproduction of Lambda(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.