Search for the Theta+ via the K+p-->pi+X reaction with a 1.2 GeV/c K+ beam

K. Miwa , S. Dairaku , D. Nakajima , S. Ajimura , J. Arvieux (1) , H. Fujimura , H. Fujioka , T. Fukuda , H. Funahashi , M. Hayata , K. Hicks , K. Imai , S. Ishimoto , T. Kameyama , S. Kamigaito , S. Kinoshita , T. Koike , Y. Ma , T. Maruta , Y. Miura , M. Miyabe , T. Nagae , T. Nakano , K. Nakazawa , M. Naruki , H. Noumi , M. Niiyama , N. Saito , Y. Sato , S. Sawada , Y. Seki , M. Sekimoto , K. Senzaka , K. Shirotori , K. Shoji , S. Suzuki , H. Takahashi , T. Takahashi , T. N. Takahashi , H. Tamura , N. Tanaka , K. Tanida , A. Toyada , T. Watanabe , M. Yosoi , R. Zavislak

1 IPNO - Institut de Physique Nucléaire d'Orsay

The Theta+ was searched for via the K+p-->pi+X reaction using the 1.2 GeV/c K+ beam at the K6 beam line of the KEK-PS 12 GeV Proton Synchrotron. In the missing mass spectrum of the K+p-->pi+X reaction, no clear peak structure was observed. Therefore a 90% C.L. upper limit of 3.5 µb/sr was derived for the differential cross section averaged over 2° to 22° in the laboratory frame of the K+p-->pi+Theta+ reaction. This upper limit is much smaller than the theoretical calculation for the t-channel process where a K0* is exchanged. From the present result, either the t-channel process is excluded or the coupling constant of gK*NTheta is quite small.

Mots clés: hyperon production; kaon-proton interactions

Domaines: Physique Nucléaire Expérimentale [nucl-ex]

K. Miwa, S. Dairaku, D. Nakajima, S. Ajimura, J. Arvieux, et al.. Search for the Theta+ via the K+p-->pi+X reaction with a 1.2 GeV/c K+ beam. Physical Review C, 2008, 77, pp.045203 (10). ⟨10.1103/PhysRevC.77.045203⟩. ⟨in2p3-00421359⟩