The γd→K+K-pn reaction has been studied to search for the evidence of the Θ+ by detecting K+K- pairs at forward angles. The Fermi-motion-corrected nK+ invariant mass distribution shows a narrow peak at 1.524±0.002+0.003 GeV/c2. The statistical significance of the peak calculated from a shape analysis is 5.1 σ, and the differential cross section for the γn→K-Θ+ reaction is estimated to be 12±2 nb/sr in the photon energy range from 2.0 to 2.4 GeV in the LEPS angular range by assuming the isotropic production of the Θ+ in the γn center-of-mass system. The obtained results support the existence of the Θ+.
ASJC Scopus subject areas
- Nuclear and High Energy Physics