2003/10/31 by Yongseok Oh, Hungchong Kim, Su Houng Lee · 3 citations
Physics and Astronomy · #High-Energy Particle Collisions Research #Particle physics theoretical and experimental studies #Quantum Chromodynamics and Particle Interactions #hep-ex #hep-ph #nucl-th
paper · pdf · doi:10.1103/physrevd.69.014009
published as Phys.Rev. D69 (2004) 014009 · 17 pages, REVTeX 4, 10 figures, revised version, to appear in Phys. Rev. D, typos corrected
arxiv created 2003/11/28 · openalex publication_date 2004/01/28 · arxiv updated 2009/12/01 · openalex created_date 2016/06/24 · openalex updated_date 2026/07/28
We investigate the photoproduction of the \ensuremathΘ+(1540) on a nucleon (\ensuremathγ\stackrel\ensuremath→nK^\ensuremath-\ensuremathΘ+, \ensuremathγ\stackrel\ensuremath→pK0\ensuremathΘ+) and the pion-induced \ensuremathΘ+ production reaction on the proton (\ensuremathπ^\ensuremath-\stackrel\ensuremath→pK^\ensuremath-\ensuremathΘ+). The total cross sections near threshold are estimated by using hadronic models with effective interaction Lagrangians and form factors that preserve the gauge invariance of the electromagnetic current. The photoproduction cross sections are found to be a few hundred nb, with the cross section on the proton being larger than that on the neutron. The pion-induced production cross section is found to be around a few hundred \ensuremathμb but sensitive to the K*N\ensuremathΘ coupling whose value is not yet known. We also study the production cross section assuming that \ensuremathΘ+ has negative parity. The cross sections are then found to be very suppressed compared to the case where \ensuremathΘ+ has positive parity. Hence, the interpretation of the \ensuremathΘ+ as an odd-parity pentaquark state seems to be disfavored from the estimates of the cross section for the photon-proton reaction from the SAPHIR experiment.