2006/05/04 by Tetsuo Hyodo, Hyodo, Tetsuo, Atsushi Hosaka +1
Physics and Astronomy · #FOS: Physical sciences #High Energy Physics - Phenomenology (hep-ph) #hep-ph
paper · pdf · doi:10.48550/arxiv.hep-ph/0605044
30 pages, 9 figures 9 tables, Talk given at International Workshop HNP06 at JAEA, Kizu, Japan, Feb. 16-18, 2006
arxiv created 2006/05/04 · arxiv updated 2009/12/01
We examine several assignments of spin and parity for the pentaquark Theta+ state (JP=1/2+,-, 3/2+,-) in connection with phenomenology of known baryon resonances, using a general framework based on the flavor symmetry. Assuming that the Theta+ belongs to an antidecuplet representation which mixes with an octet, we calculate the mass spectra of the flavor partners of the Theta+ based on the SU(3) symmetry. The decay widths of the Theta+ and nucleon partners are analyzed for the consistency check of the mixing angle obtained from the masses. It is found that a suitable choice of the mixing angle successfully reproduces the observed masses of exotics, when their spin and parity are assigned to be JP=3/2-, together with other nonexotic resonances of JP=3/2-. The decay widths of Theta -> KN, N(1520) -> pi N, and N(1700) -> pi N are also reproduced simultaneously. We then evaluate two-meson couplings of Theta+, using experimental information of nucleon partners decaying into pi pi N channels, in which the two pions are in scalar- and vector-type correlations. We examine two assignments of spin and parity JP=1/2+ and 3/2-, for which the experimental spectra of known resonances with exotic baryons are properly reproduced by an octet-antidecuplet representation mixing scheme. Using the obtained coupling constants, total cross sections of the reactions pi- p -> K- Theta+ and K+ p -> pi+ Theta+ are calculated. Substantial interference of two terms may occur in the reaction processes for the JP=1/2+ case, whereas the interference effect is rather small for the 3/2- case.