An improved study of the kappa resonance and the non-exotic s wave pi K scatterings up to root s=2.1 GeV of LASS data

摘要

We point out that the dispersion relation for the left-hand cut integral presented in one of our previous paper [H.Q. Zheng, et al., Nucl. Phys. A 733 (2004) 235] is actually free of subtraction constant, even for unequal mass elastic scatterings. A new fit to the LASS data [D. Aston, et al., LASS Collaboration, Nucl. Phys. B 296 (1988) 493] is performed and firm evidence for the existence of kappa pole is found. The correct use of analyticity also put strong constraints on threshold parameters-which are found to be in good agreement with those obtained from chiral theories. We also determined the pole parameters of K-0*(1430) 0 on the second sheet, and reconfirm the existence of K-0*(1950) on the third sheet. We stress that the LASS data do not require them to have the twin pole structure of a typical Breit-Wigner resonance. (c) 2006 Elsevier B.V. All rights reserved.