Work

Rigorous Roy-Steiner equation analysis of π K scattering at unphysical quark masses

Year: 2025

Type: article

Abstract: We perform a rigorous analysis of the π K scattering at an unphysical pion mass 391 MeV using the Roy-Steiner equations, which satisfy unitarity, analyticity, and crossing symmetry, for the first time. Stable solutions of the Roy-Steiner equations with different quantum numbers of isospin and angular momentum are obtained in the elastic energy region, by taking inputs from the π K lattice data in the inelastic region, the lattice data from the crossed π π → K K ¯ channels, the masses of f 0 ( 500 ) and K * at the same pion mass from previous study, and the Regge model. Predictions on the elastic π K scattering phase shifts and the K 0 * ( 700 ) pole content are made. Contrary to the virtual pole scenario obtained using the K -matrix method in the literature, we find that lightest strange scalar meson K 0 * ( 700 ) remains a broad resonance at m π = 391 MeV . The cross-channel dynamics is found to play a crucial role in deriving the proper pole position.

Source: Physical review. D/Physical review. D.

DOI: 10.1103/38b9-m57d

Authors: Xiong-Hui Cao, Feng-Kun Guo, Zhi-Hui Guo, Qu-Zhi Li