Hybrid Exotic Meson Decay Width

TL;DR

This study calculates the decay width of a hybrid exotic meson using lattice QCD and finite volume methods, providing insights into its decay properties and phase shifts.

Contribution

It introduces a lattice QCD approach combined with Luescher's method to determine decay widths of hybrid mesons.

Findings

Decay width of approximately 80 MeV for the hybrid meson.

Sparse phase shift data fitted with Breit-Wigner model.

Method demonstrates feasibility of decay width calculation in lattice QCD.

Abstract

We present results of a decay width calculation for a hybrid exotic meson(h, JPC=1-+) in the decay channel h to pi+a1. This calculation uses quenched lattice QCD and Luescher's finite box method. Operators for the h and pi+a1 states are used in a correlation matrix which was expanded by varying the smearing and fuzzing levels at source and sink points. Scattering phase shifts for a discrete set of relative pi+a1 momenta are determined using eigenvalues of the correlation matrix and formulae derived by Luescher. The phase shift data is very sparse, but fits to a Breit-Wigner model are made, resulting in a decay width of about 80 MeV.