Exotic Meson Decay Widths using Lattice QCD

TL;DR

This study uses lattice QCD to calculate the decay width of an exotic hybrid meson, providing insights into its decay process through finite volume methods and phase shift analysis.

Contribution

It presents the first lattice QCD calculation of the decay width for a hybrid exotic meson using Luescher's method with multiple smearing levels and quark masses.

Findings

Decay width estimated at about 60 MeV.

Phase shift data obtained for the h->pi+a1 channel.

Eigenvalue analysis yields energy spectra for scattering states.

Abstract

A decay width calculation for a hybrid exotic meson h, with JPC=1-+, is presented for the channel h->pi+a1. This quenched lattice QCD simulation employs Luescher's finite box method. Operators coupling to the h and pi+a1 states are used at various levels of smearing and fuzzing, and at four quark masses. Eigenvalues of the corresponding correlation matrices yield energy spectra that determine scattering phase shifts for a discrete set of relative pi+a1 momenta. Although the phase shift data is sparse, fits to a Breit-Wigner model are attempted, resulting in a decay width of about 60 MeV when averaged over two lattice sizes.