Determination of hybrid charmonium meson masses

TL;DR

This paper presents lattice QCD calculations of the masses and decay constants of the lightest charmonium-like hybrid mesons, focusing on the $1^{-+}$ state and its mixing with $J/a$, providing initial insights into their properties.

Contribution

The study provides the first precise lattice measurements of the $1^{-+}$ hybrid meson mass and decay constant using a variational basis and HISQ configurations with 2+1+1 flavors.

Findings

Precise mass measurement of the $1^{-+}$ hybrid meson.

Initial bound on the vector hybrid decay constant.

Analysis of mixing between hybrid and $J/a$ states.

Abstract

We report initial results from our study of the masses and decay constants of the lightest multiplet of charmonium-like hybrid mesons. We obtain precise measurements of the $1^{-+}$ state through the use of a variational basis and a large number of configurations at three lattice spacings. We use staggered fermion operators using configurations generated with the HISQ action with 2+1+1 dynamical flavours. The mixing of the vector hybrid with the $J/\psi$ is examined and a preliminary bound on the vector hybrid decay constant is presented.