A Laplace Sum-Rules Analysis of Heavy Pseudoscalar ($J^{PC}=0^{-+}$) Hybrids

TL;DR

This paper employs QCD sum-rules with Laplace analysis to predict the masses of heavy pseudoscalar hybrids, emphasizing the importance of gluon condensate contributions for stable results.

Contribution

It introduces the inclusion of a six-dimensional gluon condensate in sum-rule analysis for pseudoscalar hybrids, providing updated mass predictions for charmonium and bottomonium states.

Findings

Charmonium hybrid mass: 3.82 GeV

Bottomonium hybrid mass: 10.64 GeV

Gluon condensate stabilizes the analysis

Abstract

We use QCD sum-rules to predict ground state masses for pseudoscalar ($J^{PC}=0^{-+}$) charmonium and bottomonium hybrids. We find that the inclusion of a six-dimensional gluon condensate contribution is needed to stabilize the analyses. For the charmonium hybrid, we find a mass of $(3.82\pm0.13)$ GeV; for the bottomonium hybrid, we find a mass of $(10.64\pm0.19)$ GeV. We comment on possible phenomenological implications concerning the Y(3940).