$(Q\bar{s})^{(*)}(\bar{Q}s)^{(*)}$ molecular states from QCD sum rules: a view on Y(4140)

TL;DR

This paper uses QCD sum rules to calculate the masses of specific molecular states involving charm and strange quarks, providing evidence that supports the interpretation of Y(4140) as a D_s* D_s* molecular state.

Contribution

It systematically computes masses of $(Q\bar{s})^{(*)}(ar{Q}s)^{(*)}$ states including operators up to dimension six, offering a theoretical support for the molecular nature of Y(4140).

Findings

Mass of D_s* D_s* state is 4.13±0.10 GeV.

Computed mass agrees with Y(4140) experimental data.

Supports the molecular interpretation of Y(4140).

Abstract

Masses for the $(Q\bar{s})^{(*)}(\bar{Q}s)^{(*)}$ ($Q=c$ or $b$) molecular states are systematically computed in the framework of QCD sum rules. Technically, contributions of the operators up to dimension six are included in operator product expansion (OPE). The numerical result $4.13\pm0.10 {GeV}$ for $D_{s}^{*}\bar{D}_{s}^{*}$ agrees well with the mass $4143.0\pm2.9\pm1.2 {MeV}$ for Y(4140), which supports the $D_{s}^{*}\bar{D}_{s}^{*}$ molecular configuration for Y(4140).