Can Y(4140) be a $c \bar c s \bar s$ tetraquark ?

TL;DR

This study explores whether the Y(4140) resonance can be interpreted as a $c ar c s ar s$ tetraquark using a simple quark model, suggesting it might be a strange partner of X(3872).

Contribution

It provides a spectrum calculation for $c ar c s ar s$ tetraquarks within a simple quark model, offering insights into the nature of Y(4140) and questioning the use of effective quark masses from mesons and baryons.

Findings

Y(4140) may be a $c ar c s ar s$ tetraquark in the $J^{PC} = 1^{++}$ sector.

Y(4140) could be the strange partner of X(3872).

The $J^{PC} = 0^{++}$ sector cannot be entirely excluded.

Abstract

In this exploratory study the spectrum of tetraquarks of type $c \bar c s \bar s$ is calculated within a simple quark model with chromomagnetic interaction and effective quark masses extracted from meson and baryon spectra. It is tempting to see if this spectrum can accommodate the resonance Y(4140), observed by the CDF collaboration, but not yet confirmed. The results seem to favour the J$^{PC}$ = 1$^{++}$ sector where the coupling to the VV channel is nearly as small as that of X(3872), when described as a $c \bar c q \bar q$ tetraquark. This suggests that Y(4140) could possibly be the strange partner of X(3872), in a tetraquark interpretation. However the sector J$^{PC}$ = 0$^{++}$ cannot entirely be excluded. This work questions the practice of extracting effective quark masses containing spin independent contributions, from mesons and baryons, to be used in multiquark systems as well.