$X(3960)$, $X_0(4140)$, and other compact $cs\bar{c}\bar{s}$ states

TL;DR

This paper investigates the spectrum and decay properties of $csar{c}ar{s}$ tetraquark states using a simplified quark model, identifying potential matches with observed particles and predicting new states.

Contribution

It provides a theoretical assignment of the $X(3960)$ and $X_0(4140)$ as specific $csar{c}ar{s}$ tetraquark states and offers predictions for their decay ratios and additional states.

Findings

$X(3960)$ likely the lowest $0^{++}$ $csar{c}ar{s}$ tetraquark

$X_0(4140)$ could be the second lowest $0^{++}$ $csar{c}ar{s}$ tetraquark

Predictions for decay width ratios and suggestions for future searches

Abstract

We study the spectrum and rearrangement decays of S-wave $cs\bar{c}\bar{s}$ tetraquark states in a simplified quark model. The masses and widths are estimated by assuming that the $X(4140)$ is the lower $1^{++}$ $cs\bar{c}\bar{s}$ tetraquark. Comparing our results with experimental measurements, we find that the recently observed $X(3960)$ by LHCb can be assigned as the lowest $0^{++}$ $cs\bar{c}\bar{s}$ tetraquark state and the $X_0(4140)$ could be the second lowest $0^{++}$ $cs\bar{c}\bar{s}$ tetraquark. Predictions of ratios between partial widths for the involved tetraquarks are given. We call for searches for more $cs\bar{c}\bar{s}$ tetraquarks with $J^{PC}=1^{+-}$, $0^{++}$, and $2^{++}$.