X(3872) and Y(4140) using diquark-antidiquark operators with lattice QCD

TL;DR

This lattice QCD study investigates charmonium-like mesons, including the exotic X(3872), using a variety of operators to explore potential four-quark states and their mixing with conventional mesons.

Contribution

It introduces a comprehensive lattice QCD approach with diverse operators to analyze exotic charmonium-like states and their quark configurations.

Findings

Identification of signatures of four-quark exotic states.

Analysis of operator mixing and Fierz relations.

Insights into the structure of X(3872) and related states.

Abstract

We discuss a recent lattice study of charmonium-like mesons with $J^{PC}=1^{++}$ and three quark contents $\bar cc\bar du$, $\bar cc(\bar uu + \bar dd)$ and $\bar cc\bar ss$, where the latter two can mix with $\bar cc$. In this quantum channel, the long known exotic candidate, X(3872), resides. This simulation employs $N_f=2$, $m_\pi=266~$MeV and a large basis of $\bar cc$, two-meson and diquark-antidiquark interpolating fields, with diquarks in both anti-triplet and sextet color representations. It aims at the possible signatures of four-quark exotic states. Along the way, we discuss the relations between the diquark-antidiquark operators and the two-meson operators via the Fierz transformations.