Tetraquark States with Open Flavors

TL;DR

This paper estimates the masses of open-flavor tetraquark states with four different quark flavors using QCD sum rules, providing predictions for states in both the bottom and charm sectors that are experimentally accessible.

Contribution

The study constructs specific tetraquark currents and performs detailed QCD sum rule calculations up to dimension eight, offering new mass predictions for open-flavor tetraquark states.

Findings

Predicted tetraquark masses around 5.57 GeV and 5.58 GeV for bottom sector.

Charmed partner states predicted at approximately 2.54 GeV and 2.55 GeV.

Results suggest these states are accessible in experiments like BESIII and Belle.

Abstract

In this work, we estimate the masses of tetraquark states with four different flavors by virtue of QCD sum rules, in both $b$ and $c$ sectors. We construct four $[8_c]_{\bar{b} s} \otimes [8_c]_{\bar{d} u}$ tetraquark currents with $J^P = 0^+$, and then perform analytic calculation up to dimension eight in the Operator Product Expansion (OPE). We keep terms which are linear in the strange quark mass $m_s$, and in the end find two possible tetraquark states with masses $(5.57 \pm 0.15)$ and $(5.58 \pm 0.15)$ GeV. We find that their charmed-partner masses lie in $(2.54 \pm 0.13)$ and $(2.55 \pm 0.13)$ GeV, respectively and are hence accessible in experiments like BESIII and Belle.