Electromagnetic and hadronic decay of fully heavy tetraquark

TL;DR

This paper calculates electromagnetic and hadronic decay widths of fully heavy tetraquarks using nonrelativistic QCD, predicting branching fractions and event rates at the LHC, indicating promising detection prospects.

Contribution

It provides the first comprehensive calculation of decay widths and branching ratios for fully heavy tetraquarks within the nonrelativistic QCD framework, including predictions for LHC event rates.

Findings

Branching fractions around 10^{-4} for hadronic decays and 10^{-7}-10^{-6} for electromagnetic decays.

Predicted event numbers up to 10^3 for gamma-gamma decay and 10^6 for light hadron decay at the LHC.

Decay widths of T_{4b} estimated using dimensional analysis and velocity scaling rules.

Abstract

In this study, we compute the electromagnetic and hadronic decay widths of the S-wave fully heavy tetraquark $T_{4Q}$ ($Q=c$ or $b$) at lowest order in $\alpha_s$ and $v$, in the framework of nonrelativistic QCD. The short-distance coefficients are determined through the standard procedure of matching. The nonperturbative long-distance matrix elements are related to the phenomenological four-body Schr\"odinger wave functions at the origin, whose values are taken from literature. The branching fractions are predicted to be around $10^{-4}$ and $10^{-7}-10^{-6}$ for the $T_{4c}$ hadronic decay and electromagnetic decay, respectively. Combing our results with the $T_{4c}$ production cross sections at the LHC, we also predict the event numbers for various decay channels. With integrated luminosity $\mathcal{L}=100 \,{\rm fb}^{-1}$, it is expected that the event numbers can reach $10^3$ for $T_{4c}\to \gamma\gamma$, and $10^6$ for $T_{4c}\to {\rm LH}$, at the LHC. The detecting prospect is promising. In addition, the decay widths of $T_{4b}$ are estimated based on simple dimensional analysis as well as velocity scaling rule.