Electromagnetic and hadronic decay of fully heavy tetraquarks
Wen-Long Sang, Tao Wang, Y. Zhang, Feng Feng
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 ${\ensuremath{\alpha}}_{s}$ 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 ${10}^{\ensuremath{-}3}$ and ${10}^{\ensuremath{-}6}$ for the ${T}_{4c}$ hadronic decay and electromagnetic decay, respectively. Combining 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 $\mathcal{L}=100\text{ }\text{ }{\mathrm{fb}}^{\ensuremath{-}1}$, it is expected that the event numbers can reach ${10}^{3}--{10}^{4}$ for ${T}_{4c}\ensuremath{\rightarrow}\ensuremath{\gamma}\ensuremath{\gamma}$, and ${10}^{5}--{10}^{6}$ for ${T}_{4c}\ensuremath{\rightarrow}\mathrm{LH}$, 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.