Scalar fully-charm and bottom tetraquarks under extreme temperatures

TL;DR

This study investigates how the masses and decay constants of fully heavy tetraquarks composed of charm and bottom quarks change with temperature, using Thermal QCD Sum Rules, and finds significant reductions near the critical temperature.

Contribution

It provides the first temperature-dependent analysis of fully heavy tetraquark properties using Thermal QCD Sum Rules, including vacuum condensates up to dimension four.

Findings

Mass of $T_{4c}$ decreases by 8% near critical temperature.

Mass of $T_{4b}$ decreases by approximately 3.3%.

Decay constants reduce by about 71% and 66.6%, respectively.

Abstract

Temperature dependences of masses and current couplings of the ground state of the fully heavy tetraquarks $T_{4c}$ and $T_{4b}$, composed of charm $(c)$ and bottom $(b)$ quarks and antiquarks with spin-parities $J^{PC} = 0^{++}$ are evaluated in the diquark antidiquark picture using Thermal QCD Sum Rules including vacuum condensates up to dimension four. The calculated values for $cc\bar{c}\bar{c}$ and $bb\bar{b}\bar{b}$ tetraquark states at $T=0$ align well with the experimental data on the broad structures. Based on the numerical analyses around the critical temperature, the mass of the $T_{4c}$ state decreases by $8\%$ compared to its vacuum state, while for its b partner, this percentage is approximately $3.3\%$. For the decay constants, the reductions are approximately $71\%$ and $66.6\%$, respectively. The precise exploration of tetraquark states awaits future scrutiny in upcoming experiments, including Belle II, Super-B, PANDA, and LHCb.