Impact of a thermal medium on newly observed Zcs (3985) resonance and its b-partner

Motivated by the very recent discovery of the strange hidden-charm exotic state Z(cs) (3985) by the BESIII Collaboration, we study the possible interpretation of this exotic state the both at T = 0 and T not equal 0. We analytically compute the mass and meson-current coupling constant of this resonance with spin-parity J(P) = 1(+) at finite temperature approximation up to the sixth order of the thermal operator dimension including non-perturbative contributions. Extracting thermal mass and meson-current coupling constant sum rules, the modifications on properties of the Z(cs) (3985) state in hot medium are determined. As a by-product, the hadronic parameters of the bottom partner of Z(cs) (3985) is estimated as well. The search for temperature effects on the hadronic parameters of the hidden-charm meson Z(cs) (3985) and the bottom partner enable us to understand the phase transitions, chiral symmetry breaking, and the properties of hot-dense matter in QCD. Moreover, the full width of the resonance Z(cs) (3985) is calculated as (12.0 +/- 0.8) MeV using the strong decay in the tetraquark picture. Results for width and mass are in reasonable agreement with existing experimental data and results of other theoretical works. The information obtained about the parameters of the considered states is useful for experimental investigations of exotic mesons.

Automated summary

Motivated by the recent discovery of the exotic state Z(cs) (3985) by the BESIII Collaboration, this study explores the possible interpretation of this state at different temperatures. The mass and meson-current coupling constant of the resonance are analytically computed, considering non-perturbative contributions and up to sixth order of the thermal operator dimension. The modifications on the Z(cs) (3985) properties in a hot medium are determined by extracting thermal mass and meson-current coupling constant sum rules. Additionally, the hadronic parameters of the bottom partner of Z(cs) (3985) are estimated. The research sheds light on phase transitions, chiral symmetry breaking, and the properties of hot-dense matter in QCD.