Thermal energy of a charm-meson molecule in a pion gas
- Resource Type
- article
- Authors
- Eric Braaten; Li-Ping He; Kevin Ingles; Jun Jiang
- Source
- Journal of High Energy Physics, Vol 2024, Iss 2, Pp 1-41 (2024)
- Subject
- Properties of Hadrons
Hadronic Spectroscopy
Structure and Interactions
Finite Temperature or Finite Density
Nuclear and particle physics. Atomic energy. Radioactivity
QC770-798
- Language
- English
- ISSN
- 1029-8479
Abstract The thermal corrections to the propagator of a loosely bound charm-meson molecule in a pion gas are calculated to next-to-leading order in the heavy-meson expansion using a zero-range effective field theory. Ultraviolet divergences in the charm-meson-pair self energy are canceled by corrections to the charm-meson-pair contact vertex. Terms that are singular at the charm-meson-pair threshold can be absorbed into thermal corrections to the rest energies and kinetic masses of the charm-meson constituents. The remaining terms reduce to a thermal correction to the binding momentum that is proportional to the pion number density and suppressed by the pion/charm-meson mass ratio. The correction gives a tiny decrease in the binding energy of the charm-meson molecule relative to the charm-meson-pair threshold in the pion gas and a change in its thermal width that is small compared to the thermal widths of the charm-meson constituents. These results are encouraging for the prospects of observing X(3872) and T cc + 3875 $$ {T}_{cc}^{+}(3875) $$ in the expanding hadron gas produced by heavy-ion collisions.