Jun 5 – 9, 2023
Genova, Italy
Europe/Rome timezone

Charm meson and charm-meson molecule in an expanding hadron gas

Jun 6, 2023, 3:30 PM
DAD - Room Benvenuto (Genova, Italy)

DAD - Room Benvenuto

Genova, Italy

Contributed Heavy meson spectroscopy Heavy meson spectroscopy


Liping He (Universität Bonn)


We study the time evolution of the number of charm mesons after the kinetic freeze-out of the hadron gas produced by a central heavy-ion collision. The $\pi D^*\to \pi D^*$ reaction rates have t-channel singularities that give contributions inversely proportional to the thermal width of the $D$.  The ratio of the $D^0$ and $D^+$ production rate can differ significantly from those predicted using the measured $D^*$ branching fractions.
We then study the thermal correction to the propagator of a loosely bound charm-meson molecule in a pion gas to next-to-leading order in the heavy-meson expansion. The correction comes primarily from the complex thermal energy shift of the charm-meson constituents. The remaining correction gives a tiny decrease in the binding energy of the molecule and a tiny change in its thermal width. These results are encouraging for the prospects of observing $X(3872)$ and $T_{cc}^+(3875)$ in the expanding hadron gas produced by heavy-ion collisions.

Primary authors

Prof. Eric Braaten (Ohio State University) Roberto Bruschini (Ohio State University) Liping He (Universität Bonn) Kevin Ingles (Ohio State University) Jun Jiang (Shandong University)

Presentation materials

Peer reviewing