The production of doubly charmed exotic hadrons in heavy ion collisions

TL;DR

This paper explores how heavy ion collisions can produce doubly charmed exotic hadrons like T_cc+ in large quantities, providing a new method to study their properties and QCD dynamics.

Contribution

It demonstrates the significant enhancement in T_cc+ production in heavy ion collisions and predicts observable signatures for future experiments.

Findings

Approximately three orders of magnitude increase in T_cc+ yield in Pb-Pb collisions.

Comparable production rates of T_cc+ and X(3872) in central collisions.

Predicted rapidity, transverse momentum dependence, and elliptic flow for T_cc+.

Abstract

Hadron spectroscopy provides direct physical measurements that shed light on the non-perturbative behavior of quantum chromodynamics (QCD). In particular, various exotic hadrons such as the newly observed $T_{cc}^+$ by the LHCb collaboration, offer unique insights on the QCD dynamics in hadron structures. In this letter, we demonstrate how heavy ion collisions can serve as a powerful venue for hadron spectroscopy study of doubly charmed exotic hadrons by virtue of the extremely charm-rich environment created in such collisions. The yields of $T_{cc}^+$ as well as its potential isospin partners are computed within the molecular picture for Pb-Pb collisions at center-of-mass energy $2.76~\mathrm{TeV}$. We find about three-order-of-magnitude enhancement in the production of $T_{cc}^+$ in Pb-Pb collisions as compared with the yield in proton-proton collisions, with a moderately smaller enhancement in the yields of the isospin partners $T_{cc}^0$ and $T_{cc}^{++}$. The $T_{cc}^+$ yield is comparable to that of the $X(3872)$ in the most central collisions while shows a considerably stronger decrease toward peripheral collisions, due to a "threshold" effect of the required double charm quarks for $T_{cc}^+$. Final results for their rapidity and transverse momentum $p_T$ dependence as well as the elliptic flow coefficient are reported and can be tested by future experimental measurements.