Interactions of the doubly charmed state $T_{cc} ^+$ with a hadronic medium

TL;DR

This paper studies how the doubly charmed state T_{cc}^+ interacts with a hadronic medium, calculating absorption and production cross sections using effective field theories and QCD sum rules, revealing larger absorption than production.

Contribution

It introduces the first calculation of the T_{cc}^+ - D - D^* form factor from QCD sum rules and compares different form factor models for the first time.

Findings

Absorption cross sections are larger than production cross sections.

Calculated cross sections are an order of magnitude smaller than previous estimates.

QCD sum rule-derived form factors provide new insights into T_{cc}^+ interactions.

Abstract

We investigate the absorption and production processes of this new state in a hadronic medium, considering the reactions $T_{cc}^+ \pi, T_{cc}^+ \rho \rightarrow D^{(*)} D^{(*)} $ and the corresponding inverse reactions. We use effective field Lagrangians to account for the couplings between light and heavy mesons, and give special attention to the form factors in the vertices. We calculate here for the first time the $ T_{cc}^+ - D - D^*$ form factor derived from QCD sum rules. The results are also obtained by testing widely utilized empirical form factors. The absorption cross sections are found to be larger than the production ones. We compare our results with the only existing estimate of these quantities, presented in a work of J.~Hong, S.~Cho, T.~Song and S.~H.~Lee, in which the authors employed the quasi-free approximation. We find cross sections which are one order of magnitude smaller.