Dissociation Cross Sections of Large-Momentum Charmonia with Light Mesons in Hadronic Matter

TL;DR

This paper investigates the probability of large-momentum charmonia dissociation into multiple mesons when colliding with light mesons in hot hadronic matter, using a quark-level mechanism and temperature-dependent potentials.

Contribution

It introduces a novel multi-meson production mechanism for charmonium dissociation and derives cross sections incorporating charm-quark fragmentation and temperature effects.

Findings

Cross sections increase with energy and temperature.

At high energies, cross sections are comparable to two-to-two reactions.

Small cross sections at low energies.

Abstract

Momenta of charmonia created in Pb-Pb collisions at the Large Hadron Collider are so large that three or more mesons may be produced when the charmonia collide with light mesons in hadronic matter. We study the meson-charmonium collision in a mechanism where the collision produces two quarks and two antiquarks, the charm quark then fragmenting into charmed mesons, and the other three constituents as well as quarks and antiquarks created from vacuum give rise to two or more mesons. The absolute square of the transition amplitude for the production of two quarks and two antiquarks is derived from the $S$-matrix element, and cross-section formulas are derived from the absolute square of the transition amplitude and charm-quark fragmentation functions. With a temperature-dependent quark potential, we calculate unpolarized cross sections for inclusive $D^+$, $D^0$, $D^+_s$, or $D^{*+}$ production in scattering of charmonia by $\pi$, $\rho$, $K$, or $K^\ast$ mesons. At low center-of-mass energies of the charmonium and the light meson, the cross sections are very small. At high energies the cross sections have obvious temperature dependence, and are comparable to peak cross sections of two-to-two meson-charmonium reactions.