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Heavy quarks, and the hadrons containing them, are excellent probes of the QCD medium formed in high-energy heavy-ion collisions, as they provide essential information on the transport properties of the medium and how quarks color-neutralize into hadrons. Large theoretical and phenomenological efforts have been dedicated thus far to assess the diffusion of charm and bottom quarks in the quark-gluon plasma and their subsequent hadronization into heavy-flavor (HF) hadrons. However, the fireball formed in heavy-ion collisions also features an extended hadronic phase, and therefore any quantitative analysis of experimental observables needs to account for the rescattering of charm and bottom hadrons. This is further reinforced by the presence of a QCD cross-over transition and the notion that the interaction strength is maximal in the vicinity of the pseudo-critical temperature. We review existing approaches for evaluating the interactions of open HF hadrons in a hadronic heat bath and the pertinent results for scattering amplitudes, spectral functions and transport coefficients. While most of the work to date has focused on 𝐷-mesons, we also discuss excited states as well as HF baryons and the bottom sector. Both the HF hadro-chemistry and bottom observables will play a key role in future experimental measurements. We also conduct a survey of transport calculations in heavy-ion collisions that have included effects of hadronic HF diffusion and assess its impact on various observables.
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This content will become publicly available on February 7, 2026
Quarkonia in Medium and Transport in Heavy-Ion Collisions
The transport and spectral properties of heavy quarkonia in hot QCD matter are a central ingredient to describe their observables in high-energy heavy-ion collisions. We review recent activity in evaluating these properties, including a nonperturbative quantum many-body approach where the basic two-body interaction kernel is constrained by quantities that can be computed with good precision in thermal lattice QCD. We then give a brief overview of quarkonium transport approaches to heavy-ion collisions. Focusing on the semiclassical approach we discuss the current interpretation of charmonium and bottomonium observables at RHIC and the LHC, including excitation functions that started with 𝐽/𝜓 and 𝜓′ data from the heavy-ion program at the SPS.
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- Award ID(s):
- 2209335
- PAR ID:
- 10589587
- Publisher / Repository:
- Sissa Medialab
- Date Published:
- Page Range / eLocation ID:
- 114
- Format(s):
- Medium: X
- Location:
- Barcelona, Spain
- Sponsoring Org:
- National Science Foundation
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