Heavy-Flavor Fragmentation and Jet Structure from HF-NRevo: Bridging to Heavy-Ion Collisions

TL;DR

This work addresses heavy-flavor quarkonium fragmentation at moderate-to-large $p_T$ by introducing the HF-NRevo framework and the NRFF1.0 set, which bootstrap NRQCD-NLO initial conditions into collinear fragmentation functions evolved with $DGLAP$ in a variable-flavor-number scheme. It extends the formalism to jet physics through Semi-Inclusive Fragmenting Jet Functions (SIFJFs), enabling access to quarkonium-in-jet fragmentation and jet-substructure observables. A robust replica-based treatment of missing higher-order uncertainties provides a quantitative handle on theory errors. The framework is positioned as a vacuum baseline for in-medium fragmentation in heavy-ion collisions, with clear paths to study jet quenching, energy loss, medium-modified FFs, and in-medium hadronization including quarkonium regeneration, relevant for HL-LHC and future facilities.

Abstract

We present recent progress on the Heavy-Flavor Non-Relativistic Evolution (HF-NRevo) framework, designed to describe leading-power fragmentation of heavy-flavored hadrons at moderate to large transverse momentum. Starting from NLO NRQCD calculations for all partonic channels into pseudoscalar quarkonia, we construct the NRFF1.0 collinear fragmentation functions via DGLAP evolution in a variable-flavor number scheme. We outline future prospects in the heavy-ion context, where HF-NRevo can serve as a baseline for modeling in-medium modifications of heavy-flavor fragmentation in nuclear collisions. Its accurate modeling of the partonic hierarchy and threshold effects makes it ideally suited to explore jet-quenching sensitivity, energy-loss mechanisms, and the emergence of medium-modified fragmentation functions in the quark-gluon plasma. Moreover, it provides a natural baseline for implementing in-medium hadronization scenarios, including quarkonium regeneration and fragmentation-function apparent-shape distortion. These developments provide new handles for exploring heavy-flavor dynamics at the HL-LHC and future collider facilities.

Figures (2)

• Figure 1: NLO gluon to color-singlet $\eta_c$ ($\eta_b$) FFs. Plots adapted from Celiberto:2025euy
• Figure 2: NLO charm (bottom) to color-singlet $\eta_c$ ($\eta_b$) FFs. Plots adapted from Celiberto:2025euy.