Full energy fraction and angular dependence of medium-induced splittings in the large-$N_c$ limit
Abstract
Jets produced in relativistic heavy-ion collisions are modified by their interactions with the quark-gluon plasma (QGP), making jet substructure observables sensitive probes of QGP dynamics. A quantitative description of these modifications requires understanding how the medium affects elementary parton splittings with full dependence on both their energy fraction and splitting angle , beyond the widely used soft emitted-gluon approximation. Here, we study medium-induced splittings double-differential in and , with full resummation of multiple scatterings, and show that in the large- limit and under the harmonic oscillator (HO) approximation, all path integrals can be evaluated analytically for any splitting channel, providing a computationally efficient semi-analytical result. We also revisit the semi-hard approximation (SHA), extending it to include leading corrections in inverse powers of the partons energies, which we denote the improved semi-hard approximation (ISHA), and assess its validity through a comparison with the large--HO results. Our analysis shows that while the SHA is found to be unreliable across most of phase space, even for high-energy emitters, the ISHA provides a robust approximation for splittings where all partons are sufficiently energetic.
Keywords
Cite
@article{arxiv.2603.27846,
title = {Full energy fraction and angular dependence of medium-induced splittings in the large-$N_c$ limit},
author = {Carlota Andres and Fabio Dominguez},
journal= {arXiv preprint arXiv:2603.27846},
year = {2026}
}
Comments
40 pages, 7 figures, plus two appendices with 7 additional figures. v2: typos corrected and two figures for evolving media added