In-medium QCD splittings beyond the soft, large-Nc and harmonic-oscillator approximations all at once

by Marco Leitão (IPhT-Saclay & LIP-Lisbon)

Tuesday 30 Jun 2026, 11:00 → 12:00 US/Eastern

Small Seminar Room (Bldg 510A)

The building block of jet quenching calculations is the differential matrix-element to radiate a gluon off a highly-energetic parton in a dense QCD medium. Analytical expressions were presented more than 30 years ago in the pioneering work of BDMPS-Z. However, exact solutions have remained elusive, thus hampering the precision of jet quenching phenomenology.

We present the first calculation of QCD in-medium splitting kernels which accounts for the exact transverse kinematics of the partons, finite- corrections and a realistic medium potential, providing solutions across the entire phenomenologically relevant phase space. Building on [1], we formulate the problem as a set of tractable evolution equations and solve them using an efficient and stable numerical method based on the Faber expansion of the time-evolution propagator [2]. We analyse the applicability of the large-Nc limit and demonstrate the uncertainties associated with common approximations in the literature. This work opens a path toward more precise calculations of jet observables and for powerful new constraints of medium parameters from high-energy heavy-ion collider data.

[1] JHEP 09 (2023) 049
[2] Comput. Phys. 216 (2006) 391-402