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

19 May 2026, 16:01
1m
Patio and Auditorium Hall (CICSU)

Patio and Auditorium Hall

CICSU

Centre de conférences internationales - Sorbonne Université 4 Place Jussieu, 75005 Paris

Speaker

Marco Leitão (IPhT-Saclay & LIP-Lisbon)

Description

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 arbitrary energy fractions $z$ of the emitted gluon, finite-$N_c$ 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-$N_c$ limit and demonstrate the breakdown of the commonly employed straight-line approximation. As a phenomenological application, we compute in-medium energy–energy correlators (EECs) at LHC kinematics, quantifying the impact of the complete finite-$z$
solution and improved medium potential on jet substructure observables.

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

Track Heavy Ions

Authors

Alba Soto Ontoso (Universidad de Granada (ES)) Gregory Soyez (IPhT, CEA Saclay) Dr Guilherme Milhano (LIP-Lisbon & CERN TH) Marco Leitão (IPhT-Saclay & LIP-Lisbon)

Presentation materials