English

How many interactions does it take to modify a jet?

High Energy Physics - Phenomenology 2025-10-22 v3

Abstract

It is a continued open question how there can be an azimuthal anisotropy of high pp_\perp particles quantified by a sizable v2v_2 in p+Pb collisions when, at the same time, the nuclear modification factor RAAR_\text{AA} is consistent with unity. We address this puzzle within the framework of the jet quenching model \textsc{Jewel}. In the absence of reliable medium models for small collision systems we use the number of scatterings per parton times the squared Debye mass to characterise the strength of medium modifications. Working with a simple brick medium model we show that, for small systems and not too strong modifications, RAAR_\text{AA} and v2v_2 approximately scale with this quantity. We find that a comparatively large number of scatterings is needed to generate measurable jet quenching. Our results indicate that the RAAR_\text{AA} corresponding to the observed v2v_2 could fall within the experimental uncertainty. Thus, while there is currently no contradiction with the measurements, our results indicate that v2v_2 and RAAR_\text{AA} go hand-in-hand. We also discuss departures from scaling, in particular, due to sizable inelastic energy loss.

Keywords

Cite

@article{arxiv.2412.14983,
  title  = {How many interactions does it take to modify a jet?},
  author = {Chiara Le Roux and José Guilherme Milhano and Korinna Zapp},
  journal= {arXiv preprint arXiv:2412.14983},
  year   = {2025}
}

Comments

6 pages, 4 figures

R2 v1 2026-06-28T20:42:28.764Z