The soft drop momentum sharing fraction zg beyond leading-logarithmic accuracy

Aug 3, 2021, 4:30 PM



Pedro Cal (University of Amsterdam)


Based on:


Grooming techniques, such as soft drop, play a central role in reducing sensitivity of jets to e.g. underlying event and hadronization at current collider experiments. The momentum sharing fraction zg, of the two branches in a jet that pass the soft drop condition, is one of the most important observables characterizing a collinear splitting inside the jet, and directly probes the QCD splitting functions. In this work, we present a factorization framework that enables a systematic calculation of the corresponding cross section beyond leading-logarithmic (LL) accuracy, showing that thi measurement is not only sensitive to the QCD charge but also the spin of the parton that initiates
the jet. Our results at next-to-leading logarithmic (NLL') accuracy include non-global logarithms, and provide a first meaningful assessment of the perturbative uncertainty. We present a comparison to the available experimental data from ALICE, ATLAS, and STAR and find excellent agreement.

Primary authors

Pedro Cal (University of Amsterdam) Wouter Waalewijn (University of Amsterdam) Felix Ringer (Lawrence Berkeley National Laboratory) Kyle Lee

Presentation materials