Time-Based Reclustering for Identifying Early Jet Splittings in pp Collisions with ALICE

23 Jun 2026, 19:40
20m
Garland 064

Garland 064

Poster presentation Poster session

Speaker

Morgan Bailey Knuesel (Yale University (US))

Description

Jets are formed in the initial hard scattering of a collision and thus experience multiple scales of QCD processes. In proton-proton collisions, we may study how colored partons radiate and fragment using differential jet substructure, made possible by the ALICE detector’s low-momentum reach and high-precision tracking. More specifically, by de-clustering the jet fragmentation history splitting-by-splitting, we seek to access the earliest stages of jet evolution.

This de-clustering is commonly performed using the Cambridge-Aachen (C/A) algorithm, which invokes angular-ordering of QCD emissions to arrange the splittings from widest to narrowest. In this work, we instead present results of groomed jet substructure for jets de-clustered using the τ algorithm, which orders splittings based on the formation time (τ_form). In comparing these two algorithms in the vacuum conditions of pp collisions, we find differences that highlight sensitivity to the underlying ordering variable and are important for extending MC generators to higher orders.

These results also establish a baseline in pp collisions and motivate future applications in Pb-Pb collisions at 5.36 TeV, where the medium-induced emissions may not respect angular-ordering, and where an ordering on formation time may help tune the degree of quenching. Reliably de-clustering jets in Pb-Pb collisions will allow for investigation into modifications to jet substructure made by the medium.

Is this an experimental talk? Yes
Is this on behalf of a collaboration? Yes
Which collaboration? ALICE Collaboration
Are you willing to present as a poster if it is not selected for oral presentation? Yes

Author

Morgan Bailey Knuesel (Yale University (US))

Presentation materials