7-12 June 2021
Zoom
Europe/Paris timezone

Search for jet quenching effects in high-multiplicity proton-proton collisions at $\sqrt{s} = 13~\rm{TeV}$

Jun 10, 2021, 6:45 PM
1h
Zoom

Zoom

Experimental poster Heavy Ions Poster Session

Speaker

Artem Kotliarov (Czech Academy of Sciences (CZ))

Description

Small collision systems, such as pp or p-Pb, exhibit signatures of collective effects that are thought to be associated with quark-gluon plasma formation. The absence to date of jet quenching signals raises a question about the origin of the observed collectivity and calls for more accurate jet quenching measurements in small collision systems. In this poster, the ALICE Collaboration reports results of a novel approach to search for jet quenching effects in high-multiplicity pp collisions at $\sqrt{s}$ = 13 TeV, which are selected based on charged-particle multiplicity measured using forward scintillator detectors. In the analysis, we look for broadening of the azimuthal acoplanarity measured by the semi-inclusive distribution of charged-jets recoiling from a high transverse momentum, charged trigger hadron. Jet reconstruction is performed using anti-$k_{\rm {T}}$ algorithm with $R$ = 0.4. The measured jet yield is corrected for uncorrelated background,including multi-partonic interaction, by means of a data-driven statistical method. Comparison of recoil jet distributions measured in minimum bias and high-multiplicity events reveals significant broadening in the high-multiplicity data, resembling jet quenching. However, a qualitatively similar feature is observed in pp data simulated with the PYTHIA 8 generator, which does not account for jet quenching. We will discuss the current status of the analysis, and prospects to understand the origin of this striking phenomenon.

Primary author

Artem Kotliarov (Czech Academy of Sciences (CZ))

Presentation materials