First measurements of N-subjettiness in central Pb-Pb collisions at p root s(NN)=2.76 TeV

Kód výsledku v IS VaVaI

<a href="https://www.isvavai.cz/riv?ss=detail&h=RIV%2F68378271%3A_____%2F21%3A00547017" target="_blank" >RIV/68378271:_____/21:00547017 - isvavai.cz</a>

Nalezeny alternativní kódy

RIV/61389005:_____/21:00547017 RIV/68407700:21340/21:00352407

Výsledek na webu

<a href="https://doi.org/10.1007/JHEP10(2021)003" target="_blank" >https://doi.org/10.1007/JHEP10(2021)003</a>

DOI - Digital Object Identifier

<a href="http://dx.doi.org/10.1007/JHEP10(2021)003" target="_blank" >10.1007/JHEP10(2021)003</a>

Jazyk výsledku

angličtina

Název v původním jazyce

First measurements of N-subjettiness in central Pb-Pb collisions at p root s(NN)=2.76 TeV

Popis výsledku v původním jazyce

The ALICE Collaboration reports the first fully-corrected measurements of the N-subjettiness observable for track-based jets in heavy-ion collisions. This study is performed using data recorded in pp and Pb-Pb collisions at centre-of-mass energies of root s = 7 TeV and root s(NN) = 2.76 TeV, respectively. In particular the ratio of 2-subjettiness to 1-subjettiness, tau(2)/tau(1), which is sensitive to the rate of two-pronged jet substructure, is presented. Energy loss of jets traversing the strongly interacting medium in heavy-ion collisions is expected to change the rate of two-pronged substructure relative to vacuum. The results are presented for jets with a resolution parameter of R = 0.4 and charged jet transverse momentum of 40 <= p(T,jet) <= 60 GeV/c, which constitute a larger jet resolution and lower jet transverse momentum interval than previous measurements in heavy-ion collisions. This has been achieved by utilising a semi-inclusive hadron-jet coincidence technique to suppress the larger jet combinatorial background in this kinematic region. No significant modification of the tau(2)/tau(1) observable for track-based jets in Pb-Pb collisions is observed relative to vacuum PYTHIA6 and PYTHIA8 references at the same collision energy. The measurements of tau(2)/tau(1), together with the splitting aperture angle increment R, are also performed in pp collisions at root s = 7 TeV for inclusive jets. These results are compared with PYTHIA calculations at root s = 7 TeV, in order to validate the model as a vacuum reference for the Pb-Pb centre-of-mass energy. The PYTHIA references for tau(2)/tau(1) are shifted to larger values compared to the measurement in pp collisions. This hints at a reduction in the rate of two-pronged jets in Pb-Pb collisions compared to pp collisions.

Název v anglickém jazyce

First measurements of N-subjettiness in central Pb-Pb collisions at p root s(NN)=2.76 TeV

Popis výsledku anglicky

The ALICE Collaboration reports the first fully-corrected measurements of the N-subjettiness observable for track-based jets in heavy-ion collisions. This study is performed using data recorded in pp and Pb-Pb collisions at centre-of-mass energies of root s = 7 TeV and root s(NN) = 2.76 TeV, respectively. In particular the ratio of 2-subjettiness to 1-subjettiness, tau(2)/tau(1), which is sensitive to the rate of two-pronged jet substructure, is presented. Energy loss of jets traversing the strongly interacting medium in heavy-ion collisions is expected to change the rate of two-pronged substructure relative to vacuum. The results are presented for jets with a resolution parameter of R = 0.4 and charged jet transverse momentum of 40 <= p(T,jet) <= 60 GeV/c, which constitute a larger jet resolution and lower jet transverse momentum interval than previous measurements in heavy-ion collisions. This has been achieved by utilising a semi-inclusive hadron-jet coincidence technique to suppress the larger jet combinatorial background in this kinematic region. No significant modification of the tau(2)/tau(1) observable for track-based jets in Pb-Pb collisions is observed relative to vacuum PYTHIA6 and PYTHIA8 references at the same collision energy. The measurements of tau(2)/tau(1), together with the splitting aperture angle increment R, are also performed in pp collisions at root s = 7 TeV for inclusive jets. These results are compared with PYTHIA calculations at root s = 7 TeV, in order to validate the model as a vacuum reference for the Pb-Pb centre-of-mass energy. The PYTHIA references for tau(2)/tau(1) are shifted to larger values compared to the measurement in pp collisions. This hints at a reduction in the rate of two-pronged jets in Pb-Pb collisions compared to pp collisions.

Druh

J_imp - Článek v periodiku v databázi Web of Science

CEP obor

—

OECD FORD obor

10303 - Particles and field physics

Projekt

Výsledek vznikl pri realizaci vícero projektů. Více informací v záložce Projekty.

Návaznosti

P - Projekt vyzkumu a vyvoje financovany z verejnych zdroju (s odkazem do CEP)

Rok uplatnění

2021

Kód důvěrnosti údajů

S - Úplné a pravdivé údaje o projektu nepodléhají ochraně podle zvláštních právních předpisů

Název periodika

Journal of High Energy Physics

ISSN

1029-8479

e-ISSN

1029-8479

Svazek periodika

2021

Číslo periodika v rámci svazku

10

Stát vydavatele periodika

US - Spojené státy americké

Počet stran výsledku

34

Strana od-do

003

Kód UT WoS článku

000703983100001

EID výsledku v databázi Scopus

2-s2.0-85116808987