Underlying event properties in pp collisions at root s=13 TeV

Kód výsledku v IS VaVaI

<a href="https://www.isvavai.cz/riv?ss=detail&h=RIV%2F61389005%3A_____%2F20%3A00524544" target="_blank" >RIV/61389005:_____/20:00524544 - isvavai.cz</a>

Nalezeny alternativní kódy

RIV/68378271:_____/20:00524544 RIV/68407700:21340/20:00342805

Výsledek na webu

<a href="https://doi.org/10.1007/JHEP04(2020)192" target="_blank" >https://doi.org/10.1007/JHEP04(2020)192</a>

DOI - Digital Object Identifier

<a href="http://dx.doi.org/10.1007/JHEP04(2020)192" target="_blank" >10.1007/JHEP04(2020)192</a>

Jazyk výsledku

angličtina

Název v původním jazyce

Underlying event properties in pp collisions at root s=13 TeV

Popis výsledku v původním jazyce

This article reports measurements characterizing the Underlying Event (UE) associated with hard scatterings at midrapidity (|eta| < 0.8) in pp collisions at root s = 13 TeV. The hard scatterings are identified by the leading particle, the charged particle with the highest transverse momentum (pT leading) in the event. Charged-particle number-densities and summed transverse-momentum densities are measured in different azimuthal regions defined with respect to the leading particle direction: Toward, Transverse, and Away. The Toward and Away regions contain the fragmentation products of the hard scatterings in addition to the UE contribution, whereas particles in the Transverse region are expected to originate predominantly from the UE. The study is performed as a function of pT leading with three different p(T) thresholds for the associated particles, pT track > 0.15, 0.5, and 1.0 GeV/c. The charged-particle density in the Transverse region rises steeply for low values of pT leading and reaches a plateau. The results confirm the trend that the charged-particle density in the Transverse region shows a stronger increase with s than the inclusive charged-particle density at midrapidity. The UE activity is increased by approximately 20% when going from 7 TeV to 13 TeV pp collisions. The plateau in the Transverse region (5 <pT leading< 40 GeV/c) is further characterized by the probability distribution of its charged-particle multiplicity normalized to its average value (relative transverse activity, R-T) and the mean transverse momentum as a function of R-T. Experimental results are compared to model calculations using PYTHIA 8 and EPOS LHC. The overall agreement between models and data is within 30%. These measurements provide new insights on the interplay between hard scatterings and the associated UE in pp collisions.

Název v anglickém jazyce

Underlying event properties in pp collisions at root s=13 TeV

Popis výsledku anglicky

This article reports measurements characterizing the Underlying Event (UE) associated with hard scatterings at midrapidity (|eta| < 0.8) in pp collisions at root s = 13 TeV. The hard scatterings are identified by the leading particle, the charged particle with the highest transverse momentum (pT leading) in the event. Charged-particle number-densities and summed transverse-momentum densities are measured in different azimuthal regions defined with respect to the leading particle direction: Toward, Transverse, and Away. The Toward and Away regions contain the fragmentation products of the hard scatterings in addition to the UE contribution, whereas particles in the Transverse region are expected to originate predominantly from the UE. The study is performed as a function of pT leading with three different p(T) thresholds for the associated particles, pT track > 0.15, 0.5, and 1.0 GeV/c. The charged-particle density in the Transverse region rises steeply for low values of pT leading and reaches a plateau. The results confirm the trend that the charged-particle density in the Transverse region shows a stronger increase with s than the inclusive charged-particle density at midrapidity. The UE activity is increased by approximately 20% when going from 7 TeV to 13 TeV pp collisions. The plateau in the Transverse region (5 <pT leading< 40 GeV/c) is further characterized by the probability distribution of its charged-particle multiplicity normalized to its average value (relative transverse activity, R-T) and the mean transverse momentum as a function of R-T. Experimental results are compared to model calculations using PYTHIA 8 and EPOS LHC. The overall agreement between models and data is within 30%. These measurements provide new insights on the interplay between hard scatterings and the associated UE in pp collisions.

Druh

J_imp - Článek v periodiku v databázi Web of Science

CEP obor

—

OECD FORD obor

10304 - Nuclear physics

Projekt

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

Návaznosti

I - Institucionalni podpora na dlouhodoby koncepcni rozvoj vyzkumne organizace

Rok uplatnění

2020

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

—

Svazek periodika

2020

Číslo periodika v rámci svazku

4

Stát vydavatele periodika

US - Spojené státy americké

Počet stran výsledku

35

Strana od-do

192

Kód UT WoS článku

000531322300001

EID výsledku v databázi Scopus

2-s2.0-85084153927