Measurement of isolated prompt photon production in pp and p-Pb collisions at the LHC

Kód výsledku v IS VaVaI

<a href="https://www.isvavai.cz/riv?ss=detail&h=RIV%2F61389005%3A_____%2F25%3A00645512" target="_blank" >RIV/61389005:_____/25:00645512 - isvavai.cz</a>

Nalezeny alternativní kódy

RIV/68378271:_____/25:00645512 RIV/68407700:21340/25:00389223

Výsledek na webu

<a href="https://link.springer.com/article/10.1140/epjc/s10052-025-14802-w" target="_blank" >https://link.springer.com/article/10.1140/epjc/s10052-025-14802-w</a>

DOI - Digital Object Identifier

<a href="http://dx.doi.org/10.1140/epjc/s10052-025-14802-w" target="_blank" >10.1140/epjc/s10052-025-14802-w</a>

Jazyk výsledku

angličtina

Název v původním jazyce

Measurement of isolated prompt photon production in pp and p-Pb collisions at the LHC

Popis výsledku v původním jazyce

This paper presents the measurement of the isolated prompt photon inclusive production cross section in pp and p–Pb collisions by the ALICE Collaboration at the LHC. The measurement is performed in p–Pb collisions at centre-of-mass energies per nucleon pair of sNN=5.02TeV and 8.16 TeV, as well as in pp collisions at s=5.02TeV and 8 TeV. The cross section is obtained at midrapidity (|y|<0.7) using a charged-track based isolation momentum pTiso, ch<1.5GeV/c in a cone with radius R=0.4. The data for both collision systems are well reproduced by perturbative QCD (pQCD) calculations at next-to-leading order (NLO) using recent parton distribution functions for free (PDF) and bound (nPDF) nucleons. Furthermore, the nuclear modification factor RpA for both collision energies is consistent with unity for pT>20GeV/c. However, deviations from unity (RpA<1) of up to 20% are observed for pT<20GeV/c with limited significance, indicating the possible presence of nuclear effects in the initial state of the collision. The suppression increases with decreasing pT with a significance of 2.3σ for a non-zero slope and yields RpA<1 with a significance of 1.8σ at sNN=8.16TeV for pT<20GeV/c. In addition, a significance of 1.1σ is observed for RpA<1 at the lower collision energy sNN=5.02TeV for pT<14GeV/c. The magnitude and shape of the suppression are consistent with pQCD predictions at NLO using nPDFs that incorporate nuclear shadowing effects in the Pb nucleus.

Název v anglickém jazyce

Measurement of isolated prompt photon production in pp and p-Pb collisions at the LHC

Popis výsledku anglicky

This paper presents the measurement of the isolated prompt photon inclusive production cross section in pp and p–Pb collisions by the ALICE Collaboration at the LHC. The measurement is performed in p–Pb collisions at centre-of-mass energies per nucleon pair of sNN=5.02TeV and 8.16 TeV, as well as in pp collisions at s=5.02TeV and 8 TeV. The cross section is obtained at midrapidity (|y|<0.7) using a charged-track based isolation momentum pTiso, ch<1.5GeV/c in a cone with radius R=0.4. The data for both collision systems are well reproduced by perturbative QCD (pQCD) calculations at next-to-leading order (NLO) using recent parton distribution functions for free (PDF) and bound (nPDF) nucleons. Furthermore, the nuclear modification factor RpA for both collision energies is consistent with unity for pT>20GeV/c. However, deviations from unity (RpA<1) of up to 20% are observed for pT<20GeV/c with limited significance, indicating the possible presence of nuclear effects in the initial state of the collision. The suppression increases with decreasing pT with a significance of 2.3σ for a non-zero slope and yields RpA<1 with a significance of 1.8σ at sNN=8.16TeV for pT<20GeV/c. In addition, a significance of 1.1σ is observed for RpA<1 at the lower collision energy sNN=5.02TeV for pT<14GeV/c. The magnitude and shape of the suppression are consistent with pQCD predictions at NLO using nPDFs that incorporate nuclear shadowing effects in the Pb nucleus.

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

2025

Kód důvěrnosti údajů

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

Název periodika

European Physical Journal C

ISSN

1434-6044

e-ISSN

1434-6052

Svazek periodika

85

Číslo periodika v rámci svazku

12

Stát vydavatele periodika

DE - Spolková republika Německo

Počet stran výsledku

21

Strana od-do

1407

Kód UT WoS článku

001670443300001

EID výsledku v databázi Scopus

2-s2.0-105026609121