Direct-photon production in in elastic and high-multiplicity proton-proton collisions at root s=13 TeV

Kód výsledku v IS VaVaI

<a href="https://www.isvavai.cz/riv?ss=detail&h=RIV%2F68407700%3A21340%2F25%3A00388905" target="_blank" >RIV/68407700:21340/25:00388905 - isvavai.cz</a>

Výsledek na webu

<a href="https://doi.org/10.1016/j.physletb.2025.139645" target="_blank" >https://doi.org/10.1016/j.physletb.2025.139645</a>

DOI - Digital Object Identifier

<a href="http://dx.doi.org/10.1016/j.physletb.2025.139645" target="_blank" >10.1016/j.physletb.2025.139645</a>

Jazyk výsledku

angličtina

Název v původním jazyce

Direct-photon production in in elastic and high-multiplicity proton-proton collisions at root s=13 TeV

Popis výsledku v původním jazyce

In this letter, we present the first measurement of direct photons at the transverse momentum of 1 < p(T) < 6 GeV/c at midrapidity in inelastic and high-multiplicity proton-proton collisions at a centre-of-mass energy of root s = 13 TeV. The fraction of virtual direct photons in the inclusive virtual photon spectrum is obtained from a fit to the dielectron invariant mass spectrum. In the limit of zero invariant mass, this fraction is equal to the relative contribution of real direct photons in the inclusive real photon spectrum. Contributions from decays of light-flavour neutral mesons are estimated using independent measurements in proton-proton collisions at the same energy and the same event class. For the first time at the LHC energies, a direct-photon signal is observed at low p(T) in both inelastic and high-multiplicity event classes, with a significance of 3.2 sigma and 1.9 sigma in terms of standard deviations, correspondingly. The yield of direct photons in inelastic pp collisions is compared to perturbative QCD calculations. The integrated photon yield is studied as a function of charged-particle multiplicity and is compared to the results from other experiments and theoretical calculations. The results show a significant increase of direct-photon yield with charged-particle multiplicity.

Název v anglickém jazyce

Direct-photon production in in elastic and high-multiplicity proton-proton collisions at root s=13 TeV

Popis výsledku anglicky

In this letter, we present the first measurement of direct photons at the transverse momentum of 1 < p(T) < 6 GeV/c at midrapidity in inelastic and high-multiplicity proton-proton collisions at a centre-of-mass energy of root s = 13 TeV. The fraction of virtual direct photons in the inclusive virtual photon spectrum is obtained from a fit to the dielectron invariant mass spectrum. In the limit of zero invariant mass, this fraction is equal to the relative contribution of real direct photons in the inclusive real photon spectrum. Contributions from decays of light-flavour neutral mesons are estimated using independent measurements in proton-proton collisions at the same energy and the same event class. For the first time at the LHC energies, a direct-photon signal is observed at low p(T) in both inelastic and high-multiplicity event classes, with a significance of 3.2 sigma and 1.9 sigma in terms of standard deviations, correspondingly. The yield of direct photons in inelastic pp collisions is compared to perturbative QCD calculations. The integrated photon yield is studied as a function of charged-particle multiplicity and is compared to the results from other experiments and theoretical calculations. The results show a significant increase of direct-photon yield with charged-particle multiplicity.

Druh

J_imp - Článek v periodiku v databázi Web of Science

CEP obor

—

OECD FORD obor

10303 - Particles and field physics

Projekt

<a href="/cs/project/LM2023040" target="_blank" >LM2023040: Výzkumná infrastruktura pro experimenty v CERN</a><br>

Návaznosti

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

Rok uplatnění

2025

Kód důvěrnosti údajů

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

Název periodika

Physics Letters B

ISSN

0370-2693

e-ISSN

1873-2445

Svazek periodika

868

Číslo periodika v rámci svazku

139645

Stát vydavatele periodika

NL - Nizozemsko

Počet stran výsledku

16

Strana od-do

—

Kód UT WoS článku

001520818100003

EID výsledku v databázi Scopus

2-s2.0-105008771873