Dielectron production in central Pb-Pb collisions at root sNN=5.02 TeV

Kód výsledku v IS VaVaI

<a href="https://www.isvavai.cz/riv?ss=detail&h=RIV%2F68407700%3A21340%2F25%3A00389216" target="_blank" >RIV/68407700:21340/25:00389216 - isvavai.cz</a>

Výsledek na webu

<a href="https://doi.org/10.1103/xl6m-vbqk" target="_blank" >https://doi.org/10.1103/xl6m-vbqk</a>

DOI - Digital Object Identifier

<a href="http://dx.doi.org/10.1103/xl6m-vbqk" target="_blank" >10.1103/xl6m-vbqk</a>

Jazyk výsledku

angličtina

Název v původním jazyce

Dielectron production in central Pb-Pb collisions at root sNN=5.02 TeV

Popis výsledku v původním jazyce

The first measurement of the e(+) e(-) pair production at midrapidity and low invariant mass in central Pb-Pb collisions at root sNN = 5.02 TeV at the Large Hadron Collider is presented. The yield of e(+)e(-) pairs is compared with a cocktail of expected hadronic decay contributions in the invariant mass (m(ee)) and pair transverse momentum (p(T,ee)) ranges m(ee) < 3.5 GeV/c(2) and p(T, ee) < 8 GeV/c. For 0.18 < m(ee) < 0.5 GeV/c(2) the ratio of data to the cocktail of hadronic contributions amounts to 1.40 +/- 0.11 (stat.) +/- 0.23 (syst.) +/- 0.16 (cocktail) and 1.42 +/- 0.11 (stat.) +/- 0.23 (syst.)(+0.24) (-0.29) (cocktail), including or not including medium effects in the estimation of the heavy-flavor background, respectively. It is consistent with predictions from two different models for an additional contribution of thermal e(+)e(-) pairs from the hadronic and partonic phases. In the intermediate-mass range (1.2 < mee < 2.6 GeV/c(2)), the pair transverse impact parameter of the e(+)e(-) pairs (DCA(ee), where "DCA" denotes "distance of closest approach") is used for the first time in Pb-Pb collisions to separate displaced dielectrons from heavy-flavor hadron decays from a possible (thermal) contribution produced at the interaction point. The data are consistent with a suppression of e(+)e(-) pairs from cc and an additional prompt component. Finally, the first direct-photon measurement in the 10% most central Pb-Pb collisions at root sNN = 5.02 TeV is reported via the study of virtual direct photons in the transverse momentum range 1 < pT < 5 GeV/c. A model including prompt photons, as well as photons from the preequilibrium and fluid-dynamic phases, can reproduce the result, while being at the upper edge of the data uncertainties.

Název v anglickém jazyce

Dielectron production in central Pb-Pb collisions at root sNN=5.02 TeV

Popis výsledku anglicky

The first measurement of the e(+) e(-) pair production at midrapidity and low invariant mass in central Pb-Pb collisions at root sNN = 5.02 TeV at the Large Hadron Collider is presented. The yield of e(+)e(-) pairs is compared with a cocktail of expected hadronic decay contributions in the invariant mass (m(ee)) and pair transverse momentum (p(T,ee)) ranges m(ee) < 3.5 GeV/c(2) and p(T, ee) < 8 GeV/c. For 0.18 < m(ee) < 0.5 GeV/c(2) the ratio of data to the cocktail of hadronic contributions amounts to 1.40 +/- 0.11 (stat.) +/- 0.23 (syst.) +/- 0.16 (cocktail) and 1.42 +/- 0.11 (stat.) +/- 0.23 (syst.)(+0.24) (-0.29) (cocktail), including or not including medium effects in the estimation of the heavy-flavor background, respectively. It is consistent with predictions from two different models for an additional contribution of thermal e(+)e(-) pairs from the hadronic and partonic phases. In the intermediate-mass range (1.2 < mee < 2.6 GeV/c(2)), the pair transverse impact parameter of the e(+)e(-) pairs (DCA(ee), where "DCA" denotes "distance of closest approach") is used for the first time in Pb-Pb collisions to separate displaced dielectrons from heavy-flavor hadron decays from a possible (thermal) contribution produced at the interaction point. The data are consistent with a suppression of e(+)e(-) pairs from cc and an additional prompt component. Finally, the first direct-photon measurement in the 10% most central Pb-Pb collisions at root sNN = 5.02 TeV is reported via the study of virtual direct photons in the transverse momentum range 1 < pT < 5 GeV/c. A model including prompt photons, as well as photons from the preequilibrium and fluid-dynamic phases, can reproduce the result, while being at the upper edge of the data uncertainties.

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

PHYSICAL REVIEW C

ISSN

2469-9985

e-ISSN

2469-9993

Svazek periodika

112

Číslo periodika v rámci svazku

5

Stát vydavatele periodika

US - Spojené státy americké

Počet stran výsledku

27

Strana od-do

—

Kód UT WoS článku

001641482600001

EID výsledku v databázi Scopus

2-s2.0-105027404158