Dielectron production in central Pb-Pb collisions at √sNN=5.02TeV
The result's identifiers
Result code in IS VaVaI
<a href="https://www.isvavai.cz/riv?ss=detail&h=RIV%2F61389005%3A_____%2F25%3A00645495" target="_blank" >RIV/61389005:_____/25:00645495 - isvavai.cz</a>
Alternative codes found
RIV/68378271:_____/25:00645495
Result on the web
<a href="https://journals.aps.org/prc/abstract/10.1103/xl6m-vbqk" target="_blank" >https://journals.aps.org/prc/abstract/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>
Alternative languages
Result language
angličtina
Original language name
Dielectron production in central Pb-Pb collisions at √sNN=5.02TeV
Original language description
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.
Czech name
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Czech description
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Classification
Type
J<sub>imp</sub> - Article in a specialist periodical, which is included in the Web of Science database
CEP classification
—
OECD FORD branch
10304 - Nuclear physics
Result continuities
Project
Result was created during the realization of more than one project. More information in the Projects tab.
Continuities
I - Institucionalni podpora na dlouhodoby koncepcni rozvoj vyzkumne organizace
Others
Publication year
2025
Confidentiality
S - Úplné a pravdivé údaje o projektu nepodléhají ochraně podle zvláštních právních předpisů
Data specific for result type
Name of the periodical
Physical Review C
ISSN
2469-9985
e-ISSN
2469-9993
Volume of the periodical
112
Issue of the periodical within the volume
5
Country of publishing house
US - UNITED STATES
Number of pages
27
Pages from-to
054906
UT code for WoS article
001641482600001
EID of the result in the Scopus database
2-s2.0-105027404158