Inhaltszusammenfassung

The first measurements of dielectron production at midrapidity (|𝜂𝑐|<0.8) in proton-proton and proton-lead collisions at 𝑠NN‾‾‾‾√ = 5.02 TeV at the LHC are presented. The dielectron cross section is measured with the ALICE detector as a function of the invariant mass 𝑚T,ee and the pair transverse momentum 𝑝T,ee in the ranges 𝑚T,ee < 3.5 GeV/𝑐2 and 𝑚T,ee < 8.0 GeV/𝑐2, in both collision systems. In proton-proton collisions, the charm and beauty cross sections are determined at midrapidity from ...The first measurements of dielectron production at midrapidity (|𝜂𝑐|<0.8) in proton-proton and proton-lead collisions at 𝑠NN‾‾‾‾√ = 5.02 TeV at the LHC are presented. The dielectron cross section is measured with the ALICE detector as a function of the invariant mass 𝑚T,ee and the pair transverse momentum 𝑝T,ee in the ranges 𝑚T,ee < 3.5 GeV/𝑐2 and 𝑚T,ee < 8.0 GeV/𝑐2, in both collision systems. In proton-proton collisions, the charm and beauty cross sections are determined at midrapidity from a fit to the data with two different event generators. This complements the existing dielectron measurements performed at 𝑠√ = 7 and 13 TeV. The slope of the 𝑠√ dependence of the three measurements is described by FONLL calculations. The dielectron cross section measured in proton-lead collisions is in agreement, within the current precision, with the expected dielectron production without any nuclear matter effects for e+e− pairs from open heavy-flavor hadron decays. For the first time at LHC energies, the dielectron production in proton-lead and proton-proton collisions are directly compared at the same 𝑠NN‾‾‾‾√ via the dielectron nuclear modification factor 𝑅pPb. The measurements are compared to model calculations including cold nuclear matter effects, or additional sources of dielectrons from thermal radiation. » weiterlesen» einklappen

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Klassifikation

DDC Sachgruppe:
Physik