Soft-Dielectron Excess in Proton-Proton Collisions at s =13 TeV

Summary, in English

A measurement of dielectron production in proton-proton (pp) collisions at s=13 TeV, recorded with the ALICE detector at the CERN LHC, is presented in this Letter. The data set was recorded with a reduced magnetic solenoid field. This enables the investigation of a kinematic domain at low dielectron (ee) invariant mass mee and pair transverse momentum pT,ee that was previously inaccessible at the LHC. The cross section for dielectron production is studied as a function of mee, pT,ee, and event multiplicity dNch/dη. The expected dielectron rate from hadron decays, called hadronic cocktail, utilizes a parametrization of the measured η/π0 ratio in pp and proton-nucleus collisions, assuming that this ratio shows no strong dependence on collision energy at low transverse momentum. Comparison of the measured dielectron yield to the hadronic cocktail at 0.15

• Author: S. Acharya; J. Adolfsson; P. Christiansen; O. Matonoha; A.F. Nassirpour; A. Ohlson; A. Oskarsson; T. Richert; O.V. Rueda; D. Silvermyr; E. Stenlund; N. Zurlo
• Department/s: Particle and nuclear physics; eSSENCE: The e-Science Collaboration
• Publishing year: 2021
• Language: English
• Publication/Series: Physical Review Letters
• Volume: 127
• Issue: 4
• Links: http://dx.doi.org/10.1103/PhysRevLett.127.042302
• Document type: Journal article
• Publisher: American Physical Society
• Topic: Subatomic Physics
• Keywords: Hadrons; Collision energies; Enhancement factor; Experimental conditions; Hadron-Hadron collisions; Many-body approach; Proton proton collisions; Proton-nucleus collisions; Strong dependences; Nuclear reactions
• Status: Published
• ISBN/ISSN/Other: ISSN: 0031-9007