Cover Image

Soft-dielectron excess in proton-proton collisions at √s=13 TeV

Show other versions (256)

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 dielectro...

Full description

Saved in:
Bibliographic Details
Main Authors: Acharya, Shreyasi (Author) , Angelov, Venelin (Author) , Arslandok, Mesut (Author) , Danisch, Meike (Author) , Feuillard, Victor (Author) , Glässel, Peter (Author) , Kim, Jiyoung (Author) , Kim, Minjung (Author) , Köhler, Markus Konrad (Author) , Leardini, Lucia (Author) , López, Jorge (Author) , Martin, Nicole Alice (Author) , Ohlson, Alice (Author) , Pachmayer, Yvonne C. (Author) , Reygers, Klaus (Author) , Schicker, Rainer (Author) , Schmah, Alexander (Author) , Schmidt, Marten Ole (Author) , Stachel, Johanna (Author) , Stiefelmaier, Stephan (Author) , Windelband, Bernd (Author) , Yüncü, Alperen (Author)
Corporate Author: ALICE (Author)
Format: Article (Journal)
Language:English
Published: 23 July 2021
In: Physical review letters
Year: 2021, Volume: 127, Issue: 4, Pages: 1-13
ISSN:1079-7114
DOI:10.1103/PhysRevLett.127.042302
Online Access:Verlag, lizenzpflichtig, Volltext: https://doi.org/10.1103/PhysRevLett.127.042302
Verlag, lizenzpflichtig, Volltext: https://link.aps.org/doi/10.1103/PhysRevLett.127.042302
Get full text
Author Notes:S. Acharya et al., (A Large Ion Collider Experiment Collaboration)
Description
Summary: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<mee<0.6 GeV/c2 and for pT,ee<0.4 GeV/c indicates an enhancement of soft dielectrons, reminiscent of the “anomalous” soft-photon and soft-dilepton excess in hadron-hadron collisions reported by several experiments under different experimental conditions. The enhancement factor over the hadronic cocktail amounts to 1.61±0.13(stat)±0.17(syst,data)±0.34(syst,cocktail) in the ALICE acceptance. Acceptance-corrected excess spectra in mee and pT,ee are extracted and compared with calculations of dielectron production from hadronic bremsstrahlung and thermal radiation within a hadronic many-body approach.
Item Description:(A Large Ion Collider Experiment Collaboration): S. Acharya, V. Anguelov, M. Arslandok, M.C. Danisch, V.J.G. Feuillard, P. Glässel, J. Kim, M. Kim, M.K. Köhler, L. Leardini, J.A. Lopez, N.A. Martin, A. Ohlson, Y. Pachmayer, K. Reygers, R. Schicker, A. Schmah, M.O. Schmidt, J. Stachel, S.F. Stiefelmaier, B. Windelband, A. Yuncu [und viele weitere]
Gesehen am 03.11.2021
Im Titel steht der Buchstabe s unter dem Wurzelsymbol
Physical Description:Online Resource
ISSN:1079-7114
DOI:10.1103/PhysRevLett.127.042302

Similar Items