Observation of the γγ → ττ process in Pb + Pb collisions and constraints on the τ-Lepton anomalous magnetic moment with the ATLAS detector

This Letter reports the observation of τ-lepton-pair production in ultraperipheral lead-lead collisions Pb+Pb→Pb(γγ→ττ)Pb and constraints on the τ-lepton anomalous magnetic moment aτ. The dataset corresponds to an integrated luminosity of 1.44 nb−1 of LHC Pb+Pb collisions at √sNN=5.02 TeV recorded b...

Full description

Saved in:
Bibliographic Details
Main Authors: Aad, Georges (Author) , Baltes, Lisa Marie (Author) , Bartels, Falk (Author) , Czurylo, Marta (Author) , Rio, Fernando del (Author) , Dittmeier, Sebastian (Author) , Dunford, Monica (Author) , Franchino, Silvia (Author) , Klassen, Martin (Author) , Mkrtchyan, Tigran (Author) , Ott, Philipp (Author) , Rassloff, Damir Fabrice (Author) , Rodriguez Bosca, Sergi (Author) , Sauer, Christof (Author) , Schöning, André (Author) , Schultz-Coulon, Hans-Christian (Author) , Sothilingam, Varsiha (Author) , Stamen, Rainer (Author) , Starovoitov, Pavel (Author) , Vigani, Luigi (Author) , Weber, Sebastian (Author) , Wessels, Martin (Author) , Zinßer, Joachim (Author)
Corporate Author: ATLAS Collaboration (Author)
Format: Article (Journal)
Language:English
Published: 12 October 2023
In: Physical review letters
Year: 2023, Volume: 131, Issue: 15, Pages: 1-23
ISSN:1079-7114
DOI:10.1103/PhysRevLett.131.151802
Online Access:Verlag, kostenfrei, Volltext: https://doi.org/10.1103/PhysRevLett.131.151802
Verlag, kostenfrei, Volltext: https://link.aps.org/doi/10.1103/PhysRevLett.131.151802
Get full text
Author Notes:ATLAS Collaboration
Description
Summary:This Letter reports the observation of τ-lepton-pair production in ultraperipheral lead-lead collisions Pb+Pb→Pb(γγ→ττ)Pb and constraints on the τ-lepton anomalous magnetic moment aτ. The dataset corresponds to an integrated luminosity of 1.44 nb−1 of LHC Pb+Pb collisions at √sNN=5.02 TeV recorded by the ATLAS experiment in 2018. Selected events contain one muon from a τ-lepton decay, an electron or charged-particle track(s) from the other τ-lepton decay, little additional central-detector activity, and no forward neutrons. The γγ→ττ process is observed in Pb+Pb collisions with a significance exceeding 5 standard deviations and a signal strength of μττ=1.03+0.06−0.05 assuming the standard model value for aτ. To measure aτ, a template fit to the muon transverse-momentum distribution from τ-lepton candidates is performed, using a dimuon (γγ→μμ) control sample to constrain systematic uncertainties. The observed 95% confidence-level interval for aτ is −0.057<aτ<0.024.
Item Description:Gesehen am 14.02.2024
ATLAS Collaboration: G. Aad, L.M. Baltes, F. Bartels, M.M. Czurylo, F. Del Rio, S.J. Dittmeier, M. Dunford, S. Franchino, M. Klassen, T. Mkrtchyan, P.S. Ott, D.F. Rassloff, S. Rodriguez Bosca, C. Sauer, A. Schoening, H-C. Schultz-Coulon, V. Sothilingam, R. Stamen, P. Starovoitov, L. Vigani, S.M. Weber, M. Wessels, J. Zinsser [und 2896 weitere]
Physical Description:Online Resource
ISSN:1079-7114
DOI:10.1103/PhysRevLett.131.151802