Ústav technické a experimentální fyziky Institute of Experimental and Applied Physics

Observation of the γγ → ττ Process in Pb plus Pb Collisions and Constraints on the τ-Lepton Anomalous Magnetic Moment with the ATLAS Detector

NázevTitle
Observation of the γγ → ττ Process in Pb plus Pb Collisions and Constraints on the τ-Lepton Anomalous Magnetic Moment with the ATLAS DetectorObservation of the γγ → ττ Process in Pb plus Pb Collisions and Constraints on the τ-Lepton Anomalous Magnetic Moment with the ATLAS Detector
Druh výsledkuResult type
Článek v časopiseJournal article
AutořiAuthors
G. Aad, B. Abbott, D. C. Abbott, A. A. Abud, B. Ali, K. Augsten, B. Bergmann, T. Billoud, M. Havránek, Z. Hubáček, P. Jačka, S. Mondal, M. Myška, L. Novotný, V. Petousis, R. Polifka, S. Pospíšil, K. Smolek, A. Sopczak, V. Vacek, P. Vokáč, O. Zaplatílek
DOIDOI
10.1103/PhysRevLett.131.151802
Časopis / citaceJournal / citation
Physical Review Letters. 2023, 131(15), ISSN 0031-9007.
RokYear
2023
JazykLanguage
eng
WoSWoS
001094306100001
ScopusScopus
2-s2.0-85185370802
RIVRIV
RIV/68407700:21220/23:00372955!RIV24-MSM-21220___
ProjektProject
Centrum pokročilých aplikovaných přírodních vědCenter for advanced applied sciences; CERN-CZ III - Výzkumná infrastruktura pro experimenty v CERN - LM2023040 (2023–2026)CERN-CZ III - Výzkumná infrastruktura pro experimenty v CERN - LM2023040 (2023–2026)

AbstraktAbstract

This Letter reports the observation of tau-lepton-pair production in ultraperipheral lead-lead collisions Pb + Pb -> Pb(gamma gamma -> tau tau)Pb and constraints on the tau-lepton anomalous magnetic moment a(tau). The dataset corresponds to an integrated luminosity of 1.44 nb(-1) of LHC Pb + Pb collisions at root(NN)-N-s = 5.02 TeV recorded by the ATLAS experiment in 2018. Selected events contain one muon from a t-lepton decay, an electron or charged-particle track(s) from the other tau-lepton decay, little additional central-detector activity, and no forward neutrons. The gamma gamma -> tau tau process is observed in Pb + Pb collisions with a significance exceeding 5 standard deviations and a signal strength of mu(tau tau) = 1.03(-0.05)(+0.06) assuming the standard model value for a(tau). To measure a(tau), a template fit to the muon transverse-momentum distribution from tau-lepton candidates is performed, using a dimuon (gamma gamma -> mu mu) control sample to constrain systematic uncertainties. The observed 95% confidence-level interval for a(tau) is -0.057 < a(tau) < 0.024.

This Letter reports the observation of tau-lepton-pair production in ultraperipheral lead-lead collisions Pb + Pb -> Pb(gamma gamma -> tau tau)Pb and constraints on the tau-lepton anomalous magnetic moment a(tau). The dataset corresponds to an integrated luminosity of 1.44 nb(-1) of LHC Pb + Pb collisions at root(NN)-N-s = 5.02 TeV recorded by the ATLAS experiment in 2018. Selected events contain one muon from a t-lepton decay, an electron or charged-particle track(s) from the other tau-lepton decay, little additional central-detector activity, and no forward neutrons. The gamma gamma -> tau tau process is observed in Pb + Pb collisions with a significance exceeding 5 standard deviations and a signal strength of mu(tau tau) = 1.03(-0.05)(+0.06) assuming the standard model value for a(tau). To measure a(tau), a template fit to the muon transverse-momentum distribution from tau-lepton candidates is performed, using a dimuon (gamma gamma -> mu mu) control sample to constrain systematic uncertainties. The observed 95% confidence-level interval for a(tau) is -0.057 < a(tau) < 0.024.