Электронный каталог

Статья

Aad, G.
Observation of the *g*g *> *t*t Process in Pb+Pb Collisions and Constraints on the *t-Lepton Anomalous Magnetic Moment with the ATLAS Detector / G.Aad, F.Ahmadov, I.N.Aleksandrov, V.A.Bednyakov, I.R.Boyko, I.A.Budagov, G.A.Chelkov, A.Cheplakov, M.V.Chizhov, D.V.Dedovich, M.Demichev, A.Gongadze, M.I.Gostkin, S.N.Karpov, Z.M.Karpova, U.Kruchonak, V.Kukhtin, E.Ladygin, V.Lyubushkin, T.Lyubushkina, S.Malyukov, M.Mineev, E.Plotnikova, I.N.Potrap, N.A.Rusakovich, M.Shiyakova, A.Soloshenko, S.Turchikhin, T.Turtuvshin, I.Yeletskikh, A.Zhemchugov, N.I.Zimine, N.Huseynov, Y.Kulchitsky, [ATLAS Collab.] // Physical Review Letters [Electronic resource]. – 2023. – Vol.131, No.15. – P.151802. – URL: https://doi.org/10.1103/PhysRevLett.131.151802. – Bibliogr.:86.

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.



ОИЯИ = ОИЯИ (JINR)2023
Спец.(статьи,препринты) = С 343 е2 - Взаимодействие релятивистских ядер с ядрами