Observation of γγ → ττ in proton-proton collisions and limits on the anomalous electromagnetic moments of the τ lepton


CMS Collaboration T.

Reports on Progress in Physics, cilt.87, sa.10, 2024 (SCI-Expanded) identifier identifier

  • Yayın Türü: Makale / Tam Makale
  • Cilt numarası: 87 Sayı: 10
  • Basım Tarihi: 2024
  • Doi Numarası: 10.1088/1361-6633/ad6fcb
  • Dergi Adı: Reports on Progress in Physics
  • Derginin Tarandığı İndeksler: Science Citation Index Expanded (SCI-EXPANDED), Scopus, Academic Search Premier, Aerospace Database, INSPEC
  • Anahtar Kelimeler: CMS, exclusive production, taus
  • Yıldız Teknik Üniversitesi Adresli: Hayır

Özet

The production of a pair of τ leptons via photon-photon fusion, γ γ → τ τ , is observed for the first time in proton-proton collisions, with a significance of 5.3 standard deviations. This observation is based on a data set recorded with the CMS detector at the LHC at a center-of-mass energy of 13 TeV and corresponding to an integrated luminosity of 138 fb−1. Events with a pair of τ leptons produced via photon-photon fusion are selected by requiring them to be back-to-back in the azimuthal direction and to have a minimum number of charged hadrons associated with their production vertex. The τ leptons are reconstructed in their leptonic and hadronic decay modes. The measured fiducial cross section of γ γ → τ τ is σ obs fid = 12.4 − 3.1 + 3.8 fb . Constraints are set on the contributions to the anomalous magnetic moment ( a τ ) and electric dipole moments ( d τ ) of the τ lepton originating from potential effects of new physics on the γ τ τ vertex: a τ = 0.0009 − 0.0031 + 0.0032 and | d τ | < 2.9 × 10 − 17 e cm (95% confidence level), consistent with the standard model.