Observation of τ lepton pair production in ultraperipheral Pb-Pb collisions at √s&lt;sub&gt;NN&lt;/sub&gt;=5.02  TeV

Tumasyan, A.; Adam, W.; Andrejkovic, J.W.; Bergauer, T.; Chatterjee, S.; Damanakis, K.; Dragicevic, M.; Escalante Del Valle, A.; Hussain, P.S.; Jeitler, M.; Caminada, L.; Ebrahimi, A.; Erdmann, W.; Horisberger, R.; Ingram, Q.; Kaestli, H.C.; Kotlinski, D.; Lange, C.; Missiroli, M.; Noehte, L.; Rohe, T.; Zhokin, A.

doi:10.1103/PhysRevLett.131.151803

Observation of τ lepton pair production in ultraperipheral Pb-Pb collisions at √s_NN=5.02 TeV

Tumasyan A, Adam W, Andrejkovic JW, Bergauer T, Chatterjee S, Damanakis K, Dragicevic M, Escalante Del Valle A, Hussain PS, Jeitler M, Caminada L, Ebrahimi A, Erdmann W, Horisberger R, Ingram Q, Kaestli HC, Kotlinski D, Lange C, Missiroli M, Noehte L, Rohe T, Zhokin A, et al.

Citation

Tumasyan, A., Adam, W., Andrejkovic, J. W., Bergauer, T., Chatterjee, S., Damanakis, K., … Zhokin, A. (2023). Observation of τ lepton pair production in ultraperipheral Pb-Pb collisions at √s_NN=5.02 TeV. Physical Review Letters, 131(15), 151803 (18 pp.). https://doi.org/10.1103/PhysRevLett.131.151803

Persistent URL https://www.dora.lib4ri.ch/psi/islandora/object/psi:56611

We present an observation of photon-photon production of τ lepton pairs in ultraperipheral lead-lead collisions. The measurement is based on a data sample with an integrated luminosity of 404 μb^-1 collected by the CMS experiment at a center-of-mass energy per nucleon pair of √s_NN=5.02 TeV. The γγ→τ⁺τ^- process is observed for τ⁺τ^-events with a muon and three charged hadrons in the final state. The measured fiducial cross section is σ(γγ→τ⁺τ^-)=4.8±0.6(stat)±0.5(syst) μb, where the second (third) term corresponds to the statistical (systematic) uncertainty in σ(γγ→τ⁺τ^-) in agreement with leading-order QED predictions. Using σ(γγ→τ⁺τ^-), we estimate a model-dependent value of the anomalous magnetic moment of the τ lepton of a_τ=0.001_-0.089^+0.055.