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Preliminary study of the $\gamma\gamma\rightarrow\tau^{+}\tau^{-}$ process for the measurement of the tau anomalous magnetic moment in a hadron collider

The recent measurement of the muon's anomalous magnetic moment by the Fermilab experiment ``Muon g-2'' shows a 4.2$\sigma$ discrepancy with the theoretical prediction based on the Standard Model, serving as huge motivation for the study of new physics. An example of the later consists...

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Detalles Bibliográficos
Autor principal: CERN. Geneva. Department
Lenguaje:eng
Publicado: 2021
Materias:
Acceso en línea:http://cds.cern.ch/record/2779427
Descripción
Sumario:The recent measurement of the muon's anomalous magnetic moment by the Fermilab experiment ``Muon g-2'' shows a 4.2$\sigma$ discrepancy with the theoretical prediction based on the Standard Model, serving as huge motivation for the study of new physics. An example of the later consists in using ATLAS to perform the measurement of the anomalous magnetic moment of the tau lepton ($a_{\tau}$), using tau lepton pairs produced in photon-photon collisions generated from lead ions interactions (PbPb$\rightarrow$ PbPb$\gamma\gamma\rightarrow\tau^{+}\tau^{-}$). In this work we analyze the distributions of different observables from simulated tau leptons produced via this process and their most frequent charged decay products. This is done using MadGraph and Pythia8 generators, while the detector effects are introduced with Delphes. We compare the results obtained for a sample including only Standard Model (SM) physics and another one with additional Beyond the Standard Model (BSM) effects due to a non-zero $a_{\tau}$. Finally, the most abundant leptonic backgrounds processes $\gamma\gamma\rightarrow e^{+}e^{-}/\mu^{+}\mu^{-}$ are also generated and compared to the signal-only samples with the aim of shedding some light toward possible cuts for the reconstruction of tau decays.