Electron-positron, parton-parton and photon-photon production of $\tau$-lepton pairs: anomalous magnetic and electric dipole moments spin effects

Abstract

Anomalous contributions to the electric and magnetic dipole moments of the $\tau$ lepton from new physics scenarios have brought renewed interest in the development of new charge-parity violating signatures in $\tau$-pair production at Belle II energies, and also at higher energies of the Large Hadron Collider and the Future Circular Collider. In this paper, we discuss the effects of spin correlations, including transverse degrees of freedom, in the $\tau$-pair production and decay. These studies include calculating analytical formulas, obtaining numerical results, and building semi-realistic observables sensitive to the transverse spin correlations induced by the dipole moments of the $\tau$ lepton. The effects of such anomalous contributions to the dipole moments are introduced on top of precision simulations of $e^{-}{e}^{+}\to {\tau }^{-}{\tau }^{+}$, $q\bar{q}\to {\tau }^{-}{\tau }^{+}$ and $\gamma \gamma \to {\tau }^{-}{\tau }^{+}$ processes, involving multi-body final states. The $\tau$ decays are simulated along with radiative corrections, in particular electroweak box contributions of $WW$ and $ZZ$ exchanges are taken into account. Respective extensions of the Standard Model amplitudes and the reweighting algorithms are implemented into the KKMC Monte Carlo, which is used to simulate $\tau$-pair production in $e^{-}{e}^{+}$ collisions, and the TauSpinner program, which is used to reweight events with $\tau$ pair produced in $pp$ collisions.

arXiv comment30 pages, 5 figures; v2: introduction and summary are extended, radiative corrections are included in subsection 2.1 in framework of improved Born approximation; several references added, misprints corrected, corresponds to published version

References in corpus (32)

• The automated computation of tree-level and next-to-leading order differential cross sections, and their matching to parton shower simulations
• UFO - The Universal FeynRules Output
• Measurement of the Positive Muon Anomalous Magnetic Moment to 0.46 ppm
• Event Generation with Sherpa 2.2
• Event generator tunes obtained from underlying event and multiparton scattering measurements
• STARlight: A Monte Carlo simulation program for ultra-peripheral collisions of relativistic ions
• The automation of next-to-leading order electroweak calculations
• ZFITTER v.6.21 - A Semi-Analytical Program for Fermion Pair Production in e+e- Annihilation
• Theory of the tau lepton anomalous magnetic moment
• Measurement of underlying event characteristics using charged particles in pp collisions at $\sqrt{s}=900GeV$ and 7 TeV with the ATLAS detector
• SANCscope -- v.1.00
• Quark level and hadronic contributions to the electric dipole moment of charged leptons in the standard model
• Anomalous electromagnetic moments of $\tau$ lepton in $\gamma \gamma \to {\tau }^{+}{\tau }^{-}$ reaction in Pb+Pb collisions at the LHC
• Top Dipole Form Factors and Loop-induced CP-violation in Supersymmetry
• The tau weak-magnetic dipole moment
• Observation of the $\gamma \gamma \to \tau \tau$ process in Pb+Pb collisions and constraints on the $\tau$-lepton anomalous magnetic moment with the ATLAS detector
• TauSpinner program for studies on spin effect in tau production at the LHC
• CP Violation Beyond the Standard Model and Tau Pair Production in $e^{+}{e}^{-}$ Collisions
• Search for anomalous weak dipole moments of the tau lepton
• Dipole Form Factors and Loop-induced CP-violation in Supersymmetry
• The photon PDF within the CT18 global analysis
• The Monte Carlo Program KKMC for the Lepton or Quark Pair Production at LEP/SLC Energies -- updates of electroweak calculations
• Observation of $\tau$ lepton pair production in ultraperipheral lead-lead collisions at $\sqrt{s_{\mathrm{NN}}}$ = 5.02 TeV
• An improved search for the electric dipole moment of the $\tau$ lepton
• TauSpinner: a tool for simulating CP effects in H to tau tau decays at LHC
• Documentation of TauSpinner algorithms -- program for simulating spin effects in tau-lepton production at LHC
• Separating Electroweak and Strong interactions in Drell-Yan processes at LHC: leptons angular distributions and reference frames
• W production at LHC: lepton angular distributions and reference frames for probing hard QCD
• Production of tau lepton pairs with high pT jets at the LHC and the TauSpinner reweighting algorithm
• Spin correlations in $\tau$-lepton pair production due to anomalous magnetic and electric dipole moments
• Probing the tau electric dipole moment at BEPC-II collider energies
• The TauSpinner approach for electroweak corrections in LHC Z to ll observables

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