Related papers: Tau spin correlations and the anomalous magnetic m…
The consistency of the spin correlation strength in top quark pair production with the standard model (SM) prediction is tested in the muon + jets final state. The events are selected from pp collisions, collected by the CMS detector, at a…
We reconsider the issue of the search for a nonzero electric dipole form factor (EDM) $d_\tau(s)$ using optimal observables in $\tau^+\tau^-$ production by $e^+ e^-$ collisions in the center-of-mass energy range from the $\tau$-pair…
CP violation at low energy is investigated at the tau electromagnetic vertex. High statistics at B factories, and on top of the Upsilon resonances, allows a detailed investigation of CP-odd observables related to the tau-pair production.…
The electromagnetic dipole moments of the tau lepton and the chromoelectromagnetic dipole moments of the top quark are estimated via flavor-changing neutral currents, mediated by a new neutral massive gauge boson. We predict them in the…
Within the framework of quantum field theory and the Standard Model (SM), we investigate the prospects of studying entanglement measures and Bell-type spin-correlation observables in the electroweak process $e^- e^+\to \tau^-\tau^+$ at the…
We calculate the squared matrix element for the process e+ e- --> tau+ tau- gamma allowing for anomalous magnetic and electric dipole moments at the tau tau gamma vertex. No interferences are neglected and no approximations of light fermion…
We investigate the prospects of the search for a nonzero $\tau$ EDM form factor $d_\tau(s)$ in $\tau$ pair production by $e^+ e^-$ collisions at BEPC-II collider energies. We compute the expectation values and covariances of simple and…
The neutrinos produced in $\tau$ decays cannot be directly detected, making the reconstruction of $\tau$ kinematics challenging and affecting measurements of quantum correlations such as spin entanglement. For the process $e^+e^- \to…
The anomalous magnetic (MDM) and electric (EDM) dipole moments of the $\tau$ lepton serve as crucial indicators of new physics beyond the Standard Model. Leveraging azimuthal angular asymmetry as a novel tool in ultraperipheral collisions…
The Lorentz structure of the tau lepton's charged-current can almost be completely determined by use of stage-two spin-correlation functions for the $\{\rho ^{-},\rho ^{+}\}$and $\{a_1^{-},a_1^{+}\}$ decay modes. It is possible to test for…
Sufficiently inclusive observables in the decay of the tau lepton can be calculated using the methods of perturbative QCD. These include the asymmetry parameter $A_\tau$ that determines that angular distribution of the total hadron momentum…
This Letter reports the observation of $\tau$-lepton pair production in ultraperipheral lead-lead collisions, $\text{Pb+Pb} \to \text{Pb}(\gamma\gamma \to \tau\tau)\text{Pb}$, and constraints on the $\tau$-lepton anomalous magnetic moment,…
In a recent paper, 8 semileptonic parameters were defined to specify the most general Lorentz-invariant spin correlation functions for 2-body tau decays. These parameters can be used to search for anomalous longitudinal-versus transverse…
The possible anomalous New Physics contributions to electric and magnetic dipole moments of the $\tau$ lepton has brought renewed interest in development of new charge-parity violating signatures in the $\tau$-pair production at Belle II…
We calculate the new physics effects on the anomalous magnetic moment of the muon in the framework of the two Higgs doublet model. We predict an upper bound for the lepton flavor violating coupling, which is responsible for the point like…
We discuss the sensitivity of the $\gamma\gamma \to \tau^+\tau^-$ process in ultraperipheral Pb+Pb collisions at LHC energies on the anomalous magnetic moment of $\tau$ lepton ($a_\tau$). We derive the corresponding cross sections…
The Lorentz structure of the tau lepton's charged-current can almost be completely determined by use of stage-two spin-correlation functions for the $\{\rho ^{-},\rho ^{+}\}$ and $\{a_1^{-},a_1^{+}\}$ decay modes It is possible to test for…
In semi-leptonic $B$ decays with a tau lepton, features of the production process are imprinted on the tau helicity states. Since the tau momentum cannot be fully reconstructed experimentally, the available information on the tau properties…
We have investigated the electromagnetic moments of the tau lepton in $e^{+}e^{-} \rightarrow e^{+}\gamma^{*} \gamma^{*} e^{-}\rightarrow e^{+}\tau \bar{\tau}e^{-}$ process at the CLIC. We have obtained 95% confidence level bounds on the…
Precise measurements of the lepton properties provide stringent tests of the Standard Model and accurate determinations of its parameters. We overview the present status of tau physics, highlighting the most recent developments, and discuss…