Related papers: New physics and tau $g-2$ using LHC heavy ion coll…
We point out that heavy new physics contributions in leptonic dipole moments and high-energy cross-sections of lepton pairs into Higgs bosons and photons are connected model-independently. In particular, we demonstrate that a muon collider,…
Tau leptons play an important role in the physics program at the LHC. They are used in searches for new phenomena like the Higgs boson or Supersymmetry and in electroweak measurements. Identifying hadronically decaying tau leptons with good…
In this work we study the sensitivity on the anomalous magnetic and electric dipole moments of the tau-neutrino in the framework of the $SU(2)_L\times U(1)_Y\times U(1)_{B-L}$ electroweak model at future $e^+e^-$ linear colliders as the ILC…
We calculate chirally enhanced corrections to the muon's electric and magnetic dipole moments in two-Higgs-doublet models extended by vector-like leptons, and we explore a sharp correlation between $h \rightarrow \mu^+ \mu^-$ and the muon's…
We present the first calculation of photon-initiated $\tau$ pair production in the presence of non-zero anomalous magnetic ($a_\tau$) and/or electric dipole ($d_\tau$) moments of the $\tau$ lepton that accounts for the non-trivial interplay…
We present an observation of photon-photon production of $\tau$ lepton pairs in ultraperipheral lead-lead collisions. The measurement is based on a data sample with an integrated luminosity of 404 $\mu$b$^{-1}$ collected by the CMS…
Pair production of tau leptons in two photon collision ${\gamma\gamma \to \tau^{+}\tau}^{-}$ is studied at CLIC to test CP violating QED couplings of tau leptons. CP violating effects are investigated using tau pair spin correlations which…
We report a measurement of the electric dipole moment of the $\tau$ lepton ($d_\tau$) using an 833~fb$^{-1}$ data sample collected near the $\Upsilon(4S)$ resonance, with the Belle detector at the KEKB asymmetric-energy $e^+ e^-$ collider.…
We argue that the anomalous magnetic moment of the electron (a_e) can be used to probe new physics. We show that the present bound on new-physics contributions to a_e is 8*10^-13, but the sensitivity can be improved by about an order of…
We have searched for a CP violation signature arising from an electric dipole moment (d_tau) of the tau lepton in the e+e- -> tau+tau- reaction. Using an optimal observable method and 29.5 fb^{-1} of data collected with the Belle detector…
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…
Tau-pair production in the process e+e- -> e+e-tau+tau- was studied using data collected by the DELPHI experiment at LEP2 during the years 1997 - 2000. The corresponding integrated luminosity is 650 pb^{-1}. The values of the cross-section…
A review of the theoretical and experimental values for the charged lepton (electron and muon) anomalous magnetic moment $a_l= (g_l-2)/2$ is presented. Employing the most accurate value for the fine structure constant $\alpha^{-1}=…
Motivated by the $b \to c \tau \overline{\nu}$ anomalies, we study non-resonant searches for new physics at the large hadron collider (LHC) by considering final states with an energetic and hadronically decaying $\tau$ lepton, a $b$-jet and…
This thesis presents a study of the decays $\tau\rightarrow e\nu\overline{\nu}$ identified after a selection of $\tau^+\tau^-$ events produced in $e^+e^-$ collisions at LEP. These collisions, predominantly mediated by a $Z^0$ boson, offer a…
We calculate the prediction for the anomalous weak-magnetic form factor of the tau lepton at $q^2=M_Z^2$ within the Standard Model. With all particles on-shell, this is a electroweak gauge invariant quantity. Its value is $a_\tau^w (M_Z^2)=…
We obtain new bounds for the magnetic dipole moments of the tau lepton. These limits on the magnetic couplings of the tau to the electroweak gauge bosons (gamma, W, Z) are set in a model independent way using the most general effective…
The long-standing difference between the experimental measurement and the standard-model prediction for the muon's anomalous magnetic moment, $a_{\mu} = (g_{\mu}-2)/2$, may be explained by the presence of new weakly interacting particles…
Testing New-Physics (NP) scenarios that couple predominantly to the third generation is notoriously difficult experimentally, as exemplified by comparing limits for the $\tau$ lepton dipole moments to those of electrons and muons. In this…
We establish model independent bounds on the anomalous magnetic and electric dipole moments of the tau-lepton using the two-photon processes $\gamma\gamma \to \tau^+\tau^-$ and $\gamma\gamma \to \tau^+\tau^-\gamma$. We use ${\cal L}=10, 50,…