Conveners
Session 2a: Test of fundamental symmetries with tau lepton
- Swagato Banerjee (University of Louisville (US))
Session 2a: Test of fundamental symmetries with tau lepton
- Bertrand Echenard (California Institute of Technology)
Session 2a: Test of fundamental symmetries with tau lepton
- Alexey Petrov (Wayne State University)
I will provide a short overview on deviations of the Standard Model symmetries within tau lepton processes. I will consider from dynamic dependent symmetries such as universality to the breaking of global symmetries, namely lepton flavor, lepton number or baryon number violations.
In the last couple of decades, there has been a tremendous growth of interest in testing fundamental symmetries, such as CPT and the Lorentz invariance of special relativity. Using effective field theory, it has been possible to parameterize a much broader range of symmetry violations that had previously been envisioned or tested. The new possibilities include different patterns of symmetry...
In the quest to map out the structure of the proton in exquisite detail, the Electron Ion Collider (EIC) will collide electrons and protons at high energy with unprecedented luminosity.
In this talk I will discuss how to exploit the features of the EIC to explore physics beyond the Standard Model. I will focus on charged-lepton-flavor-violating (CLFV) interactions in which an electron is...
Within the Standard Model Effective Field Theory framework, with operators up to dimension 6, we perform a model-independent analysis of the lepton-flavour-violating processes involving tau leptons. Namely, we study hadronic tau decays and $\ell$-$\tau$ conversion in nuclei, with $\ell = e,\mu$. Based on available experimental limits, we establish constraints on the Wilson coefficients of the...
Lorentz invariance is among the most fundamental and tested symmetries in physics. Measurements from over two decades of experiments place stringent constraints on many Lorentz-violating interactions affecting the particles of the Standard Model. However, a large class of interactions inducing charged-lepton-flavor violation remains largely unexamined. In this talk, we discuss dominant...
We present in full analytic form the partial widths for the lepton flavor violating decays $L^\pm \to \ell^\pm \ell'^{+} \ell'^{-}$, with $L = \tau, \mu$ and $\ell^{(\prime)} = \mu, e$, mediated by neutrino oscillations in the one-loop diagrams. Compared to the first result by Petcov:1976ff, which was obtained in the nonphysical zero momentum limit $\mathcal{P} \ll m_{\nu} \ll M_W$, we retain...
We report on the first search for electron-muon flavor violation in the decay of a b quark and anti-b quark bound state. A search for the LFV decay Υ(3S) → e± μ∓ in a sample of 118 million Υ(3S) mesons from 27 fb−1 of data collected with the BABAR detector at the SLAC PEP-II e+e− collider operating with a 10.36 GeV center-of-mass energy revealed no signal. We set a limit on the branching...
Many theories beyond the Standard Model predict new phenomena, such as Z’, W’ bosons, or heavy leptons, in final states with isolated, high-pt leptons (e/mu/tau). Searches for new physics with such signatures, produced either resonantly or non-resonantly, are performed using the ATLAS experiment at the LHC. This includes a novel search that exploits the lepton-charge asymmetry in events with...
In the past half a dozen years or so, the tau lepton has become the central focus for many reasons. Foremost in this is the fact that there are strong experimental hints that the tau is intimately involved in strong indications of lepton universality violations (LUV). Moreover, it is no longer just one type of experiments but rather three different types are involved and in each case the...
Searches for the violation of lepton flavor universality (LFU) are critical precision tests of the standard model (SM) motivated by the growing number of anomalies reported in several measurements in the flavor sector (quarks and leptons) in the last decades. At the Belle II experiment, thanks to the large amount of tau-lepton pairs produced in electron-positron annihilation, it is possible to...
Using the Belle II data from the early Phase III data taking, we reconstructed the tau
leptons using the 3-prong τ decays. This decay mode is used for the tau-lepton mass
measurement using the pseudomass technique developed by the ARGUS experiment. Though
this measurement is expected to be limited by statistics and imperfect knowledge of
the detector performance, we foresee that Belle II...
