Conveners
Session 4
- Lei Zhang (Nanjing University)
This talk presents a model independent search for an additional heavy, mostly sterile, neutral lepton (HNL) which is capable of mixing with the Standard Model tau neutrino with a mixing strength of $|𝑈\tau 4|2$, corresponding to the square of the extended Pontecorvo–Maki–Nakagawa–Sakata (PMNS) matrix element. HNLs are hypothetical particles predicted by many beyond Standard Model theories,...
The ratios $R_{\tau/P}\equiv \Gamma(\tau\to P \nu_\tau[\gamma])/\Gamma(P\to \mu \nu_\mu[\gamma]) (P=\pi, K)$ provide sensitive tests of lepton universality $|g_\tau/g_\mu|=1$ and are a useful tool for new physics searches. We improve previous computations of the corresponding radiative corrections, within Chiral Perturbation Theory with resonances, complying with known QCD limits. We find...
The HFLAV tau branching fraction fit results are used to compute lepton universality tests and Vus, using the recently published radiative corrections for the tau hadronic branching fractions. The HFLAV tau fit is included in the HFLAV report that has been recently submitted for publication.
