Simultaneous determinations of τ polarisation and ντ helicity using the decay τ → a1ντ

The Τ - Polarisation Test for the H / a → Τ + Τ − Signal at the Lhc

The correlation between the two τ-polarisations is predicted to be opposite (+ − / − +) for the H/A → τ + τ − signal, while it corresponds to the same sign combinations for the Drell-Yan (+ + / − −) and t ¯ t (−−) backgrounds. We show that this correlation can serve as a distinctive test to confirm the presence of the MSSM Higgs bosons H and A in their hadronic τ + τ − decay channels at the LHC.

Measurement of the - - + - branching fraction and a τ → ηπ π π ντ search for a second - class current in the - ( 958 ) - decay τ → η π ντ ′

Rare Radiative B → Τ + Τ − Γ Decay

The radiative B → τ + τ − γ decay is investigated in the framework of the Standard Model. When only short (short and long together) distance contributions are taken into account, the Branching Ratio is found as 9.54 × 10 −9 (1.52 × 10 −8), for the value of the cut δ = 0.01 imposed on the photon energy.

First Observation of the Decay τ − → φK − ν τ

We present the first observation of τ lepton decays to hadronic final states with a φ-meson. This analysis is based on 401 fb of data accumulated at the Belle experiment. The branching fraction obtained is B(τ− → φK−ντ ) = (4.05 ± 0.25 ± 0.26) × 10.

Spectral distribution for the decay τ → ν τ Kπ

With the newly available data sets on hadronic τ decays from theB-factories BABAR and BELLE, and future data from BESIII, precise information on the decay distributions will soon become available. This calls for an improvement of the decay spectra also on the theoretical side. In this work, the distribution function for the decay τ → ντKπ will be presented with the relevantKπ vector and scalar ...