We describe the simulation of tau decays in the Herwig++ event generator, which includes sophisticated modelling of the hadronic currents and full treatment of spin correlation effects. The structure of the simulation makes it easy to add new models of tau decay, change the parameters of the existing models, and use the models from tau decay for the decay of other particles. The results are com...

We discuss the uses of conversion electron pairs for extracting photon polarization information in weak radiative B decays. Both cases of leptons produced through a virtual and real photon are considered. Measurements of the angular correlation between the (Kπ) and (e+e−) decay planes in B → K∗(→ Kπ)γ(∗)(→ e+e−) decays can be used to determine the helicity amplitudes in the radiative B → K∗γ de...

The electroweak penguin mediated B → Xsll decay is a good probe to study beyond the Standard Model physics at low energy. The effect of new physics could be observed as corrections to the branching fraction, di-lepton invariant mass spectrum, and to the Wilson coefficients such as C9, C10, and a phase of C7 [1-10]. Experimentally, the exclusive B → Kll decay was observed by the Belle collaborat...

The branching fractions for !ee, , and hh are measured using data collected with the, where the rst errors are statistical, the second systematic, and h refers either to a charged or K. Also measured is the tau mass, m=(1778.21.4) MeV. Lepton universality is aarmed by the resulting relative branching fractions (B/Be=0.97770.00630.0087, B h /Be=0.64840.00410.0060) and the charged-current gauge c...

A concise geometrical formulation of N = 4 supergravity containing an antisymmetric tensor gauge field is given in central charge superspace: graviphotons are identified in the super–vielbein on the same footing as the vierbein and the Rarita–Schwinger fields. As a consequence of superspace soldering, Chern–Simons terms in the fieldstrength of the antisymmetric tensor arise as an intrinsic prop...

We consider theories with a spontaneously broken gauged R-symmetry, which can only occur in supergravity models. These give rise to cosmic R-strings upon which gravitino zero modes can exist. We construct solutions to the Rarita-Schwinger spin-3/2 equation describing the gravitino in the field of these cosmic strings and show that under some conditions these solutions may give rise to gravitino...

Sufficiently inclusive observables in the decay of the tau lepton can be calculated using the methods of perturbative QCD. These include the asymmetry parameter Aτ that determines that angular distribution of the total hadron momentum in the decay of a polarized tau. It should be possible to measure Aτ accurately using existing data from LEP. Reliable estimates of theoretical errors are essenti...

We have derived constraints on the tau neutrino mass and fourth generation mixing from an analysis of the partial widths of tau lepton decays, in particular: τ−→ e−ν̄eντ , τ −→μ−ν̄μντ , τ →π −ντ , and τ →K −ντ . We present predictions for the tau decay widths, allowing for a non-zero tau neutrino mass, mντ , and for mixing with a neutrino of mass mνL > MZ/2, which is parametrised using a Cabibbo-...

We analyze well-posedness of a scattering problem of time-harmonic electromagnetic waves by periodic structures with sign-changing coefficients. Transmission problems for Maxwell’s equations with sign-changing coefficients in bounded domains have been recently studied by Bonnet-Ben Dhia and co-workers in the so-called T -coercivity framework. In this article we generalize such framework for per...