Radiative corrections to semileptonic decays of charged hyperons

We have studied the radiative corrections to the lepton energy spectrum in semileptonic hyperon decays. The calculation is performed relativistically for the baryons as well as for the leptons, under the assumption of the effective current-current interaction of the V-?A type for the baryonic part. We obtain the explicit formula of radiative corrections to the lepton energy spectrum which we can exactly evaluate in case of charged hyperon decays. Numerical values of the radiative corrections to the decays rate and the shape of the lepton energy spectrum are also given for some decay modes. It is shown that the spectral shape is little affected by the radiative corrections.     

Pole contributions in semileptonic decays of D mesons

The contributions of the axial-vector and vector resonance states to D → P(V)l $\bar \nu$ _l decays are investigated on the basis of phenomenological chiral Lagrangians. It is shown that inclusion of such intermediate states improves agreement with experimental data.     

Full electroweak one-loop radiative corrections to squark decays in the MSSM

We present results on the full one-loop electroweak radiative corrections to the squark decay partial widths into charginos and neutralinos. We show the renormalization framework, and present numerical results for the third squark family. The corrections can reach values of 10%, which are comparable to the radiative corrections from the strong sector of the model. Therefore they should be taken into account for the precise extraction of the SUSY parameters at future colliders.     

Resummed photon spectrum in radiative upsilon decays

We present a theoretical prediction for the photon spectrum in radiative upsilon decay including the effects of resumming the end point region, E(gamma)-->M(upsilon)/2. Our approach is based on nonrelativistic QCD (NRQCD) and the soft-collinear effective theory. We find that our results give much better agreement with data than the leading order NRQCD prediction.     

First-order radiative corrections to polarized muon decay spectrum

The first-order QED corrections to the polarized muon decay spectrum are considered. The exact dependence on electron and muon masses is kept. Numerical results are presented.