ar X iv : h ep - p h / 04 07 01 6 v 1 1 J ul 2 00 4 Numerical Evaluation of One - Loop Diagrams Near Exceptional Momentum Configurations

ar X iv : h ep - p h / 04 07 07 9 v 1 7 J ul 2 00 4 Multi - leg calculations with the GRACE / 1 - LOOP system

ar X iv : h ep - e x / 04 08 01 4 v 1 6 A ug 2 00 4 Plans for Kaon Physics at BNL

ar X iv : h ep - p h / 04 07 16 3 v 1 14 J ul 2 00 4 Quark - gluon vertex model and lattice - QCD data

A model for the dressed quark-gluon vertex, at zero gluon momentum, is formed from a nonperturbative extension of the two Feynman diagrams that contribute at 1-loop in perturbation theory. The required input is an existing ladder-rainbow model Bethe-Salpeter kernel from an approach based on the Dyson-Schwinger equations; no new parameters are introduced. The model includes an Ansatz for the tri...

ar X iv : h ep - p h / 04 02 14 7 v 2 1 J ul 2 00 4 Contribution of dimension - six bosonic operators to H → γγ at one - loop level

The decay process H → γγ is examined in a model-independent way within the effective Lagrangian approach. Contribution of a set of irreducible one-loop diagrams involving SU(2)×U(1) invariant dimension-six bosonic operators is evaluated explicitly. The calculation is intended to fill a gap that exists in the current literature on the subject. keywords: electroweak interactions; effective Lagran...

ar X iv : h ep - p h / 04 07 09 4 v 1 8 J ul 2 00 4 Two - loop Splitting Amplitudes

Splitting amplitudes govern the behavior of scattering amplitudes at the momenta of external legs become collinear. In this talk we outline the calculation of two-loop splitting amplitudes via the unitarity sewing method. This method retains the simple factorization properties of light-cone gauge, but avoids the need for prescriptions such as the principal value or Mandelstam-Leibbrandt ones. T...