b-quark decay in the collinear approximation

b-quark decay in the collinear approximation

The semileptonic decay of a b-quark, b → clν, is considered in the relativistic limit where the decay products are approximately collinear. Analytic results for the double differential lepton energy distributions are given for finite charm-quark mass. Their use for the fast simulation of isolated lepton backgrounds from heavy quark decays is discussed.

B-hadron production in top quark decay

We present the energy distribution of b-flavoured hadrons in top quark decay using the PYTHIA and HERWIG event generators, which we tune to LEP and SLD data. We find that fitting the string and cluster models is essential to reproduce the ee data and to reliably predict B-hadron production in top decay. We also compare the PYTHIA and HERWIG results with the ones yielded by resummed calculations...

The Decay B → π ` ν in Heavy Quark Effective Theory

We present a systematic analysis of the B(∗) → π ` ν weak decay form factors to order 1/mb in the heavy quark effective theory, including a discussion of renormalization group effects. These processes are described by a set of ten universal functions (two at leading order, and eight at order 1/mb), which are defined in terms of matrix elements of operators in the effective theory. In the soft p...

Decay in Soft-collinear Effective Theory

Sea quark effects in B Spectroscopy and Decay Constants

We present comprehensive results for the spectrum and decay constants of hadrons containing a single b quark. The heavy quark is simulated using an O(1/M) NRQCD action and the light quark using the O(a) tadpole-improved clover action on gauge configurations containing two degenerate flavours of sea quarks at βnf =2 = 5.6 provided by the HEMCGC collaboration. We present detailed results for the ...