Soft-Gluon Resummation for Bottom Fragmentation in Top Quark Decay
UPRF-2002-12
MPI-PhT 2002-34
September 2002
M. Cacciari[1], G. Corcella[2] and A. D. Mitov
[3]
[1] Universita` degli Studi di Parma and
I.N.F.N., Gruppo collegato di Parma,
Parco Area delle Scienze, 43100 Parma, Italy
[2]
Munich, Max-Planck-Institut
[3]
Rochester Unuversity
We study soft-gluon radiation in top quark decay within the framework of
perturbative fragmentation functions. We present results for the b-quark energy
distribution, accounting for soft-gluon resummation in both the MSbar
coefficient function and in the initial condition of the perturbative fragmentation
function. The results show remarkable improvement and the b-quark energy
spectrum in top quark decay exhibits very little dependence on factorization
and renormalization scales. We present some hadron-level results in both x_b
and moment space by including non-perturbative information determined from
e+e- data.