  I study bottom quark fragmentation in the Standard Model Higgs decay H->b
bbar, within the framework of perturbative fragmentation functions. I resum
large collinear logarithms ln(m_H^2/m_b^2) in the next-to-leading logarithmic
(NLL) approximation, using the DGLAP evolution equations. Soft contributions to
the MSbar coefficient function and to the initial condition of the perturbative
fragmentation function are resummed to NLL accuracy as well. The implementation
of collinear and soft resummation has a relevant impact on the b energy
spectrum, which exhibits a milder dependence on factorization and
renormalization scales and on the Higgs mass. I present some predictions on the
energy distribution of b-flavoured hadrons in Higgs decay, making use of data
from LEP and SLD experiments to fit a few hadronization models. I also compare
the phenomenological results yielded by a few processes recently provided with
NLL collinear and soft resummations.
