Fragmentation of bottom quarks in top quark decay

We review the main aspects of the fragmentation of bottom quarks in top quark decay. The NLO b-quark energy spectrum presents large mass logarithms ln(m 2 /m 2 ), which can be re- summed by the use of the approach of perturbative fragmentation functions. Large soft contributions in both coefficient function and initial condition of the per turbative fragmentation function have been resummed as well. Results on the energy distribution of b quarks and b-flavoured hadrons are finally presented in both x and moment spaces. In this paper we investigate bottom fragmentation in top decay within the framework of perturbative fragmentation functions (3). We shall resum collinear logarithms ∼ ln(m 2 /m 2) and soft terms that appear in the next-to-leading order (NLO) b-quark energy distribution. We shall present results on the b-quark energy spectrum in top quark decay and investigate the impact of collinear and soft resummation. Hadron-level results on b-flavoured hadrons will be shown in xB and moment spaces.