Charmed quark fragmentation in B-mesons decays

It is well known that large nonfragmentational contributions to inclusive production of charmed particles appear at low energies. In the case of charm production in $B$-meson decays these contributions arise from the participation of the light valent quark from the $B$-meson and can be easily described phenomenologically. These contributions affect $D$-meson spectra and essentially change ratios between yields of different $D$-meson states.