1201.4039 (Damir Becirevic et al.)

D-meson decay constants and a check of factorization in non-leptonic
B-decays    [PDF]

Damir Becirevic, Vittorio Lubicz, Francesco Sanfilippo, Silvano Simula, Cecilia Tarantino

We compute the vector meson decay constants fD*, fDs* from the simulation of
twisted mass QCD on the lattice with Nf = 2 dynamical quarks. When combining
their values with the pseudoscalar D(s)-meson decay constants, we were able (i)
to show that the heavy quark spin symmetry breaking effects with the charm
quark are large, fDs*/fDs = 1.26(3), and (ii) to check the factorization
approximation in a few specific B-meson non-leptonic decay modes. Besides our
main results, fD* = 278 \pm 13 \pm 10 MeV, and fDs* = 311 \pm 9 MeV, other
phenomenologically interesting results of this paper are: fDs*/fD* = 1.16 \pm
0.02 \pm 0.06, fDs*/fD = 1.46 \pm 0.05 \pm 0.06, and fDs/fD* = 0.89 \pm 0.02
\pm 0.03. Finally, we correct the value for B(B0 \rightarrow D+ pi-) quoted by
PDG, and find B(B0 \rightarrow D+ pi-) = (7.8 \pm 1.4) \times 10-7.
Alternatively, by using the ratios discussed in this paper, we obtain B(B0
\rightarrow D+ pi-) = (8.3 \pm 1.0 \pm 0.8)\times10-7.

View original: http://arxiv.org/abs/1201.4039