  B-hadron physics plays a fundamental role to test and improve our
understanding of flavor dynamics within and beyond the Standard Model. Of
particular phenomenological interest are beauty hadron lifetime ratios and,
width differences and semileptonic CP-asymmetries in B_d and B_s systems. We
discuss their theoretical predictions which, in the last years, have been
improved thanks to accurate lattice calculations of operator matrix elements
and perturbative computations of Wilson coefficients.
