Speaker
Francesco Moretti
Description
The total decay widths of heavy mesons can be systematically calculated
in terms of an expansion in the two parameters $1/m_Q$ and
$\alpha_s(m_Q)$, where $Q=c,b$ denotes the heavy quark. The dominant
contributions to meson lifetime splittings stem from terms which are
suppressed by $1/m_Q^3$ with respect to the leading universal contribution
to the total decay width. We calculate three-loop contributions of
order $\alpha_s^2/m_q^3$ to the lifetime ratios $\tau(B^+)/\tau(B_d^0)$, $\tau(D^+)/\tau(D^0)$,
and $\tau(D_s^+)/\tau(D^+)$ in the limit of exact isospin and U-spin
symmetry, respectively. Furthermore, we present new $\alpha_s/m_q^3$
corrections to the Cabibbo-suppressed terms in $\tau(B^+)/\tau(B_d^0)$.
| Discipline | Theory |
|---|---|
| Topic | Heavy Quark Decays |
Authors
Francesco Moretti
Matthias Steinhauser
Pascal Reeck
(Karlsruhe Institute of Technology)
Prof.
Ulrich Nierste