Related papers: Virtual corrections to the decay $b \to s \gamma$
We present an exact $\alpha_s$ calculation of the Wilson coefficients associated with the dipole moment operators. We also give an estimate of the branching ratio for $b\rightarrow s \gamma$. We find that higher dimensional effects are…
We evaluate non factorizable $O(\alpha\alpha_s)$ corrections to the process $Z\to b\bar{b}$ due to the virtual t-quark. All two-loop vertex diagrams with $W$'s and charged ghosts $\Phi$'s are included. They are evaluated in the large…
The short distance QCD corrections to $b\to s\gamma \gamma$ are calculated in the leading logarithmic approximation. The equivalence of operator basis reduction for S-matrix elements by using the equations of motion or by proving a low…
We give a summary about the various contributions which have to be calculated in order to obtain the next-to-leading logarithmic result for the branching ratio $BR(B \to X_s \gamma)$. Combining all these ingredients, which were obtained by…
In $B \to X_s \gamma $ there are perturbative $QCD$ corrections at order $\alpha_s$ not only to the single quark line process $ b \to s \gamma$ but also coming from a set of diagrams where the weak interaction vertex involves a gluon which…
We present our results for the NNLL virtual corrections to the matrix elements of the operators O_1 and O_2 for the inclusive process b\to s\ell^+\ell^- in the kinematical region q^2>4m_c^2, where q^2 is the invariant mass squared of the…
We compute the $O(\alpha_s)$ corrections to the Wilson coefficient of the chromomagnetic operator in inclusive semileptonic B decays. The results are employed to evaluate the complete $O(\alpha_s \Lambda^2/m_b^2)$ correction to the…
Uncertainties in the theoretical prediction for the inclusive $\bar B\to X_s\gamma$ decay rate are examined. Certain nonperturbative effects involving a virtual $c\bar c$ loop, which are calculable using the operator product expansion, are…
In a recent paper, we presented the calculation of the order (alpha_s) virtual corrections to b->s l+ l- and of those bremsstrahlung terms which are needed to cancel the infrared divergences. In the present paper we work out the remaining…
We compute the complete two-loop O(alpha) Wilson coefficients relevant for radiative decays of the B meson in the SM. This is a necessary step in the calculation of the O(alpha alpha_s^n ln^n m_b/M_W) corrections and improves on our…
The O(alpha) electroweak radiative corrections to gamma gamma --> WW --> 4f within the electroweak Standard Model are calculated in double-pole approximation (DPA). Virtual corrections are treated in DPA, leading to a classification into…
One of the most important O($\alpha_s^2$) corrections to the $B \to X_s \gamma$ branching ratio originates from interference of contributions from the current-current and photonic dipole operators. Its value has been estimated using an…
Recent developements in the calculation of the NNLO QCD corrections to the charm quark mass dependent matrix elements in B -> X_s gamma are reported. Special emphasis is put on the new results of the virtual O(alpha_s^2) fermionic…
We compute three-loop vertex corrections to $b\to s\gamma$ induced by current-current operators. The results are presented as expansions in $m_c/m_b$ with numerical coefficients which allow to cover all relevant values for the heavy quark…
We calculate the fermionic corrections to the photon-energy spectrum of Bbar -> X_sgamma which arise from the self-interference of the chromomagnetic dipole operator Q_8 at next-to-next-to-leading order by applying naive non-abelianization.…
In these proceedings, we briefly review the individual interference contribution of the electromagnetic dipole operator $\mathcal{O}_{7}$ to the double differential decay width $d\Gamma_{77}/(ds_1\, ds_2)$ for the process $\bar{B} \to X_s…
Combining our results for various O(alpha_s^2) corrections to the weak radiative B-meson decay, we are able to present the first estimate of the branching ratio at the next-to-next-to-leading order in QCD. We find BR(B -> X_s gamma) = (3.15…
A new class of enhanced non-perturbative corrections to the inclusive B->X_s+gamma decay rate is identified, which contribute first at order Lambda/m_b in the heavy-quark expansion and cannot be described using a local operator product…
It is shown that the inclusive rate of the rare weak radiative decays $B \to X_s \gamma$ contains a series of nonperturbative corrections, whose `short distance' scale is set by $m_c^{-1}$, rather than by $m_b^{- 1}$. The first correction…
We compute the virtual O(alpha_s^2) fermionic contributions to the charm quark mass dependent matrix elements of the B -> X_s gamma decay. In the case of a massless quark loop insertion into the gluon propagator, our result obtained as an…