Related papers: Fermionic NNLL corrections to b -> s \gamma
We report on recent theoretical progress in radiative B decays. We focus on a calculation of logarithmically enhanced QED corrections to the branching ratio and forward-backward asymmetry in the inclusive rare decay anti-B --> X(s) l+ l-,…
If the fourth generation fermions exist, the new quarks could influence the branching ratio of the decay $B_s \to \nu \bar{\nu} \gamma$. We obtain two solutions of the fourth generation CKM factor $V^*_{t's} V_{t'b}$ from the decay of $B…
We study in the BFKL approach the total hadronic cross section for the collision of two virtual photons for energies in the range of LEP2 and of future linear colliders. The BFKL resummation is done at the next-to-leading order in the BFKL…
The inclusive B -> Xs l+ l- decay rate in the large q^2 region (q^2 > m_{\psi'}^2) receives significant nonperturbative corrections. The resulting uncertainties can be drastically reduced by normalizing the rate to the B -> Xu l nu rate…
We address the nonperturbative calculation of the inclusive decay rate of semileptonic $B_{(s)}$-meson decays from lattice QCD. Precise Standard-Model predictions are key ingredients in searches for new physics, and this type of computation…
We calculate the leading-order matrix element for exclusive decays of $b \to s\gamma$ in the quenched approximation of lattice QCD on a $24^3\times48$ lattice at $\beta=6.2$, using an O(a)-improved fermion action. The matrix element is used…
We compute the next-to-next-to-leading order (NNLO) QCD corrections to the hadronic decay rates of the pseudoscalar quarkonia, at the lowest order in velocity expansion. The validity of NRQCD factorization for inclusive quarkonium decay…
The decay of B mesons can be predicted within the Heavy Quark Expansion as the decay of a free bottom quark plus corrections which are suppressed by powers of $1/m_b$. This contribution to Loops&Legs 2024 describes the calculation of the…
In this analysis, we present the contribution associated with the chromomagnetic dipole operator O_8 to the double differential decay width d\Gamma/(ds_1 ds_2) for the inclusive process $\bar{B} \to X_s \gamma \gamma$. The kinematical…
We provide a compendium of techniques that can be used to compute $O(N_f\alpha^2)$ corrections to low-energy electroweak processes. Specifically, these are the 2-loop electroweak corrections containing a light fermion loop. It is shown that…
The inclusive decay rate b to ccs is enhanced considerably due to perturbative QCD corrections. We recalculate the dominant part of the NLO-QCD corrections, because they cannot be reconstructed from the literature and we give the full…
We find some errors in previous calculation of leading log QCD corrections to $b \to s\gamma $ decay, which include corrections from $m_{top}$ to $M_W$ in addition to corrections from $M_{W}$ to $m_b$. The inclusive decay rate is found to…
We review some selected rare B decays calculated in next-to-leading order accuracy in the Standard Model (SM). These include the radiative decays $B \to (X_s,K^*,\rho)\gamma$ and the semileptonic decays $B \to (X_s,K,K^*) \ell^+ \ell^-$,…
We present general model-independent formulae for the branching ratios and the direct tagged CP asymmetries for the inclusive B -> Xd gamma and B -> Xs gamma modes. We also update the corresponding SM predictions.
We obtain predictions for a number of radiative decays $B_{(s)}\to V\gamma$, $V$ the vector meson, which proceed through the weak-annihilation mechanism. Within the factorization approximation, we take into account the photon emission from…
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…
We present the next-to-next-to-leading order ($\alpha \alpha_s^2$) corrections to the first moment of the polarized virtual photon structure function $g_1^\gamma(x,Q^2,P^2)$ in the kinematical region $Q^2\gg P^2 \gg \Lambda^2$ in QCD. We…
Two loop electroweak corrections to b --> s gamma decays are computed. Fermion and photonic loop effects are found to reduce R = BR(b --> s gamma)/BR(b --> c e nu) by 8+-2% and lead to the standard model prediction BR(B --> X_s gamma)=(3.28…
The most general QCD next-to-leading anomalous-dimension matrix of all possible four-fermion, dimension-six $\Delta F=2$ operators is computed. The results of this calculation can be used in many phenomenological applications, among which…
In this paper, we investigate the factorization hypothesis step by step for the exclusive process $B \to \rho$ at next-to-leading order (NLO) with the collinear factorization approach, and then we extend our results to the $k_T$…