Related papers: Fermionic NNLL corrections to b -> s \gamma
The calculation of the $O(N_f\alpha^2)$ corrections to muon decay is described. These are the 2-loop diagrams containing a massless fermion loop and they form an important gauge-invariant subclass. It is shown that all such diagrams can be…
We present the results of the O(alpha_s) two-loop virtual corrections to the differential decay width dGamma(B -> X_s l+ l-)/ds, where s is the invariant mass squared of the lepton pair. Those contributions from gluon bremsstrahlung which…
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.…
We calculate the set of O(\alpha_s) corrections to the double differential decay width d\Gamma_{77}/(ds_1 \, ds_2) for the process \bar{B} \to X_s \gamma \gamma originating from diagrams involving the electromagnetic dipole operator O_7.…
The order $\alpha_s$ corrections to the Wilson coefficients of the dipole operators ($O_7,O_8$) at the matching scale $\mu =m_W$ are a crucial ingredient for a complete next- to-leading logarithmic calculation of the branching ratio for $b…
We compute next-to-next-to-leading order QCD corrections to the partonic processes $b\to c \bar{u} d$ and $b\to c \bar{c} s$, which constitute the dominant decay channels in standard model predictions for $B$-meson lifetimes within the…
We compute the virtual next-to-leading corrections to the impact factors or off-shell coefficient functions in the high-energy limit. When combined with the known real corrections, these results will provide the complete NLO corrections to…
We discuss nonperturbative contributions to the inclusive rare $B$ decays $B\to X_s\gamma$ and $B\to X_s\ell^+\ell^-$. We employ an operator product expansion and the heavy quark effective theory to compute the leading corrections to the…
Many contributions to the decay rate of the inclusive radiative $\bar{B}\rightarrow X_s \gamma$ transition have been calculated to NNLO in QCD during the past decades. However, there are still a few unknown contributions from multi-parton…
We perform the first global fit to inclusive $B\to X_s\gamma$ measurements using a model-independent treatment of the nonperturbative $b$-quark distribution function, with next-to-next-to-leading logarithmic resummation and…
The B -> X_s gamma branching ratio is currently measured with around 5% accuracy. Further improvement is expected from Belle II. To match such a precision on the theoretical side, evaluation of O(alpha_s^2) corrections to the partonic decay…
Uncertainties in the theoretical prediction for the inclusive $B\to X_s\gamma$ decay rate are discussed. We emphasize that there is no operator product expansion for this process. Nonetheless, some nonperturbative effects involving a…
We calculate the three-loop master integrals of Ref. [1] [arXiv:1709.02160] in analytic form. This allows us to present the fermionic contributions to the $\Delta B=2$ Wilson coefficients of the $B$-$\bar B$ decay matrix in…
We review the NLL QCD calculations for the branching ratio of B -> X_s gamma in the SM. In particular, we emphasize the problem related to the definition of the charm quark mass which leads to a rather large uncertainty of the NLL…
We complete the next-to-next-to-leading order QCD calculation of the branching ratio for B -> X_s l^+ l^- including recent results for the three-loop anomalous dimension matrix and two-loop matrix elements. These new contributions modify…
The calculation of next-to-leading order (NLO) perturbative corrections at fixed operator dimension in Standard Model Effective Field Theory (SMEFT) has been a topic of much recent interest. In this paper we obtain the NLO corrections from…
Part of the order $\alpha_s$ correction to the inclusive $B\to X_s\,\gamma$ photon spectrum is enhanced by $\log(m_b^2/m_s^2)$. We discuss its origin and sum the corrections proportional to $[\alpha_s\log(m_b^2/\mu^2)]^n$ to all orders.…
We sum up the next-to-next-to-leading logarithmic virtual electroweak corrections to the high energy asymptotics of the neutral current four-fermion processes for light fermions to all orders in the coupling constants using the evolution…
The inclusive radiative decay of the B meson is known to provide strong constraints on many popular extensions of the Standard Model. Such constraints crucially depend on precision of the Standard Model predictions. One of the main…
I discuss the calculation of the next-to-leading logarithmic (NLL) corrections to the BFKL resummation, as well as some of the issues that arise in this formalism at NLL. In particular I consider the large size and apparent instability of…