Related papers: Two-loop virtual corrections to B --> X_s l^+ l^- …
We calculate the O(alpha_s) corrections to the double differential decay width dGamma_{77}/(ds_1 ds_2) for the process B -> X_s gamma gamma originating from diagrams involving the electromagnetic dipole operator O_7. The kinematical…
Using a known result by Falk et al. for the 1/m_b^2 correction to the dilepton invariant mass spectrum in the decay B \rightarrow X_s \mu^+ \mu^-, we calculate the 1/m_b^2 correction to the left-right muon polarization asymmetry in this…
We calculate the virtual and bremsstrahlung fermionic corrections due to the interference of the electro- and chromomagnetic dipole operators in the inclusive \bar{B}\to X_s\gamma decay at O(\alpha_s^2) and present analytical results for…
We present the results of the calculation of QCD corrections to the matching conditions for the Wilson coefficients of operators mediating the transition b->s l^+l^- in the context of the MSSM. Within a scenario with decoupled heavy gluino…
We use the Mellin-Barnes representation in order to improve the theoretical estimate of mass corrections to the width of light pseudoscalar meson decay into a lepton pair, $P\to l^+l^-$ . The full resummation of the terms…
In this paper the complete two-loop corrections to the Higgs-boson decay, H -> gamma gamma, are presented. The evaluations of both QCD and electroweak corrections are based on a numerical approach. The results cover all kinematical regions,…
The virtual corrections to the production cross section of a Standard Model Higgs boson are computed up to order \alpha_s^4. Using an effective Lagrangian for the limit M_t -> \infty, we evaluate the relevant massless two-loop vertex…
We briefly discuss the status of the NNLL QCD calculations in the inclusive rare B decay $B \to X_s \ell^+ \ell^-$. Two important ingredients, the two-loop matrix elements of the four quark operator ${\cal O}_2$ and the bremsstrahlung…
We present a concise review of the recent theoretical progress concerning the standard model calculation of the inclusive radiative anti-B --> X(s) gamma decay. Particular attention is thereby devoted to the calculations of the…
We investigate the double Dalitz decays $B_s \to l^+ l^- l'^+ l'^-$ on the basis of the effective Hamiltonian for the transition $b \bar{s} \to l^+ l^-$, and universal form factors suggested by QCD. The correlated mass spectrum of the two…
We calculate one-loop corrections to the decays of the next-to-lightest neutralino $\tilde{\chi}_2^0$ into the lightest neutralino $\tilde{\chi}_1^0$ and two leptons; this includes diagrams where a real photon is emitted. In cases where…
We calculate nonperturbative ${\cal O}(\Lambda^2_{QCD}/m^2_c)$ corrections to the dilepton invariant mass spectrum and the forward-backward charge asymmetry in $B\to X_se^+e^-$ decay using a heavy quark expansion approach. The method has…
We study model-independently the implications of non-standard scalar and pseudoscalar interactions for the decays b ->s gamma, b -> s g, b -> s l^+l^- (l=e,mu) and B_s -> mu^+ mu^-. We find sizeable renormalization effects from scalar and…
The radiative corrections to the pure leptonic decay $D_s{\longrightarrow} {\ell}{{\nu}}_{\ell}$ up-to one-loop order is presented. We find the virtual photon loop corrections to $D_s{\longrightarrow} {\tau}{{\nu}}_{\tau}$ is negative and…
In this paper we take the first step towards a complete next-to-next-to-leading logarithmic (NNLL) calculation of the inclusive decay rate for $B \to X_s\gamma$. We consider the virtual corrections of order $\alphas^2 n_f$ to the matrix…
A detailed standard model (SM) calculation of the O(alpha_s) virtual corrections to the decay width for b -> s g is presented (g denotes a gluon). Also the complete expressions for the corresponding bremsstrahlung corrections are given.…
We obtain the leading divergences at two-loop order for the decays $K_{S} \to \gamma \gamma$ and $K_{S} \to \gamma~\l^+ \l^-$ using only one-loop diagrams. We then find the double chiral logarithmic corrections to the decay branching ratio…
Low- and intermediate mass Higgs bosons decay preferably into fermion pairs. The one-loop electroweak corrections to the respective decay rates are dominated by a flavour-independent term of ${\cal O}(G_Fm_t^2)$. We calculate the two-loop…
We investigate the radiative dileptonic decays $B_s(B_d)\to\gamma l^+l^-$ within the standard model. Using the constituent quark model, the branching ratios turn out to be around $5\times 10^{-9}$ for $B_s\to \gamma \mu^+\mu^- $ and around…
The calculation of the $O(\a_s)$ virtual corrections to the matrix element of the inclusive decay $b \to s \gamma$ is reported. These contributions drastically reduce the large renormalization scale dependence of the leading logarithmic…