Related papers: On the Standard Model predictions for $R_K$ and $R…
It has been pointed out that supersymmetric extensions of the Standard Model can induce significant changes to the theoretical prediction of the ratio $\Gamma(K\rightarrow e\nu)/\Gamma (K\rightarrow\mu\nu)\equiv R_{K}$, through lepton…
Precision electroweak measurements at LEP currently check the validity of the Standard Model to about one part in a thousand. Any successful model of physics beyond the Standard Model must be consistent with these observations. The impact…
We present upgraded theoretical predictions for inclusive and exclusive radiative decays of {\it B} mesons. Our results include those next-to-leading order corrections that have already been computed. Our best estimates in the Standard…
The cross-section for $\gamma\gamma\to W^+ W^-$ with arbitrary polarized photons and W bosons is calculated within the electroweak Standard Model including the complete virtual and soft-photonic ${\cal O}(\alpha)$ corrections. We present a…
Semileptonic $b \to c$ transitions, and in particular the ratios $R(D^{(*)}) = \frac{\Gamma(B \rightarrow D^{(*)} \tau \nu )}{\Gamma(B \rightarrow D^{(*)} \ell \nu )}$, can be used to test the universality of the weak interactions. In light…
Assuming the existence of a new real scalar singlet $s^0$ coupled to the Standard Model via a scalar quartic portal interaction, we compute the radiative corrections to the decay rates of the heavy scalar mass eigenstate to a couple of…
We review recent theoretical progress in the computation of radiative corrections beyond one loop within the standard model of electroweak interactions, both in the gauge and Higgs sectors. In the gauge sector, we discuss universal…
Radiative corrections are studied within an extension of the standard model, containing extra singlet scalars. The calculations determine the effect of a large width of the Higgs boson on radiative corrections. They throw some light on the…
The LHCb measurements on the B ->$ K^*$$\mu^+ \mu^-$ angular observables have shown slight deviations from their Standard Model predictions. The significance of the deviations in the B -> $K^*$$\mu^+ \mu^-$ decay depends on the assumptions…
We reinvestigate the leading QCD corrections to the radiative decay $b \to s \gamma for supersymmetric extensions of the Standard Model. Although the major contributions to the corrections originate from the running of the effective…
We calculate the next-to-leading corrections to the branching ratio of exclusive $B\to K^* \gamma$ decay. The renormalization scale dependence is reduced compared to the leading logarithmic result but there remains a dependence on a cutoff…
If the top is very heavy, m_t >> M_Z, the dominant radiative correction effects in all electroweak precision tests can be exactly characterized in terms of two quantities, the rho-parameter and the GIM violating Z -> b bbar coupling. These…
We calculate the rates and lepton (l) invariant mass distributions for decays of the form 0^{-+}->l^+l^-\gamma, which are important radiative corrections to the purely leptonic decays 0^{-+}->l^+l^-. Our approach uses the loop diagrams…
We present a comprehensive calculation of the $K_L\to\gamma^*\gamma^*$ form factor in dispersion theory, using input from the leptonic decays $K_L\to\ell^+\ell^-\gamma$, $K_L\to \ell_1^+\ell_1^-\ell_2^+\ell_2^-$, the hadronic mode $K_L\to…
We investigate the radiative process of the $\Lambda_b\rightarrow \Lambda \gamma$ in the standard model as well as models with one or two compact universal extra dimensions. Using the form factors entered to the low energy matrix elements,…
Radiative corrections to $B \to D \ell \nu_{\ell}$ decays can have an impact on predictions and measurements of the lepton universality ratios $\mathcal{R}(D^+)$ and $\mathcal{R}(D^0)$. These proceedings summarise a study on the comparison…
We report a high-precision calculation of the Standard Model electroweak radiative corrections in the $K\to \pi e^+\nu(\gamma)$ decay as a part of the combined theory effort to understand the existing anomaly in the determinations of…
We critically reassess the theoretical uncertainties in the Standard Model calculation of the $B \to K^* \ell^+ \ell^-$ observables, focusing on the low $q^2$ region. We point out that even optimized observables are affected by sizable…
The rare decay B --> K* mu+ mu- is considered to be a golden channel for LHCb, as the polarization of the K* allows a precise angular reconstruction resulting in many observables that offer new important tests of the Standard Model and its…
Tests of lepton-universality as rate ratios in $b\to s \ell\ell$ transitions can be predicted very accurately in the Standard Model. The deficits with respect to expectations reported by the LHCb experiment in muon-to-electron ratios of the…