相关论文: SANCnews: Sector 4f, Charged Current

We present measurements of the branching fractions for the decays B+/- --> a1(1260)+/- pi0 and B+/- --> a1(1260)0 pi+/- from a data sample of 232 * 10^6 BB pairs produced in e+e- annihilation through the Y(4S) resonance. We measure the…

The rare K -> pi nu anti-nu decays play a central role in testing the Standard Model and its extensions. Upcoming experiments plan to measure the decay rates with high accuracy. Yet, unknown higher-order electroweak corrections result in a…

We work out a specific class of three-loop diagrams (of order $\alpha_s^2$) contributing to the decay amplitude for $b \to s \gamma$ associated with the current-current operators $O_1$ and $O_2$ at the physical value of the charm-quark mass…

We present simple analytic expressions for the distributions of the Bhabha scattering process with emission of one hard photon, including weak boson exchanges, and with longitudinal polarization of the initial electron. The results from the…

An informal review is given of the status and direction of experiments on radiative B decays -- b -> s gamma and b -> d gamma. Branching fractions for exclusive and inclusive b -> s gamma decays, CP asymmetry limits, the photon energy…

It is proposed to exploit the decay of the meson ${B}^+ \rightarrow p \pi^+ \pi^+ \bar{\Sigma}_c^{--}$ and of its charge conjugate $B^-$ copiously produced at LHC to obtain a sample of $\Lambda_c$ baryons through the strong decay $\Sigma_c…

The complete O(alpha) electroweak radiative corrections to e+e- --> WW --> 4f in the electroweak Standard Model are presented in the double-pole approximation. We give analytical and numerical results for the non-factorizable corrections…

We consider large-angle two photon production in $e^+ e^-$ annihilation as a possible process to monitor the luminosity of a future $e^+ e^-$ circular collider (FCC-ee). We review and assess the status of the theoretical accuracy by…

We present a new Monte-Carlo generator, {\tt ee$\in$MC}, for the simulation of $e^{+}e^{-} \to \mu^{+} \mu^{-} (\gamma) $, $e^{+}e^{-} \to \tau^{+}\tau^{-} (\gamma) $ and $\tau$ lepton decays which is suitable for $e^{+}e^{-}$ colliders…

The simulation of radioactive decays is a common task in Monte-Carlo systems such as Geant4. Usually, a system either uses an approach focusing on the simulations of every individual decay or an approach which simulates a large number of…

Hints of lepton flavor universality violation observed in various flavor ratios such as $R_D$, $R_{D^*}$, $R_{J/\psi}$, $P_\tau^{D^*}$ and $F_L^{D^*}$ in $B\to D^{(*)}\,\ell \, \nu$ and $B_c\to J/\psi \, \ell\, \nu$ charge current decays…

We present general one-loop contributions to the decay processes $H\rightarrow f\bar{f}\gamma$ including all possible the exchange of the additional heavy vector gauge bosons, heavy fermions, and charged (also neutral) scalar particles in…

We report measurements of branching fractions and charge asymmetries of exclusive decays of neutral and charged B mesons into two-body final states containing a charmonium state and a light strange meson. The charmonium mesons considered…

The study of flavour-changing neutral currents (FCNC) gives access to important tests of the Standard Model (SM) and allows to search for hints of beyond the SM phenomena. We present here the study of the very rare decays $B^0\rightarrow…

We present the results of a complete analysis of the one loop electroweak corrections to $e^-e^+\to\gamma\gamma, ~Z\gamma, ~ZZ$ in the Standard (SM) and the Minimal Supersymmetric Standard Model (MSSM). A special emphasis is put on the high…

For the first time the next-to-leading-order electroweak corrections to the full off-shell production of two top quarks that decay leptonically are presented. This calculation includes all off-shell, non-resonant, and interference effects…

The electroweak O(alpha) contribution to the resonant single W production in a general 4-fermion process is discussed with particular emphasis on a gauge invariant decomposition into a QED-like and weak part. The cross section in the…

We present a detailed study of the charged current Drell-Yan process, which includes the exact O(alpha) electroweak corrections properly matched with leading-log effects due to multiple-photon emission, as required by the experiments at the…

We present the Monte Carlo program BHAGEN95, for calculating the cross-section of the Bhabha scattering process at LEP1/SLC and LEP2 energies, usable with continuity from small to large-angle configurations. We discuss some improvements in…

Understanding radiation effects in spacecraft components is critical for predicting long-term performance degradation. In this work, a Geant4 Monte Carlo model is developed to compute charge and energy deposition in satellite solar-cell…