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

Some of the recent measurements in the neutral current sector $b\rightarrow s l^+l^-$ ($l=e$ or $\mu$) as well as in the charged current sector $b \rightarrow c \tau \bar{\nu}$ show significant deviations from their Standard Model…

We investigate the prospects for resonant di-Higgs and heavy Higgs production searches at the 14 TeV HL-LHC in the combination of $bb\gamma\gamma$ and $4l$ channels, as a probe of a possible first order electroweak phase transition in real…

In this publication electroweak next-to-leading order corrections to semileptonic B-meson decays into (pseudo)scalar final states are presented. To this end, these corrections of O(alpha G_F) have been calculated in the QED-enhanced…

The $b \rightarrow s \gamma$, $b \rightarrow d \gamma$ and $b \rightarrow s \ell^+ \ell^-$ processes are allowed at higher order via the electroweak loop or box diagrams in the Standard model. It is sensitive probe to search for new physics…

We perform a loop-level analysis of charged-current (CC) processes involving light leptons and quarks within the Standard Model Effective Field Theory (SMEFT). This work is motivated by the high precision reached in experiment and Standard…

We study the loop induced rare decays $B_s(B_d)\to\gamma\nu\bar\nu$ within the standard model. Both constituent quark model and pole model are used and the branching ratios turn out to be of the orders of $10^{-8}$ for $B_s\to \gamma \nu…

General one-loop contributions to the decay amplitudes $H\rightarrow \nu_l\bar{\nu}_l\gamma$ are presented, considering all possible contributions of additional heavy vector gauge bosons, fermions, and charged (and also neutral) scalar…

We calculate the full two-loop electroweak matching corrections to the operator governing the decay B_q --> l^+ l^- in the Standard Model. Their inclusion removes an electroweak scheme and scale uncertainty of about 7% of the branching…

Radiative corrections to the process e+ e- to t tbar are calculated in one-loop approximation of the Standard Model. There exist results from several groups. This talk provides further comparisons of the complete elektroweak contributions,…

A large set of techniques needed to compute decay rates at the two-loop level are derived and systematized. The main emphasis of the paper is on the two Standard Model decays H -> gamma gamma and H -> g g. The techniques, however, have a…

We study various FCNC involving heavy quarks in the Standard Model (SM) with a sequential fourth generation. After imposing $B\to X_s\gamma$, $B\to X_sl^+l^-$ and $Z\to b\bar{b}$ constraints, we find ${\cal B}(Z\to s\bar{b}+\bar{s}b)$ can…

We report on a search for pair production of a fourth generation charge -1/3 quark (b') in pbar p collisions at sqrt(s) = 1.8 TeV at the Fermilab Tevatron using an integrated luminosity of 93 pb^-1. Both quarks are assumed to decay via…

It is shown that in the decays $B_c(2P)\to B_c^* \gamma^\mathrm{hard}$, $B_c(3P)\to B_c^* \gamma^\mathrm{hard}$ and $B_c(2S)\to B_c^* +\pi^+\pi^-$ followed by the decay $B_c^*\to B_c +\gamma^\mathrm{soft}$ the loss of the soft photon…

The experimental measurements of flavor-changing neutral-current B-meson decays governed by b --> s + (gamma, l^+ l^-) transitions have entered a new level of precision. Recent results by Belle, CDF, Babar, and LHCb on B -->K^(*) l^+ l^-…

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-,…

One-loop contributions to the decay $H\rightarrow \nu_l\bar{\nu}_l\gamma$ with $l=e, \mu, \tau$ within standard model framework are revisited in this paper. We derive two representations for the form factors in this calculation. As a…

One-loop radiative corrections to the charged Higgs coupling to two fermions and to the charged Higgs fermionic decay are studied. A renormalization scheme is proposed including the definition of the parameter $\tan\beta$ through the…

This manual describes version 2.2 of the Monte Carlo event generator UNIBAB for large angle Bhabha scattering at LEP and SLC. UNIBAB implements higher order electromagnetic radiative corrections and the effects of soft photon exponentiation…

Rare radiative decays based on b->s+gamma transitions are among the most prominent examples of flavor-changing neutral current processes. They benefit from good theoretical control and experimental accessibility, large sensitivity to…

The rare decays of $\Lambda_b$ baryon governed by the quark level transitions $ b \to s$, are investigated in the fourth quark generation model popularly known as SM4. Recently it has been shown that SM4, which is a very simple extension of…