Related papers: One Loop Calculations of Rare B-decays Beyond the …
In this article we investigate in detail the possibility of accounting for the $b\to s\ell^+\ell^-$ and $(g-2)_\mu$ anomalies via loop contributions involving with new scalars and fermions. For this purpose, we first write down the most…
We analyze the semileptonic rare decays of $B$ meson to $K_{1} (1270)$ and $K_{1} (1400)$ axial vector mesons. The $B\to K_{1} (1270,1400) \ell^+ \ell^-$ decays are significant flavor changing neutral current decays of the $B$ meson. These…
Rare $K \to \pi \nu \bar \nu$ decays, being dominated by short distance contributions within the Standard Model (SM), open a window for New Physics (NP) searches at low energies. The $ K \to \pi \nu \bar\nu $ branching ratios are expected…
We investigate the possibility that the CP violation due to the soft supersymmetry breaking terms in squark mixing can give significant contributions to the various $\gamma$ related parameters in B decays, different from those of the…
A brief overview of the recent measurements of the branching ratio of the rare $K_L^0 \to \mu^+ \mu^-$ decay in the context of their agreement with the Standard Model (SM) is given. It is shown that KEK result well correlates with the SM…
The Standard Model (SM) does not contain by definition any new physics (NP) contributions to any observable but contains four CKM parameters which are not predicted by this model. We point out that if these four parameters are determined in…
The effects of the electroweak symmetry breaking sector in rare $B$ and $K$ decays are considered in the presence of new strong dynamics at a large energy scale. In the context of the low energy effective lagrangian of the symmetry breaking…
Aspects of the quark mixings and flavor changing interactions are investigated in electroweak models with singlet quarks. The effects on the ordinary quark mixing are determined in terms of the quark masses and the parameters describing the…
In the framework of minimal supersymmetry with general flavour mixing in the squark sector we consider dominant beyond leading order (BLO) effects in the rare processes $\bar{B}\to X_s\gamma$, $\bar{B}_s\mu^+\mu^-$ and $\bar{B}_s-B_s$…
Measurements from the LHCb experiment and $B$ factories have revealed several discrepancies in angular observables of rare semileptonic $B$ decays involving the quark-level transition $b \to s \ell^+ \ell^-$. In this work, we conduct a…
Weak radiative decays of the B mesons belong to the most important flavor changing processes that provide constraints on physics at the TeV scale. In the derivation of such constraints, accurate standard model predictions for the inclusive…
The recent Tevatron result on the top quark forward-backward asymmetry, which deviates from its standard model prediction by 3.4$\sigma$, has prompted many authors to build new models to account for this anomaly. Among the various…
We study the exclusive semileptonic $B$-meson decays $B\to K(\pi)\ell^+\ell^-$, $B\to K(\pi)\nu\bar\nu$, and $B\to\pi\tau\nu$, computing observables in the Standard model using the recent lattice-QCD results for the underlying form factors…
We examine squark--gluino loop effects on the process $b \to s \gamma$ in minimal supersymmetry with general flavor mixing in the squark sector. In the regime of heavy squarks and gluino, we derive analytic expressions for the beyond--LO…
Semi-leptonic $B$ decays provide promising channels to test the Standard Model, search for signs of new physics, or determine fundamental parameters like CKM matrix elements. We present an update on our calculation of short distance…
Two of the outstanding discrepancies between weak interaction phenomenology and the standard model come in the large size of the $\Delta I={1\over 2}$ enhancement in $K$ decays and in the small value of the $B$ semileptonic branching ratio.…
In full one-loop generality and in next-to-leading order in QCD, we study rare top to Higgs boson flavour changing decay processes $t\to q h$ with $q=u,c$ quarks, in the general MSSM with R-parity conservation. Our primary goal is to search…
The presence of a new decay mode relaxes the current mass exclusion limits on vectorlike quarks considerably. We consider the case of a weak-singlet vectorlike $B$ quark that can decay to a singlet scalar or pseudoscalar $\Phi$. In an…
We revisit the rare decays of the Higgs boson to two different quarks in the Standard Model, which arise at the one-loop level. We perform Taylor series expansions to the complete form factors of the decay amplitudes, according to their…
We explore the impact of topflavour model to $B-\bar{B}$ mixings and rare decays of $B$ mesons. By the flavour-changing neutral current interactions of this model, the $B-\bar{B}$ mixing amplitudes are substantially affected while it is…