相关论文: $B \to X_s l^+l^-$ in the left-right supersymmetri…
We analyze the inclusive semileptonic decays B -> X_s l^+ l^- in the framework of the supersymmetric standard model with non-universal soft-breaking terms at GUT scale. We show that the general trend of universal and non-universal models is…
Semileptonic B meson decays induced by $b \to s(d) l^+ l^-$ flavour changing neutral current (FCNC) transitions are very important to probe the quark-flavour sector of the standard model (SM) and also offer a probe to test new physics (NP).…
I point out that $B \to X_q \l^+ \l^-$ decays $(q = s, d)$ are sensitive probes of possible violation of CKM unitarity. I compute the decay rates and asymmetries in a minimal extension of the Standard Model containing an additional…
We study the effect of the FCNC mediated $Z$ boson in the rare semileptonic baryonic decays $\Lambda_b \to \Lambda l^+ l^-$. We consider the model where the standard model fermion sector is extended by an extra vector like down quark, as a…
Rare B meson decays mediated by flavour changing neutral current (FCNC) transition play interesting role to probe the flavour sector of the standard model (SM). Generally at the tree level, FCNC processes are not allowed in the SM but…
After a brief review of the inclusive and exclusive rare semileptonic decays of B mesons in the standard model (SM), an overview of recent theoretical developments in this field is given. New physics effects on various observables such as…
We study the rare semileptonic and radiative leptonic B_s decays in the universal extra dimension model. In this scenario, with a single extra dimension, there exists only one new parameter beyond those of the standard model, which is the…
The recent observation by the CLEO Collaboration of the inclusive decay $b\to s\gamma$ with a branching fraction consistent with the expectations of the Standard Model is used to constrain the parameter space of the Left-Right Symmetric…
We study the semileptonic decays B -> Xs e+ e- and B -> Xs mu+ mu- in generic supersymmetric extensions of the Standard Model. SUSY effects are parameterized using the mass insertion approximation formalism and differences with the…
The rare decay $b \to s \gamma$ is studied in the left-right supersymmetric model. We give explicit expressions for all the amplitudes associated with the supersymmetric contributions coming from gluinos, charginos and neutralinos in the…
The relatively clean theoretical probes of the Standard Model (SM), and the various theories beyond the SM, provided by radiative, semi-leptonic and (purely) leptonic decays of B-mesons have become increasingly important. Due to the large…
In recent times, several hints of lepton non-universality have been observed in semileptonic $B$ meson decays, both in the charged-current ($b \to c l \bar \nu_l$) and neutral-current ($b \to s ll $) transitions. Motivated by these…
In this paper, we study the extended Standard Model (SM) with an extra Higgs doublet and right-handed neutrinos. If the symmetry to distinguish the two Higgs doublets is not assigned, flavor changing neutral currents (FCNCs) involving the…
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…
We update the standard model predictions for the branching ratios of the decays B -> (K,K*,Xs) l^+ l^-, with l=e,mu. Using the measurements of BR(B -> Xs gamma) and BR(B -> K l^+ l^-) as well as the upper limits on BR(B -> (K*,Xs) l^+…
Recently the semileptonic decays $B\to X_s e^+ e^-$, $B\to X_s \mu^+ \mu^-$ in generic supersymmetric extensions of the Standard Model have been studied in ref.~\cite{noi}. In this talk I review the main points of this analysis. SUSY…
The flavor changing neutral current processes $K_L \to \pi^0 e^+ e^-$, $B \to X_s e^+ e^-$ and $B \to X_s \mu^+ \mu^-$ are studied within the minimal supersymmetric extension of the Standard Model. We first examine the rates for these decay…
The semi-leptonic baryonic $b\to s$ decay, $\Lambda_b\rightarrow \Lambda \ell^+\ell^-$, has been studied and new angular observables and asymmetries have been proposed which can test the presence of new physics beyond the standard model.
Rare flavour-changing neutral-current transitions of the type $s \to d \ell^+\ell^-(\nu\bar\nu)$ and $b \to s \ell^+\ell^-(\nu\bar\nu)$ are analysed in supersymmetric extensions of the Standard Model with generic flavour couplings. It is…
We begin to analyze and contrast the predictions for the decay $b\to s\ell^+\ell^-$ in the Left-Right Symmetric Model(LRM) with those of the Standard Model(SM). In particular, we show that the forward-backward asymmetry of the lepton…