Related papers: Lambda_b -> Lambda l+ l- decay within family non-u…
We present the angular distribution of the four-fold $B\to\rho (\to\pi\pi)\mu^{+}\mu^{-}$ and $B\to a_{1}(\to\rho_{\parallel, \perp}\pi)\mu^{+}\mu^{-}$ decays both in the Standard Model and the family non-universal $Z^{\prime}$ model. At…
In the event of an observation of neutrinoless double beta decay, a relevant question would be: what lepton number violating physics is responsible for the decay? The exchange of Majorana neutrinos and/or supersymmetric particles may…
Recent measurements of semileptonic $B$-meson decays into $\tau$-leptons are somewhat higher than expected in the standard model. Although the deviations are less than 3$\sigma$, they suggest the possibility of new physics affecting…
Double-lepton polarization asymmetries in the (B -> l^+ l^- gamma) decay are calculated using the most general, model independent form of the effective Hamiltonian including all possible forms of the interaction. The dependencies of the…
The $\lambda$ mechanism ($W_L$-$W_R$ exchange) of the neutrinoless double beta decay ($0\nu\beta\beta$-decay), which has origin in left-right symmetric model with right-handed gauge boson at TeV scale, is investigated. The revisited…
We present a full angular distribution of the four body $\Lambda_b\to\Lambda(\to N\pi)\ell^+\ell^-$ decay where the leptons are massive and the $\Lambda_b$ is unpolarized, in an operator basis which includes the Standard Model operators,…
We study the differential decay rate for the rare $\Lambda_b \to \Lambda (\to N \pi)\ell^+\ell^-$ transition, including a determination of the complete angular distribution, assuming unpolarized $\Lambda_b$ baryons. On the basis of a…
We examine the T-odd transverse lepton and $\Lambda$ polarizations in the baryonic decays of $\Lambda_b\to\Lambda l^+l^- (l=e ,\mu)$ to study the T violating effects. We show that the lepton polarizations are suppressed but the $\Lambda$…
The observation potential of the decay B+ -> K+K+pi- with the ATLAS detector at LHC is described in this paper. In the Standard Model this decay mode is highly suppressed, while in models beyond the Standard Model it could be significantly…
The weak decays of $\Lambda_b \to \Lambda l^{+} l^{-}$ ($l=e, \mu$) are investigated in Minimal Supersymmetric Standard Model (MSSM) and also in Supersymmetric (SUSY) SO(10) Grand Unified Models. In MSSM the special attention is paid to the…
We investigate the rare decay $\Lambda_b \to \Lambda \gamma$ which receives both short and long distance contributions. We estimate the long distance contributions and find them very small. The form factors are obtained from $\Lambda_c \to…
We present NNLL results for the double differential decay width dGamma(b -> X_s l+ l-)/(dsh dcos(theta)), where theta is the angle between the momenta of the b-quark and the l+, measured in the rest-frame of the lepton pair. From these…
The neutrinoless double beta ($0\nu\beta\beta$) decay is studied in the framework of left-right symmetric model. The coexistence of left and right handed currents induces rather complicated interactions in the mixing of lepton and hadrons,…
A multi-Higgs model with an extra neutral gauge boson ($Z'$) is introduced. One scalar Higgs boson ($H_2$) in this model decays dominantly into a photon pair. The $Z'$ decay to $\mu^+\mu^-$ gets a much larger branching ratio than the $Z$…
It has been shown that the anomalies observed in $\bar B\to D^{(\ast)}\tau\bar\nu_\tau$ and $\bar B\to \bar K\ell^+\ell^-$ decays can be resolved by adding a single scalar or vector leptoquark to the Standard Model, while constraints from…
In recent years, lepton flavour violating (LFV) decays are one of the most trending topics to probe new physics (NP). The latest results of LHCb have motivated us to study the LFV decays through b to s transition. The branching ratios,…
We study the decay width, forward-backward asymmetry and the longitudinal lepton polarization for the exclusive decay B --> K^* l^+ l^- in the two Higgs doublet model with three level flavor changing neutral currents (model III) and analyse…
We study the decay B -> K* l+ l- in the QCD factorization approach and propose a new integrated observable whose dependence on the form factors is almost negligible, consequently the non--perturbative error is significantly reduced and…
Decay rate and forward-backward asymmetries in B -> K_{1} l^{+} l ^{-}, K_{1} is the axial vector meson, are calculated in the universal extra dimension (UED) model. The dependence of these physical quantities on the compactification radius…
Heavy quark decays provide a very advantageous investigation to test the Standard Model (SM). Recently, promising experiments with \textit{b} quark, as well as the analysis of the huge data sets produced at the B factories, have led to an…