相关论文: Effect of both Z and Z'-mediated flavor-changing n…

We investigate the rare baryonic ${\Lambda}_b\rightarrow{\Lambda}l^+ l^-$ decays in a non-universal $Z'$ model, which is one of the well-motivated extensions of the standard model (SM). Considering the effects of $Z'$-mediated…

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…

Anomalous b --> s transitions from LHCb data may suggest a new massive gauge boson Z' that couples to the left-handed b --> s current, which in turn implies a coupling to the t --> c current. In this paper, we study flavor-changing neutral…

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…

We analyze the effect of the non-universal $Z$ boson in the rare decays $B_s \to l^+ l^- $, $B_s \to l^+ l^- \gamma $ and $Z \to b \bar s$ decays. These decays involve the FCNC mediated $ b \to s $ transitions, and are found to be very…

This presentation reviews the main results of our recent work [A.K., D.M., N.N., Phys. Rev. D97, 053007 (2018)] on rare radiative leptonic decays $B_{d,s}\to\gamma\mu^+\mu^-$ and $B_{d,s}\to\gamma e^+e ^-$ induced by flavour-changing…

We study the effect of the FCNC on rare $B$ decays in the beyond standard model with vector like singlet quarks. It has been shown that $b \rightarrow s \gamma $ does not receive sizable contribution compared with that of the standard model…

We study the effect of -mediated flavor-changing neutral current on the decays. The branching ratios of these decays can be enhanced remarkably in the non-universal model. Our estimated branching ratios are enhanced significantly from their…

We investigate $ B_s^0\rightarrow l^+ l^-\gamma $ decays in a nonuniversal Z' model derived from extension of the standard model (SM). Considering the Z'-mediated flavor changing neutral current (FCNC) effects we calculate the branching…

In recent years, $B_s$ decays into $tau^+tau^-$ has attracted a lot of attention since it is very sensitive to the structure of standard model (SM) and potential source of new physics beyond SM. In this paper, we study the effect of both Z…

We study the implications of flavour-changing neutral currents (FCNC's) in a model with the $SU(2)_l\times SU(2)_h\times U(1)_Y$ electroweak gauge symmetry for several anomalies appearing in $b\to s \ell\bar \ell$ induced $B$ decays in LHCb…

We study the three body lepton flavor violating (LFV) decays $\mu^- \to e^- e^+ e^-$, $\tau^- \to l_i^- l_j^+ l_j^-$ and the semileptonic decay $\tau \to \mu \phi $ in the flavor changing neutral current (FCNC) mediated $Z$ boson model. We…

We propose the local $(B-L)_{\mu\tau}$ model, which minimally retains the local $B-L$ extension for the sake of neutrino phenomenologies, and at the same time presents an invisible gauge boson $Z'$ with mass $\sim {\cal O}(10)$ MeV to…

The rare top decay t-> c l+l-, which involves flavor violation, is studied as a possible probe of new physics. This decay is analyzed with the simplest Standard Model extensions with additional gauge symmetry formalism. The considered…

The weak decays of doubly heavy $\Xi_{QQ}$ baryon induced by flavor changing $b \to d$ and $ c \to u$ flavor changing neutral current within the light cone sum rules are studied. Using the parallel components of the light cone distribution…

With the discovery of the doubly heavy $\Xi_{cc}$ baryon, comprehensive studies of the properties of the doubly heavy baryons are started. In the present work, we examine the $\Xi_{bb} \to \Sigma_b \ell^+ \ell^-$ and $\Xi_{cc} \to \Sigma_c…

We study the effects of an extra U(1)' gauge boson with flavor changing couplings with fermion mass eigenstates on certain B meson decays that are sensitive to such new physics contributions. In particular, we examine to what extent the…

We investigate in detail the flavor structure of the minimal 331 model and its implications for several flavor changing neutral current (FCNC) processes. In this model, where the weak SU(2)_L gauge group of the Standard Model is extended to…

We present a search for flavor changing neutral currents (FCNC) in decays of top quarks. The analysis is based on a search for $t\bar{t}\rightarrow\ell'\nu\ell\bar{\ell}$+jets ($\ell, \ell' = e,\mu$) final states using 4.1 {\rm fb}$^{-1}$…

In recent times, several discrepancies at the level of $(2-3)\sigma$ have been observed in the decay processes mediated by flavour changing neutral current (FCNC) transitions $b \to s \ell^+ \ell^-$, which may be considered as the…