相关论文: t-c gamma and t-cg in warped extra dimensions

We discuss exclusive radiative decays in QCD factorization within the Standard Model. In particular, we consider the decays B -> V gamma, with a vector meson K* or rho in the final state, and the double radiative modes B_s -> gamma gamma…

The one-loop induced top quark decay $t\to u_1\bar{u}_2u_2$ ($u_i=u,c$) is calculated in the context of the standard model. The dominant contribution to this top quark decay arises from the Feynman diagrams induced by the off-shell…

Due to the large production cross-section, many of the top quark properties can be measured very precisely at the LHC. A very few recent results, probed only through the top quark decay vertices are presented here. These results are based…

We have investigated the flavor changing top quark physics on the dimension-six anomalous $tq\gamma$ ($q=u,c$) couplings through the process $pp\to p\gamma \gamma p\to p t\bar{q}p$ at the LHC by considering different forward detector…

Theoretical predictions for the top quark rare decays are reviewed within and beyond the standard model. Expectations at the CERN Large Hadron Collider are discussed.

The decays of top quark $t\rightarrow c\gamma,\;t\rightarrow cg,\;t\rightarrow cZ,\;t\rightarrow ch$ are extremely rare processes in the standard model (SM). The predictions on the corresponding branching ratios in the SM are too small to…

A simple relativistic model of heavy-light mesons is applied to the rare decay B -> K* gamma in the standard model. We find Gamma(B -> K* gamma)/Gamma(b -> s gamma)=(17 \pm 4)% and BR(B -> K* gamma)=(4.8 \pm 1.9) \times 10^{-5}(V_cb/.04)^2.…

We investigate extremely rare top quark decays at a future proton-proton collider with centre-of-mass energy of 100 TeV. We focus on two decay modes: radiative decay with a $Z$ boson, $t \rightarrow b WZ$, and flavour-changing neutral decay…

Exclusive rare $B \to K^{(*)} \ell^+ \ell^-$, $B \to K^{(*)} \nu \bar \nu$ and $B \to K^* \gamma$ decays are studied within the Applequist-Cheng-Dobrescu model, an extension of the Standard Model in presence of universal extra dimensions.…

We explore the sensitivity of the flavour changing neutral currents among c and u quarks in the context of the Minimal Supersymmetric Standard Model. The standard model rate for c->u gamma can be enhanced by up to two orders of magnitudes…

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 flavor-changing top-quark decay $t\to c h$, where $h$ is the lightest CP-even Higgs boson in the minimal supersymmetric standard model, is examined in the R-parity-violating supersymmetric model. Within the existing bounds on the…

We investigate the radiative B_c -> rho^+ gamma and B_c -> K^{*+} gamma decays in the standard model. The transition form factors are calculated in the framework of the light cone QCD sum rules method. We estimate the branching ratios of…

We study a new method for detecting non-universal gauge bosons $Z'$ via considering their effects on rare top decays. We calculate the contributions of the non-universal gauge bosons $Z'$ predicted by topcolor-assisted technicolor (TC2)…

The spectroscopic parameters and decay channels of the scalar tetraquark $ T_{bb;\overline{u}\overline{s}}^{-}$ (in what follows $T_{b:\overline{s} }^{-} $) are investigated. The mass and coupling of the $T_{b:s}^{-}$ are calculated using…

The rare $B_c \to D_{s,d}^{*} l^+ l^-$ decays are investigated in the framework of the three point QCD sum rules approach. Considering the gluon condensate corrections to the correlation function, the form factors relevant to these…

The rare radiative flavour changing top decays $t\to c\gamma$ and $t\to cg$ (and the even rarer $t\to u\gamma$ and $t\to ug$) have been processes of interest for decades as they offer a key probe for studying top quark properties. However…

We study the anomalous FCNC $tq\gamma$ and $tqg$ couplings via $pp\to Wb\gamma+X$ signal process including realistic detector effects for both leptonic and hadronic decay channels of the W boson at 100 TeV FCC-hh. The relevant background…

In the framework of the top triangle moose $(TTM)$ model, we analyze the rare decays $\Lambda_{b}\rightarrow \Lambda l^{+}l^{-} (l=e,\mu,\tau)$ by using the form factors calculated in full $QCD$. We calculate the contributions of the new…

I report on developments in the experimental and phenomenological understanding of the rare decays of mesons containing b and c quarks, especially as they pertain to the understanding of the CKM matrix and the testing of the standard model.…