相关论文: Probing new physics through $B^*_s \rightarrow \mu…
The rare flavour-changing neutral current decay $B_s\to\mu^+\mu^-$ is among the most important indirect probes of new physics at the LHC, as it is strongly suppressed in the Standard Model, very sensitive to new physics effects, and…
We consider the effect of new physics interactions in the form of tensor operators on the branching ratio of B_s --> l+ l- gamma where l=e, mu. We find that the present data on the inclusive branching ratio B --> X_s l+ l- puts a strong…
The LHCb experiment has recently established a sizable width difference between the mass eigenstates of the $B_s$-meson system. This phenomenon leads to a subtle difference at the 10% level between the experimental branching ratios of $B_s$…
Leptonic rare decays of $B^0_{s,d}$ mesons offer a powerful tool to search for physics beyond the Standard Model. The $B^0_{s}\to\mu^+\mu^-$ decay has been observed at the Large Hadron Collider and the first measurement of the effective…
Recent experimental results on angular observables in the rare decay $B\to K^*\mu^+\mu^-$ show significant deviations from Standard Model predictions. We investigate the possibility that these deviations are due to new physics. Combining…
Transitions of the type $b \to s l^+ l^-$ are flavour changing neutral current processes where new physics can enter in competing loop diagrams with respect to the Standard Model contributions. In these decays several observables sensitive…
Recently several measurements in the neutral current sector $b\rightarrow s l^+l^-$ ($l=e$ or $\mu$) as well as in the charged current sector $b \rightarrow c \tau \bar{\nu}$ show significant deviations from their Standard Model…
\noindent A search for the decays $B^0_{s}\rightarrow \mu^+ \mu^- \mu^+ \mu^-$ and $B^0 \rightarrow \mu^+ \mu^- \mu^+ \mu^-$ is performed using data, corresponding to an integrated luminosity of 1.0\ensuremath{\{\,fb}^{-1}}\xspace,…
We study the rare $\Lambda_b\to\Lambda\mu^+\mu^-$ decay in the Standard Model and beyond. Beyond the Standard Model we include new vector and axial-vector operators, scalar and pseudo-scalar operators, and tensor operators in the effective…
I review the status of the rare decays B_s --> mu+mu- and B_d --> mu+mu-. The latest Standard Model predictions for the corresponding branching ratios are discussed. An overview of additional observables that are accessible in the B_s -->…
We perform a comprehensive study of the impact of new-physics operators with different Lorentz structures on decays involving the b -> s mu+ mu- transition. We examine the effects of new vector-axial vector (VA), scalar-pseudoscalar (SP)…
The rare decays {$B^- \to \tau \bar\nu$}, \mbox{$B \to \tau^+ \tau^-$}, {$b \to X \nu \bar\nu$} and \mbox{$b \to X \tau^+ \tau^-$} all contain third generation leptons in the final state, and hence are sensitive to new physics that couples…
Recent measurements of $R_{D^*}$ have reduced tension with the Standard Model prediction. Taking all the present data into account, we obtain the values of the Wilson coefficients of each new physics four-fermion operator of a given Lorentz…
Recent measurements of exclusive $B^{-} \to \tau^{-}\,\nu$ and $B^0 \to \pi^{+}\,l^{-}\,\bar{\nu}_l$ decays via the $b \to u\,l\,\nu$ transition process differ from the standard model expectation and, if they persist in future $B$…
Unparticle contributions to the recently measured decay mode $B_s\to\mu^+\mu^-$ are analyzed. We consider only the scalar unparticles because vector unparticles are expected to provide negligible contributions. Assuming that the relevant…
Recently, the LHCb Collaboration provided updated measurements for the lepton flavour ratios $R_K$ and $R_{K^*}$. The currently observed values align with the predictions of the standard model. In light of these recent updates, our…
Latest measurement of the ratio of branching ratios $R_D = \mathcal B(B \to D\,\tau\,\nu)/\mathcal B(B \to D\,l\,\nu)$ and $R_{D^{\ast}} = \mathcal B(B \to D^{\ast}\,\tau\,\nu)/\mathcal B(B \to D^{\ast}\,l\,\nu)$, where $l$ is either an…
We perform a study of the Standard Model (SM) fit to the mixing quantities $\Delta M_{B_s}$, and $\Delta \Gamma_{B_s}/\Delta M_{B_s}$ in order to bound contributions of New Physics to $B_s$ mixing. We then use this to explore the branching…
A number of observables related to the $b \to s \ell^+ \ell^-$ transition show deviations from their standard model predictions. A global fit to the current $b\rightarrow s\ell^+\ell^-$ data suggests several new physics solutions.…
We study the decays of $B\to K^{(*)} \ell^{+} \ell^{-}$ in split supersymmetry with R-parity violation. We find that the decay branching ratio of $B\to K\tau^+\tau^-$ in the new physics model due to the scalar interactions can be $1.8\times…