Related papers: Fourth generation effect on $\Lambda_b$ decays
If the fourth generation fermions exist, the new quarks could influence the branching ratios of the decays of $B\to X_s \gamma$ and $B\to X_sl^+l^-$. We obtain two solutions of the fourth generation CKM factor $V^{*}_{t^{'}s}V_{t^{'}b}$…
We study CP violation in b-baryon decays of $\Xi_b^- \to \Xi^- D$ with $D = D^0, \bar{D}^0$ and $D_i~(i=1,2)$. We find that these baryonic decay processes provide an ideal opportunity to measure the weak phase due to the absence of the…
We consider the phenomenology of the fourth generation heavy quarks which would be pair produced at the LHC. We show that if such a quark with a mass in the phenomenologically interesting range of 400 GeV--600 GeV decays to a light quark…
Motivated by the first observation of CP violation in $b$-baryon decays, the search for baryonic decays exhibiting large CP violation will be a primary focus in the coming years. We propose that significant CP-violating effects exist in the…
Rare $b \to s\ell^+\ell^-$ flavour-changing-neutral-current processes provide important tests of the Standard Model of particle physics. Angular observables in exclusive $b \to s\ell^+\ell^-$ processes can be particularly powerful as they…
We discuss the most important Physics thus far extracted from studies of B meson decays. Measurements of the four CP violating angles accessible in B decay are reviewed as well as direct CP violation. A detailed discussion of the…
We present a short overview of recent work on the topic of flavour violation in the presence of a sequential fourth generation (4G) of quarks and leptons. We discuss the implications of this simple extension of the Standard Model (SM3) for…
This study investigates the influence of the fourth generation quarks on the total branching ratio and the single lepton polarizations in \Lambda_b --> \Lambda \ell^+ \ell^- decay. Taking $|V_{t's}V_{t'b}| {0.01-0.03} with phase just below…
The experimental decay branching ratios of mesons like $B_s\to \ell\bar \ell$ and $B_d\to \ell\bar \ell$ ($\ell=e$ or $\mu$) do not agree completely with the standard model (SM). Cartan's supersymmetry predicts relation of the coupling of…
Motivated by the latest improved measurements of B-meson decays, we make a comprehensive analysis of the impact of a family non-universal $Z^{\prime}$ boson on $B_s-\bar{B}_s$ mixing and two-body hadronic B-meson decays, all being…
We study the effect of a sequential fourth generation on b\to s gamma, B_s mixing, B\to K^{(*)}\ell^+\ell^-, X_s\ell^+\ell^- and \phi K_S, taking into account the presence of a new CP phase in quark mixing. We find that the effects via…
The baryonic $b\to s$ transition $\Lambda_b\to\Lambda^{(*)}\nu{\bar\nu}$ is analyzed. We combine the mesonic counterpart $B^+\to K^+\nu{\bar\nu}$ and $B^0\to K^{*0}\nu{\bar\nu}$ as well as other observables involving $B$ mesons like…
We study various FCNC involving heavy quarks in the Standard Model (SM) with a sequential fourth generation. After imposing $B\to X_s\gamma$, $B\to X_sl^+l^-$ and $Z\to b\bar{b}$ constraints, we find ${\cal B}(Z\to s\bar{b}+\bar{s}b)$ can…
Semileptonic decays of Lambda_b and Lambda_c baryons are studied within the Relativistic Three-Quark Model using finite heavy quark mass values. Employing the same parameters as have been used previously for the description of exclusive…
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…
The long-awaited $B_s\to \mu^+\mu^-$ mode has finally been observed at rate consistent with Standard Model, albeit lower by 1.2$\sigma$. There is some hint for New Physics in the rarer $B_d^0 \to \mu^+\mu^-$ decay, especially if the…
This study examines the influence of the fourth generation quarks on the double lepton polarizations forward--backward asymmetries in B \rar K^\ast \ell^+ \ell^- decay. We obtain that for both (muon, tau) channels the magnitude and the sign…
With updated experimental data and improved theoretical calculations, several significant deviations are being observed between the Standard Model predictions and the experimental measurements of the branching ratios of $\bar{B}_{(s)}^0\to…
In these lectures I first cover radiative and semileptonic B decays, including the QCD corrections for the quark subprocesses. The exclusive modes and the evaluation of the hadronic matrix elements, i.e. the relevant hadronic form factors,…
Rare decays $\Lambda_b \to \Lambda \gamma$ and $\Lambda_b \to \Lambda l^{+} l^{-}$ (l= e, $\mu$) are examined. We use QCD sum rules to calculate the hadronic matrix elements governing the decays. The $\Lambda$ polarization in the decays is…