相关论文: A Simple Approach to Fourth Generation Effects in …
If the fourth generation fermions exist, the new quarks could influence the branching ratio of the rare $B\to K^{*}\nu\bar{\nu}$ decay. Two possible solutions of the fourth generation CKM factor $(V^{*}_{\acute{t}s}V_{\acute{t}b})^(\pm)$…
If the fourth generation fermions exist, the new quarks could influence the branching ratio of the decay $B_s \to \nu \bar{\nu} \gamma$. We obtain two solutions of the fourth generation CKM factor $V^*_{t's} V_{t'b}$ from the decay of $B…
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 the contributions to the branching ratios of $B_{s(d)}\to \gamma \gamma$ decay in the sequential fourth generation model (SM4). We find that the theoretical values of the branching ratios, ${\rm BR}(B_{s(d)}\to\gamma\gamma)$,…
We investigate the influence of the fourth generation of quarks on the branching ratio, the CP-asymmetry and the polarization asymmetries in $B \rar \rho \ell^+ \ell^-$ decay. Taking $|V_{t'd}V_{t'b}|\sim 0.001$ with phase about $10^\circ$,…
Influence of the fourth generation, if ever exists, on the experimentally measurable quantities such as invariant dilepton mass distribution, lepton forward-backward asymmetry, and the ratio (Gamma_L/Gamma_T) of the decay widths when K*…
We calculate the branching ratios of $B_{s,d}\to \gamma \gamma$ decay in the sequential fourth generation model. We find that the theoretical values of the branching ratios, ${\rm BR}(B_{s}\to\gamma\gamma)$, including the contributions of…
We investigate the influence of the fourth generation quarks on the branching ratio and the CP-asymmetry in B -->\pi \ell^+ \ell^- decay. Taking the |V_{t'd}V_{t'b}| ~ 0.001 with phase about 10 degree, which is consistent with the…
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…
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…
Using the theoretical and experimental results on $B \to X_s \gamma$, a four-generation SM is analyzed to constrain the combination of the $4\times 4$ Cabibbo-Kobayashi-Maskawa factor $V_{t^\prime s}^* V_{t^\prime b}$ as a function of the…
We present a model-independent analysis of rare B decays, $B \to K^{(*)} \nu \nu$. The effect of possible new physics is written in terms of dimension-6 four-fermi interactions. The lepton number violating scalar- and tensor-type…
We critically review the assumption that no new physics is acting in tree-level $B$-meson decays and study the consequences for the ultimate precision in the direct determination of the CKM angle $\gamma$. In our exploratory study we find…
We study the effects of the fourth generation of quarks on the total branching ratio and the lepton polarizations in $\bar{B}_{0}\rightarrow K_{0}^{\ast}(1430)l^{+}l^{-}$($l$ = $\mu $, $\tau $) decay. Taking fourth generation quark mass…
Using firmly established experimental inputs such as epsilon_K, Delta M_d, Delta M_s, BR(B -> tau nu), gamma, V_cb along with corresponding lattice matrix elements which have been well studied and are in full QCD such as B_K, SU3 breaking…
There are several anomalous measurements in the decays induced by the quark level transition $b \to s \mu^+ \mu^-$, which do not agree with the predictions of the Standard Model. These measurements could be considered as signatures of…
We analyze the new physics effects in semileptonic $\bar{B_s} \to K^{*+}(\to K\pi) \ell^- \bar{\nu}_\ell$ decay induced by the $b \to u \ell \nu_{\ell}$ quark level transition. We consider the vector, scalar and tensor new physics Lorentz…
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…
We present a theoretical reappraisal of the branching ratios and CP asymmetries for the decays $ B \to X_q \ell^+ \ell^-$, with $q=d,s$, taking into account current theoretical uncertainties in the description of the inclusive decay…
We analyze the possibility of having new physics effects in the decay rate difference, $\Delta \Gamma_d$, of neutral $B_d$ mesons. Three different sources of enhancement are considered, CKM unitarity violations, beyond standard model…