arXiv subjects

Chao-Qiang Geng

Publications and source records attributed to Chao-Qiang Geng.

189 records · Page 11Linked to original sources

arXiv2005

Dilepton decays and oscillation of $B_{s}$ in split supersymmetry with R-parity violation

We study $B$ physics phenomenology in the scenario of split supersymmetry without R-parity. By assuming the constraints of bilinear (trilinear) R-parity violating couplings, which are introduced to solve the problem of the atmospheric (solar) neutrino mass, we show that the decay branching ratios of $B_{s}\to \ell^{+} \ell^{-}$ and the mixing of $B_s-\bar{B}_s$ can be large. Explicitly, we find that $B(B_s\toμ^+μ^-)=O(10^{-7})$ and $Δm_{B_s}=O(10^{-9}) GeV$, which should be observed at future hadron colliders.

hep-ph↗

arXiv2005

Looking for forward backward asymmetries in $B\to K μ^+ μ^-$ and $K^+\to π^+μ^+μ^-$

We investigate the possibility of scalar interaction affecting the forward backward asymmetry in the decay mode $B\to K μ^+ μ^-$. Using the scalar contribution and advocating Cheng-Sher type ansatz we obtain sizable forward backward asymmetry. Furthermore, we study the effect of the scalar interaction in $K^+ \to π^+ μ^+ μ^-$. It is pointed out that non-zero forward backward asymmetry in $B\to K l^+ l^-$, if found in future B-factories, may indicate the new physics in the scalar sector.

hep-ph↗

arXiv2005

Scalar interactions and the polarizations of $B\to ϕK^*$

We try to understand the polarization puzzle in $B\to ϕK^*$ decays with a simple Higgs model associated with flavor changing neutral current at tree level. The new interactions can effectively reduce the longitudinal polarization $|A_0|^2$. In particular, we find that if the couplings of $b$-quark in different chiralities to Higgs are the same, the transverse polarization $|A_\perp|^2$ can receive the largest contribution and its value can be as large as 30%. On the other hand, with opposite sign in the couplings, the other transverse polarization $|A_{\parallel}|^2$ is enhanced.

hep-ph↗

arXiv2005

Lepton angular asymmetries in semileptonic charmful B decays

We study the lepton angular distributions in $B\to D^{(*)} \ell ν_{\ell}$ decays. The lepton angular asymmetries in the decays with the general effective interactions are examined. We demonstrate that the asymmetries are sensitive to new physics with a right-handed quark current.

hep-ph↗

arXiv2005

Novel two-loop SUSY effects on CP asymmetry in $B\to ϕK_{s}$

Inspired by the exotic measurements on the CP asymmetry in $B\to ϕK_{s}$, we study a new diagram in supersymmetric models which can make the difference $\sin2ϕ^{eff}_{1}(J/ΨK_{s})-\sin2ϕ^{eff}_{1}(ϕK_{s})$ to be $20-50%$ after satisfying the constraint from $b\to s γ$. We also find that the direct CP asymmetry of $b\to s γ$ could be $\sim 10%$ and testable at $B$ factories.

hep-ph↗

arXiv2003

The difficulty in the decay constants and spectra of $D^{*}_{sJ}$

We examine the compatibility in predicted masses and the decay constants of $D^{*}_{sJ}$ mesons in terms of two-quark contents. We find that the results of a specific model, which is governed by heavy quark limit, will encounter a challenge to fit both spectra and decay constants simultaneously.

hep-ph↗

arXiv2001

Exclusive Decays of $B\to K^{(*)}l^+l^-$ in the PQCD

We study the exclusive decays of $B\to K^{(*)}l^+l^-$ within the framework of the PQCD. We obtain the form factors for the $B\to K^{(*)}$ transitions in all allowed values of $q^2$, which agree with the lattice results. We find that our distributions of the decay rates and leptonic asymmetries are consistent with that given in the other QCD models in the literature.

hep-ph↗

arXiv1994

Limit on $Br(b\to s g)$ in Two Higgs Doublet Models

Using the recent CLEO measurement of $Br(b\to s γ)$, we find that the branching ratio of $b\to s g$ cannot be larger than $10\%$ in two Higgs doublet models. The small experimental value of $Br(b\to e\barνX)$ can no longer be explained by charged Higgs boson effects.

hep-ph↗

arXiv1994

Possibility of $m_t < M_W + m_b$ for SUSY-type of Two Higgs Doublet Model

Allowing for realistic uncertainties in input parameters, we demonstrate that the present CLEO limit of $5.4\times 10^{-4}$ for inclusive $b\to sγ$ decay does not yet fully exclude the $t\to bH^+$ decay possibility in supersymmetric type of two Higgs doublet models. Combined with direct search for $t\to bH^+$ via $H^+\to τ^+ν$ at the Tevatron, we conclude that $\tanβ\sim 1$ is the ``allowed" window for $m_{H^+} < m_t < M_W$. The possibility becomes excluded, however, {\it if} the CLEO limit is pushed below $4\times 10^{-4}$.

hep-ph↗