arXiv subjects
Publications and source records attributed to A. Ioannissian.
The direct CP-violation in the left-right symmetric $SU(2) \times SU(2) \times U(1)$ model is investigated for the decay $b \rightarrow sγ$. The calculated CP-asymmetry for the wide range of parameters can be larger than in standard model and can have an opposite sign.
We estimate the long distance (LD) contribution to the magnetic part of the $s \to dγ$ transition using the Vector Meson Dominance approximation $(V=ρ,ω,ψ_i)$. We find that this contribution may be significantly larger than the short distance (SD) contribution to $s \to dγ$ and could possibly saturate the present experimental upper bound on the $Ω^-\to Ξ^-γ$ decay rate, $Γ^{\rm MAX}_{Ω^-\to Ξ^-γ} \simeq 3.7\times10^{-9}$eV. For the decay $B_s \to B^*_dγ$, which is driven by $s \to dγ$ as well, we obtain an upper bound on the branching ratio $BR(B_s \to B_d^*γ)<3\times10^{-8}$ from $Γ^{\rm MAX}_{Ω^-\to Ξ^-γ}$. Barring the possibility that the Quantum Chromodynamics coefficient $a_2(m_s)$ be much smaller than 1, $Γ^{\rm MAX}_{Ω^-\to Ξ^-γ}$ also implies the approximate relation $\frac{2}{3} \sum_i \frac{g^2_{ψ_i}(0)}{m^2_{ψ_i}} \simeq \frac{1}{2} \frac{g^2_ρ(0)}{m^2_ρ} + \frac{1}{6}\frac{g^2_ω(0)}{m^2_ω}$. This relation agrees quantitatively with a recent independent estimate of the l.h.s. by Deshpande et al., confirming that the LD contributions to $b \to sγ$ are small. We find that these amount to an increase of $(4\pm2)\%$ in the magnitude of the $b \to s γ$ transition amplitude, relative to the SD contribution alone.
We demonstrate that the long distance contribution to $B^{\pm} \to ρ^{\pm} γ$ may have a large effect on the decay rate and through it on the CP violating partial rate asymmetry. The change in the asymmetry can be between a factor of 0.4 and 1.4 with respect to the effect of the short distance contribution alone, depending on the values of the CKM parameters $ρ$ and $η$ .
We parametrize phenomenologically possible new physics effects and calculate their influence on the invariant dilepton mass spectrum and the Dalitz plot for the decays $B \to K \ell^+ \ell^-$ and $B \to K^\ast \ell^+ \ell^-$. Especially the decay into $K^*$ yields a wealth of new information on the form of the new interactions since the Dalitz plot is sensitive to subtle interference effects. We also show how transversely polarized $K^*$-mesons give additional information.