Multiscale Technicolor and b→sγb \to s \gamma

Correction to the $b\rightarrow s\gamma$ branching ratio in the multiscale walking technicolor model (MWTCM) is examined. For the original MWTCM, the correction is too large to explain the recent CLEO data. We show that if topcolor is further introduced, the branching ratio in the topcolor assisted MWTCM can be in agreement with the CLEO data for a certain range of the parameters.Comment: 11 pages, Latex, no macros, 3 figures, hard copy is available upon request. to appear in Z. Phys.

Charmless decays B -> PP, PV, and effects of new strong and electroweak penguins in Topcolor-assisted Technicolor model

Based on the low energy effective Hamiltonian with generalized factorization, we calculate the new physics contributions to the branching ratios and CP-violating asymmetries of the two-body charmless hadronic decays $B \to PP, PV$ from the new strong and electroweak penguin diagrams in the TC2 model. The top-pion penguins dominate the new physics corrections, and both new gluonic and electroweak penguins contribute effectively to most decay modes. For tree-dominated decay modes $B \to \pi \pi, \rho \pi, etc,$ the new physics corrections are less than 10%. For decays $B \to K^{(*)} \pi$, $K^{(*)} \eta$, $etc$, the new physics enhancements can be rather large (from $- 70$ to $\sim 200$) and are insensitive to the variations of $N_c^{eff}$, $k^2$, $\eta$ and $m_{\tilde{\pi}}$ within the reasonable ranges. For decays $B^0 \to \phi \pi$, $\phi \eta^{(')}$, $K^* \bar{K}^0$ and $\rho^+ K^0$, $\delta {\cal B}$ is strongly $N_c^{eff}-$dependent: varying from -90% to $\sim 1680$ in the range of $N_c^{eff}=2-\infty$. The new physics corrections to the CP-violating asymmetries ${\cal A}_{CP}$ vary greatly for different B decay channels. For five measured CP asymmetries of $B \to K \pi, K \eta', \omega \pi$ decays, $\delta {\cal A}_{CP}$ is only about 20% and will be masked by large theoretical uncertainties. The new physics enhancements to interesting $B \to K \eta'$ decays are significant in size ($\sim 50$), insensitive to the variations of input parameters and hence lead to a plausible interpretation for the unexpectedly large $B \to K \eta'$ decay rates. The TC2 model predictions for branching ratios and CP-violating asymmteries of all fifty seven $B \to PP, PV$ decay modes are consistent with the available data within one or two standard deviations.Comment: Latex file, 56 pages with 11 ps and eps figures. to be published in Eur.Phys.J.