Related papers: Determination of $\gamma$ from the $\eta - \eta'$ …
We have studied charmless two-body B decays involving $\eta$ and $\eta'$ in the framework of QCD improved factorization appraoch. The spectator hard scattering mechanism for $\eta'$ production have been re-examined and extended, which…
The decays $B_d\to\pi^\mp K^\pm$ and $B^\pm\to\pi^\pm K$ provide interesting constraints on the angle $\gamma$ of the unitarity triangle of the CKM matrix. It is shown that bounds on $\gamma$ can also be obtained from the time evolution of…
The large discrepancy recently observed between $B \ra J/\Psi + K (K^*)$ data and commonly used hadronic form factor models might be due to a breakdown of the factorization assumption. By showing that the $B \ra \eta_c + K (K^*)$ rates can…
We discuss the exclusive radiative decays $B\to K^{*}\gamma$, $B \to\rho\gamma$, and $B\to\omega\gamma$ in QCD factorization within the Standard Model. The analysis is based on the heavy-quark limit of QCD. Our results for these decays are…
In this paper we perform a comprehensive study of the four $B \to K \etap$ decays in the pQCD factorization approach. We calculate the CP-averaged branching ratios and CP-violating asymmetries of $B \to K\etap$ decays in the ordinary…
The $B_s \to D_s^{(*)\pm} K^\mp$ decays allow a theoretically clean determination of $\phi_s+\gamma$, where $\phi_s$ is the $B^0_s$-$\bar B^0_s$ mixing phase and $\gamma$ the usual angle of the unitarity triangle. A sizable $B_s$ decay…
The decays $B_d\to \pi^+ \pi^-$ and $B_s\to K^+ K^-$ are related to each other by interchanging all down and strange quarks, i.e. through the $U$-spin flavour symmetry of strong interactions. A completely general parametrization of the…
As we pointed out recently, the neutral decays $B_d\to\pi^\mp K^\pm$ and $B_d\to\pi^0K$ may provide non-trivial bounds on the CKM angle $\gamma$. Here we reconsider this approach in the light of recent CLEO data, which look very…
In the framework of QCD factorization, we study $B^{+(0)} \to \eta' K^{+(0)}$ decays. In order to more reliably determine the phenomenological parameters $X_H$ and $X_A$ arising from end-point divergences in the hard spectator scattering…
We use QCD sum-rules to study the decays $\phi \to \eta \gamma$ and $\phi \to \eta^\prime \gamma$, obtaining ${\cal B}(\phi \to \eta \gamma)=(1.15 \pm 0.2) 10^{-2}$ and ${\cal B}(\phi \to \eta^\prime \gamma)=(1.18 \pm 0.4) 10^{-4}$, in very…
Using the latest LHCb measurements of time-dependent CP violation in the B^0_s -> K^+K^- decay, a U-spin relation between the decay amplitudes of B^0_s -> K^+K^- and B^0 -> \pi^+\pi^- decay processes allows constraints to be placed on the…
The nonet symmetry scheme seems to describe rather well the masses and $\eta-\eta^{\prime}$ mixing angle of the ground state pseudo-scalar mesons and is thus expected to be also a good approximation for the matrix elements of the…
The charm content in $\eta'$ is estimated using the QCD U(1) axial anomaly applied to $b\to s g g \to \eta' s$. We find $f_{\eta'}^{(c)} \approx - 3.1$ MeV for $m_c = 1.3$ GeV. Our estimate agrees with other independent methods by Feldmann…
As we pointed out recently, the neutral decays $B_d\to\pi^\mp K^\pm$ and $B_d\to\pi^0K$ may provide non-trivial bounds on the CKM angle $\gamma$. In this paper, we reconsider this approach in the light of recent CLEO data, which look very…
A recent combination of measurements performed by the LHCb collaboration determined that $\gamma=(63.8^{+3.5}_{-3.7})^\circ$. The fit combined the results of $\gamma$ and charm measurements, which resulted in precision improvements for the…
An improved flavor SU(3) method is presented for determining the weak angle $\gamma$ of the unitarity triangle using decay rates for $B^+\to K\pi, B^+\to K^+\bar K^0$ and $B^+\to \pi^+\eta$ (or $B^0\to K\pi$ and $B_s\to K \pi$), their…
We study $B\to J/\Psi \eta^{(\prime)}$ decays and suggest two methods to determine the $\eta-\eta^{\prime}$ mixing angle. We calculate not only the factorizable contribution in QCD facorization scheme but also the nonfactorizable hard…
The CKM angle $\gamma$ is measured for the first time from mixing-induced $CP$ violation between $B^0_s \rightarrow D_s^\mp K^\pm \pi^\pm \pi^\mp$ and $\bar{B}^0_s \rightarrow D_s^\pm K^\mp \pi^\mp \pi^\pm$ decays reconstructed in…
We calculate the main observables in $B_{u,d}\to (\rho,\omega,K^*)\gamma$ and $B_s\to (\bar K^*,\phi)\gamma$ decays, i.e. branching ratios and CP and isospin asymmetries. We include QCD factorisation results and also the dominant…
In view of future plans for accurate measurements of the theoretically clean branching ratios Br(K+ -> pi+ nu nu) and Br(KL -> pi0 nu nu), that should take place in the next decade, we collect the relevant formulae for quantities of…