Measurement of the Decays $B^0_sto J/psi,phi(1020)$, $B^0_{s}to J/psi,f_2(1525)$ and $B^0_sto J/psi,K^+K^-$ at Belle

We report a measurement of the branching fraction of the decay $B^0_sto J/psi,phi(1020)$, evidence and a branching fraction measurement for $B^0_sto J/psi,f_2(1525)$, and the determination of the total $B^0_sto J/psi,K^+K^-$ branching fraction, including the resonant and non-resonant contributions to the $K^+K^-$ channel. We also determine the $S$-wave contribution within the $phi(1020)$ mass region. The absolute branching fractions are $mathcal{B}[B^0_sto J/psi,phi(1020)]=(1.25 pm 0.07left(mathrm{stat}right)pm 0.08left(mathrm{syst}right)pm 0.22left(f_sright))times 10^{-3}$, $mathcal{B}[B^0_sto J/psi,f_2(1525)]=(0.26pm 0.06left(mathrm{stat}right)pm 0.02left(mathrm{syst}right) pm 0.05left(f_sright))times 10^{-3}$ and $mathcal{B}[B^0_sto J/psi,K^+K^-] = (1.01pm 0.09left(mathrm{stat}right) pm 0.10left(mathrm{syst}right)pm 0.18left(f_sright))times 10^{-3}$, where the last systematic error is due to the branching fraction of $bbar{b}to B^{(*)}_s B^{(*)}_s$. The branching fraction ratio is found to be $mathcal{B}[B^0_sto J/psi,f_2(1525)]/mathcal{B}[B^0_sto J/psi,phi(1020)]=(21.5pm 4.9left(mathrm{stat}right) pm2.6left(mathrm{syst}right))%$. All results are based on a 121.4 fb$^{-1}$ data sample collected at the $Upsilon(5S)$ resonance by the Belle experiment at the KEKB asymmetric-energy $e^+e^-$ collider.

Measurement of the form factors of the decay B0 -> D*- ell+ nu and determination of the CKM matrix element |Vcb|

This article describes a determination of the Cabibbo-Kobayashi-Maskawa matrix element $|V_{cb}|$ from the decay $B^0to D^{*-}ell^+ u_ell$ using 711 fb$^{-1}$ of Belle data collected near the $Upsilon(4S)$ resonance. We simultaneously measure the product of the form factor normalization $mathcal{F}(1)$ and the matrix element $|V_{cb}|$ as well as the three parameters $rho^2$, $R_1(1)$ and $R_2(1)$, which determine the form factors of this decay in the framework of the Heavy Quark Effective Theory. The results, based on about 120,000 reconstructed $B^0to D^{*-}ell^+ u_ell$ decays, are $rho^2=1.214pm 0.034pm 0.009$, $R_1(1)=1.401pm 0.034pm 0.018$, $R_2(1)=0.864pm 0.024pm 0.008$ and $mathcal{F}(1)|V_{cb}|=(34.6pm 0.2pm 1.0)times 10^{-3}$. The branching fraction of $B^0to D^{*-}ell^+ u_ell$ is measured at the same time; we obtain a value of $mathcal{B}(B^0 to D^{*-}ell^+ u_ell) = (4.58 pm 0.03 pm 0.26) %$. The errors correspond to the statistical and systematic uncertainties. These results give the most precise determination of the form factor parameters and $mathcal{F}(1)|V_{cb}|$ to date. In addition, a direct, model-independent determination of the form factor shapes has been carried out.