Measurement of the Moments of the Photon Energy Spectrum in B -> X_s gamma Decays and Determination of |V_cb| and m_b at Belle

Using the previous Belle measurement of the inclusive photon energy in $Bto X_sgamma$ decays, we determine the first and second moments of this spectrum for minimum photon energies in the $B$ meson rest frame ranging from 1.8 to 2.3 GeV. Combining these measurements with recent Belle data on the lepton energy and hadronic mass moments in $Bto X_cell u$ decays, we perform fits to theoretical expressions derived in the 1S and kinetic mass schemes and extract the magnitude of the Cabibbo-Kobayashi-Maskawa (CKM) matrix element $V_{cb}$, the $b$-quark mass and other non-perturbative parameters. In the 1S scheme analysis we find $|V_{cb}|=(41.56pm 0.68(mathrm{fit})pm 0.08(tau_B))times 10^{-3}$ and $m_b^mathrm{1S}=(4.723pm 0.055)$ GeV. In the kinetic scheme, we obtain $|V_{cb}|=(41.58pm 0.69(mathrm{fit})pm 0.08(tau_B)pm 0.58(mathrm{th}))times 10^{-3}$ and $m_b^mathrm{kin}=(4.543pm 0.075)$ GeV.