Wolfgang Dungel | Searcharxiv

arXiv2009

Exclusive semileptonic b -> c decays at Belle

We present analyses of exclusive semileptonic b -> c decays based on data samples collected by the Belle detector at the KEK-B e+ e- asymmetric collider. The first topic are precision measurements of the Cabibbo-Kobayashi-Maskawa matrix element |V_{cb}| and the HQET form factor parameters ρ^2, R_1 and R_2 extracted from B^+ -> \bar{D}^{*0} \ell^+ νdecays using untagged Upsilon(4S) events. Additionally, a test of the form factor parametrization is performed. Secondly, measurements of B -> D^* τνand B -> D τνdecays are presented, where the accompanying second B meson is tagged and reconstructed. Branching fractions of the semi-tauonic decays are measured.

hep-ex↗

arXiv2008

Semileptonic Decays at Belle

We present three analyses based on data samples collected by the Belle detector at the KEKB e+e- asymmetric energy collider. The first one contains the measurement of the branching fractions and q^2 distributions of exclusive charmless semileptonic B decays, which are used to extract the Cabibbo-Kobayashi-Maskawa matrix element |V_{ub}|. The sample of events is obtained by fully reconstructing one of the B mesons in selected hadronic modes. The second analysis determines the branching fraction and the form factors rho^2, R_1 and R_2 for the exclusive decay B^0 -> D^{*-} \ell^+ ν. These measurements are used to extract the Cabibbo-Kobayashi-Maskawa matrix element |V_{cb}|. The third analysis investigates B -> D^{**} \ell νdecays and determines branching ratios for the four modes D_{0}^{*}, D_{1}, D_{1}^{'} and D_{2}^{*} for both charged and neutral B decays.

hep-ex↗