Measurement of the decay $B\to D\ellν_\ell$ in fully reconstructed events and determination of the Cabibbo-Kobayashi-Maskawa matrix element $|V_{cb}|$

R. Glattauer, C. Schwanda, A. Abdesselam, I. Adachi, K. Adamczyk, H. Aihara, S. Al Said, D. M. Asner, T. Aushev, R. Ayad, T. Aziz, I. Badhrees, A. M. Bakich, V. Bansal, E. Barberio, B. Bhuyan, J. Biswal, G. Bonvicini, A. Bozek, M. Bračko, F. Breibeck, T. E. Browder, D. Červenkov, V. Chekelian, A. Chen, B. G. Cheon, K. Chilikin, R. Chistov, K. Cho, V. Chobanova, Y. Choi, D. Cinabro, J. Dalseno, M. Danilov, N. Dash, J. Dingfelder, Z. Doležal, A. Drutskoy, D. Dutta, S. Eidelman, H. Farhat, J. E. Fast, T. Ferber, A. Frey, B. G. Fulsom, V. Gaur, N. Gabyshev, A. Garmash, R. Gillard, Y. M. Goh, P. Goldenzweig, B. Golob, D. Greenwald, J. Haba, P. Hamer, T. Hara, J. Hasenbusch, K. Hayasaka, H. Hayashii, W. -S. Hou, C. -L. Hsu, T. Iijima, K. Inami, G. Inguglia, A. Ishikawa, H. B. Jeon, D. Joffe, K. K. Joo, T. Julius, K. H. Kang, E. Kato, T. Kawasaki, C. Kiesling, D. Y. Kim, J. B. Kim, J. H. Kim, K. T. Kim, M. J. Kim, S. H. Kim, Y. J. Kim, K. Kinoshita, P. Kodyš, S. Korpar, P. Križan, P. Krokovny, T. Kuhr, A. Kuzmin, Y. -J. Kwon, I. S. Lee, L. Li, Y. Li, J. Libby, Y. Liu, D. Liventsev, P. Lukin, J. MacNaughton, M. Masuda, D. Matvienko, K. Miyabayashi, H. Miyata, R. Mizuk, G. B. Mohanty, S. Mohanty, A. Moll, H. K. Moon, R. Mussa, E. Nakano, M. Nakao, T. Nanut, Z. Natkaniec, M. Nayak, N. K. Nisar, S. Nishida, S. Ogawa, S. Okuno, C. Oswald, P. Pakhlov, G. Pakhlova, B. Pal, H. Park, T. K. Pedlar, L. Pesántez, R. Pestotnik, M. Petrič, L. E. Piilonen, C. Pulvermacher, J. Rauch, E. Ribežl, M. Ritter, A. Rostomyan, H. Sahoo, Y. Sakai, S. Sandilya, L. Santelj, T. Sanuki, V. Savinov, O. Schneider, G. Schnell, A. J. Schwartz, Y. Seino, K. Senyo, O. Seon, M. E. Sevior, V. Shebalin, T. -A. Shibata, J. -G. Shiu, B. Shwartz, A. Sibidanov, F. Simon, Y. -S. Sohn, A. Sokolov, E. Solovieva, M. Starič, T. Sumiyoshi, U. Tamponi, Y. Teramoto, K. Trabelsi, V. Trusov, M. Uchida, Y. Unno, S. Uno, P. Urquijo, Y. Usov, C. Van Hulse, P. Vanhoefer, G. Varner, K. E. Varvell, V. Vorobyev, A. Vossen, C. H. Wang, M. -Z. Wang, P. Wang, Y. Watanabe, E. Won, H. Yamamoto, Y. Yamashita, Y. Yook, Z. P. Zhang, V. Zhilich, V. Zhulanov, A. Zupanc

Published 2015-10-13Version 1

We present a determination of the magnitude of the Cabibbo-Kobayashi-Maskawa matrix element $|V_{cb}|$ using the decay $B\to D\ell\nu_\ell$ ($\ell=e,\mu$) based on 711 fb$^{-1}$ of $e^+e^-\to \Upsilon(4S)$ data recorded by the Belle detector and containing $772 \times 10^6$ $B\bar{B}$ pairs. One $B$ meson in the event is fully reconstructed in a hadronic decay mode while the other, on the signal side, is partially reconstructed from a charged lepton and either a $D^+$ or $D^0$ meson in a total of 23 hadronic decay modes. The isospin-averaged branching fraction of the decay $B\to D\ell\nu_\ell$ is found to be $\mathcal{B}(B^0 \to D^- \ell^+ \nu_{\ell})=(2.31\pm 0.03(\mathrm{stat})\pm 0.11(\mathrm{syst}))\%$. Analyzing the differential decay rate as a function of the hadronic recoil with the parameterization of Caprini, Lelouch and Neubert and using the form-factor prediction $\mathcal{G}(1)=1.0541\pm 0.0083$ calculated by FNAL/MILC, we obtain $\eta_\mathrm{EW}|V_{cb}|=(40.12\pm 1.34)\times 10^{-3}$, where $\eta_\mathrm{EW}$ is the electroweak correction factor. Alternatively, assuming the model-independent form-factor parameterization of Boyd, Grinstein and Lebed and using lattice QCD data from the FNAL/MILC and HPQCD collaborations, we find $\eta_\mathrm{EW}|V_{cb}|=(41.10 \pm 1.14)\times 10^{-3}$.