Artigo Acesso aberto Revisado por pares

Measurement of the CKM matrix element | V c b | from B 0 → D <mml:mrow…

2019; American Physical Society; Volume: 100; Issue: 5 Linguagem: Inglês

10.1103/physrevd.100.052007

ISSN

2470-0037

Autores

E. Waheed, P. Urquijo, D. Ferlewicz, I. Adachi, K. Adamczyk, H. Aihara, S. Al Said, D. M. Asner, H. Atmacan, T. Aushev, R. Ayad, V. Babu, I. Badhrees, V. Bansal, P. K. Behera, C. Beleño, F. U. Bernlochner, B. Bhuyan, T. Bilka, J Biswal, A. Bobrov, G. Bonvicini, A. Bożek, M. Bračko, T. E. Browder, M. Campajola, D. Červenkov, P. Chang, V. Chekelian, A. Chen, B. G. Cheon, K. Chilikin, H. E. Cho, K. Cho, S.-K. Choi, K. Choi, S. Choudhury, D. Cinabro, S. Cunliffe, S. Di Carlo, Z. Doležal, T. V. Dong, D. Dossett, S. Eidelman, D. Epifanov, J. E. Fast, B. G. Fulsom, R. B. Garg, V. Gaur, A. Garmash, A. Giri, P. Goldenzweig, B. Golob, O. Grzymkowska, J. Haba, T. Hara, K. Hayasaka, H. Hayashii, M. T. Hedges, W.-S. Hou, C.-L. Hsu, T. Iijima, K. Inami, G. Inguglia, A. Ishikawa, M. Iwasaki, Y. Iwasaki, W. W. Jacobs, H. B. Jeon, S. Jia, Yu Jin, D. Joffe, K. K. Joo, J. Kahn, A. B. Kaliyar, G. Karyan, T. Kawasaki, C. H. Kim, D. Y. Kim, K. T. Kim, S. H. Kim, K. Kinoshita, P. Kodyš, S. Korpar, D. Kotchetkov, P. Križan, R. Kroeger, P. Krokovny, T. Kuhr, R. Kulasiri, A. Kuzmin, Y. Kwon, J. S. Lange, J. Y. Lee, S. C. Lee, C. H. Li, Lei Li, Y. B. Li, L. Li Gioi, J. Libby, K. Lieret, D. Liventsev, P.-C. Lu, T. Luo, J. MacNaughton, M. Masuda, D. Matvienko, M. Merola, F. Metzner, K. Miyabayashi, H. Miyata, R. Mizuk, G. B. Mohanty, T. Mori, R. Mussa, I. Nakamura, M. Nakao, K. J. Nath, Z. Natkaniec, M. Nayak, M. Niiyama, N. K. Nisar, S. Nishida, K. Nishimura, S. Ogawa, H. Ono, P. Pakhlov, G. Pakhlova, B. Pal, S. Pardi, H. Park, S.-H. Park, S. Paul, R. Pestotnik, L. E. Piilonen, V. Popov, E. Prencipe, M. T. Prim, A. Rostomyan, G. Russo, Y. Sakai, M. Salehi, S. Sandilya, T. Sanuki, V. Savinov, O. Schneider, G. Schnell, J. Schueler, C. Schwanda, Y. Seino, K. Senyo, O. Seon, M. E. Sevior, V. Shebalin, C. P. Shen, J.-G. Shiu, B. Shwartz, F. Simon, A. Sokolov, E. Solovieva, S. Stanič, M. Starič, Z. S. Stottler, J. Strube, T. Sumiyoshi, M. Takizawa, K. Tanida, F. Tenchini, K. Trabelsi, M. Uchida, T. Uglov, Y. Unno, S. Uno, Y. Usov, G. Varner, K. E. Varvell, A. Vinokurova, A. Vossen, C. H. Wang, M.-Z. Wang, Pengliang Wang, E. Won, S. B. Yang, H. Ye, Y. Yusa, Z. P. Zhang, V. Zhilich, V. Zhukova,

Tópico(s)

High-Energy Particle Collisions Research

Resumo

We present a new measurement of the Cabibbo-Kobayashi-Maskawa matrix element $|{V}_{cb}|$ from ${B}^{0}\ensuremath{\rightarrow}{D}^{*\ensuremath{-}}{\ensuremath{\ell}}^{+}{\ensuremath{\nu}}_{\ensuremath{\ell}}$ decays, reconstructed with the full Belle data set of $711\text{ }\text{ }{\mathrm{fb}}^{\ensuremath{-}1}$ integrated luminosity. Two form factor parametrizations, originally conceived by the Caprini-Lellouch-Neubert (CLN) and the Boyd, Grinstein and Lebed (BGL) groups, are used to extract the product $\mathcal{F}(1){\ensuremath{\eta}}_{\mathrm{EW}}|{V}_{cb}|$ and the decay form factors, where $\mathcal{F}(1)$ is the normalization factor and ${\ensuremath{\eta}}_{\mathrm{EW}}$ is a small electroweak correction. In the CLN parametrization we find $\mathcal{F}(1){\ensuremath{\eta}}_{\mathrm{EW}}|{V}_{cb}|=(35.06\ifmmode\pm\else\textpm\fi{}0.15\ifmmode\pm\else\textpm\fi{}0.56)\ifmmode\times\else\texttimes\fi{}{10}^{\ensuremath{-}3}$, ${\ensuremath{\rho}}^{2}=1.106\ifmmode\pm\else\textpm\fi{}0.031\ifmmode\pm\else\textpm\fi{}0.007$, ${R}_{1}(1)=1.229\ifmmode\pm\else\textpm\fi{}0.028\ifmmode\pm\else\textpm\fi{}0.009$, ${R}_{2}(1)=0.852\ifmmode\pm\else\textpm\fi{}0.021\ifmmode\pm\else\textpm\fi{}0.006$. For the BGL parametrization we obtain $\mathcal{F}(1){\ensuremath{\eta}}_{\mathrm{EW}}|{V}_{cb}|=(34.93\ifmmode\pm\else\textpm\fi{}0.23\ifmmode\pm\else\textpm\fi{}0.59)\ifmmode\times\else\texttimes\fi{}{10}^{\ensuremath{-}3}$, which is consistent with the world average when correcting for $\mathcal{F}(1){\ensuremath{\eta}}_{\mathrm{EW}}$. The branching fraction of ${B}^{0}\ensuremath{\rightarrow}{D}^{*\ensuremath{-}}{\ensuremath{\ell}}^{+}{\ensuremath{\nu}}_{\ensuremath{\ell}}$ is measured to be $\mathcal{B}({B}^{0}\ensuremath{\rightarrow}{D}^{*\ensuremath{-}}{\ensuremath{\ell}}^{+}{\ensuremath{\nu}}_{\ensuremath{\ell}})=(4.90\ifmmode\pm\else\textpm\fi{}0.02\ifmmode\pm\else\textpm\fi{}0.16)%$. We also present a new test of lepton flavor universality violation in semileptonic $B$ decays, $\frac{\mathcal{B}({B}^{0}\ensuremath{\rightarrow}{D}^{*\ensuremath{-}}{e}^{+}\ensuremath{\nu})}{\mathcal{B}({B}^{0}\ensuremath{\rightarrow}{D}^{*\ensuremath{-}}{\ensuremath{\mu}}^{+}\ensuremath{\nu})}=1.01\ifmmode\pm\else\textpm\fi{}0.01\ifmmode\pm\else\textpm\fi{}0.03$. The errors quoted correspond to the statistical and systematic uncertainties, respectively. This is the most precise measurement of $\mathcal{F}(1){\ensuremath{\eta}}_{\mathrm{EW}}|{V}_{cb}|$ and form factors to date and the first experimental study of the BGL form factor parametrization in an experimental measurement.

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