1. Measurement of $\mathcal{R}(D)$ and $\mathcal{R}(D^{\ast})$ with a semileptonic tagging method
- Author
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The Belle Collaboration, Abdesselam, A., Adachi, I., Adamczyk, K., Aihara, H., Said, S. Al, Arinstein, K., Arita, Y., Asner, D. M., Aso, T., Atmacan, H., Aulchenko, V., Aushev, T., Ayad, R., Aziz, T., Babu, V., Badhrees, I., Bahinipati, S., Bakich, A. M., Bala, A., Ban, Y., Bansal, V., Barberio, E., Barrett, M., Bartel, W., Bay, A., Behera, P., Belhorn, M., Belous, K., Berger, M., Bernlochner, F. U., Besson, D., Bhardwaj, V., Bhuyan, B., Biswal, J., Bloomfield, T., Blyth, S., Bobrov, A., Bondar, A., Bonvicini, G., Bookwalter, C., Boulahouache, C., Bozek, A., Bračko, M., Braun, N., Breibeck, F., Brodzicka, J., Browder, T. E., Caria, G., Červenkov, D., Chang, M. -C., Chang, P., Chao, Y., Chekelian, V., Chen, A., Chen, K. -F., Chen, P., Cheon, B. G., Chilikin, K., Chistov, R., Cho, K., Chobanova, V., Choi, S. -K., Choi, Y., Cinabro, D., Crnkovic, J., Cunliffe, S., Dalseno, J., Danilov, M., Dash, N., Di Carlo, S., Dingfelder, J., Doležal, Z., Dossett, D., Drásal, Z., Drutskoy, A., Dubey, S., Dutta, D., Dutta, K., Eidelman, S., Epifanov, D., Falke, S., Farhat, H., Fast, J. E., Feindt, M., Ferber, T., Frey, A., Frost, O., Fulsom, B. G., Gaur, V., Gabyshev, N., Ganguly, S., Garmash, A., Gelb, M., Gemmler, J., Getzkow, D., Gillard, R., Giordano, F., Glattauer, R., Goh, Y. M., Goldenzweig, P., Golob, B., Greenwald, D., Perdekamp, M. Grosse, Grygier, J., Grzymkowska, O., Guan, Y., Guido, E., Guo, H., Haba, J., Hamer, P., Han, Y. L., Hara, K., Hara, T., Hasegawa, Y., Hasenbusch, J., Hayasaka, K., Hayashii, H., He, X. H., Heck, M., Hedges, M. T., Heffernan, D., Heider, M., Heller, A., Higuchi, T., Himori, S., Hirose, S., Horiguchi, T., Hoshi, Y., Hoshina, K., Hou, W. -S., Hsiung, Y. B., Hsu, C. -L., Huschle, M., Hyun, H. J., Igarashi, Y., Iijima, T., Imamura, M., Inami, K., Inguglia, G., Ishikawa, A., Itagaki, K., Itoh, R., Iwabuchi, M., Iwasaki, M., Iwasaki, Y., Iwata, S., Jacobs, W. W., Jaegle, I., Jeon, H. B., Jia, S., Jin, Y., Joffe, D., Jones, M., Joo, K. K., Julius, T., Kahn, J., Kakuno, H., Kaliyar, A. B., Kang, J. H., Kang, K. H., Kapusta, P., Karyan, G., Kataoka, S. U., Kato, E., Kato, Y., Katrenko, P., Kawai, H., Kawasaki, T., Keck, T., Kichimi, H., Kiesling, C., Kim, B. H., Kim, D. Y., Kim, H. J., Kim, H. -J., Kim, J. B., Kim, J. H., Kim, K. T., Kim, M. J., Kim, S. H., Kim, S. K., Kim, Y. J., Kinoshita, K., Kleinwort, C., Klucar, J., Ko, B. R., Kobayashi, N., Koblitz, S., Kodyš, P., Koga, Y., Korpar, S., Kotchetkov, D., Kouzes, R. T., Križan, P., Krokovny, P., Kronenbitter, B., Kuhr, T., Kulasiri, R., Kumar, R., Kumita, T., Kurihara, E., Kuroki, Y., Kuzmin, A., Kvasnička, P., Kwon, Y. -J., Lai, Y. -T., Lange, J. S., Lee, D. H., Lee, I. S., Lee, S. -H., Leitgab, M., Leitner, R., Levit, D., Lewis, P., Li, C. H., Li, H., Li, J., Li, L., Li, X., Li, Y., Gioi, L. Li, Libby, J., Limosani, A., Liu, C., Liu, Y., Liu, Z. Q., Liventsev, D., Loos, A., Louvot, R., Lubej, M., Lukin, P., Luo, T., MacNaughton, J., Masuda, M., Matsuda, T., Matvienko, D., Matyja, A., Metzner, F., McOnie, S., Mikami, Y., Miyabayashi, K., Miyachi, Y., Miyake, H., Miyata, H., Miyazaki, Y., Mizuk, R., Mohanty, G. B., Mohanty, S., Mohapatra, D., Moll, A., Moon, H. K., Mori, T., Morii, T., Moser, H. -G., Mrvar, M., Müller, T., Muramatsu, N., Mussa, R., Nagamine, T., Nagasaka, Y., Nakahama, Y., Nakamura, I., Nakamura, K. R., Nakano, E., Nakano, H., Nakano, T., Nakao, M., Nakayama, H., Nakazawa, H., Nanut, T., Nath, K. J., Natkaniec, Z., Nayak, M., Nedelkovska, E., Negishi, K., Neichi, K., Ng, C., Niebuhr, C., Niiyama, M., Nisar, N. K., Nishida, S., Nishimura, K., Nitoh, O., Nozaki, T., Ogawa, A., Ogawa, S., Ohshima, T., Okuno, S., Olsen, S. L., Ono, H., Ono, Y., Onuki, Y., Ostrowicz, W., Oswald, C., Ozaki, H., Pakhlov, P., Pakhlova, G., Pal, B., Palka, H., Panzenböck, E., Park, C. -S., Park, C. W., Park, H., Park, K. S., Paul, S., Peak, L. S., Pedlar, T. K., Peng, T., Pesántez, L., Pestotnik, R., Peters, M., Petrič, M., Piilonen, L. E., Poluektov, A., Prasanth, K., Prim, M., Prothmann, K., Pulvermacher, C., Purohit, M. V., Rauch, J., Reisert, B., Ribežl, E., Ritter, M., Rorie, J., Rostomyan, A., Rozanska, M., Rummel, S., Ryu, S., Sahoo, H., Salehi, M., Saito, T., Sakai, K., Sakai, Y., Sandilya, S., Santel, D., Santelj, L., Sanuki, T., Sasaki, J., Sasao, N., Sato, Y., Savinov, V., Schlüter, T., Schneider, O., Schnell, G., Schönmeier, P., Schram, M., Schwanda, C., Schwartz, A. J., Schwenker, B., Seidl, R., Seino, Y., Semmler, D., Senyo, K., Seon, O., Seong, I. S., Sevior, M. E., Shang, L., Shapkin, M., Shebalin, V., Shen, C. P., Shibata, T. -A., Shibuya, H., Shimizu, N., Shinomiya, S., Shiu, J. -G., Shwartz, B., Sibidanov, A., Simon, F., Singh, J. B., Sinha, R., Smerkol, P., Sohn, Y. -S., Sokolov, A., Soloviev, Y., Solovieva, E., Stanič, S., Starič, M., Steder, M., Strube, J. F., Stypula, J., Sugihara, S., Sugiyama, A., Sumihama, M., Sumisawa, K., Sumiyoshi, T., Suzuki, K., Suzuki, S., Suzuki, S. Y., Suzuki, Z., Takeichi, H., Takizawa, M., Tamponi, U., Tanaka, M., Tanaka, S., Tanida, K., Taniguchi, N., Taylor, G. N., Tenchini, F., Teramoto, Y., Tikhomirov, I., Trabelsi, K., Trusov, V., Tsuboyama, T., Uchida, M., Uchida, T., Uehara, S., Ueno, K., Uglov, T., Unno, Y., Uno, S., Uozumi, S., Urquijo, P., Ushiroda, Y., Usov, Y., Vahsen, S. E., Van Hulse, C., Vanhoefer, P., Varner, G., Varvell, K. E., Vervink, K., Vinokurova, A., Vorobyev, V., Vossen, A., Wagner, M. N., Waheed, E., Wang, B., Wang, C. H., Wang, J., Wang, M. -Z., Wang, P., Wang, X. L., Watanabe, M., Watanabe, Y., Wedd, R., Wehle, S., White, E., Widmann, E., Wiechczynski, J., Williams, K. M., Won, E., Yabsley, B. D., Yamada, S., Yamamoto, H., Yamaoka, J., Yamashita, Y., Yamauchi, M., Yashchenko, S., Ye, H., Yelton, J., Yook, Y., Yuan, C. Z., Yusa, Y., Zhang, C. C., Zhang, L. M., Zhang, Z. P., Zhao, L., Zhilich, V., Zhukova, V., Zhulanov, V., Ziegler, M., Zivko, T., Zupanc, A., and Zwahlen, N.
- Subjects
High Energy Physics - Experiment - Abstract
We report a measurement of the ratios of branching fractions $\mathcal{R}(D) = {\cal B}(\bar{B} \to D \tau^- \bar{\nu}_{\tau})/{\cal B}(\bar{B} \to D \ell^- \bar{\nu}_{\ell})$ and $\mathcal{R}(D^{\ast}) = {\cal B}(\bar{B} \to D^* \tau^- \bar{\nu}_{\tau})/{\cal B}(\bar{B} \to D^* \ell^- \bar{\nu}_{\ell})$, where $\ell$ denotes an electron or a muon. The results are based on a data sample containing $772\times10^6$ $B\bar{B}$ events recorded at the $\Upsilon(4S)$ resonance with the Belle detector at the KEKB $e^+ e^-$ collider. The analysis utilizes a method where the tag-side $B$ meson is reconstructed in a semileptonic decay mode, and the signal-side $\tau$ is reconstructed in a purely leptonic decay. The measured values are $\mathcal{R}(D)= 0.307 \pm 0.037 \pm 0.016$ and $\mathcal{R}(D^{\ast})= 0.283 \pm 0.018 \pm 0.014$, where the first uncertainties are statistical and the second are systematic. These results are in agreement with the Standard Model predictions within $0.2$ and $1.1$ standard deviations, respectively, while their combination agrees with the Standard Model predictions within $1.2$ standard deviations., Comment: 12 pages, 6 figures
- Published
- 2019