1203.6647 (The Belle Collaboration et al.)

Measurements of Branching Fractions and Time-dependent CP Violating
Asymmetries in $B^{0} \to D^{(*)\pm}D^{\mp}$ Decays    [PDF]

The Belle Collaboration, M. Röhrken, I. Adachi, H. Aihara, D. M. Asner, V. Aulchenko, T. Aushev, A. M. Bakich, M. Barrett, K. Belous, V. Bhardwaj, B. Bhuyan, M. Bischofberger, A. Bondar, G. Bonvicini, A. Bozek, M. Bračko, O. Brovchenko, T. E. Browder, M. -C. Chang, A. Chen, P. Chen, B. G. Cheon, K. Chilikin, I. -S. Cho, K. Cho, Y. Choi, J. Dalseno, Z. Doležal, Z. Drásal, A. Drutskoy, S. Eidelman, J. E. Fast, M. Feindt, V. Gaur, N. Gabyshev, A. Garmash, Y. M. Goh, J. Haba, H. Hayashii, Y. Horii, Y. Hoshi, W. -S. Hou, Y. B. Hsiung, H. J. Hyun, T. Iijima, A. Ishikawa, R. Itoh, M. Iwabuchi, Y. Iwasaki, T. Julius, J. H. Kang, T. Kawasaki, C. Kiesling, H. J. Kim, H. O. Kim, J. B. Kim, J. H. Kim, K. T. Kim, M. J. Kim, Y. J. Kim, K. Kinoshita, B. R. Ko, S. Koblitz, P. Kodyš, S. Korpar, R. T. Kouzes, P. Križan, P. Krokovny, B. Kronenbitter, T. Kuhr, T. Kumita, Y. -J. Kwon, S. -H. Lee, J. Li, Y. Li, J. Libby, C. Liu, Y. Liu, Z. Q. Liu, D. Liventsev, R. Louvot, K. Miyabayashi, H. Miyata, R. Mizuk, G. B. Mohanty, A. Moll, T. Mori, N. Muramatsu, Y. Nagasaka, E. Nakano, M. Nakao, Z. Natkaniec, S. Nishida, O. Nitoh, S. Ogawa, T. Ohshima, S. Okuno, S. L. Olsen, H. Ozaki, G. Pakhlova, C. W. Park, H. Park, H. K. Park, K. S. Park, T. K. Pedlar, R. Pestotnik, M. Petrič, L. E. Piilonen, A. Poluektov, M. Prim, K. Prothmann, M. Ritter, S. Ryu, H. Sahoo, Y. Sakai, T. Sanuki, Y. Sato, O. Schneider, C. Schwanda, A. J. Schwartz, K. Senyo, O. Seon, M. E. Sevior, M. Shapkin, C. P. Shen, T. -A. Shibata, J. -G. Shiu, B. Shwartz, A. Sibidanov, F. Simon, J. B. Singh, P. Smerkol, Y. -S. Sohn, A. Sokolov, E. Solovieva, S. Stanič, M. Starič, K. Sumisawa, T. Sumiyoshi, K. Trabelsi, M. Uchida, S. Uehara, Y. Unno, S. Uno, P. Urquijo, P. Vanhoefer, G. Varner, K. E. Varvell, V. Vorobyev, C. H. Wang, M. -Z. Wang, P. Wang, M. Watanabe, Y. Watanabe, K. M. Williams, E. Won, H. Yamamoto, Y. Yamashita, D. Zander, Z. P. Zhang, V. Zhilich, V. Zhulanov, A. Zupanc

We report measurements of branching fractions and time-dependent CP asymmetries in $B^{0} \to D^{+}D^{-}$ and $B^{0} \to D^{*\pm}D^{\mp}$ decays using a data sample that contains $(772 \pm 11)\times 10^6 B\bar{B}$ pairs collected at the $\Upsilon(4S)$ resonance with the Belle detector at the KEKB asymmetric-energy $e^+ e^-$ collider. We determine the branching fractions to be $\mathcal{B}(B^{0} \to D^{+}D^{-})=(2.12 \pm 0.16 \pm 0.18)\times 10^{-4}$ and $\mathcal{B}(B^{0} \to D^{*\pm}D^{\mp}=(6.14 \pm 0.29 \pm 0.50)\times 10^{-4}$. We measure CP asymmetry parameters $\mathcal{S}_{D^{+}D^{-}} = -1.06_{-0.14}^{+0.21} \pm 0.08$ and $\mathcal{C}_{D^{+}D^{-}} = -0.43 \pm 0.16 \pm 0.05$ in $B^{0} \to D^{+}D^{-}$ and $\mathcal{A}_{D^{*}D} = +0.06 \pm 0.05 \pm 0.02$, $\mathcal{S}_{D^{*}D} = -0.78 \pm 0.15 \pm 0.05$, $\mathcal{C}_{D^{*}D} = -0.01 \pm 0.11 \pm 0.04$, $\Delta\mathcal{S}_{D^{*}D} = -0.13 \pm 0.15 \pm 0.04$ and $\Delta\mathcal{C}_{D^{*}D} = +0.12 \pm 0.11 \pm 0.03$ in $B^{0} \to D^{*\pm}D^{\mp}$, where the first uncertainty is statistical and the second is systematic. We exclude the conservation of CP symmetry in both decays at equal to or greater than $4\sigma$ significance.

View original: http://arxiv.org/abs/1203.6647