Measurement of the branching fractions for Cabibbo-suppressed decays $D^{+}\to K^{+} K^{-}π^{+}π^{0}$ and $D_{(s)}^{+}\to K^{+}π^{-}π^{+}π^{0}$ at Belle
Belle Collaboration, L. K. Li, A. J. Schwartz, K. Kinoshita, E. Won, H. Aihara, S. Al Said, D. M. Asner, H. Atmacan, V. Aulchenko, T. Aushev, R. Ayad, V. Babu, … 展开作者
Belle Collaboration, L. K. Li, A. J. Schwartz, K. Kinoshita, E. Won, H. Aihara, S. Al Said, D. M. Asner, H. Atmacan, V. Aulchenko, T. Aushev, R. Ayad, V. Babu, S. Bahinipati, K. Belous, J. Bennett, M. Bessner, V. Bhardwaj, T. Bilka, A. Bobrov, D. Bodrov, G. Bonvicini, J. Borah, A. Bozek, M. Bračko, P. Branchini, T. E. Browder, A. Budano, M. Campajola, D. Červenkov, P. Chang, A. Chen, B. G. Cheon, H. E. Cho, K. Cho, S. -J. Cho, S. -K. Choi, Y. Choi, S. Choudhury, D. Cinabro, S. Cunliffe, S. Das, N. Dash, G. De Nardo, G. De Pietro, R. Dhamija, F. Di Capua, Z. Doležal, T. V. Dong, D. Dossett, D. Epifanov, A. Frey, B. G. Fulsom, R. Garg, V. Gaur, A. Garmash, A. Giri, P. Goldenzweig, E. Graziani, D. Greenwald, T. Gu, Y. Guan, K. Gudkova, C. Hadjivasiliou, K. Hayasaka, H. Hayashii, D. Herrmann, W. -S. Hou, C. -L. Hsu, K. Inami, A. Ishikawa, R. Itoh, M. Iwasaki, W. W. Jacobs, S. Jia, Y. Jin, D. Kalita, A. B. Kaliyar, K. H. Kang, T. Kawasaki, C. Kiesling, C. H. Kim, D. Y. Kim, K. -H. Kim, K. T. Kim, Y. -K. Kim, P. Kodyš, T. Konno, A. Korobov, S. Korpar, E. Kovalenko, P. Križan, P. Krokovny, T. Kuhr, M. Kumar, R. Kumar, K. Kumara, A. Kuzmin, Y. -J. Kwon, Y. -T. Lai, T. Lam, M. Laurenza, S. C. Lee, J. Li, Y. Li, Y. B. Li, L. Li Gioi, J. Libby, K. Lieret, D. Liventsev, A. Martini, M. Masuda, T. Matsuda, D. Matvienko, S. K. Maurya, F. Meier, M. Merola, F. Metzner, K. Miyabayashi, R. Mizuk, G. B. Mohanty, H. K. Moon, M. Nakao, Z. Natkaniec, A. Natochii, L. Nayak, M. Nayak, N. K. Nisar, S. Nishida, H. Ono, P. Oskin, P. Pakhlov, G. Pakhlova, S. Pardi, H. Park, S. -H. Park, A. Passeri, S. Patra, S. Paul, T. K. Pedlar, R. Pestotnik, L. E. Piilonen, T. Podobnik, E. Prencipe, M. T. Prim, A. Rostomyan, N. Rout, G. Russo, D. Sahoo, S. Sandilya, A. Sangal, L. Santelj, V. Savinov, G. Schnell, J. Schueler, C. Schwanda, Y. Seino, K. Senyo, M. E. Sevior, M. Shapkin, C. Sharma, J. -G. Shiu, F. Simon, J. B. Singh, A. Sokolov, E. Solovieva, M. Starič, Z. S. Stottler, M. Sumihama, M. Takizawa, U. Tamponi, K. Tanida, F. Tenchini, M. Uchida, T. Uglov, K. Uno, S. Uno, Y. Ushiroda, Y. Usov, R. van Tonder, G. Varner, K. E. Varvell, A. Vossen, E. Waheed, E. Wang, M. -Z. Wang, X. L. Wang, S. Watanuki, O. Werbycka, J. Wiechczynski, B. D. Yabsley, W. Yan, S. B. Yang, H. Ye, J. Yelton, J. H. Yin, C. Z. Yuan, Z. P. Zhang, V. Zhilich, V. Zhukova
We present measurements of the branching fractions for the singly Cabibbo-suppressed decays $D^+\to K^{+}K^{-}π^{+}π^{0}$ and $D_s^{+}\to K^{+}π^{-}π^{+}π^{0}$, and the doubly Cabibbo-suppressed decay $D^{+}\to K^{+}π^{-}π^{+}π^{0}$, based on 980 ${\rm fb}^{-1}$ of data recorded by the Belle experiment at the KEKB $e^{+}e^{-}$ collider. We measure these modes relative to the Cabibbo-favored modes $D^{+}\to K^{-}π^{+}π^{+}π^{0}$ and $D_s^{+}\to K^{+}K^{-}π^{+}π^{0}$. Our results for the ratios of branching fractions are $B(D^{+}\to K^{+}K^{-}π^{+}π^{0})/B(D^{+}\to K^{-}π^{+}π^{+}π^{0}) = (11.32 \pm 0.13 \pm 0.26)\%$, $B(D^{+}\to K^{+}π^{-}π^{+}π^{0})/B(D^{+}\to K^{-}π^{+}π^{+}π^{0}) = (1.68 \pm 0.11\pm 0.03)\%$, and $B(D_s^{+}\to K^{+}π^{-}π^{+}π^{0})/B(D_s^{+}\to K^{+}K^{-}π^{+}π^{0}) = (17.13 \pm 0.62 \pm 0.51)\%$, where the uncertainties are statistical and systematic, respectively. The second value corresponds to $(5.83\pm 0.42)\times\tan^4θ_C$, where $θ_C$ is the Cabibbo angle; this value is larger than other measured ratios of branching fractions for a doubly Cabibbo-suppressed charm decay to a Cabibbo-favored decay. Multiplying these results by world average values for $B(D^{+}\to K^{-}π^{+}π^{+}π^{0})$ and $B(D_s^{+}\to K^{+}K^{-}π^{+}π^{0})$ yields $B(D^{+}\to K^{+}K^{-}π^{+}π^{0})= (7.08\pm 0.08\pm 0.16\pm 0.20)\times10^{-3}$, $B(D^{+}\to K^{+}π^{-}π^{+}π^{0})= (1.05\pm 0.07\pm 0.02\pm 0.03)\times10^{-3}$, and $B(D_s^{+}\to K^{+}π^{-}π^{+}π^{0}) = (9.44\pm 0.34\pm 0.28\pm 0.32)\times10^{-3}$, where the third uncertainty is due to the branching fraction of the normalization mode. The first two results are consistent with, but more precise than, the current world averages. The last result is the first measurement of this branching fraction.
Cabibbo-Suppressed Decays of D^+ to pi^+ pi^0, K^+ K^0, and K^+ pi^0
利用CLEO II和II.V探测器收集的对应于13.7 fb^-1的数据样本，我们报告了对D^+介子的两种Cabibbo抑制衰变模式的新的分支分数测量结果：Br（D^+ to pi^+ pi^0）=（1.3 +/- 0.2）x 10^-3和Br（D^+ to \bar{K}^0 K^+）=（5.2 +/- 0.6）x 10^-3，这是对过去测量的显著改进。误差包括统计和系统的不确定性，以及绝对D^+分支分数尺度的不确定性。我们还设定了第一个90%置信水平的上限，即卡比博双重抑制衰变模式的分支分数Br（D^+ to K^+ pi ^0）< 4.2 x 10^-4。
Belle II合作在SuperKEKB能量非对称e+ e对撞机上运行一个大幅升级的Belle探测器。Belle II将于2018年开始记录在Upperdance（4S）能量下的碰撞，目标是到2025年收集50 ab^{-1}的数据，是Belle实验的50倍。我们报告了测量与电荷宇称破坏相关的量的前景，特别强调了Cabibbo-Kobayashi-Maskawa角phi_3（γ）和与夸克混合矩阵元Vub相关的半轻子B介子衰变中的可观测量。
Asymmetries from the interference between Cabibbo-favored and doubly-Cabibbo-suppressed D decays
利用现有的实验数据对$D\to Kπ$和$D_s^+\to K K $衰变进行了唯象分析，其中包括Cabibbo有利模和双Cabibbo抑制模.分析中考虑了衰变常数和形状因子对SU（3）对称性破缺的影响。三个不对称，$R(D^0)$，$R(D^+)$，和$R(D_s^+)$，这是通过Cabbibo的青睐和双重Cabibbo抑制衰变之间的干扰产生的，估计。理论计算结果与实测结果吻合较好。
A search for D0-D0bar mixing and doubly-Cabibbo-suppressed decays of the D0 in hadronic final states
本文介绍了在费米实验室E791（一个固定靶粲强子产生实验）中寻找D 0-D 0巴混合和D 0的双重Cabibbo抑制衰变的结果。我们在衰变链D* -> pi D 0->（K pi或K pi pi pi）中寻找混合的证据。如果D* 衰变产生的π介子的电荷与D衰变产生的K介子的电荷相同（一个"错误符号“事件），混合可能已经发生。通过分析衰变时间的分布，可以将混合与其他来源的错误符号事件（如双重Cabibbo抑制衰变）区分开来。我们没有看到混合的证据。考虑到可能的CP破坏，我们对r_{mix}（混合衰变与非混合衰变之比）的结果是r_{mix}（D 0 bar-> D 0）=（0.18_{-0.39}^{+0.43} +-0.17）%和r_{mix}（D 0-> D 0 bar）=（0.70_{-0.53}^{+0.58} +-0.18）%。这些结果的敏感性与以前的测量结果相当，但在拟合数据时所作的假设明显更一般。我们提出的结果，从许多适合我们的数据在各种假设下。如果我们假设r_{mix} = 0，我们发现双Cabibbo抑制衰变与Cabibbo有利衰变的比值分别为r_{dcs}（K pi）=（0.68_{-0.33}^{+0.34} +-0.07）%和r_{dcs}（K pi pi pi）=（0.25_{-0.34}^{+0.36} +-0.03）%.
