Search for $B^0$ Decays to Invisible Final States ($+γ$) at Belle
Belle Collaboration, Y. Ku, P. Chang, I. Adachi, K. Adamczyk, H. Aihara, D. M. Asner, T. Aushev, R. Ayad, P. Behera, C. Bele\ {n}o, J. Bennett, V. Bhardwaj, T. … 展开作者
Belle Collaboration, Y. Ku, P. Chang, I. Adachi, K. Adamczyk, H. Aihara, D. M. Asner, T. Aushev, R. Ayad, P. Behera, C. Bele\ {n}o, J. Bennett, V. Bhardwaj, T. Bilka, J. Biswal, G. Bonvicini, A. Bozek, M. Bračko, M. -C. Chang, V. Chekelian, K. Chilikin, K. Cho, S. -K. Choi, Y. Choi, D. Cinabro, S. Cunliffe, N. Dash, G. De Nardo, T. V. Dong, S. Eidelman, D. Epifanov, J. E. Fast, B. G. Fulsom, R. Garg, V. Gaur, N. Gabyshev, A. Garmash, P. Goldenzweig, O. Grzymkowska, Y. Guan, O. Hartbrich, K. Hayasaka, H. Hayashii, M. Hernandez Villanueva, T. Higuchi, W. -S. Hou, C. -L. Hsu, K. Huang, K. Inami, G. Inguglia, A. Ishikawa, R. Itoh, M. Iwasaki, Y. Iwasaki, S. Jia, Y. Jin, K. H. Kang, T. Kawasaki, H. Kichimi, C. Kiesling, C. H. Kim, D. Y. Kim, T. D. Kimmel, K. Kinoshita, P. Kodyš, S. Korpar, P. Križan, R. Kroeger, P. Krokovny, T. Kuhr, R. Kulasiri, R. Kumar, Y. -J. Kwon, Y. -T. Lai, Y. B. Li, L. Li Gioi, J. Libby, K. Lieret, C. MacQueen, D. Matvienko, M. Merola, R. Mizuk, G. B. Mohanty, T. J. Moon, T. Mori, R. Mussa, Z. Natkaniec, M. Nayak, N. K. Nisar, S. Nishida, K. Nishimura, K. Ogawa, S. Ogawa, H. Ono, P. Oskin, P. Pakhlov, G. Pakhlova, H. Park, S. -H. Park, S. Patra, T. K. Pedlar, R. Pestotnik, L. E. Piilonen, T. Podobnik, V. Popov, M. T. Prim, M. Ritter, M. Röhrken, A. Rostomyan, N. Rout, G. Russo, Y. Sakai, L. Santelj, T. Sanuki, V. Savinov, G. Schnell, J. Schueler, C. Schwanda, A. J. Schwartz, K. Senyo, M. Shapkin, J. -G. Shiu, B. Shwartz, A. Sokolov, E. Solovieva, M. Starič, Z. S. Stottler, M. Sumihama, T. Sumiyoshi, M. Takizawa, U. Tamponi, K. Tanida, F. Tenchini, K. Trabelsi, M. Uchida, T. Uglov, Y. Unno, S. Uno, P. Urquijo, Y. Usov, G. Varner, K. E. Varvell, A. Vinokurova, C. H. Wang, E. Wang, M. -Z. Wang, P. Wang, X. L. Wang, M. Watanabe, E. Won, X. Xu, S. B. Yang, H. Ye, C. Z. Yuan, Z. P. Zhang, V. Zhukova
We report searches for $B^0\to\rm{invisible}$ and $B^0\to\rm{invisible}+γ$ decays, where the energy of the photon is required to be larger than 0.5 GeV. These results are obtained from a $711\,{\rm fb}^{-1}$ data sample that contains $772 \times 10^6 B\bar{B}$ pairs and was collected near the $Υ\,(4S)$ resonance with the Belle detector at the KEKB $e^+ e^-$ collider. We observe no significant signal for either decay and set upper limits on their branching fractions at $90\%$ confidence level of $\mathcal{B}\,(B^0\to\rm{invisible}) < 7.8\times10^{-5}$ and $\mathcal{B}\,(B^0\to\rm{invisible}+γ) < 1.6\times10^{-5}$.
Search for B0 Decays to Invisible Final States and to nu nubar gamma
我们建立了B 0衰变到最终状态的分支分数的上限，其中衰变产物是完全不可见的（即，没有可观测到的最终状态粒子），并且对于B 0衰变到nubar γ。在标准模型中，这些衰变的分支分数低于当前的实验灵敏度，但标准模型之外的各种物理模型预测这些通道的重要贡献。利用斯坦福直线加速器中心PEP-II e+e储存环上的BaBar实验在Y（4S）共振下收集的8850万个B Bbar对，我们在90%置信水平下建立了B 0->不可见的分支分数的上限为22 x 10^-5，B 0-> nu nubar gamma的分支分数的上限为4.7 x 10^-5。
Search for the Invisible Decay of $\jpsi$ in $ψ(2S)\toπ+π^-J/ψ$
使用14.0百万个$ψ(2S) events collected with the BES-II detector, a search for the decay of the $ \jpsi $ to an invisible final state in $ \psipto $ is performed. The $ \jpsi $ peak in the distribution of mass recoiling against the $ π^+π^- $ is used to tag $ $ invisible decay. No signal is found, and an upper limit at the 90% confidence level is determined to be $ 1.2 \times 10^{-2} $ for the ratio $ \frac{{\cal B}(\jpsi\ar {invisible})}{{\cal B}(\jpsi\arμ^+μ^-)} $. This is the first search for $ J/J $衰减到不可见的最终状态。
Observation of two narrow mesons in the D+_s pi^0 and D+_s pi^0 gamma final states. Results from BaBar, Belle and CLEO
BaBar实验在质心能量接近10.6 GeV的包含$e^{+}e^{-}$相互作用中发现了一个窄态，记为D*_{sJ}（2317）+，其质量分布在D+s pi ^0不变质量分布中接近2.32 GeV/c^2。同样的实验也暗示了在D+ s π ^0伽马能谱中，在2.46 GeV/c^2附近存在第二个新态。这些发现触发了CLEO和Belle实验寻找与D+_s介子耦合的新态。他们证实了D*_{sJ}（2317）^+态的存在，并为D*_{sJ}（2458）^+态的存在提供了证据。Belle不仅在连续e+e-湮灭中，而且在B衰变中报告了这两种状态的证据。这两个新的窄共振的特点是质量显着低于预测的潜在的模型，足以关闭最自然的衰变模式，从而迫使违反同位旋过渡。他们的发现令人惊讶，因为它与显然已建立的理论的预期相矛盾。这种情况也导致了理论方面的巨大努力。
Study of Transitions and Decays of Bottomonia at Belle
本文综述了从Belle探测器在不同厄普塞隆共振态记录的e+ e-数据中对bottomonium态跃迁和衰变的研究。我们还报道了最近在Y（2S）数据样本中对χ_{bJ}（1 P）到41个强子末态的分支分数的研究。在该研究中，首次对τ total <2.4MeV时χ b 0（1 P）的宽度设定了90%置信上限。
