High-resolution search for the $Θ^{+}$ pentaquark via a pion-induced reaction at J-PARC
PARC E19 Collaboration, M. Moritsu, S. Adachi, M. Agnello, S. Ajimura, K. Aoki, H. C. Bhang, B. Bassalleck, E. Botta, S. Bufalino, N. Chiga, H. Ekawa, P. Evtouk… 展开作者
PARC E19 Collaboration, M. Moritsu, S. Adachi, M. Agnello, S. Ajimura, K. Aoki, H. C. Bhang, B. Bassalleck, E. Botta, S. Bufalino, N. Chiga, H. Ekawa, P. Evtoukhovitch, A. Feliciello, H. Fujioka, S. Hayakawa, F. Hiruma, R. Honda, K. Hosomi, Y. Ichikawa, M. Ieiri, Y. Igarashi, K. Imai, N. Ishibashi, S. Ishimoto, K. Itahashi, R. Iwasaki, C. W. Joo, S. Kanatsuki, M. J. Kim, S. J. Kim, R. Kiuchi, T. Koike, Y. Komatsu, V. V. Kulikov, S. Marcello, S. Masumoto, Y. Matsumoto, K. Matsuoka, K. Miwa, T. Nagae, M. Naruki, M. Niiyama, H. Noumi, Y. Nozawa, R. Ota, K. Ozawa, N. Saito, A. Sakaguchi, H. Sako, V. Samoilov, M. Sato, S. Sato, Y. Sato, S. Sawada, M. Sekimoto, K. Shirotori, H. Sugimura, S. Suzuki, H. Takahashi, T. Takahashi, T. N. Takahashi, H. Tamura, T. Tanaka, K. Tanida, A. O. Tokiyasu, N. Tomida, Z. Tsamalaidze, M. Ukai, K. Yagi, T. O. Yamamoto, S. B. Yang, Y. Yonemoto, C. J. Yoon, K. Yoshida
The pentaquark $Θ^+$ has been searched for via the $π^-p \to K^-X$ reaction with beam momenta of 1.92 and 2.01 GeV/$c$ at J-PARC. A missing mass resolution of 2 MeV (FWHM) was achieved but no sharp peak structure was observed. The upper limits on the production cross section averaged over the scattering angle from 2$^{\circ}$ to 15$^{\circ}$ in the laboratory frame were found to be less than 0.28 $μ$b/sr at the 90\% confidence level for both the 1.92- and 2.01-GeV/$c$ data. The systematic uncertainty of the upper limits was controlled within 10\%. Constraints on the $Θ^+$ decay width were also evaluated with a theoretical calculation using effective Lagrangian. The present result implies that the width should be less than 0.36 and 1.9 MeV for the spin-parity of $1/2^+$ and $1/2^-$, respectively.
Understanding the nature of the heavy pentaquarks and searching for them in pion-induced reactions
利用开粲强子再散射图研究了反应$π^- p \to π^- J/ψp$。由于再散射振幅中存在三角形奇异性（TS），TS峰可以模拟$J/ψp$不变质量分布中的类五夸克共振，这可能会给我们对奇异态性质的理解带来模糊性.由于TS机制具有高度的过程依赖性，在不同过程中寻找重五夸克态可以帮助我们澄清这些不确定性。
Accessing proton generalized parton distributions and pion distribution amplitudes with the exclusive pion-induced Drell-Yan process at J-PARC
广义部分子分布（GPD）编码的强子部分子结构的多维信息出现在硬排斥反应的因式分解描述的积木。核子GPD是通过轻子束的深虚康普顿散射和深虚介子产生来实现的。与强子束互补的探测是π介子诱导的Drell-Yan过程。在本文中，我们讨论了最近的理论进展，描述这一过程的核子GPD和π分布振幅。此外，我们解决的可行性测量专有π介子诱导的Drell-Yan过程$π^- p \to μ^+μ^- n$通过光谱仪在高动量光束线正在建设中的日本J-PARC。在J-PARC实现这样的测量将提供一个新的测试微扰QCD描述的一类新的硬排斥反应。它还将提供在大型类时虚拟环境中实验性地访问核子GPD的可能性。
Regarding the possibility to observe the LHCb hidden-charm strange pentaquark $P_{cs}(4459)^0$ in antikaon-induced $J/ψ$ meson production on protons and nuclei near the $J/ψ$$Λ$ production threshold
Feasibility demonstration of a high-momentum, high-purity muon beamline at the J-PARC Hadron Experimental Facility
Research Center for Nuclear Physics (RCNP), The University of Osaka（大阪大学核物理研究中心）；Institute of Particle and Nuclear Studies (IPNS), High Energy Accelerator Research Organization (KEK)（高能加速器研究机构粒子与核研究研究所）；Institute of Physics, Academia Sinica（中央研究院物理学研究所）；Department of Physics, Graduate school of Science, Kyoto University（京都大学理学研究科物理学系）；Department of Physics, Graduate School of Science, The University of Osaka（大阪大学理学研究科物理学系）；Center for Science Adventure and Collaborative Research Advancement (SACRA), Graduate school of Science, Kyoto University（京都大学理学研究科科学冒险与协同研究推进中心）
