Moon, B.*; Jungclaus, A.*; Nadja, H.*; Gargano, A.*; Lozeva, R.*; Moon, C.-B.*; Orlandi, R.; 他66名*
Physical Review C, 103(3), p.034320_1 - 034320_15, 2021/03
At RIKEN RIBF facility, the beta decay of Sb and Sb were studied and several new excited states were assigned to the level schemes of Te and Te. The structure of these Te isotopes deduced from the level scheme is compared with state-of-the-art shell-model calculations using different effective interactions. The comparison with calculations permits to determine the spectroscopic factors and deformation of these isotopes close to doubly magic Sn.
山我 拓巳*; 橋本 直; 谷田 聖; 他66名*
Physical Review C, 102(4), p.044002_1 - 044002_14, 2020/10
We have performed an exclusive measurement of the reaction at an incident kaon momentum of . In the invariant mass spectrum, a clear peak was observed below the mass threshold of , as a signal of the kaonic nuclear bound state, . The binding energy, decay width, and -wave Gaussian reaction form-factor of this state were observed to be , , and , respectively. The total production cross-section of , determined by its decay mode, was . We estimated the branching ratio of the state to the and decay modes as , by assuming that the physical processes leading to the final states are analogous to those of .
山我 拓巳*; 橋本 直; 谷田 聖; 他66名*
JPS Conference Proceedings (Internet), 26, p.023008_1 - 023008_6, 2019/11
There is a long-standing argument of the existence of kaonic nucleus, which is a bound state of anti-kaon and nucleus. Theoretically, its existence is strongly supported, however its binding energy and width have not been established yet. It is strongly desired to have an experiment to investigate the simplest kaonic nucleus, so-called bound state. We performed an experiment to search for via the in-flight reaction at J-PARC. By studying invariant mass spectrum in the final state and its dependence on momentum transfer of , we observed a resonant state located below . The mass and width of this resonant state are MeV/, and MeV, respectively, which can be naturally interpreted as a theoretically predicted bound state.
Resmi, P. K.*; 谷田 聖; Belle Collaboration*; 他166名*
Journal of High Energy Physics (Internet), 2019(10), p.178_1 - 178_27, 2019/10
We present the first model-independent measurement of the CKM unitarity triangle angle using decays, where indicates either a or meson. Measurements of the strong-phase difference of the amplitude obtained from CLEO-c data are used as input. This analysis is based on the full Belle data set of events collected at the resonance. We obtain and the suppressed amplitude ratio . Here the first uncertainty is statistical, the second is the experimental systematic, and the third is due to the precision of the strong-phase parameters measured from CLEO-c data. The 95% confidence interval on is , which is consistent with the current world average.
Adare, A.*; 長谷川 勝一; 今井 憲一; 永宮 正治*; 佐甲 博之; 佐藤 進; 谷田 聖; PHENIX Collaboration*; 他666名*
Physical Review Letters, 123(2), p.022301_1 - 022301_10, 2019/07
The PHENIX collaboration presents first measurements of low-momentum (0.4 3 GeV/) direct-photon yields from AuAu collisions at = 39 and 62.4 GeV. For both beam energies the direct-photon yields are substantially enhanced with respect to expectations from prompt processes, similar to the yields observed in AuAu collisions at = 200. Analyzing the photon yield as a function of the experimental observable reveals that the low-momentum (1 GeV/) direct-photon yield is a smooth function of and can be well described as proportional to with 1.25. This new scaling behavior holds for a wide range of beam energies at the Relativistic Heavy Ion Collider and Large Hadron Collider, for centrality selected samples, as well as for different, collision systems. At a given beam energy the scaling also holds for high (5 GeV/) but when results from different collision energies are compared, an additional -dependent multiplicative factor is needed to describe the integrated-direct-photon yield.
Mizuk, R.*; 谷田 聖; Belle Collaboration*; 他166名*
Physical Review Letters, 117(14), p.142001_1 - 142001_7, 2016/09
Using data collected with the Belle detector at the KEKB asymmetric-energy collider, we measure the energy dependence of the cross sections from thresholds up to 11.02 GeV. We find clear and peaks with little or no continuum contribution. We study the resonant substructure of the transitions and find evidence that they proceed entirely via the intermediate isovector states and . The relative fraction of these states is loosely constrained by the current data: The hypothesis that only is produced is excluded at the level of 3.3 standard deviations, while the hypothesis that only is produced is not excluded at a significant level.