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Huang, Z.*; Wang, W.*; Ye, H.*; Bao, S.*; Shangguan, Y.*; Liao, J.*; Cao, S.*; 梶本 亮一; 池内 和彦*; Deng, G.*; et al.
Physical Review B, 109(1), p.014434_1 - 014434_9, 2024/01
被引用回数:0TbMnSn is a correlated topological magnet with a Mn-based kagome lattice, in which a Chern gap opens at the Dirac point at low temperatures. The magnetic moment direction of the ferrimagnetic order changes from in the kagome plane to the out-of-plane upon cooling, which is essential for generating the Chern gap, but the underlying mechanism for the spin reorientation remains elusive. Here, we investigate the spin-reorientation transition in TbMnSn using neutron scattering. We provide direct evidence for the spin-reorientation transition and unveil the coexistence of two Tb modes at 200 K. To account for these results, we put forward a model based on SU(N) spin-wave theory, in which there is a temperature evolution of the ground state Tb orbitals, driven by the crystalline electric field, single-ion anisotropy, and exchange interactions between Tb and Mn ions. Our findings shed light on the complex magnetism of TbMnSn, despite its relatively simple ground state magnetic structure, and provide insights into the mechanisms for tuning magnetic topological materials.
Cao, L.*; 谷田 聖; Belle Collaboration*; 他199名*
Physical Review Letters, 127(26), p.261801_1 - 261801_8, 2021/12
被引用回数:5 パーセンタイル:49.47(Physics, Multidisciplinary)The first measurements of differential branching fractions of inclusive semileptonic decays are performed using the full Belle data set of 711 fb of integrated luminosity at the resonance and for . Differential branching fractions are reported as a function of the lepton momentum, the four-momentum-transfer squared, light-cone momenta, the hadronic mass, and the hadronic mass squared. They are obtained by subtracting the backgrounds from semileptonic decays and other processes, and corrected for resolution and acceptance effects. The measured distributions are compared to predictions from inclusive and hybrid calculations.
Cao, L.*; 谷田 聖; Belle Collaboration*; 他236名*
Physical Review D, 104(1), p.012008_1 - 012008_32, 2021/07
被引用回数:10 パーセンタイル:65.5(Astronomy & Astrophysics)We present measurements of partial branching fractions of inclusive semileptonic decays using the full Belle data set of 711 fb of integrated luminosity at the resonance and for . Inclusive semileptonic decays are CKM suppressed and measurements are complicated by the large background from CKM-favored transitions, which have a similar signature. Using machine learning techniques, we reduce this and other backgrounds effectively, whilst retaining access to a large fraction of the phase space and high signal efficiency. We measure partial branching fractions in three phase-space regions covering about to of the accessible phase space. The most inclusive measurement corresponds to the phase space with lepton energies of GeV, and we obtain from a two-dimensional fit of the hadronic mass spectrum and the four-momentum-transfer squared distribution, with the uncertainties denoting the statistical and systematic error. We find from an average of four calculations for the partial decay rate with the third uncertainty denoting the average theory error. This value is higher but compatible with the determination from exclusive semileptonic decays within 1.3 standard deviations.
Lei, A. L.*; Cao, L. H.*; Yang, X. Q.*; 田中 和夫*; 兒玉 了祐*; He, X. T.*; 三間 圀興*; 中村 龍史; 乗松 孝好*; Yu, W.*; et al.
Physics of Plasmas, 16(2), p.020702_1 - 020702_4, 2009/02
被引用回数:12 パーセンタイル:42.72(Physics, Fluids & Plasmas)反転コーンにおける高速電子の伝播に関するシミュレーション及び実験的研究を行った。コーン形状ターゲットは高速点火核融合において、高エネルギー発生及びレーザーの集光を目的として利用されている。本研究では、コーンターゲットを電子のガイディングを目的として利用することが可能であることを示した。反転コーンの先端部にレーザーを照射することで、多くの高速電子が発生する。これらの電子はコーンの側面に誘起される電磁場によってガイドされることがシミュレーションにより確認された。この現象を大型レーザーを使った実験により調べ、大電流が発生する場合においても電子のガイディングが起こることが確認された。