Edagawa, Tomoatsu*; Yoshida, Kazuki; Chazono, Yoshiki*; Ogata, Kazuyuki*
Physical Review C, 107(5), p.054603_1 - 054603_7, 2023/05
The effective polarization of the residual nucleus in the proton-induced knockout reaction is investigated within the distorted wave impulse approximation framework. The strong absorption of the emitted particle results in strong selectivity on the reaction "position" depending on the third component of the single-particle orbital angular momentum of the particle inside a nucleus, hence on the spin direction of the reaction residue.
Sakai, Hironori; Tokiwa, Yoshifumi; Opletal, P.; Kimata, Motoi*; Awaji, Satoshi*; Sasaki, Takahiko*; Aoki, Dai*; Kambe, Shinsaku; Tokunaga, Yo; Haga, Yoshinori
Physical Review Letters, 130(19), p.196002_1 - 196002_6, 2023/05
The superconducting (SC) phase diagram in uranium ditelluride is explored under magnetic fields () along the hard magnetic -axis using a high-quality single crystal with = 2.1 K. Simultaneous electrical resistivity and AC magnetic susceptibility measurements discern low- and high-field SC (LFSC and HFSC, respectively) phases with contrasting field-angular dependence. Crystal quality increases the upper critical field of the LFSC phase, but the of T, at which the HFSC phase appears, is always the same through the various crystals. A phase boundary signature is also observed inside the LFSC phase near , indicating an intermediate SC phase characterized by small flux pinning forces.
Pedersen, L. G.*; Sahin, E.*; Grgen, A.*; Bello Garrote, F. L.*; Tsunoda, Yusuke*; Otsuka, Takaharu*; Niikura, Megumi*; Orlandi, R.; 59 of others*
Physical Review C, 107(4), p.044301_1 - 044301_10, 2023/04
Kim, Y.*; Oka, Makoto; Suenaga, Daiki*; Suzuki, Kei
Physical Review D, 107(7), p.074015_1 - 074015_15, 2023/04
A chiral effective theory of scalar and vector diquarks is formulated, which is based on chiral symmetry and includes interactions between scalar and vector diquarks with one or two mesons. We find that the diquark interaction term with two mesons breaks the and flavor symmetries. To determine the coupling constants of the interaction Lagrangians, we investigate one-pion emission decays of singly heavy baryons (, and , , ), where baryons are regarded as diquark-heavy-quark two-body systems. Using this model, we present predictions of the unobserved decay widths of singly heavy baryons. We also study the change of masses and strong decay widths of singly heavy baryons under partial restoration of chiral symmetry.
Okumura, Takuma*; Hashimoto, Tadashi; 40 of others*
Physical Review Letters, 130(17), p.173001_1 - 173001_7, 2023/04
Pohl, T.*; Sun, Y. L.*; Obertelli, A.*; Lee, J.*; Gmez-Ramos, M.*; Ogata, Kazuyuki*; Yoshida, Kazuki; Cai, B. S.*; Yuan, C. X.*; Brown, B. A.*; et al.
Physical Review Letters, 130(17), p.172501_1 - 172501_8, 2023/04
We report on the first proton-induced single proton- and neutron-removal reactions from the neutron deficient O nucleus with large Fermi-surface asymmetry at 100 MeV/nucleon. Our results provide the first quantitative contributions of multiple reaction mechanisms including the quasifree knockout, inelastic scattering, and nucleon transfer processes. It is shown that the inelastic scattering and nucleon transfer, usually neglected at such energy regime, contribute about 50% and 30% to the loosely bound proton and deeply bound neutron removal, respectively.
Nonaka, Yosuke*; Wakabayashi, Yuki*; Shibata, Goro; Sakamoto, Shoya*; Ikeda, Keisuke*; Chi, Z.*; Wan, Y.*; Suzuki, Masahiro*; Tanaka, Arata*; Tanaka, Masaaki*; et al.
Physical Review Materials (Internet), 7(4), p.044413_1 - 044413_10, 2023/04
Ishihara, Kota*; Kobayashi, Masayuki*; Imamura, Kumpei*; Konczykowski, M.*; Sakai, Hironori; Opletal, P.; Tokiwa, Yoshifumi; Haga, Yoshinori; Hashimoto, Kenichiro*; Shibauchi, Takasada*
Physical Review Research (Internet), 5(2), p.L022002_1 - L022002_6, 2023/04
Lower superconducting critical fields of UTe have been determined. Orthorhombic UTe has magnetic easy axis along the -axis. We found perpendicular to showed anomalous enhancement. By comparing with anisotropy of upper critical fields, effect of magnetic fluctuations on superconductivity is suggested.
Sekino, Yuta*; Tajima, Hiroyuki*; Uchino, Shun
Physical Review Research (Internet), 5(2), p.023058_1 - 023058_12, 2023/04
We investigate the spectrum of spin conductivity for a miscible two-component Bose-Einstein condensate (BEC) that exhibits spin superfluidity. By using the Bogoliubov theory, the regular part being the spin conductivity at finite ac frequency and the spin Drude weight characterizingthe delta-function peak at zero frequency are analytically computed. We demonstrate that the spectrum exhibits a power-law behavior at low frequency, reflecting gapless density and spin modes specific to the binary BEC. At the phase transition points into immiscible and quantum-dropletstates, the change in quasiparticle dispersion relations modifies the power law. In addition, the spin Drude weight becomes finite, indicating zero spin resistivity due to spin superfluidity. Our results also suggest that the Andreev-Bashkin drag density is accessible by measuring the spin conductivity spectrum.
Massey, D.*; Williams, C. D.*; Mu, J.*; Masters, A. J.*; Motokawa, Ryuhei; Aoyagi, Noboru; Ueda, Yuki; Antonio, M. R.*
Journal of Physical Chemistry B, 127(9), p.2052 - 2065, 2023/03
Nagai, Yuki; Shinaoka, Hiroshi*
Journal of the Physical Society of Japan, 92(3), p.034703_1 - 034703_8, 2023/03
no abstracts in English
Opletal, P.; Sakai, Hironori; Haga, Yoshinori; Tokiwa, Yoshifumi; Yamamoto, Etsuji; Kambe, Shinsaku; Tokunaga, Yo
Journal of the Physical Society of Japan, 92(3), p.034704_1 - 034704_5, 2023/03
We investigate the physical properties of a single crystal of uranium telluride UTe. We have confirmed that UTe crystallizes in the hexagonal structure with three nonequivalent crystallographic uranium sites. The paramagnetic moments are estimated to be approximately 1 per the uranium site, assuming a uniform moment on all the sites. A ferromagnetic phase transition occurs at = 48 K, where the in-plane magnetization increases sharply, whereas the out of-plane component does not increase significantly. With decreasing temperature further below under field-cooling conditions, the out-of-plane component increases rapidly around T= 26 K. In contrast, the in-plane component hardly changes at T. Specific heat measurement indicates no -type anomaly around T, so this is a cross-over suggesting a reorientation of the ordering moments or successive magnetic ordering on the part of the multiple uranium sites.
Kitamura, Ryo; Futatsukawa, Kenta*; Hayashi, Naoki; Hirano, Koichiro; Kondo, Yasuhiro; Kosaka, Satoshi*; Miyao, Tomoaki*; Morishita, Takatoshi; Nemoto, Yasuo*; Oguri, Hidetomo
Physical Review Accelerators and Beams (Internet), 26(3), p.032802_1 - 032802_12, 2023/03
A bunch-shape monitor (BSM) is a useful device for performing longitudinal beam tuning using the pointwise longitudinal phase distribution measured at selected points in the beam transportation. To measure the longitudinal phase distribution of a low-energy negative hydrogen (H) ion beam, highly oriented pyrolytic graphite (HOPG) was adopted for the secondary-electron-emission target to mitigate the thermal damage due to the high-intensity beam loading. The HOPG target enabled the measurement of the longitudinal phase distribution at the center of a 3-MeV H ion beam with a high peak current of about 50 mA. The longitudinal bunch width was measured using HOPG-BSM at the test stand, which was consistent with the beam simulation. The correlation measurement between the beam transverse and longitudinal planes was demonstrated using HOPG-BSM. The longitudinal Twiss and emittance measurement with the longitudinal Q-scan method was conducted using HOPG-BSM.
Nagai, Yuki; Tanaka, Akinori*; Tomiya, Akio*
Physical Review D, 107(5), p.054501_1 - 054501_16, 2023/03
no abstracts in English
Nakata, Koki; Suzuki, Kei
Physical Review Letters, 130(9), p.096702_1 - 096702_6, 2023/03
Quantum fluctuations of quantum fields induce a zero-point energy shift under spatial boundary conditions. This quantum phenomenon, called the Casimir effect, has been attracting much attention beyond the hierarchy of energy scales, whereas its application to spintronics has not yet been investigated enough, particularly to ferrimagnetic thin films. Here we fill this gap. Using the lattice field theory, we investigate the Casimir effect induced by quantum fields for magnons and find that the magnonic Casimir effect can arise not only in antiferromagnets but also in ferrimagnets (e.g., YIG). Thus, we pave the way for magnonic Casimir engineering.
Okubo, Takahiro*; Takei, Akihiro*; Tachi, Yukio; Fukatsu, Yuta; Deguchi, Kenzo*; Oki, Shinobu*; Shimizu, Tadashi*
Journal of Physical Chemistry A, 127(4), p.973 - 986, 2023/02
The identification of adsorption sites of Cs on clay minerals has been studied in the fields of environmental chemistry. The nuclear magnetic resonance (NMR) experiments allow direct observations of the local structures of adsorbed Cs. The NMR parameters of Cs, derived from solid-state NMR experiments, are sensitive to the local neighboring structures of adsorbed Cs. However, determining the Cs positions from NMR data alone is difficult. This paper describes an approach for identifying the expected atomic positions of Cs adsorbed on clay minerals by combining machine learning (ML) with experimentally observed chemical shifts. A linear ridge regression model for ML is constructed from the smooth overlap of atomic positions descriptor and gauge-including projector augmented wave (GIPAW) ab initio data. The Cs chemical shifts can be instantaneously calculated from the Cs positions on any clay layers using ML. The inverse analysis from the ML model can derive the atomic positions from experimentally observed chemical shifts.
Kitaori, Aki*; Kanazawa, Naoya*; Kida, Takanori*; Narumi, Yasuo*; Hagiwara, Masayuki*; Kindo, Koichi*; Takeuchi, Tetsuya*; Nakamura, Ai*; Aoki, Dai*; Haga, Yoshinori; et al.
Journal of the Physical Society of Japan, 92(2), p.024702_1 - 024702_6, 2023/02
Chen, J.*; Yamamoto, Kei; Zhang, J.*; Ma, J.*; Wang, H.*; Sun, Y.*; Chen, M.*; Ma, J.*; Liu, S.*; Gao, P.*; et al.
Physical Review Applied (Internet), 19(2), p.024046_1 - 024046_9, 2023/02
Fujihara, Masayoshi; Hagihara, Masato; Morita, Katsuhiro*; Murai, Naoki; Koda, Akihiro*; Okabe, Hirotaka*; Mitsuda, Setsuo*
Physical Review B, 107(5), p.054435_1 - 054435_8, 2023/02
The = 1/2 Heisenberg linear chain antiferromagnet is the simplest spin model; nevertheless it serves as a platform for various quantum many-body phenomena. Here, we report the magnetic behavior of a quasi-one-dimensional antiferromagnet KCuPOHO. A long-range commensurate antiferromagnetic order with ordered moment 0.31(1) per spin occurs at = 11.7(1) K. Above , the inelastic neutron excitation is characterized by a two spinon continuum. The intrachain interaction and interchain interaction are estimated to be 172 K and 4.25(4) K, respectively; thus the ratio of the / = 0.0247(3). At lower energies, below , a spin gap is observed in the dispersive excitations. These results are consistent with characteristics observed in weakly interacting = 1/2 Heisenberg chain system.
Kunieda, Satoshi; Iwamoto, Osamu; Fukahori, Tokio; Chiba, Satoshi*
European Physical Journal A, 59(1), p.2_1 - 2_8, 2023/01
Optical model or coupled-channels calculation serves as an entrance to sophisticated calculation of nuclear data. It was a great contribution of Dr. Efrem Sh. Soukhovitsukii who has developed an excellent computation scheme which takes account of the low-lying collective nuclear structure in terms of the soft-rotator + vibrational model, and integrated it into the coupled-channels calculation. In Japan, we had a fortuitous experience with him in parametrization of the optical model potential (OMP) and to employ this methodology in nuclear data evaluation for JENDL. Firstly, we summarize our collaborative works with him in this paper. Secondly, let us have a discussion on a new parameterization of OMP which we obtained for light nuclei within his framework, quite recently. It was found that values of the potential parameters themselves are rather similar among different nuclei while the nuclear deformation describes one of the main characteristics of each isotopes.