Wada, Yuki*; Enoto, Teruaki*; Nakazawa, Kazuhiro*; Furuta, Yoshihiro; Yuasa, Takayuki*; Nakamura, Yoshitaka*; Morimoto, Takeshi*; Matsumoto, Takahiro*; Makishima, Kazuo*; Tsuchiya, Harufumi
Physical Review Letters, 123(6), p.061103_1 - 061103_6, 2019/08
Enoto, Teruaki*; Wada, Yuki*; Tsuchiya, Harufumi
Nippon Butsuri Gakkai-Shi, 74(4), p.192 - 200, 2019/04
no abstracts in English
Hashimoto, Tadashi; Tanida, Kiyoshi; 67 of others*
Physics Letters B, 789, p.620 - 625, 2019/02
We observed a distinct peak in the invariant mass spectrum of , well below , , the mass threshold of the to be bound to two protons. By selecting a relatively large momentum-transfer region MeV/, one can clearly separate the peak from the quasi-free process, followed by the non-resonant absorption by the non-resonant absorption by the two spectator-nucleons . We found that the simplest fit to the observed peak gives us a Breit-Wignerpole position at MeV having a width MeV, and the -wave Gaussian reaction form-factor parameter MeV/, as a new form of the nuclear bound system with strangeness -"".
Yokoyama, Akihiko*; Kitayama, Yuta*; Fukuda, Yoshiki*; Kikunaga, Hidetoshi*; Murakami, Masashi*; Komori, Yukiko*; Yano, Shinya*; Haba, Hiromitsu*; Tsukada, Kazuaki; Toyoshima, Atsushi*
Radiochimica Acta, 107(1), p.27 - 32, 2019/01
Bartiyar, H.*; Can, K. U.*; Erkol, G.*; Oka, Makoto; Takahashi, Toru*
Physical Review D, 98(11), p.114505_1 - 114505_14, 2018/12
Transition amplitude of spin 3/2 double-charm baryon to spin 1/2 ground state was evaluated in the lattice QCD, the first principle.
Nakajima, Taro*; Inamura, Yasuhiro; Ito, Takayoshi*; Oishi, Kazuki*; Oike, Hiroshi*; Kagawa, Fumitaka*; Kikkawa, Akiko*; Taguchi, Yasujiro*; Kakurai, Kazuhisa*; Tokura, Yoshinori*; et al.
Physical Review B, 98(1), p.014424_1 - 014424_5, 2018/07
We investigated the phase-transition kinetics of magnetic skyrmion lattice (SkL) in MnSi by means of stroboscopic small-angle neutron scattering (SANS). Temporal evolutions of SANS patterns were measured with time resolution of 13 ms while sweeping temperature as fast as 50 Ks. It turned out that the paramagnetic-to-SkL transition immediately occurs upon traversing the equilibrium phase boundary on the rapid cooling, whereas the SkL-to-conical transition can be kinetically avoided to realize the low-temperature metastable SkL with a long-range magnetic order. The formation of the metastable SkL was found to be strongly dependent not only on cooling rate, but also on magnetic eld and trajectory in the H-T phase diagram.
Wada, Yuki*; Bowers, G. S.*; Enoto, Teruaki*; Kamogawa, Masashi*; Nakamura, Yoshitaka*; Morimoto, Takeshi*; Smith, D.*; Furuta, Yoshihiro*; Nakazawa, Kazuhiro*; Yuasa, Takayuki*; et al.
Geophysical Research Letters, 45(11), p.5700 - 5707, 2018/06
Ikeda, Yoshimasa*; Takamura, Masato*; Hakoyama, Tomoyuki*; Otake, Yoshie*; Kumagai, Masayoshi*; Suzuki, Hiroshi
Tetsu To Hagane, 104(3), p.138 - 144, 2018/03
Neutron engineering diffraction is a powerful technique which provides the information of the micro structure of steels in bulk-average, while X-ray diffraction or Electron backscatter diffraction can provide information only from the surface layer. However, such measurement using neutron diffraction is typically performed in a large facility such as a reactor and a synchrotron, while a compact neutron source has never been used for this purpose. Authors have recently developed a neutron diffractometer installed in Riken Accelerator driven compact Neutron Source (RANS) and succeeded in the measurement of texture evolution of a steel sheet. In this study, we made an attempt to measure the volume fraction of retained austenite by RANS. Background noise was carefully eliminated in order to detect as many diffraction peaks as possible with low flux neutrons. The volume fraction was estimated by Rietveld analysis. The accuracy of the measurement result was discussed by comparing with those obtained by a large neutron facility (J-PARC TAKUMI). The volume fraction obtained by RANS with reasonable measurement time, i.e. 30 to 300 min, showed only 1 to 2 % discrepancies with those obtained in J-PARC. These comparisons suggest that neutron diffraction by RANS is capable of quantitative analysis of the volume fraction of crystal phases, showing the possibility of practical use of an in-house compact neutron source in the industry.
Tanaka, Taiki*; Narikiyo, Yoshihiro*; Morita, Kosuke*; Fujita, Kunihiro*; Kaji, Daiya*; Morimoto, Koji*; Yamaki, Sayaka*; Wakabayashi, Yasuo*; Tanaka, Kengo*; Takeyama, Mirei*; et al.
Journal of the Physical Society of Japan, 87(1), p.014201_1 - 014201_9, 2018/01
Excitation functions of quasielastic scattering cross sections for the Ca + Pb, Ti + Pb, and Ca + Cm reactions were successfully measured by using the gas-filled recoil-ion separator GARIS. Fusion barrier distributions were extracted from these data, and compared with the coupled-channels calculations. It was found that the peak energies of the barrier distributions for the Ca + Pb and Ti + Pb systems coincide with those of the 2n evaporation channel cross sections for the systems, while that of the Ca + Cm is located slightly below the 4n evaporation ones. This results provide us helpful information to predict the optimum beam energy to synthesize superheavy nuclei.
Enoto, Teruaki*; Wada, Yuki*; Furuta, Yoshihiro*; Nakazawa, Kazuhiro*; Yuasa, Takayuki*; Okuda, Kazufumi*; Makishima, Kazuo*; Sato, Mitsuteru*; Sato, Yosuke*; Nakano, Toshio*; et al.
Nature, 551(7681), p.481 - 484, 2017/11
Bahtlyar, H.*; Can, K. U.*; Erkol, G.*; Oka, Makoto; Takahashi, Toru*
Physics Letters B, 772, p.121 - 126, 2017/09
We evaluate the electromagnetic transition on 2+1 flavor lattices corresponding to a pion mass of MeV. We extract the magnetic Sachs and Pauli form factors which give the - transition magnetic moment and the decay rates of baryons. We did not find a signal for the magnetic form factor of the neutral transition , which is suppressed by the U-spin flavor symmetry. As a byproduct, we extract the magnetic form factors and the magnetic moments of and baryons, which give an insight to the dynamics of , and quarks having masses at different scales.
Kaji, Daiya*; Morita, Kosuke*; Morimoto, Koji*; Haba, Hiromitsu*; Asai, Masato; Fujita, Kunihiro*; Gan, Z.*; Geissel, H.*; Hasebe, Hiroo*; Hofmann, S.*; et al.
Journal of the Physical Society of Japan, 86(3), p.034201_1 - 034201_7, 2017/03
The fusion reaction of Ca + Cm Lv was studied using the gas-filled recoil-ion separator GARIS at RIKEN. A total of seven and spontaneous-fission decay chains were observed, which would originate from the reaction products of the element 116, Lv and Lv. Decay properties observed in the chains are in good agreement with the previously published ones. However, one of the chains showed a discrepancy, indicating the new spontaneous-fission branch in Cn or the production of the new isotope Lv.
Eichler, R.*; Asai, Masato; Brand, H.*; Chiera, N. M.*; Di Nitto, A.*; Dressler, R.*; Dllmann, Ch. E.*; Even, J.*; Fangli, F.*; Goetz, M.*; et al.
EPJ Web of Conferences (Internet), 131, p.07005_1 - 07005_7, 2016/12
In recent years gas-phase chemical studies assisted by physical pre-separation allowed for the productions and investigations of fragile single molecular species of superheavy elements. The latest highlight is the formation of very volatile hexacarbonyl compound of element 106, Sg(CO). Following this success, second-generation experiments were performed to measure the first bond dissociation energy between the central metal atom and the surrounding ligand. The method using a tubular decomposition reactor was developed and successfully applied to short-lived Mo(CO), W(CO), and Sg(CO).
Ikebe, Kimiyoshi; Umezawa, Koji*; Higo, Junichi*
Biophysical Reviews, 8(1), p.45 - 62, 2016/03
Ohae, Chiaki*; Harries, J.; Iwayama, Hiroshi*; Kawaguchi, Kentaro*; Kuma, Susumu*; Miyamoto, Yuki*; Nagasono, Mitsuru*; Nakajima, Kyo*; Nakano, Itsuo*; Shigemasa, Eiji*; et al.
Journal of the Physical Society of Japan, 85(3), p.034301_1 - 034301_10, 2016/03
Ikebe, Kimiyoshi; Sakuraba, Shun*; Kono, Hidetoshi
PLOS Computational Biology, 12(3), p.e1004788_1 - e1004788_13, 2016/03
Usoltsev, I.*; Eichler, R.*; Wang, Y.*; Even, J.*; Yakushev, A.*; Haba, Hiromitsu*; Asai, Masato; Brand, H.*; Di Nitto, A.*; Dllmann, Ch. E.*; et al.
Radiochimica Acta, 104(3), p.141 - 151, 2016/03
Conditions of the production and decomposition of hexacarbonyl complexes of short-lived Mo and W isotopes were investigated to study thermal stability of the heaviest group 6 hexacarbonyl complex Sg(CO). A tubular flow reactor was tested to decompose the hexacarbonyl complexes and to extract the first bond dissociation energies. A silver was found to be the most appropriate reaction surface to study the decomposition of the group 6 hexacarbonyl. It was found that the surface temperature at which the decomposition occurred was correlated to the first bond dissociation energy of Mo(CO) and W(CO), indicating that the first bond dissociation energy of Sg(CO) could be determined with this technique.
Kaji, Daiya*; Morimoto, Koji*; Wakabayashi, Yasuo*; Takeyama, Mirei*; Asai, Masato
JPS Conference Proceedings (Internet), 6, p.030106_1 - 030106_4, 2015/06
A Si-Ge detector array was newly installed at the focal plane of the gas-filled recoil ion separator GARIS to perform - (X-rays) spectroscopy for superheavy nuclei. The performance of the array was tested using the Pb(Ca,2n)No and Pb(Ca,xn)No [x=1,2,3] reactions. rays originating from the decay of No and No were clearly observed in prompt coincidence with the particles.
Kaji, Daiya*; Morimoto, Koji*; Wakabayashi, Yasuo*; Takeyama, Mirei*; Yamaki, Sayaka*; Tanaka, Kengo*; Haba, Hiromitsu*; Huang, M.*; Murakami, Masashi*; Kanaya, Jumpei*; et al.
JPS Conference Proceedings (Internet), 6, p.030107_1 - 030107_4, 2015/06
Performance of the new gas-filled recoil ion separator GARIS-II was investigated using asymmetric Ne-induced fusion reactions. The use of He-H mixture gas for the gas-filled magnet significantly reduced background scattered particles detected at the focal-plane Si detector, and increased a transmission of the asymmetric reaction products. A target-identification system was newly installed for efficient measurements of excitation functions without changing beam energy nor target.
Harries, J.; Iwayama, Hiroshi*; Nagasono, Mitsuru*; Togashi, Tadashi*; Yabashi, Makina*; Kuma, Susumu*; Nakajima, Kyo*; Miyamoto, Yuki*; Ohae, Chiaki*; Sasao, Noboru*; et al.
Journal of Physics B; Atomic, Molecular and Optical Physics, 48(10), p.105002_1 - 105002_9, 2015/05