81 results on '"H. Kuboki"'
Search Results
2. Charge stripping of ^{238}U ion beam by helium gas stripper
- Author
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H. Imao, H. Okuno, H. Kuboki, S. Yokouchi, N. Fukunishi, O. Kamigaito, H. Hasebe, T. Watanabe, Y. Watanabe, M. Kase, and Y. Yano
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Nuclear and particle physics. Atomic energy. Radioactivity ,QC770-798 - Abstract
Development of a nondestructive, efficient electric-charge-stripping method is a key requirement for next-generation high-intensity heavy-ion accelerators such as the RIKEN Radioactive-Isotope Beam Factory. A charge stripper employing a low-Z gas is an important candidate applicable to high-intensity uranium beams for replacing carbon-foil strippers. In this study, a high-beam-transmission charge-stripping system employing helium gas for ^{238}U beams injected at 10.8 MeV/u was developed and demonstrated for the first time. The charge-state evolution measured using helium in a thickness range of 0.24–1.83 mg/cm^{2} is compared with theoretical predictions. Energy attenuation and energy spread due to the helium stripper are also investigated.
- Published
- 2012
- Full Text
- View/download PDF
3. Charge-state distribution of ^{238}U in nitrogen gas and carbon foil at 14 and 15 MeV/nucleon
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H. Kuboki, H. Okuno, H. Hasebe, S. Yokouchi, N. Fukunishi, Y. Higurashi, J. Ohnishi, T. Nakagawa, H. Imao, O. Kamigaito, A. Goto, M. Kase, and Y. Yano
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Nuclear and particle physics. Atomic energy. Radioactivity ,QC770-798 - Abstract
The charge-state distributions of ^{238}U with energies of 14 and 15 MeV/nucleon were measured using nitrogen (N_{2}) gas and carbon foil (C-foil) charge strippers. The most probable charge states of ^{238}U with energies of 14 and 15 MeV/nucleon in N_{2} gas attain equilibrium at 60.8 and 62.4, whereas those in C-foils attain equilibrium at 75.8 and 76.7, respectively. Novel empirical formulas for the accurate prediction of the equilibrium charge states of ^{238}U with energies 10–20 MeV/nucleon in gases and C-foil were derived by fitting the data in the energy range of 1–20 MeV/nucleon. The charge states predicted by using the formulas for gases and C-foil are in good agreement with the data in the energy range of 10–20 MeV/nucleon within an average of 0.23 and 0.21, respectively.
- Published
- 2011
- Full Text
- View/download PDF
4. Low-Z gas stripper as an alternative to carbon foils for the acceleration of high-power uranium beams
- Author
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H. Okuno, N. Fukunishi, A. Goto, H. Hasebe, H. Imao, O. Kamigaito, M. Kase, H. Kuboki, Y. Yano, S. Yokouchi, and A. Hershcovitch
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Nuclear and particle physics. Atomic energy. Radioactivity ,QC770-798 - Abstract
The RIKEN accelerator complex started feeding the next-generation exotic beam facility radioisotope beam factory (RIBF) with heavy-ion beams from 2007 after the successful commissioning of RIBF at the end of 2006. Many improvements made from 2007 to 2010 were instrumental in increasing the intensity of various heavy-ion beams. However, the available beam intensity of very heavy ion beams, especially uranium beams, is far below our goal of 1 pμA (6×10^{12} particles/s). In order to achieve this goal, upgrade programs are already in progress; the programs include the construction of a new 28-GHz superconducting electron cyclotron resonance ion source and a new injector linac. However, the most serious problem, that of a charge stripper for high-power uranium beams, still remains unsolved, despite extensive research and development work using large foils mounted on a rotating cylinder and a N_{2} gas stripper. A gas stripper is free from problems related to lifetime, though the equilibrium charge state in this stripper is considerably lower than that in a carbon foil, owing to the absence of the density effect. Nevertheless, the merits of gas strippers motivated us to develop a low-Z gas stripper to achieve a higher equilibrium charge state even in gases. We measured the electron-loss and electron-capture cross sections of uranium ions in He gas as a function of their charge state at 11, 14, and 15 MeV/nucleon. The equilibrium charge states extracted from the intersection of the lines of the two cross sections were promisingly higher than those in N_{2} gas by more than 10. Simple simulations of charge development along the stripper thickness were performed by assuming the measured cross sections. The simulation results show that about 1 mg/cm^{2} of He gas should be accumulated to achieve a charge state higher than that of N_{2} gas, notwithstanding the difficulty in accumulation of this helium amount owing to its fast dispersion. However, we now believe that the following two solutions can overcome this difficulty: a gas cell with a very large differential pumping system and a gas cell with a plasma window. Their merits and demerits are discussed in the paper.
- Published
- 2011
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- View/download PDF
5. Charge-state distribution measurements of ^{238}U and ^{136}Xe at 11 MeV/nucleon using gas charge stripper
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H. Kuboki, H. Okuno, S. Yokouchi, H. Hasebe, T. Kishida, N. Fukunishi, O. Kamigaito, A. Goto, M. Kase, and Y. Yano
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Nuclear and particle physics. Atomic energy. Radioactivity ,QC770-798 - Abstract
The charge-state distributions and equilibrium charge states of uranium (^{238}U) and xenon (^{136}Xe) ions at 11 MeV/nucleon were determined using a gas charge stripper. A differential pumping system facilitated the increase of the nitrogen gas thickness up to 1.3 mg/cm^{2}, which is sufficient for the most probable charge state to attain equilibrium. The charge states of ^{238}U attain equilibrium at 56.0, 56.6, and 55.7 in N_{2}, Ar, and CO_{2} media with thicknesses of 125, 79, and 126 μg/cm^{2}, respectively, while those of ^{136}Xe attain equilibrium at 40.5, 40.1, and 40.3 in N_{2}, Ar, and CO_{2} media with thicknesses of 163, 95, and 139 μg/cm^{2}, respectively. The equilibrium charge states of ^{136}Xe are acceptable for acceleration by the subsequent cyclotron. The measured data of ^{238}U were used to devise an empirical formula for the prediction of the equilibrium charge state in gaseous media over the energy region of 0.01–60 MeV/nucleon. The equilibrium charge state of ^{136}Xe as predicted by the devised formula is in good agreement with the data.
- Published
- 2010
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6. J-PARC-HI Collaboration
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J.K. Ahn, Y. Akamatsu, M. Asakawa, S. Ashikaga, O. Busch, E. Chishiro, M. Chiu, T. Chujo, P. Cirkovic, T. Csörgő, G. David, D. Devetak, M. Djordjevic, S. Esumi, H. Fujii, K. Fukushima, P. Garg, T. Gunji, T. Hachiya, H. Hamagaki, H. Harada, M. Harada, S. Hasegawa, Y. Hashimoto, T. Hatsuda, N. Hayashi, K. Hirano, T. Hirano, B.S. Hong, H. Hotchi, S.H. Hwang, Y. Ichikawa, T. Ichisawa, K. Imai, M. Inaba, K. Ishii, K. Itakura, T. Ito, J. Kamiya, M. Kaneta, H. Kato, S. Kato, N. Kikuzawa, B.C. Kim, E.J. Kim, T. Kimura, M. Kinsho, R. Kitamura, M. Kitazawa, Y. Kondo, A. Kovalenko, H. Kuboki, Y. Kurimoto, Y. Liu, X. Luo, T. Maruyama, S. Meigo, Y. Miake, A. Miura, T. Miyao, J. Milosevic, D. Mishra, T. Morishita, K. Morita, Y. Morita, K. Moriya, K. Murase, R. Muto, L. Nadjdjerdj, S. Nagamiya, A. Nakamura, T. Nakamura, T. Nakanoya, Y. Nara, M. Naruki, K. Niki, K. Nishio, C. Nonaka, T. Nonaka, M. Ogino, H. Oguri, C. Ohmori, A. Ohnishi, M. Oka, A. Okabe, M. Okamura, K. Oyama, K. Ozawa, P.K. Saha, T.R. Saito, A. Sakaguchi, T. Sakaguchi, S. Sakai, H. Sako, K. Sato, S. Sato, Y. Sato, S. Sawada, T. Shibata, K. Shigaki, S. Shimansky, T. Shimokawa, M. Shimomura, K. Shindo, S. Shinozaki, M. Shirakata, Y. Shobuda, M. Stojanovic, K. Suganuma, H. Sugimura, Y. Sugiyama, H. Takahashi, T. Takayanagi, Y. Takeuchi, F. Tamura, H. Tamura, J. Tamura, K.H. Tanaka, Y. Tanaka, N. Tani, K. Tanida, M. Tomisawa, T. Toyama, Y. Watanabe, N. Xu, K. Yamamoto, M. Yamamoto, S. Yokkaichi, I.K. Yoo, M. Yoshii, and M. Yoshimoto
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Nuclear and High Energy Physics - Published
- 2021
7. Development of a rotating graphite carbon disk stripper
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Hiroshi Imao, Mutsuaki Murakami, Masayuki Kase, Masamitsu Tachibana, Osamu Kamigaito, Hiroki Okuno, H. Kuboki, Hiroo Hasebe, Nobuhisa Fukunishi, and Atsushi Tatami
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Materials science ,Metallurgy ,Graphite carbon - Published
- 2018
8. Performance of neutron polarimeter SMART-NPOL
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H. Kuboki, Kimiko Sekiguchi, Shumpei Noji, Hideyuki Sakai, Kenjiro Miki, Takeo Kawabata, Kentaro Yako, and Kenji Suda
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Physics ,Nuclear and High Energy Physics ,Nuclear Theory ,Polarimetry ,Polarimeter ,Scintillator ,Polarization (waves) ,Nuclear physics ,Time of flight ,Deuterium ,Double scattering ,Neutron ,Nuclear Experiment ,Instrumentation - Abstract
The neutron polarimeter SMART-NPOL has been constructed at the RIKEN Accelerator Research Facility for measuring polarization correlations of proton–neutron systems. The SMART-NPOL system consists of 12 parallel neutron counter planes of two dimensionally position-sensitive plastic scintillators with a size of 60 × 60 × 3.0 cm 3 . Polarimetry measurements were made using the analyzing power of the H 1 ( n ⇒ , n ) H 1 reaction occurring in the plastic scintillators. The effective analyzing power of SMART-NPOL was measured with polarized neutrons from the zero-degree Li 6 ( d ⇒ , n ⇒ ) reaction with an incident deuteron energy of 135 MeV / A . The effective analyzing power thus obtained was 0.26 ± 0 . 01 stat ± 0 . 03 syst and the double scattering efficiency was 1.1 × 10 - 3 .
- Published
- 2007
9. Study of spin parts of three nucleon forces via breakup reactions at intermediate energies
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Masaki Sasano, Hideyuki Sakai, Naoya Sakamoto, H. Okamura, Takeo Kawabata, Kimiko Sekiguchi, Tomotsugu Wakasa, K. Itoh, Yusuke T. Maeda, H. Kuboki, Tomohiro Uesaka, Satoshi Sakaguchi, Y. Takahashi, Kenji Suda, Kentaro Yako, and Yoshiko Sasamoto
- Subjects
Nuclear physics ,Physics ,Nuclear and High Energy Physics ,Particle physics ,Nuclear Theory ,Physics::Accelerator Physics ,Nuclear Experiment ,Nucleon ,Breakup ,Spin-½ - Abstract
Measurements of deuteron–proton breakup reactions at 135 MeV/A have been made at RIKEN Accelerator Research Facility, focusing on the specific coplanar configurations. The obtained results are compared with the Faddeev calculations based on the modern nucleon–nucleon forces together with the Tucson-Melbourne99, and UrbanaIX three nucleon forces.
- Published
- 2007
10. Measurement of cross section and various spin observables in the pd elastic scattering at 392 MeV
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T. Kaneda, Kunihiro Fujita, Yusuke T. Maeda, K. Suda, H. Kuboki, Kichiji Hatanaka, H. Okamura, Kimiko Sekiguchi, H. Tanabe, M. Takechi, E. Ihara, Kentaro Yako, Yuji Tameshige, Hiroshi Matsubara, Tomohiro Uesaka, Masanori Dozono, Y. Satou, Hideyuki Sakai, Yasuhiro Sakemi, Tomotsugu Wakasa, N. Uchigashima, Atsushi Tamii, and T. Ohta
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Physics ,Nuclear physics ,Elastic scattering ,Faddeev equations ,Cross section (physics) ,Nuclear Theory ,Nuclear force ,Observable ,Atomic physics ,Nuclear Experiment ,Nucleon ,Three-body problem ,Spin (physics) - Abstract
The cross sections and spin observables of the pd elastic scattering have been measured at 392 MeV. The results are compared with the prediction of Faddeev calculations with and without including a three nucleon force.
- Published
- 2007
11. Measurements of the n→d scattering at 250 MeV and three-nucleon forces
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Henryk Witała, Kentaro Yako, H. Kuboki, Kenji Suda, Tomotsugu Wakasa, H. Okamura, Takeo Kawabata, Yuji Shimizu, Katsumasa Fujita, Kichiji Hatanaka, Hiroyuki Kamada, Kimiko Sekiguchi, Masaki Sasano, Hideyuki Sakai, Yasuhiro Sakemi, Atsushi Tamii, Yusuke T. Maeda, M. B. Greenfield, M. Hatano, T. Saito, Junichiro Kamiya, and Yuji Tameshige
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Nuclear physics ,Physics ,Elastic scattering ,Nuclear and High Energy Physics ,Cross section (physics) ,Scattering ,Nuclear Theory ,Nuclear cross section ,Nucleon - Abstract
The differential cross sections and the vector analyzing powers for the nd elastic scattering at E n = 250 MeV have been measured for the study of the three-nucleon force (3NF) effects in the Coulomb-free system. To cover a wide angular region, the experiments were performed by using two different methods at the ( n , p ) facility and at the NTOF facility which constructed at the Research Center for Nuclear Physics (RCNP). The results were compared with theoretical predictions of the Faddeev calculations based on the modern nucleon-nucleon (NN) forces with the three-nucleon force (3NF). The inclusion of 3NFs leads to a good description of the cross section except for the backward angles. The results were also compared with the theoretical predictions with relativistic corrections. The direct data-to-data comparison of the cross sections of the nd and pd was performed.
- Published
- 2007
12. Study of three-nucleon force effects in break-up with BINA
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A. Ramazani, R. Benard, Stanisław Kistryn, Mladen Kiš, Kimiko Sekiguchi, Kenjiro Miki, A. Kozela, Shumpei Noji, M. Mahjour-Shafiei, Kentaro Yako, Aleksandra Biegun, Hideyuki Sakai, H. Kuboki, R. Sworst, Nasser Kalantar-Nayestanaki, H. R. Amir-Ahmadi, Yusuke T. Maeda, H. Mardanpour, Y. Takahashi, E. Stephan, J. G. Messchendorp, Mohammad Eslami-Kalantari, and Masaki Sasano
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Physics ,Elastic scattering ,Nuclear physics ,Nuclear and High Energy Physics ,Deuterium ,Scattering ,Phase space ,Nuclear Theory ,Detector ,Work (physics) ,Nuclear Experiment ,Nucleon ,Beam (structure) - Abstract
Extensive studies of three-nucleon force (3NF) effects in elastic proton-deuteron scattering have been performed at KVI and elsewhere in the past. In the present work, we explored 3NF effects in the break-up scattering process by performing high precision measurement of vector analyzing powers and differential cross sections using a 190 MeV polarized-proton beam on a liquid deuterium target. The experiment was performed by exploiting a new detector called Big Instrument for Nuclear-polarization Analysis, BINA. Its unique design enables coverage of almost the complete reaction phase space. Preliminary differential cross sections and vector analyzing powers are presented and results are compared with state-of-the-art three-nucleon calculations.
- Published
- 2007
13. Measurement of the 2H(d,pn) reaction at 0 degrees at 270 MeV
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Satoshi Sakaguchi, Kimiko Sekiguchi, Shumpei Noji, K. Kawabata, Y. Takahashi, Yoshiko Sasamoto, N. Sakamoto, Tomohiro Uesaka, Hideyuki Sakai, Y. Satou, Masaki Sasano, Kenjiro Miki, H. Kuboki, Kenji Suda, Kentaro Yako, K. Itoh, and Yusuke T. Maeda
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Nuclear physics ,Physics ,Nuclear and High Energy Physics ,Energy spectrum ,Physics::Accelerator Physics ,Atomic physics ,Impulse (physics) ,Nuclear Experiment ,Relative energy - Abstract
The energy spectrum of the 2 H(d,pn) reaction at 0° at 270 MeV was obtained at RIKEN Accelerator Research Facility. The spectrum in the kinematical region where the resulting pn pair has the relative energy smaller than ∼2 MeV was analyzed by plane-wave impulse approximation calculations assuming the configurations of final state interaction with s-wave.
- Published
- 2007
14. Determination of the Gamow-Teller transition strength to 116In(g.s.) by the 116Cd(p,n) reaction at 300 MeV for the study of the nuclear matrix element of the two-neutrino double beta decay
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K. Itoh, Takahiro Kawabata, Tomohiro Uesaka, Kimiko Sekiguchi, Satoshi Sakaguchi, Kenji Suda, Shumpei Noji, H. Kuboki, Kichiji Hatanaka, Hideyuki Sakai, Yoshiko Sasamoto, M. B. Greenfield, Tomotsugu Wakasa, Atsushi Tamii, D. Frekers, Kazuo Muto, Kenjiro Miki, Yukie Maeda, Hiroyuki Okamura, Masaki Sasano, Kentaro Yako, and Masanori Dozono
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Nuclear reaction ,Physics ,Nuclear physics ,Nuclear and High Energy Physics ,Helium-3 ,Double beta decay ,Isotopes of cadmium ,Giant resonance ,Atomic physics ,Ground state ,Beta decay ,Radioactive decay - Abstract
The 116Cd(p,n) experiment at 300 MeV has been performed for deducing the Gamow-Teller (GT) transition strengths B(GT−) in 116In. For the transition to the ground state, the B(GT−) value of 0.26 ± 0.02 is obtained. From this B(GT−) value and the B(GT+) value by a beta-decay experiment, the contribution of the intermediate ground state of 116In to the nuclear matrix element is deduced to be 0.070 ± 0.003. The B(GT−) value obtained herein is a factor of 8 less than that obtained from a previous (3He,t) measurement. This discrepancy, as well as differences in the distribution of low energy GT strength, and the width and peak energy of the GT giant resonance may be explained if the target used in the (3He,t) measurement is a Cd target with natural abundance.
- Published
- 2007
15. Precision measurement of vector and tensor analyzing powers in elastic deuteron-proton scattering
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Kimiko Sekiguchi, Takahiro Kawabata, Tomohiro Uesaka, Yusuke T. Maeda, H. Kuboki, Satoshi Sakaguchi, H. R. Amir-Ahmadi, Nasser Kalantar-Nayestanaki, K. Itoh, H. Mardanpour, J. G. Messchendorp, Henryk Witała, N. Sakamoto, Kentaro Yako, A. Deltuva, Masaki Sasano, Yoshiko Sasamoto, Y. Takahashi, Kenji Suda, Hideyuki Sakai, and Research unit Nuclear & Hadron Physics
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Physics ,CALIBRATION ,Range (particle radiation) ,Nuclear and High Energy Physics ,FEW-NUCLEON SYSTEMS ,POLARIZATION ,Degree (graph theory) ,Scattering ,Nuclear Theory ,FOS: Physical sciences ,Beam polarization ,Computational physics ,EFFECTIVE-FIELD THEORY ,Angular distribution ,Deuterium ,Proton scattering ,Tensor ,Nuclear Experiment (nucl-ex) ,Nuclear Experiment ,3-NUCLEON FORCE - Abstract
High-precision vector and tensor analyzing powers of elastic deuteron-proton (d + p) scattering have been measured at intermediate energies to investigate effects of three-nucleon forces. Angular distributions in the range of 70-120 degrees in the center-of mass frame for incident-deuteron energies Ed (lab)(d) = 130 and 180 MeV were obtained using the RIKEN facility. The beam polarization was unambiguously determined by measuring the C-12(d,alpha)B-10(2(+)) reaction at 0 degrees. Results of the measurements are compared with state-of-the-art three-nucleon calculations. The present modeling of nucleon-nucleon forces and its extension to the three-nucleon system is not sufficient to describe the high-precision data consistently and requires, therefore; further investigation.
- Published
- 2007
16. Isovector effective NN interaction in Si28(p→,n→)P28(6−) at 198 MeV
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Y. Nagasue, M. Yamaguchi, S. Asaji, Masaki Sasano, Kichiji Hatanaka, Hideyuki Sakai, Tomotsugu Wakasa, H. Kuboki, Atsushi Tamii, Takashi Ishida, Tetsuo Noro, Hiroyuki Kamada, Y. Hagihara, M. Ichimura, Kunihiro Fujita, Yasuhiro Sakemi, Yuji Shimizu, and Yuji Tameshige
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Physics ,Nuclear and High Energy Physics ,Isovector ,Scattering ,Isospin ,Observable ,Inelastic scattering ,Impulse (physics) ,Atomic physics ,Nuclear Experiment ,Polarization (waves) ,Electron scattering - Abstract
We report measurements of the cross section and a complete set of polarization observables for the Si 28 ( p → , n → ) P 28 ( 6 − ) reaction at a bombarding energy of 198 MeV. The data are compared with distorted wave impulse approximation calculations employing response functions normalized to inelastic electron scattering. The spin-longitudinal polarized cross section I D q is slightly over-predicted by the calculations, while the normal spin-transverse polarized cross section I D n is significantly under-predicted. The calculated in-plane spin-transverse I D p and spin-scalar I D 0 polarized cross sections agree well with the experimental data. These results are consistent with those for Si 28 ( p → , p → ′ ) Si 28 ( 6 − , T = 1 ) scattering at the same energy, and thus it is concluded that isospin-mixing effects are not responsible for the discrepancy between theory and experiment in the ( p → , p → ′ ) case. Energy half-off-shell effects as medium effects on the effective nucleon–nucleon interaction are also investigated and found to be too small to be responsible for the discrepancy.
- Published
- 2007
17. Charge state distribution ofKr86in hydrogen and helium gas charge strippers at2.7 MeV/nucleon
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M. Kase, H. Hasebe, H. Imao, H. Kuboki, Hiroki Okuno, N. Fukunishi, Osamu Kamigaito, and E. Ikezawa
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Physics ,Nuclear and High Energy Physics ,Physics and Astronomy (miscellaneous) ,Helium gas ,Hydrogen ,Stripping (chemistry) ,Cyclotron ,chemistry.chemical_element ,Charge (physics) ,Surfaces and Interfaces ,law.invention ,Nuclear physics ,chemistry ,law ,Physics::Accelerator Physics ,Atomic physics ,Nuclear Experiment ,Nucleon ,State distribution ,Beam (structure) - Abstract
Heavy-ion beam charge stripping at 2.7 MeV/u is studied, experimentally and theoretically, for different low-Z gas stripper targets.
- Published
- 2014
18. First experiment of 6He with a polarized proton target
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Y. Yanagisawa, Yuichi Ichikawa, Kimiko Sekiguchi, Kentaro Yako, Takashi Wakui, Y. Satou, Nori Aoi, H. Kuboki, M. Hatano, T. Ikeda, Tomohiro Uesaka, T. K. Onishi, N. Sakamoto, K. Itoh, Yusuke T. Maeda, Atsushi Tamii, N. Matsui, Tsuyoshi Ohnishi, T. Saito, Hironori Iwasaki, Kenji Suda, Takeo Kawabata, Hideyuki Sakai, and Masaki Sasano
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Physics ,Nuclear and High Energy Physics ,Spin polarization ,media_common.quotation_subject ,Low magnetic field ,Hadron ,Physics::Accelerator Physics ,Nuclear fusion ,Atomic physics ,Polarization (waves) ,Asymmetry ,Optical potential ,media_common - Abstract
We have constructed a new type of spin polarized solid proton target which can be operated under a low magnetic field of 0.08T and a high temperature of 100 K. We have measured for the first time the polarization asymmetry of an unstable beam of 6He at an energy of 71 MeV/u. Optical potential analyses have been carried out.
- Published
- 2005
19. 6He scattering with polarized proton target
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K. Itoh, M. Hatano, Takashi Wakui, Tomohiro Uesaka, Hideyuki Sakai, Tomoki Saito, Kenji Suda, Tsuyoshi Ohnishi, Masaki Sasano, Y. Yanagisawa, Takeo Kawabata, T. Ikeda, Kimiko Sekiguchi, H. Kuboki, Takaharu Onishi, Yusuke T. Maeda, Yuichi Ichikawa, Kentaro Yako, Hironori Iwasaki, N. Sakamoto, Y. Satou, Nori Aoi, Atsushi Tamii, and N. Matsui
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Physics ,Proton ,Scattering ,media_common.quotation_subject ,chemistry.chemical_element ,Polarization (waves) ,Asymmetry ,Magnetic field ,chemistry ,Low magnetic field ,Physics::Accelerator Physics ,Atomic physics ,Helium ,media_common - Abstract
A new type of the spin polarized solid proton target has been constructed which can be operated under a low magnetic field of 0.08 T and a high temperature of 100 K. First polarization asymmetry measurement with an unstable beam of 6He with an energy of 71 MeV/u has been successfully carried out.
- Published
- 2005
20. MEASUREMENT OF DIFFERENTIAL CROSS SECTIONS AND VECTOR ANALYZING POWERS FOR THE ${\vec n}d$ REACTION AT 250 MEV
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Kichiji Hatanaka, T. Ikeda, K. Itoh, Hideyuki Sakai, Yusuke T. Maeda, Y. Shimizu, H. Kuboki, Yukihiko Kitamura, Kunihiro Fujita, M. Hatano, J. Rapaport, D. Hirooka, Hiroyuki Kamada, Yasuhiro Sakemi, Atsushi Tamii, H. Okamura, Hiroyuki S. Kato, Kentaro Yako, N. Sakamoto, M. B. Greenfield, Takeshi Saito, Y. Sato, Tomotsugu Wakasa, S. Sakoda, N. Uchigashima, Junichiro Kamiya, K. Suda, and Kimiko Sekiguchi
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Nuclear physics ,Physics ,Elastic scattering ,Nuclear and High Energy Physics ,General Physics and Astronomy ,Astronomy and Astrophysics ,Nuclear cross section ,Coulomb effect ,Differential (mathematics) - Abstract
To study the three-nucleon force (3NF) effects without ambiguities from the Coulomb effect, the differential cross sections and the vector analyzing powers for the [Formula: see text] elastic scattering at En = 245 MeV have been measured at θcm = 85° - 180°. The data are compared to the results of Faddeev calculations using modern nucleon-nucleon (NN) forces with and without 3NF. Additionally we have a plan to extend our measurement to the forward angular region where the Coulomb effect is expected to be large. We carried out the test experiment and measured the differential cross sections at θcm = 21°.
- Published
- 2003
21. MEASUREMENT OF p+d ELASTIC SCATTERING AT EP = 392 MEV
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M. Hatano, Yusuke T. Maeda, H. Okamura, K. Suda, Yukihiko Kitamura, Kichiji Hatanaka, H. Kuboki, Hideyuki Sakai, Yuji Shimizu, Junichiro Kamiya, Takaomi Ishida, Takeshi Saito, Tomotsugu Wakasa, N. Uchigashima, Y. Satou, Kentaro Yako, Atsushi Tamii, and Kimiko Sekiguchi
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Physics ,Nuclear physics ,Elastic scattering ,Nuclear and High Energy Physics ,Nuclear Theory ,General Physics and Astronomy ,Astronomy and Astrophysics ,Observable ,Scattering length ,Nuclear Experiment ,Nucleon ,Spin-½ - Abstract
The cross sections and spin observables of the p+d elastic scattering have been measured at 392 MeV. The results are compared with the results of Faddeev calculations with and without including the three nucleon force.
- Published
- 2003
22. Shallow and diffuse spin-orbit potential for proton elastic scattering from neutron-rich helium isotopes at 71 MeV/nucleon
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Y. Nakayama, Satoshi Sakaguchi, Takashi Nakamura, T. Kawahara, K. Itoh, Yuichi Ichikawa, Kimiko Sekiguchi, H. Kuboki, Hideyuki Sakai, Tomohiro Uesaka, Y. Shimizu, Taro Nakao, Yoshiko Sasamoto, N. Aoi, Masatoshi Itoh, T. Shimamura, Yosuke Kondo, Takashi Wakui, and T. Kawabata
- Subjects
Elastic scattering ,Physics ,Nuclear and High Energy Physics ,Nuclear Theory ,Proton ,Scattering ,FOS: Physical sciences ,Radius ,Nuclear physics ,Nuclear Theory (nucl-th) ,Neutron ,Atomic physics ,Nuclear Experiment (nucl-ex) ,Nucleon ,Nuclear Experiment ,Isotopes of helium ,Spin-½ - Abstract
Vector analyzing powers for proton elastic scattering from 8He at 71 MeV/nucleon have been measured using a solid polarized proton target operated in a low magnetic field of 0.1 T. The spin-orbit potential obtained from a phenomenological optical model analysis is found to be significantly shallower and more diffuse than the global systematics of stable nuclei, which is an indication that the spin-orbit potential is modified for scattering involving neutron-rich nuclei. A close similarity between the matter radius and the root-mean-square radius of the spin-orbit potential is also identified., Comment: 6 pages, 4 figures, accepted for publication in Physical Review C Rapid Communication
- Published
- 2013
- Full Text
- View/download PDF
23. Charge stripping ofU238ion beam by helium gas stripper
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M. Kase, H. Hasebe, H. Imao, Hiroki Okuno, Y. Yano, N. Fukunishi, Yutaka Watanabe, Osamu Kamigaito, H. Kuboki, T. Watanabe, and S. Yokouchi
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Physics ,Nuclear and High Energy Physics ,Physics and Astronomy (miscellaneous) ,Helium gas ,Ion beam ,chemistry.chemical_element ,Surfaces and Interfaces ,Uranium ,Stripping (fiber) ,chemistry ,Physics::Accelerator Physics ,Atomic physics ,Helium ,Beam (structure) - Abstract
Development of a nondestructive, efficient electric-charge-stripping method is a key requirement for next-generation high-intensity heavy-ion accelerators such as the RIKEN Radioactive-Isotope Beam Factory. A charge stripper employing a low-$Z$ gas is an important candidate applicable to high-intensity uranium beams for replacing carbon-foil strippers. In this study, a high-beam-transmission charge-stripping system employing helium gas for $^{238}\mathrm{U}$ beams injected at $10.8\text{ }\text{ }\mathrm{MeV}/\mathrm{u}$ was developed and demonstrated for the first time. The charge-state evolution measured using helium in a thickness range of $0.24--1.83\text{ }\text{ }\mathrm{mg}/{\mathrm{cm}}^{2}$ is compared with theoretical predictions. Energy attenuation and energy spread due to the helium stripper are also investigated.
- Published
- 2012
24. Gamow-Teller transition strengths in the intermediate nucleus of the116Cd double-βdecay by the116Cd(p,n)116In and116Sn(n,p)116In reactions at 300 MeV
- Author
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Kimiko Sekiguchi, Tomohiro Uesaka, Amand Faessler, Takeo Kawabata, Yukie Maeda, Atsushi Tamii, Kazuo Muto, Tomotsugu Wakasa, Kichiji Hatanaka, Shumpei Noji, Hideyuki Sakai, H. Kuboki, Masaki Sasano, K. Itoh, Y. Shimizu, Yasuhiro Sakemi, M. B. Greenfield, Vadim Rodin, Yuji Tameshige, Kentaro Yako, Masanori Dozono, Kunihiro Fujita, Yoshiko Sasamoto, H. Okamura, and Kenjiro Miki
- Subjects
Physics ,Nuclear and High Energy Physics ,Isovector ,Double beta decay ,Quasiparticle ,Atomic physics ,Random phase approximation ,Multipole expansion ,Spectral line ,Energy (signal processing) ,Spin-½ - Abstract
The double-differential cross sections for the ${}^{116}$Cd$(p,\phantom{\rule{-0.16em}{0ex}}n)$ and ${}^{116}$Sn$(n,\phantom{\rule{-0.16em}{0ex}}p)$ reactions were measured at 300 MeV for studying the nuclear matrix element of the ${}^{116}$Cd $\ensuremath{\beta}\ensuremath{\beta}$ decay. A multipole decomposition technique was applied to the spectra to extract the Gamow-Teller (GT) component. The integrated GT strengths up to an excitation energy of 30 MeV in the intermediate nucleus ${}^{116}$In are $40\ifmmode\pm\else\textpm\fi{}6$ and $11\ifmmode\pm\else\textpm\fi{}1$ in the $(p,\phantom{\rule{-0.16em}{0ex}}n)$ and $(n,\phantom{\rule{-0.16em}{0ex}}p)$ spectra, respectively, including the component from the isovector spin monopole (IVSM). The spectra are compared with those obtained from a theoretical calculation with a quasiparticle random phase approximation, where the contribution from the IVSM component as well as the interference effect between the GT and IVSM components are fully taken into account.
- Published
- 2012
25. Analyzing power in elastic scattering of6He from a polarized proton target at 71 MeV/nucleon
- Author
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Kimiko Sekiguchi, Satoshi Sakaguchi, Tomohiro Uesaka, Taro Nakao, Y. Satou, H. Okamura, Shinichi Ishikawa, K. Amos, Nori Aoi, Hideyuki Sakai, Yasuo Yamamoto, Y. Hashimoto, M. Shinohara, R. Matsuo, Emiko Hiyama, Yasunori Iseri, M. Tanifuji, D. Suzuki, Takashi Wakui, Takeo Kawabata, Hironori Iwasaki, Masaki Sasano, Kenji Suda, Yoshihiko Takahashi, Yoshiko Sasamoto, H. Kuboki, Masatoshi Itoh, Atsushi Tamii, Yusuke T. Maeda, T. Kawahara, K. Itoh, Mitsutaka Yamaguchi, Yuichi Ichikawa, M. Ichikawa, Kentaro Yako, and Steven Karataglidis
- Subjects
Physics ,Elastic scattering ,Nuclear and High Energy Physics ,Nuclear Theory ,Proton ,Scattering ,Hadron ,FOS: Physical sciences ,Coupling (probability) ,Nuclear Theory (nucl-th) ,Neutron ,Nuclear Experiment (nucl-ex) ,Atomic physics ,Nuclear Experiment ,Nucleon ,Isotopes of helium - Abstract
The vector analyzing power has been measured for the elastic scattering of neutron-rich 6He from polarized protons at 71 MeV/nucleon making use of a newly constructed solid polarized proton target operated in a low magnetic field and at high temperature. Two approaches based on local one-body potentials were applied to investigate the spin-orbit interaction between a proton and a 6He nucleus. An optical model analysis revealed that the spin-orbit potential for 6He is characterized by a shallow and long-ranged shape compared with the global systematics of stable nuclei. A semimicroscopic analysis with a alpha+n+n cluster folding model suggests that the interaction between a proton and the alpha core is essentially important in describing the p+6He elastic scattering. The data are also compared with fully microscopic analyses using non-local optical potentials based on nucleon-nucleon g-matrices., 20 pages, 20 figures, accepted by Physical Review C
- Published
- 2011
26. Charge-state distribution ofU238in nitrogen gas and carbon foil at 14 and15 MeV/nucleon
- Author
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H. Hasebe, H. Imao, S. Yokouchi, Jun-ichi Ohnishi, Hiroki Okuno, T. Nakagawa, Akira Goto, Y. Higurashi, Osamu Kamigaito, H. Kuboki, N. Fukunishi, Y. Yano, and M. Kase
- Subjects
Physics ,Nuclear and High Energy Physics ,Range (particle radiation) ,Physics and Astronomy (miscellaneous) ,Nuclear Theory ,Cyclotron ,chemistry.chemical_element ,Charge (physics) ,Surfaces and Interfaces ,Nitrogen ,law.invention ,chemistry ,law ,Nitrogen gas ,Physics::Accelerator Physics ,Atomic physics ,Nuclear Experiment ,Nucleon ,Carbon ,FOIL method - Abstract
The charge-state distributions of U with energies of 14 and 15 MeV=nucleon were measured using nitrogen (N2) gas and carbon foil (C-foil) charge strippers. The most probable charge states of U with energies of 14 and 15 MeV=nucleon in N2 gas attain equilibrium at 60.8 and 62.4, whereas those in C-foils attain equilibrium at 75.8 and 76.7, respectively. Novel empirical formulas for the accurate prediction of the equilibrium charge states of U with energies 10–20 MeV=nucleon in gases and C-foil were derived by fitting the data in the energy range of 1–20 MeV=nucleon. The charge states predicted by using the formulas for gases and C-foil are in good agreement with the data in the energy range of 10–20 MeV=nucleon within an average of 0.23 and 0.21, respectively.
- Published
- 2011
27. Low-Z gas stripper as an alternative to carbon foils for the acceleration of high-power uranium beams
- Author
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S. Yokouchi, N. Fukunishi, M. Kase, Hiroki Okuno, Akira Goto, H. Imao, Osamu Kamigaito, Y. Yano, H. Kuboki, Ady Hershcovitch, and H. Hasebe
- Subjects
Physics ,Nuclear and High Energy Physics ,Physics and Astronomy (miscellaneous) ,Cyclotron ,chemistry.chemical_element ,Order (ring theory) ,Charge (physics) ,Surfaces and Interfaces ,Resonance (particle physics) ,Charged particle ,law.invention ,Nuclear physics ,chemistry ,law ,Physics::Accelerator Physics ,lcsh:QC770-798 ,lcsh:Nuclear and particle physics. Atomic energy. Radioactivity ,Atomic physics ,Nucleon ,Helium ,Intensity (heat transfer) - Abstract
The RIKEN accelerator complex started feeding the next-generation exotic beam facility radioisotope beam factory (RIBF) with heavy-ion beams from 2007 after the successful commissioning of RIBF at the end of 2006. Many improvements made from 2007 to 2010 were instrumental in increasing the intensity of various heavy-ion beams. However, the available beam intensity of very heavy ion beams, especially uranium beams, is far below our goal of $1\text{ }\text{ }\mathrm{p}\ensuremath{\mu}\mathrm{A}$ ($6\ifmmode\times\else\texttimes\fi{}{10}^{12}\text{ }\text{ }\mathrm{particles}/\mathrm{s}$). In order to achieve this goal, upgrade programs are already in progress; the programs include the construction of a new 28-GHz superconducting electron cyclotron resonance ion source and a new injector linac. However, the most serious problem, that of a charge stripper for high-power uranium beams, still remains unsolved, despite extensive research and development work using large foils mounted on a rotating cylinder and a ${\mathrm{N}}_{2}$ gas stripper. A gas stripper is free from problems related to lifetime, though the equilibrium charge state in this stripper is considerably lower than that in a carbon foil, owing to the absence of the density effect. Nevertheless, the merits of gas strippers motivated us to develop a low-$Z$ gas stripper to achieve a higher equilibrium charge state even in gases. We measured the electron-loss and electron-capture cross sections of uranium ions in He gas as a function of their charge state at 11, 14, and $15\text{ }\text{ }\mathrm{MeV}/\mathrm{nucleon}$. The equilibrium charge states extracted from the intersection of the lines of the two cross sections were promisingly higher than those in ${\mathrm{N}}_{2}$ gas by more than 10. Simple simulations of charge development along the stripper thickness were performed by assuming the measured cross sections. The simulation results show that about $1\text{ }\text{ }\mathrm{mg}/{\mathrm{cm}}^{2}$ of He gas should be accumulated to achieve a charge state higher than that of ${\mathrm{N}}_{2}$ gas, notwithstanding the difficulty in accumulation of this helium amount owing to its fast dispersion. However, we now believe that the following two solutions can overcome this difficulty: a gas cell with a very large differential pumping system and a gas cell with a plasma window. Their merits and demerits are discussed in the paper.
- Published
- 2011
28. Charge-state distribution measurements ofU238andXe136at11 MeV/nucleonusing gas charge stripper
- Author
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H. Hasebe, N. Fukunishi, T. Kishida, Akira Goto, Y. Yano, Hiroki Okuno, H. Kuboki, Osamu Kamigaito, S. Yokouchi, and M. Kase
- Subjects
Physics ,Nuclear and High Energy Physics ,Physics and Astronomy (miscellaneous) ,chemistry.chemical_element ,Charge (physics) ,Surfaces and Interfaces ,State (functional analysis) ,Ion ,Xenon ,chemistry ,Nitrogen gas ,Atomic physics ,Nucleon ,State distribution ,Energy (signal processing) - Abstract
The charge-state distributions and equilibrium charge states of uranium ($^{238}\mathrm{U}$) and xenon ($^{136}\mathrm{Xe}$) ions at $11\text{ }\text{ }\mathrm{MeV}/\mathrm{nucleon}$ were determined using a gas charge stripper. A differential pumping system facilitated the increase of the nitrogen gas thickness up to $1.3\text{ }\text{ }\mathrm{mg}/{\mathrm{cm}}^{2}$, which is sufficient for the most probable charge state to attain equilibrium. The charge states of $^{238}\mathrm{U}$ attain equilibrium at 56.0, 56.6, and 55.7 in ${\mathrm{N}}_{2}$, Ar, and ${\mathrm{CO}}_{2}$ media with thicknesses of 125, 79, and $126\text{ }\text{ }\ensuremath{\mu}\mathrm{g}/{\mathrm{cm}}^{2}$, respectively, while those of $^{136}\mathrm{Xe}$ attain equilibrium at 40.5, 40.1, and 40.3 in ${\mathrm{N}}_{2}$, Ar, and ${\mathrm{CO}}_{2}$ media with thicknesses of 163, 95, and $139\text{ }\text{ }\ensuremath{\mu}\mathrm{g}/{\mathrm{cm}}^{2}$, respectively. The equilibrium charge states of $^{136}\mathrm{Xe}$ are acceptable for acceleration by the subsequent cyclotron. The measured data of $^{238}\mathrm{U}$ were used to devise an empirical formula for the prediction of the equilibrium charge state in gaseous media over the energy region of $0.01--60\text{ }\text{ }\mathrm{MeV}/\mathrm{nucleon}$. The equilibrium charge state of $^{136}\mathrm{Xe}$ as predicted by the devised formula is in good agreement with the data.
- Published
- 2010
29. Analyzing power for proton elastic scattering from the neutron-richHe6nucleus
- Author
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K. Suda, Takashi Wakui, M. Shinohara, M. Tanifuji, Yoshihiko Takahashi, K. Amos, Emiko Hiyama, Hideyuki Sakai, Tomohiro Uesaka, Hironori Iwasaki, H. Kuboki, Y. Hashimoto, Taro Nakao, Yoshiko Sasamoto, Yuichi Ichikawa, Shinichi Ishikawa, R. Matsuo, T. Kawahara, K. Itoh, M. Ichikawa, Yasunori Iseri, Satoshi Sakaguchi, Kentaro Yako, Masaki Sasano, Kimiko Sekiguchi, Masatoshi Yamaguchi, Yukie Maeda, Y. Satou, Nori Aoi, Yasuo Yamamoto, Atsushi Tamii, Masatoshi Itoh, Takeo Kawabata, S. Karataglidis, D. Suzuki, and H. Okamura
- Subjects
Nuclear physics ,Physics ,Elastic scattering ,Nuclear and High Energy Physics ,Proton ,Scattering ,Nuclear Theory ,Hadron ,Nuclear structure ,Neutron ,Nuclear Experiment ,Nucleon ,Isotopes of helium - Abstract
Vector analyzing power for the proton-{sup 6}He elastic scattering at 71 MeV/nucleon has been measured for the first time, with a newly developed polarized proton solid target, which works at a low magnetic field of 0.09 T. The results are found to be incompatible with a t-matrix folding model prediction. Comparisons of the data with g-matrix folding analyses clearly show that the vector analyzing power is sensitive to the nuclear structure model used in the reaction analysis. The {alpha}-core distribution in {sup 6}He is suggested to be a possible key for understanding the nuclear structure sensitivity.
- Published
- 2010
30. Spin–isospin selectivity in three-nucleon forces
- Author
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Shumpei Noji, M. Mahjour-Shafiei, R. Benard, H. Kuboki, J. G. Messchendorp, A. Ramazani-Moghaddam-Arani, Yusuke T. Maeda, Masaki Sasano, Kenjiro Miki, A. Kozela, M. Kis, St. Kistryn, Hideyuki Sakai, Aleksandra Biegun, E. Stephan, R. Sworst, Yoshiyuki Takahashi, Nasser Kalantar-Nayestanaki, H. R. Amir-Ahmadi, Mohammad Eslami-Kalantari, Kimiko Sekiguchi, H. Mardanpour, Kentaro Yako, L. Joulaeizadeh, Research unit Nuclear & Hadron Physics, and KVI - Center for Advanced Radiation Technology
- Subjects
TENSOR ANALYZING POWERS ,Nuclear forces ,Nuclear and High Energy Physics ,Particle physics ,Nuclear Theory ,FOS: Physical sciences ,VECTOR ,Nuclear physics ,BREAKUP ,Three-nucleon force ,Nuclear force ,Nuclear Experiment (nucl-ex) ,Nuclear Experiment ,nuclear forces ,proton–deuteron break-up ,three-nucleon force ,polarization phenomena ,Elastic scattering ,Physics ,Polarization phenomena ,Detector ,Polarization (waves) ,ELASTIC-SCATTERING ,Isospin ,N channel ,Proton-deuteron break-up ,Nucleon ,Selectivity - Abstract
Precision data are presented for the break-up reaction, $^2{\rm H}(\vec p,pp)n$, within the framework of nuclear-force studies. The experiment was carried out at KVI using a polarized-proton beam of 190 MeV impinging on a liquid-deuterium target and by exploiting the detector, BINA. Some of the vector-analyzing powers are presented and compared with state-of-the-art Faddeev calculations including three-nucleon forces effect. Significant discrepancies between the data and theoretical predictions were observed for kinematical configurations which correspond to the $^2{\rm H}(\vec p,^2$He$)n$ channel. These results are compared to the $^2{\rm H}(\vec p,d)p$ reaction to test the isospin sensitivity of the present three-nucleon force models. The current modeling of two and three-nucleon forces is not sufficient to describe consistently polarization data for both isospin states., 4 pages, 3 figures, submitted to PRL
- Published
- 2010
31. First experiment of 6He with a polarized proton target
- Author
-
M. Hatano, H. Sakai, T. Wakui, T. Uesaka, N. Aoi, Y. Ichikawa, T. Ikeda, K. Itoh, H. Iwasaki, T. Kawabata, H. Kuboki, Y. Maeda, N. Matsui, T. Ohnishi, T. K. Onishi, T. Saito, N. Sakamoto, M. Sasano, Y. Satou, K. Sekiguchi, K. Suda, A. Tamii, Y. Yanagisawa, and K. Yako
- Published
- 2009
32. Gamow-Teller Strength Distributions inSc48by theCa48(p,n)andTi48(n,p)Reactions and Two-Neutrino Double-βDecay Nuclear Matrix Elements
- Author
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Kentaro Yako, Shumpei Noji, Takeo Kawabata, Y. Tameshige, Kazuo Muto, H. Kuboki, D. Frekers, H. Zheng, K. Suda, Kichiji Hatanaka, M. B. Greenfield, Hiroshi Matsubara, Hideyuki Sakai, Satoshi Sakaguchi, Yukie Maeda, Kenjiro Miki, Tomohiro Uesaka, Kimiko Sekiguchi, Tomotsugu Wakasa, Yoshiko Sasamoto, E. Ihara, Atsushi Tamii, Yasuhiro Sakemi, T. H. Okabe, Y. Shimizu, Masaki Kato, Masanori Dozono, Masaki Sasano, and H. Okamura
- Subjects
Physics ,Double beta decay ,Nuclear Theory ,Shell (structure) ,General Physics and Astronomy ,Neutrino ,Atomic physics ,Nuclear Experiment ,Nuclear matrix ,Multipole expansion ,Beta decay ,Excitation ,Spectral line - Abstract
The double-differential cross sections for the 48Ca(p,n) and 48Ti(n,p) reactions were measured at 300 MeV. A multipole decomposition technique was applied to the spectra to extract the Gamow-Teller (GT) components. The integrated GT strengths up to an excitation energy of 30 MeV in 48Sc are 15.3+/-2.2 and 2.8+/-0.3 in the (p,n) and (n,p) spectra, respectively. In the (n,p) spectra additional GT strengths were found above 8 MeV where shell models within the fp shell-model space predict almost no GT strengths, suggesting that the present shell-model description of the nuclear matrix element of the two-neutrino double-beta decay is incomplete.
- Published
- 2009
33. Three-nucleon force effects in theH1(d→,p→p)nreaction at 135 MeV/nucleon
- Author
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Kimiko Sekiguchi, Andreas Nogga, Henryk Witała, Kentaro Yako, Yoshiko Sasamoto, W. Glöckle, Tomohiro Uesaka, Hiroyuki Kamada, Tomotsugu Wakasa, R. Skibiński, H. Kuboki, Satoshi Sakaguchi, H. Okamura, K. Itoh, Naoya Sakamoto, K. Suda, Hideyuki Sakai, Takeo Kawabata, Yukie Maeda, Yoshihiko Takahashi, Jacek Golak, and Masaki Sasano
- Subjects
Nuclear reaction ,Physics ,Nuclear and High Energy Physics ,Particle physics ,Faddeev equations ,Proton ,Scattering ,Nuclear Theory ,Observable ,Nuclear physics ,Deuterium ,Nuclear force ,Nuclear Experiment ,Nucleon - Abstract
The deuteron to proton polarization transfer coefficients ${K}_{\mathit{yy}}^{{y}^{'}}$ and ${K}_{y}^{{y}^{'}}$ together with the deuteron analyzing powers are measured in three coplanar configurations of the deuteron-proton breakup reaction with a 135-MeV/nucleon polarized deuteron beam at the RIKEN Accelerator Research Facility. The data are compared with theoretical predictions based on exact solutions of the three-nucleon ($3N$) Faddeev equations with high-precision nucleon-nucleon ($\mathit{NN}$) forces, alone or combined with two $3N$ force (3NF) models, the $2\ensuremath{\pi}$-exchange Tucson-Melbourne${}^{'}(99)$ (${\mathrm{TM}}^{'}99$) and Urbana IX. Large 3NF effects have been found for all the measured observables. Predicted effects are supported by the data, with the exception of the vector analyzing power ${A}_{y}^{d}$. For this observable, theory based on only $\mathit{NN}$ forces is sufficient to explain the data. The behavior of the breakup analyzing powers is found to be different from the corresponding observables in elastic nucleon-deuteron scattering.
- Published
- 2009
34. Gamow-Teller strength distributions in 48Sc by the 48Ca(p,n) and 48Ti(n,p) reactions and two-neutrino double-beta decay nuclear matrix elements
- Author
-
K, Yako, M, Sasano, K, Miki, H, Sakai, M, Dozono, D, Frekers, M B, Greenfield, K, Hatanaka, E, Ihara, M, Kato, T, Kawabata, H, Kuboki, Y, Maeda, H, Matsubara, K, Muto, S, Noji, H, Okamura, T H, Okabe, S, Sakaguchi, Y, Sakemi, Y, Sasamoto, K, Sekiguchi, Y, Shimizu, K, Suda, Y, Tameshige, A, Tamii, T, Uesaka, T, Wakasa, and H, Zheng
- Abstract
The double-differential cross sections for the 48Ca(p,n) and 48Ti(n,p) reactions were measured at 300 MeV. A multipole decomposition technique was applied to the spectra to extract the Gamow-Teller (GT) components. The integrated GT strengths up to an excitation energy of 30 MeV in 48Sc are 15.3+/-2.2 and 2.8+/-0.3 in the (p,n) and (n,p) spectra, respectively. In the (n,p) spectra additional GT strengths were found above 8 MeV where shell models within the fp shell-model space predict almost no GT strengths, suggesting that the present shell-model description of the nuclear matrix element of the two-neutrino double-beta decay is incomplete.
- Published
- 2009
35. Gamow-Teller unit cross sections of the(p,n)reaction at 198 and 297 MeV on medium-heavy nuclei
- Author
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Kimiko Sekiguchi, Takeo Kawabata, Yoshitaka Fujita, Yukie Maeda, Y. Takahashi, Tomotsugu Wakasa, H. Okamura, S. Asaji, Y. Hagihara, Y. Shimizu, Kichiji Hatanaka, Yasuhiro Sakemi, M. B. Greenfield, Hideyuki Sakai, Kentaro Yako, Kunihiro Fujita, Atsushi Tamii, Yuji Tameshige, H. Kuboki, T. Saito, and Masaki Sasano
- Subjects
Physics ,Nuclear and High Energy Physics ,Transition strength ,Continuum (set theory) ,Atomic physics ,Unit (ring theory) ,Energy (signal processing) - Abstract
Gamow-Teller (GT) unit cross sections, ${\stackrel{\ifmmode \hat{}\else \^{}\fi{}}{\ensuremath{\sigma}}}_{\mathrm{GT}}$, are obtained at 198 and 297 MeV by measuring the double differential cross sections at ${0}^{\ifmmode^\circ\else\textdegree\fi{}}$ for the $(p,n)$ reaction on $^{58}\mathrm{Ni}$, $^{70}\mathrm{Zn}$, $^{114}\mathrm{Cd}$, $^{118}\mathrm{Sn}$, and $^{120}\mathrm{Sn}$. The mass dependence of ${\stackrel{\ifmmode \hat{}\else \^{}\fi{}}{\ensuremath{\sigma}}}_{\mathrm{GT}}$ and the ratio of ${\stackrel{\ifmmode \hat{}\else \^{}\fi{}}{\ensuremath{\sigma}}}_{\mathrm{GT}}$ to the Fermi unit cross section, ${\stackrel{\ifmmode \hat{}\else \^{}\fi{}}{\ensuremath{\sigma}}}_{\mathrm{F}}$, $({R}^{2})$ are also derived in the mass region of $58\ensuremath{\leqslant}A\ensuremath{\leqslant}120$. The ${\stackrel{\ifmmode \hat{}\else \^{}\fi{}}{\ensuremath{\sigma}}}_{\mathrm{GT}}$ value for $^{90}\mathrm{Zr}$ at 297 MeV interpolated using the $A$-dependence obtained herein agrees with that used in a previous analysis where the GT transition strength over a wide energy region up to the continuum was discussed. However, the deduced $^{64}\mathrm{Ni}$${\stackrel{\ifmmode \hat{}\else \^{}\fi{}}{\ensuremath{\sigma}}}_{\mathrm{GT}}$ value at 198 MeV is 20% smaller than that obtained from the analysis of a previous $(n,p)$ measurement. The present ${R}^{2}$ values in the mass region heavier than $^{42}\mathrm{Ca}$ are larger than those in the region up to $^{42}\mathrm{Ca}$ and increase as a function of $A$.
- Published
- 2009
36. Measurements of the [sup 116]Cd(p,n) and [sup 116]Sn(n,p) reactions at 300 MeV for studying Gamow-Teller transition strengths in the intermediate nucleus of the [sup 116]Cd double-β decay
- Author
-
M. Sasano, H. Sakai, K. Yako, K. Miki, S. Noji, T. Wakasa, M. Dozono, K. Fujita, M. B. Greenfield, K. Hatanaka, T. Kawabata, H. Kuboki, Y. Maeda, H. Okamura, Y. Sakemi, K. Sekiguchi, Y. Shimizu, Y. Tameshige, A. Tamii, T. Uesaka, Y. Sasamoto, K. Itoh, K. Muto, Osvaldo Civitarese, Ivan Stekl, and Jouni Suhonen
- Subjects
Physics ,medicine.anatomical_structure ,law ,Double beta decay ,Giant resonance ,Nuclear Theory ,Cyclotron ,medicine ,Atomic physics ,Nuclear Experiment ,Nucleus ,law.invention - Abstract
The double differential cross sections for the 116Cd(p,n) and 116Sn(n,p) reactions at 300 MeV have been measured over a wide excitation‐energy region including Gamow‐Teller (GT) giant resonance (GTGR) for studying GT transition strengths in the intermediate nucleus of the 116Cd double‐β decay, namely 116In. A large amount of the strengths in the β+ direction has been newly found in the energy region up to 30 MeV, which may imply that the GT strengths in the GTGR region contribute to the nuclear matrix element of the two‐neutrino double‐β decay.
- Published
- 2009
37. On Ling's binomial and negative binomial distributions of order k
- Author
-
N. Kashiwagi, H. Kuboki, S. Aki, and Katuomi Hirano
- Subjects
Statistics and Probability ,Combinatorics ,Binomial distribution ,Beta negative binomial distribution ,Beta-binomial distribution ,Poisson binomial distribution ,Negative binomial distribution ,Multinomial distribution ,Central binomial coefficient ,Statistics, Probability and Uncertainty ,Negative multinomial distribution ,Mathematics - Abstract
Type II binomial distribution of order k was introduced by Ling (1988). In this article the probability function, the probability generating function and asymptotic properties of the distribution are discussed. Some properties of the corresponding negative binomial distribution of order k , which was introduced by Ling (1989) are also examined.
- Published
- 1991
38. A systematic study of 3NF effects in p plus d break-up with BINA at 190 MeV
- Author
-
A. Kozela, H. R. Amir-Ahmadi, Shumpei Noji, St. Kistryn, E. Stephan, Yusuke T. Maeda, M. Mahjour-Shafiei, Aleksandra Biegun, M. Kis, Mohammad Eslami-Kalantari, Kenjiro Miki, Masaki Sasano, J. G. Messchendorp, Y. Takahashi, Kentaro Yako, H. Kuboki, H. Mardanpour, Hideyuki Sakai, R. Sworst, R. Benard, Nasser Kalantar-Nayestanaki, Kimiko Sekiguchi, A. Ramazani-Moghaddam-Arani, and KVI - Center for Advanced Radiation Technology
- Subjects
Physics ,Detector ,Nuclear Theory ,three-nucleon force ,break-up reactions ,vector analyzing powers ,differential cross sections ,Faddeev calculations ,Atomic physics ,Nuclear Experiment ,Atomic and Molecular Physics, and Optics ,Beam (structure) ,Differential (mathematics) - Abstract
A systematic study of three-nucleon force (3NF) effects in break-up reactions has been carried out at KVI at several energies. In this article, the p + d -> p + p + n reaction with a polarized-proton beam of 190 MeV will be discussed. The experiment was performed by exploiting a new detector called BINA. Some results for high-precision vector analyzing powers and differential cross sections are presented and compared with state-of-the-art Faddeev calculations with or without 3NF.
- Published
- 2008
39. ANALYZING POWER MEASUREMENT FOR PROTON ELASTIC SCATTERING ON 6<font>He</font>
- Author
-
K. Yako, H. Iwasaki, H. Okamura, Y. Satou, T. Wakui, M. Sasano, Yoshihiko Takahashi, Y. Ichikawa, K. Sekiguchi, Y. Sasamoto, T. Nakao, M. Yamaguchi, T. Kawahara, Y. Hashimoto, H. Sakai, K. Itoh, Nori Aoi, Satoshi Sakaguchi, M. Shinohara, Daisuke Suzuki, K. Suda, A. Tamii, R. Matsuo, N. Sakamoto, Y. Maeda, T. Kawabata, T. Uesaka, M. Ichikawa, Masatoshi Itoh, and H. Kuboki
- Subjects
Nuclear physics ,Elastic scattering ,Physics ,Proton ,Spin–orbit interaction ,Atomic physics ,Mott scattering ,Small-angle neutron scattering ,Isotopes of helium ,Power (physics) - Published
- 2008
40. Differential cross section and analyzing power measurements forn→delastic scattering at 248 MeV
- Author
-
Kichiji Hatanaka, Hideyuki Sakai, M. Österlund, Jacek Golak, A. Öhrn, Tomotsugu Wakasa, R. Skibiński, Kimiko Sekiguchi, Takeo Kawabata, A. Deltuva, H. Okamura, Jan Blomgren, Atsushi Tamii, P. Mermod, W. Glöckle, Henryk Witała, Kenji Suda, P. U. Sauer, Yuji Tameshige, Kentaro Yako, M. B. Greenfield, M. Hatano, J. Rapaport, T. Saito, Y. Shimizu, Yasuhiro Sakemi, H. Kuboki, Andreas Nogga, Masaki Sasano, A. C. Fonseca, Junichiro Kamiya, Katsumasa Fujita, Yusuke T. Maeda, and Hiroyuki Kamada
- Subjects
Nuclear physics ,Elastic scattering ,Physics ,Nuclear and High Energy Physics ,Cover (topology) ,Scattering ,Nuclear Theory ,Coulomb ,Nuclear cross section ,Scattering length ,Few-body systems ,Atomic physics ,Energy (signal processing) - Abstract
The differential cross sections and vector analyzing powers for $\mathit{nd}$ elastic scattering at ${E}_{n}=248$ MeV were measured for $10\ifmmode^\circ\else\textdegree\fi{}--180\ifmmode^\circ\else\textdegree\fi{}$ in the center-of-mass (c.m.) system. To cover the wide angular range, the experiments were performed separately by using two different setups for forward and backward angles. The data are compared with theoretical results based on Faddeev calculations with realistic nucleon-nucleon ($\mathit{NN}$) forces such as AV18, CD Bonn, and Nijmegen I and II, and their combinations with the three-nucleon forces (3NFs), such as Tucson-Melbourne 99 (TM99), Urbana IX, and the coupled-channel potential with \ensuremath{\Delta}-isobar excitation. Large discrepancies are found between the experimental cross sections and theory with only $2N$ forces for ${\ensuremath{\theta}}_{\mathrm{c}.\mathrm{m}.}g90\ifmmode^\circ\else\textdegree\fi{}$. The inclusion of 3NFs brings the theoretical cross sections closer to the data but only partially explains this discrepancy. For the analyzing power, no significant improvement is found when 3NFs are included. Relativistic corrections are shown to be small for both the cross sections and the analyzing powers at this energy. For the cross sections, these effects are mostly seen in the very backward angles. Compared with the $\mathit{pd}$ cross section data, quite significant differences are observed at all scattering angles that cannot be explained only by the Coulomb interaction, which is usually significant at small angles.
- Published
- 2007
41. PERFORMANCE EVALUATION OF NPOL AT RIKEN
- Author
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K. Suda, Kenjiro Miki, H. Kuboki, Shumpei Noji, Kimiko Sekiguchi, Takeo Kawabata, Hideyuki Sakai, and Kentaro Yako
- Published
- 2007
42. FOCAL PLANE POLARIMETER FOR A TEST OF EPR PARADOX
- Author
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H. Matsubara, Y. Satou, K. Sekiguchi, K. Itoh, K. Suda, N. Matsui, A. Tamii, Hideyuki Sakai, H. Kuboki, T. Saito, T. Ikeda, M. Sasano, K. Yako, Y. Maeda, T. Kawabata, and T. Uesaka
- Subjects
Physics ,Spectrum analyzer ,Optics ,Cardinal point ,Proton ,business.industry ,Scattering ,Scintillation counter ,Figure of merit ,Polarimeter ,business ,Spectrograph - Abstract
A proton polarimeter EPOL has been constructed at the focal plane of the spectrograph SMART at RIKEN. EPOL is designed for the test of EPR paradox in a two proton system by measuring the spin-correlation of the ' H ( d , p p [ ' S o ] ) n reaction at E d = 270 MeV. EPOL consists of a spin-analyzer target (graphite slab), plastic scintillation counter hodoscopes and multi-wire drift chambers. EPOL is capable of identifying the trajectories of two protons before and after scattering in the analyzer target. EPOL has been calibrated at Ep = 12&160 MeV. The effective analyzing power is 0.17-0.23 and the figure of merit is 0.7-2.6 x lop3, both of which increase with incident energy.
- Published
- 2007
43. Analyzing Power Measurement for Elastic Scattering of 6He on Polarized Protons
- Author
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Hideyuki Sakai, H. Okamura, T. Kawahara, Tomohiro Uesaka, K. Itoh, Yoshihiko Takahashi, M. Itoh, Taro Nakao, H. Kuboki, D. Suzuki, Takeo Kawabata, Kenji Suda, Masatoshi Yamaguchi, Hironori Iwasaki, Satoshi Sakaguchi, Kimiko Sekiguchi, M. Shinohara, R. Matsuo, Yoshiko Sasamoto, Yuichi Ichikawa, Y. Satou, Atsushi Tamii, Nori Aoi, Naoya Sakamoto, Yusuke T. Maeda, Masaki Sasano, Takashi Wakui, Y. Hashimoto, M. Ichikawa, and Kentaro Yako
- Subjects
Physics ,Elastic scattering ,Proton ,Nuclear Theory ,chemistry.chemical_element ,Polarization (waves) ,Magnetic field ,Low energy ,Recoil ,chemistry ,Low magnetic field ,Physics::Accelerator Physics ,Atomic physics ,Nuclear Experiment ,Helium - Abstract
Vector analyzing power was measured for the proton elastic scattering on 6He at 71 MeV/u. We applied a solid polarized proton target, which was operated in a low magnetic field of 88 mT and at high temperature of 100 K, to a radioactive‐isotope beam experiment. Low energy recoil protons were successfully detected due to the modest operation conditions of the target. Selection of p+6He elastic scattering events was clearly carried out with detected protons. Absolute values of the analyzing power were determined for the first time.
- Published
- 2007
44. Search for Narrow Dibaryon Resonances via the p + d Scattering
- Author
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T. Uesaka, H. Kuboki, S. Shimomoto, H. Sakai, M. Hatano, K. Sekiguchi, K. Fujita, T. Wakasa, K. Sagara, Y. Tameshige, M. Sasano, A. Tamii, K. Hatanaka, Y. Maeda, T. Kudoh, M. Shiota, Yasuhiro Sakemi, T. Saito, K. Yako, Yohei Shimizu, and J. Kamiya
- Subjects
Physics ,Nuclear physics ,Particle physics ,Scattering - Published
- 2007
45. Publisher’s Note: Spin Correlations of Strongly Interacting Massive Fermion Pairs as a Test of Bell’s Inequality [Phys. Rev. Lett.97, 150405 (2006)]
- Author
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Masaki Sasano, Kimiko Sekiguchi, K. Suda, T. Ikeda, Hideyuki Sakai, K. Itoh, Takeo Kawabata, Kentaro Yako, Yusuke T. Maeda, Atsushi Tamii, N. Matsui, Tomoki Saito, Y. Satou, H. Kuboki, Chary Rangacharyulu, and Tomohiro Uesaka
- Subjects
Physics ,Quantum nonlocality ,Bell state ,Local hidden variable theory ,Quantum mechanics ,General Physics and Astronomy ,Fermion ,Bell test experiments ,Quantum entanglement ,Quantum statistical mechanics ,Spin-½ - Published
- 2006
46. Spin Correlations of Strongly Interacting Massive Fermion Pairs as a Test of Bell’s Inequality
- Author
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Masaki Sasano, Hideyuki Sakai, Kentaro Yako, T. Saito, H. Kuboki, K. Itoh, T. Ikeda, Y. Satou, Takeo Kawabata, Kenji Suda, Kimiko Sekiguchi, Tomohiro Uesaka, Chary Rangacharyulu, Atsushi Tamii, N. Matsui, and Yusuke T. Maeda
- Subjects
Physics ,Bell's theorem ,Quantum mechanics ,Hidden variable theory ,Hadron ,General Physics and Astronomy ,High Energy Physics::Experiment ,Quantum Physics ,Fermion ,Quantum ,Isotopes of helium ,Randomness ,Spin-½ - Abstract
We report the results of the first-time test of the local hidden variable theories (Bell-Clauser-Horne-Shimony-Holt) involving strongly interacting pairs of massive spin 1/2 hadrons from the decay of short-lived (tau10;-21sec) 2He spin-singlet state, populated in the nuclear reaction 2H+;1H--;2He+n. The novel features of this experiment are (a) the use of an 'event-ready' [corrected] detector of nearly 100% efficiency to prepare an unbiased sample and (b) a focal-plane polarimeter of full 2pi sr acceptance with a random "post selection" of the reference axes. The spin-correlation function is deduced to be S[exp](pi/4)=2.83+/-0.24stat+/-0.07sys. This result is in agreement with nonlocal quantum mechanical prediction and it violates the Bell-CHSH inequality of |S|or=2 at a confidence level of 99.3%.
- Published
- 2006
47. Search for supernarrow dibaryons via thepd→ppXandpd→pdXreactions
- Author
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M. Hatano, T. Kudoh, M. Shiota, Yusuke T. Maeda, Tomohiro Uesaka, Kimiko Sekiguchi, Masaki Sasano, H. Kuboki, Junichiro Kamiya, Tomotsugu Wakasa, Yuji Tameshige, Kentaro Yako, T. Saito, K. Sagara, S. Shimomoto, Yuji Shimizu, Yasuhiro Sakemi, Kichiji Hatanaka, Hideyuki Sakai, Kunihiro Fujita, and Atsushi Tamii
- Subjects
Nuclear physics ,Physics ,Nuclear and High Energy Physics ,Meson ,Deuterium ,Mass spectrum ,Production (computer science) ,Atomic physics ,Resonance (chemistry) ,Particle identification - Abstract
Supernarrow dibaryons (SNDs) have been searched for by the $\mathit{pd}\ensuremath{\rightarrow}\mathit{ppX}$ and $\mathit{pd}\ensuremath{\rightarrow}\mathit{pdX}$ reactions at ${E}_{p}=295$ MeV over a mass range of 1898 to 1953 MeV, where three candidates of SNDs were found at the Moscow Meson Factory. The experiment was carried out at the Research Center for Nuclear Physics using a two-arm magnetic spectrometer system and a liquid deuterium target. A good mass resolution of 1 MeV and a low background condition were achieved. No resonance structure was observed in the missing mass spectra. Upper limits of the SND production cross section were determined.
- Published
- 2006
48. CONSTRUCTION OF POLARIZED PROTON TARGET AND FIRST EXPERIMENT WITH 6HE
- Author
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K. Suda, N. Aoi, Takaharu Onishi, T. Wakui, A. Tamii, M. Hatano, H. Iwasaki, K. Sekiguchi, K. Yako, T. Kawabata, H. Sakai, K. Itoh, T. Saito, T. Uesaka, Y. Yanagisawa, N. Sakamoto, H. Kuboki, T. Ikeda, and M. Sasano
- Subjects
Physics ,Nuclear magnetic resonance ,Proton ,Spin polarization ,Atomic physics - Published
- 2005
49. MEASUREMENTS OF n + d ELASTIC SCATTERING AT 250 MeV AND THE THREE-NUCLEON FORCES
- Author
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H. Okamura, H. Sakai, T. Kudoh, K. Itoh, Ỹ. Shimizu, M. B. Greenfield, Kichiji Hatanaka, Y. Nagasue, K. Fujita, Tomotsugu Wakasa, Yasuhiro Sakemi, Kenji Suda, M. Hatano, Junichiro Kamiya, Atsushi Tamii, Kimiko Sekiguchi, Kentaro Yako, Hiroyuki Kamada, H. Kuboki, Takeo Kawabata, Y. Hagiwara, T. Saito, Y. Maeda, and Masaki Sasano
- Subjects
Nuclear physics ,Elastic scattering ,Physics ,Scattering length ,Nucleon - Published
- 2005
50. TENSOR ANALYZING POWER OF THE 16O(d, 2He) REACTION AT 0 DEGREES AND STRUCTURE OF THE SPIN-DIPOLE RESONANCES
- Author
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H. Kuboki, K. Sekiguchi, K. Itoh, A. Tamii, M. Hatano, R. Suzuki, Y. Satou, T. Uesaka, K. Suda, H. Sakai, Y. Maeda, H. Okamura, T. Ikeda, N. Sakamoto, K. Yako, T. Saito, and H. Kumasaka
- Subjects
Physics ,Dipole ,Classical mechanics ,Condensed matter physics ,Structure (category theory) ,Tensor ,Spin (physics) ,Power (physics) - Published
- 2005
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