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Ohta T, Fujiwara M, Hotta T, Ide I, Ishizaki K, Kohri H, Yanai Y, Yosoi M. Monitoring the build-up of hydrogen polarization for polarized hydrogen-deuteride (HD) targets with nuclear magnetic resonance (NMR) at 17 T. THE REVIEW OF SCIENTIFIC INSTRUMENTS 2020; 91:095104. [PMID: 33003818 DOI: 10.1063/5.0005696] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/25/2020] [Accepted: 08/20/2020] [Indexed: 06/11/2023]
Abstract
We report on the frozen-spin polarized hydrogen-deuteride (HD) targets for photoproduction experiments at SPring-8/LEPS. Pure HD gas with a small amount of ortho-H2 (∼0.1%) and a very small amount of para-D2 (∼0.001%) was liquefied and solidified by liquid helium. The temperature of the produced solid HD was reduced to about 30 mK with a dilution refrigerator. A magnetic field (17 T) was applied to the HD to grow the polarization with the static method. After the aging of the HD at low temperatures in the presence of a high-magnetic field strength for three months, the polarization froze. Almost all ortho-H2 molecules were converted to para-H2 molecules. Most remaining para-D2 molecules were converted to ortho-D2 molecules. The para-H2 and ortho-D2 molecules exhibited weak spin interactions with the HD. If the concentrations of the ortho-H2 and para-D2 were reduced appropriately at the beginning of the aging process, the aging time can be shortened. We have developed a new nuclear magnetic resonance (NMR) system to measure the relaxation times (T1) of the 1H and 2H nuclei with two frequency sweeps at the respective frequencies of 726 MHz and 111 MHz and succeeded in the monitoring of the polarization build-up at decreasing temperatures from 600 mK to 30 mK at 17 T. Automatic NMR measurements with the frequency sweeps enabled us to omit the use of a manual tuning circuit and to remove magnetic field sweeps with eddy current heat. This technique enables us to optimize the concentration of the ortho-H2 and to efficiently polarize the HD target within a shortened aging time.
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Affiliation(s)
- T Ohta
- Department of Radiology, The University of Tokyo Hospital, Tokyo 113-8655, Japan
| | - M Fujiwara
- Research Center for Nuclear Physics, Osaka University, Ibaraki, Osaka 567-0047, Japan
| | - T Hotta
- Research Center for Nuclear Physics, Osaka University, Ibaraki, Osaka 567-0047, Japan
| | - I Ide
- Nagoya University, Chikusa-ku, Nagoya, Aichi 464-8602, Japan
| | - K Ishizaki
- Nagoya University, Chikusa-ku, Nagoya, Aichi 464-8602, Japan
| | - H Kohri
- Research Center for Nuclear Physics, Osaka University, Ibaraki, Osaka 567-0047, Japan
| | - Y Yanai
- Research Center for Nuclear Physics, Osaka University, Ibaraki, Osaka 567-0047, Japan
| | - M Yosoi
- Research Center for Nuclear Physics, Osaka University, Ibaraki, Osaka 567-0047, Japan
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5
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Kohri H, Shiu SH, Chang WC, Yanai Y, Ahn DS, Ahn JK, Chen JY, Daté S, Ejiri H, Fujimura H, Fujiwara M, Fukui S, Gohn W, Hicks K, Hosaka A, Hotta T, Hwang SH, Imai K, Ishikawa T, Joo K, Kato Y, Kon Y, Lee HS, Maeda Y, Mibe T, Miyabe M, Morino Y, Muramatsu N, Nakano T, Nakatsugawa Y, Nam SI, Niiyama M, Noumi H, Ohashi Y, Ohta T, Oka M, Parker JD, Rangacharyulu C, Ryu SY, Sawada T, Shimizu H, Strokovsky EA, Sugaya Y, Sumihama M, Tsunemi T, Uchida M, Ungaro M, Wang SY, Yosoi M. Differential Cross Section and Photon-Beam Asymmetry for the γ[over →]p → π^{-}Δ^{++}(1232) Reaction at Forward π^{-} Angles for E_{γ}=1.5-2.95 GeV. PHYSICAL REVIEW LETTERS 2018; 120:202004. [PMID: 29864366 DOI: 10.1103/physrevlett.120.202004] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/24/2018] [Revised: 03/11/2018] [Indexed: 06/08/2023]
Abstract
Differential cross sections and photon-beam asymmetries for the γ[over →]p→π^{-}Δ^{++}(1232) reaction have been measured for 0.7<cosθ_{π}^{c.m.}<1 and E_{γ}=1.5-2.95 GeV at SPring-8/LEPS. The first-ever high statistics cross-section data are obtained in this kinematical region, and the asymmetry data for 1.5<E_{γ}(GeV)<2.8 are obtained for the first time. This reaction has a unique feature for studying the production mechanisms of a pure uu[over ¯] quark pair in the final state from the proton. Although there is no distinct peak structure in the cross sections, a non-negligible excess over the theoretical predictions is observed at E_{γ}=1.5-1.8 GeV. The asymmetries are found to be negative in most of the present kinematical regions, suggesting the dominance of π exchange in the t channel. The negative asymmetries at forward meson production angles are different from the asymmetries previously measured for the photoproduction reactions producing a dd[over ¯] or an ss[over ¯] quark pair in the final state. Advanced theoretical models introducing nucleon resonances and additional unnatural-parity exchanges are needed to reproduce the present data.
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Affiliation(s)
- H Kohri
- Research Center for Nuclear Physics, Osaka University, Ibaraki, Osaka 567-0047, Japan
- Institute of Physics, Academia Sinica, Taipei 11529, Taiwan
| | - S H Shiu
- Institute of Physics, Academia Sinica, Taipei 11529, Taiwan
- Department of Physics, National Central University, Taoyuan City 32001, Taiwan
| | - W C Chang
- Institute of Physics, Academia Sinica, Taipei 11529, Taiwan
| | - Y Yanai
- Research Center for Nuclear Physics, Osaka University, Ibaraki, Osaka 567-0047, Japan
| | - D S Ahn
- RIKEN Nishina Center, 2-1 Hirosawa, Wako, Saitama 351-0198, Japan
| | - J K Ahn
- Department of Physics, Korea University, Seoul 02841, Republic of Korea
| | - J Y Chen
- Light Source Division, National Synchrotron Radiation Research Center, Hsinchu 30076, Taiwan
| | - S Daté
- Japan Synchrotron Radiation Research Institute, Sayo, Hyogo 679-5143, Japan
| | - H Ejiri
- Research Center for Nuclear Physics, Osaka University, Ibaraki, Osaka 567-0047, Japan
| | - H Fujimura
- Wakayama Medical College, Wakayama 641-8509, Japan
| | - M Fujiwara
- Research Center for Nuclear Physics, Osaka University, Ibaraki, Osaka 567-0047, Japan
- National Institutes for Quantum and Radiological Science and Technology, Tokai, Ibaraki 319-1195, Japan
| | - S Fukui
- Research Center for Nuclear Physics, Osaka University, Ibaraki, Osaka 567-0047, Japan
| | - W Gohn
- Department of Physics, University of Connecticut, Storrs, Connecticut 06269-3046, USA
| | - K Hicks
- Department of Physics and Astronomy, Ohio University, Athens, Ohio 45701, USA
| | - A Hosaka
- Research Center for Nuclear Physics, Osaka University, Ibaraki, Osaka 567-0047, Japan
| | - T Hotta
- Research Center for Nuclear Physics, Osaka University, Ibaraki, Osaka 567-0047, Japan
| | - S H Hwang
- Korea Research Institute of Standards and Science (KRISS), Daejeon 34113, Republic of Korea
| | - K Imai
- Advanced Science Research Center, Japan Atomic Energy Agency, Tokai, Ibaraki 319-1195, Japan
| | - T Ishikawa
- Research Center for Electron Photon Science, Tohoku University, Sendai, Miyagi 982-0826, Japan
| | - K Joo
- Department of Physics, University of Connecticut, Storrs, Connecticut 06269-3046, USA
| | - Y Kato
- Kobayashi-Maskawa Institute, Nagoya University, Nagoya, Aichi 464-8602, Japan
| | - Y Kon
- Research Center for Nuclear Physics, Osaka University, Ibaraki, Osaka 567-0047, Japan
| | - H S Lee
- Rare Isotope Science Project, Institute for Basic Science, Daejeon 34047, Korea
| | - Y Maeda
- Proton Therapy Center, Fukui Prefectural Hospital, Fukui 910-8526, Japan
| | - T Mibe
- High Energy Accelerator Organization (KEK), Tsukuba, Ibaraki 305-0801, Japan
| | - M Miyabe
- Research Center for Electron Photon Science, Tohoku University, Sendai, Miyagi 982-0826, Japan
| | - Y Morino
- High Energy Accelerator Organization (KEK), Tsukuba, Ibaraki 305-0801, Japan
| | - N Muramatsu
- Research Center for Electron Photon Science, Tohoku University, Sendai, Miyagi 982-0826, Japan
| | - T Nakano
- Research Center for Nuclear Physics, Osaka University, Ibaraki, Osaka 567-0047, Japan
| | - Y Nakatsugawa
- High Energy Accelerator Organization (KEK), Tsukuba, Ibaraki 305-0801, Japan
| | - S I Nam
- Department of Physics, Pukyong National University (PKNU), Busan 608-737, Republic of Korea
| | - M Niiyama
- Department of Physics, Kyoto University, Kyoto 606-8502, Japan
| | - H Noumi
- Research Center for Nuclear Physics, Osaka University, Ibaraki, Osaka 567-0047, Japan
| | - Y Ohashi
- Japan Synchrotron Radiation Research Institute, Sayo, Hyogo 679-5143, Japan
| | - T Ohta
- Research Center for Nuclear Physics, Osaka University, Ibaraki, Osaka 567-0047, Japan
| | - M Oka
- Research Center for Nuclear Physics, Osaka University, Ibaraki, Osaka 567-0047, Japan
| | - J D Parker
- Department of Physics, Kyoto University, Kyoto 606-8502, Japan
| | - C Rangacharyulu
- Department of Physics and Engineering Physics, University of Saskatchewan, Saskatoon, Saskatchewan S7N 5E2, Canada
| | - S Y Ryu
- Research Center for Nuclear Physics, Osaka University, Ibaraki, Osaka 567-0047, Japan
| | - T Sawada
- Institute of Physics, Academia Sinica, Taipei 11529, Taiwan
- Physics Department, University of Michigan, Michigan 48109-1040, USA
| | - H Shimizu
- Research Center for Electron Photon Science, Tohoku University, Sendai, Miyagi 982-0826, Japan
| | - E A Strokovsky
- Research Center for Nuclear Physics, Osaka University, Ibaraki, Osaka 567-0047, Japan
- Joint Institute for Nuclear Research, Dubna, Moscow Region 142281, Russia
| | - Y Sugaya
- Research Center for Nuclear Physics, Osaka University, Ibaraki, Osaka 567-0047, Japan
| | - M Sumihama
- Department of Education, Gifu University, Gifu 501-1193, Japan
| | - T Tsunemi
- Department of Physics, Kyoto University, Kyoto 606-8502, Japan
| | - M Uchida
- Department of Physics, Tokyo Institute of Technology, Tokyo 152-8551, Japan
| | - M Ungaro
- Department of Physics, University of Connecticut, Storrs, Connecticut 06269-3046, USA
| | - S Y Wang
- Institute of Physics, Academia Sinica, Taipei 11529, Taiwan
| | - M Yosoi
- Research Center for Nuclear Physics, Osaka University, Ibaraki, Osaka 567-0047, Japan
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7
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Kohri H, Ahn DS, Ahn JK, Akimune H, Asano Y, Chang WC, Daté S, Ejiri H, Fukui S, Fujimura H, Fujiwara M, Hasegawa S, Hicks K, Hosaka A, Hotta T, Imai K, Ishikawa T, Iwata T, Kawai H, Kim ZY, Kino K, Kumagai N, Makino S, Matsuda T, Matsumura T, Matsuoka N, Mibe T, Miyabe M, Miyachi Y, Morita M, Muramatsu N, Nakano T, Nam SI, Niiyama M, Nomachi M, Ohashi Y, Ohkuma H, Ooba T, Oshuev DS, Rangacharyulu C, Sakaguchi A, Sasaki T, Shagin PM, Shiino Y, Shimizu A, Shimizu H, Sugaya Y, Sumihama M, Titov AI, Toi Y, Toyokawa H, Wakai A, Wang CW, Wang SC, Yonehara K, Yorita T, Yoshimura M, Yosoi M, Zegers RGT. Near-threshold Lambda(1520) production by the gamma(p)-->K{+}Lambda(1520) reaction at forward K+ angles. PHYSICAL REVIEW LETTERS 2010; 104:172001. [PMID: 20482102 DOI: 10.1103/physrevlett.104.172001] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/30/2009] [Indexed: 05/29/2023]
Abstract
Differential cross sections and photon-beam asymmetries for the gamma(p)-->K{+}Lambda(1520) reaction have been measured with linearly polarized photon beams at energies from the threshold to 2.4 GeV at 0.6<cos(theta){c.m.}{K}<1. A new bump structure was found at W approximately 2.11 GeV in the cross sections. The bump is not well reproduced by theoretical calculations introducing a nucleon resonance with J<or=3/2. This result suggests that the bump might be produced by a nucleon resonance possibly with J>or=5/2 or by a new reaction process, for example, an interference effect with the phi photoproduction having a similar bump structure in the cross sections.
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Affiliation(s)
- H Kohri
- Research Center for Nuclear Physics, Osaka University, Ibaraki, Osaka 567-0047, Japan
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8
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Hicks K, Keller D, Kohri H, Ahn DS, Ahn JK, Akimune H, Asano Y, Chang WC, Daté S, Ejiri H, Fukui S, Fujimura H, Fujiwara M, Hasegawa S, Hotta T, Imai K, Ishikawa T, Iwata T, Kato Y, Kawai H, Kim ZY, Kino K, Kumagai N, Makino S, Matsuda T, Matsumura T, Matsuoka N, Mibe T, Miyabe M, Miyachi Y, Morita M, Muramatsu N, Nakano T, Niiyama M, Nomachi M, Oh Y, Ohashi Y, Ohkuma H, Ooba T, Parker J, Rangacharyulu C, Sakaguchi A, Sasaki T, Shagin PM, Shiino Y, Shimizu A, Shimizu H, Sugaya Y, Sumihama M, Toi Y, Toyokawa H, Wakai A, Wang CW, Wang SC, Yonehara K, Yorita T, Yoshimura M, Yosoi M, Zegers RGT. Cross sections and beam asymmetry for K;{+}Sigma;{*-} photoproduction from the deuteron at E_{gamma}=1.5-2.4 GeV. PHYSICAL REVIEW LETTERS 2009; 102:012501. [PMID: 19257183 DOI: 10.1103/physrevlett.102.012501] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/19/2008] [Indexed: 05/27/2023]
Abstract
The Sigma(1385) resonance, or Sigma;{*}, is well known as part of the standard baryon decuplet with spin J=3/2. Measurements of the reaction gammap-->K;{+}Sigma;{*0} are difficult to extract due to overlap with the nearby Lambda(1405) resonance. However, the reaction gamman-->K;{+}Sigma;{*-} has no overlap with the Lambda(1405) due to its charge. Here we report the first measurement of cross sections and beam asymmetries for photoproduction of the Sigma;{*-} from a deuteron target. The cross sections at forward angles range from 0.4 to 1.2 mub, with a broad maximum near E_{gamma} approximately 1.8 GeV. The beam asymmetries are negative, in contrast with positive values for the gamman-->K;{+}Sigma;{-} reaction.
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Affiliation(s)
- K Hicks
- Department of Physics and Astronomy, Ohio University, Athens, Ohio 45701, USA
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