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1.
133Sm was produced via fusion evaporation in the reaction 40Ca+96Ru. Its β-delayed proton decay was studied by means of “p-γ” coincidence in combination with a He-jet tape transport system, including half-lives, proton energy spectra, γ-transitions following the proton emissions, and the branching ratios to the low-lying states in the grand-daughter nuclei. The possible spins and parities of 133Sm were extracted by fitting the experimental data with a statistical model calculation. The configuration-constrained nuclear potential energy surfaces of 133Sm were calculated by using the Woods-Saxon Strutinsky method. Comparing the experimental and calculated results, the spins and parities of 133Sm were assigned to be 5/2+ and 1/2-, which is reconciled with our published simple (EC+β+) decay scheme of 133Sm in 2001. In addition, our experimental data on the beta-delayed proton decay of 149Yb reported in Eur. Phys. J., 2001, A12: 1—4 was also analyzed by using the same method. The spin and parity of 149Yb was assigned to be 1/2-. 相似文献
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MA Fei ZHOU Xiao-Hong ZHENG Yong XU Shu-Wei XIE Yuan-Xiang CHEN Liang ZHANG Yu-Hu LI Zhan-Kui QIANG Yun-Hua LEI Xiang-Guo GUO Ying-Xiang GUO Song DING Bing WANG Hai-Xia LI Guang-Shun ZHOU Hou-Bing 《中国物理快报》2010,27(6):59-61
The β-delayed proton decay of 147Er is studied experimentally using the 58 Ni+92Mo reaction at a beam energy of 383 MeV. Based on a He-jet apparatus coupled with a tape transport system, the β-delayed proton radioactivities both from the vδl/2 ground state and the vh11/2 isomer in 147 Er are identified by proton-7 coincidence measurements. By analyzing the time distribution of the 4+ → 2+-γ transition in the grand-daughter nucleus 146Dy, a half-life of 1.6 ± 0.2s is determined for the Vh11/2 isomer in 147 Er. The half-life for the ground state of 147Er is estimated to be 3.2±1.2 s. 相似文献
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XU Shu-Wei XIE Yuan-Xiang XING Ye-Bing XU Fu-Rong LIU Hong-Liang LI Zhan-Kui 《中国物理C(英文版)》2006,30(6):526-529
140Tb and 141Dy were produced via fusion evaporation in the reaction 40Ca+106Cd. Their β-delayed proton decays were studied by means of “p-γ” coincidence in combination with a He-jet tape transport system, including half-lives, proton energy spectra, γ-transitions following the proton emissions, and the branching ratios to the low-lying states in the grand-daughter nuclei. The ground-state spins and parities of 140Tb and 141Dy were extracted as 7± and 9/2±, respectively, by fitting the experimental data with a statistical model calculation. The configuration-constrained nuclear potential energy surfaces (NPES) of 140Tb and 141Dy were calculated by using the Woods-Saxon Strutinsky method, which indicate the ground-state spins and parities of 140Tb and 141Dy to be 7+and 9/2-, respectively. In addition, the configuration-constrained NPES of 143Dy was also calculated by using the same method. From the NPES a 1/2+ ground state and a 11/2- isomer with the excitation energy of 198keV were found. The calculated results are consistent with our experimental data on the decay of 143Dy reported in Eur. Phys. J., 2003, A16: 347—351. 相似文献
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YU Yong XIE Yuan-Xiang XU Shu-Wei LI Zhan-Kui PAN Qiang-Yan WANG Chun-Fang XING Jian-Ping ZHANG Tian-Mei 《中国物理C(英文版)》2001,25(2):108-114
Isotopes,130Nd and 140Tb were produced using enriched targets 96Ru and 106Cd, respectively,bombarded by 36Ar ion beam. The two nuclides were identified and studied by a He-jet tape transport system in combination with "X-γ" and "γ-γ" coincidence measure- ments. The half-life of 130Nd was determined to be (13±2)s. The EC/β+ decay scheme of 130Nd was proposed for the first time, and the spins and parties of the ground-state and observed low-lying states in the daughter nucleus 130Pr were speculated tentatively. The previous simple EC/β+ decay scheme of 140Tb was revised, and the spin-parity of its groundstate was assigned to be 7+. 相似文献
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Zhankui Li Shuwe Xui Yuanxiang Xie Yong Yu Chunfang Wang Ianping Xing Qiangyan Pan Qingyuan Hu Shihong Li Hongyan Chen Tianmei Zhang 《The European Physical Journal A - Hadrons and Nuclei》1999,5(4):351-352
A #-delayed proton activity with a half-life of 1.2 - 0.2 s was assigned to 89Ru on the basis of a p-%(X) coincidence measurement in the reaction of 58Ni (36Ar, 2p3n ) using a He-jet tape transport system. The measured delayed-proton spectrum of 89Ru and relative proton branching ratios to the low-lying states in 88Mo were compared with statistical model calculations. 相似文献
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XIE YuanXiang XU ShuWei Li ZhanKui YU Yong PAN QiangYan WANG ChunFang ZHANG TianMei LONG GuiLu LI YanSong 《中国物理C(英文版)》2000,24(8):719-724
130Pm and 128 Pr were produced by irradiation of 96Ru with 171MeV 36Ar beam,and a He-jet recoil tape transport system transported radioactivities to shielded reigon. Based on X-γ-t and γ-γ-t coincidence measurements ,the (EC+β+)decay scheme of 130Pm was proposed for the first time and the (EC+β+)decay scheme of 128Pr was revised. 相似文献
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LOU Jian-Ling LI Zhi-Huan YE Yan-Lin JIANG Dong-Xing HUA Hui LI Xiang-Qing ZHANG Shuang-Quan ZHENG Tao GE Yu-Chen KONG Zan LV Lin-Hui LI Chen LU Fei FAN Feng-Ying LI Zhong-Yu CAO Zhong-Xin MA Li-Ying Faisal XU Hu-Shan HU Zheng-Guo WANG Meng LEIXiang-Guo DUAN Li-Min XIAO Zhi-Gang ZHAN Wen-Long XIAO Guo-Qing HUANG Tian-Heng FU Fen ZHANG Xue-Heng ZHENG Chuan YU Yu-Hong TU Xiao-Lin ZHANG Ya-Peng YANG Yan-Yun ZHANG Hong-Bin TANG Bin TIAN Yu-Lin OU Yang-Zhen HUANG Mei-Rong XU Zhi-Guo YUE Ke GAO Qi 《中国物理快报》2008,25(6):1992-1995
The β-delayed neutron and γ energy spectra taken from the decay of neutron-rich nucleus 21N were measured by using the β-γ and β-n coincidence detection method. Thirteen new neutron groups ranging from 0.28MeV to 4.98MeV and with a total branching ratio of 88.7±4.2% were observed andpresented. One γ transition with an energy of 1222keV emitted from the excited state of 21O, and four γ transitions with energies of 1674, 2397, 2780, and 3175keV emitted from the excited states of 20O were identified in the β decay chain of 21N. The β decay half-life for 21N is determined to be 82.9±1.9ms. The uncertainty of half-life is much smaller than the previous result. 相似文献
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WANG Xu-Dong XIE Yuan-Xiang XU Shu-Wei LI Zhan-Kui GUO Bin LENG Chang-Geng WANG Chun-Fang YU Yong 《中国物理C(英文版)》2002,26(8):797-802
By irradiation of an enriched target of 96Ru with 40Ca and using a helium-jet fast tape transport system in combination with X-γ and γ-γ coincidence measurements,the very neutron deficient isotope 133Sm was produced and studied. A simple(EC+β+) decay scheme of Sm is proposed for the first time. A by product 133Pr was produced simultaneously because of the 98-102Ru contents of the ruthenium target. The half-life of an 11/2- low-lying isomeric state in 133Pr has been measured to be (1.1±0.2)s. Using single-particle model,the reduced transition probabilities of the 11/2- isomers in 131,133,135,137Pr are extracted from their experimental half-lives and compared with the Weisskopf estimate. 相似文献
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WANG Hong-Wei WU He-Yu JIN Gen-Ming ZHANG Bao-Guo XIAO Zhi-Gang DUAN Li-Min WEI Zhi-Yong LI Zu-Yu LU Zhao-Hui LIU Yong-Ying CHEN Ke-Liang HU Rong-Jiang ZHU Hai-Dong CEN Ling WANG Su-Fang LI Xiang-Qing CHEN Tao HUA Hui 《中国物理C(英文版)》2001,25(8):731-735
Through the 20Na β+ 20Ne→16O+α process,the half-life and β+ delayed α decay spectrum of 20Na have been measured on the Radioactive Ion Beam Line in Lanzhou(RIBLL). The 20Na was identified through TOF-ΔE method and alpha particle was measured by four Si(Au) surface barrier detectors. The half life of 20 Na is(459±7)ms. Result shows that in addition to nine high excitation energy levels with Ed≥2.688MeV, three low excitation energy levels of 20Na with Ed=0.890 & 1.054,1.991,2.424 & 2.457MeV were observed in the experiment. The relative intensity for 1.991MeV level, a more important energy level in the center of mass system energy region from 1.6 to 2.5MeV obtained in this experiment is much higher than the existed one. We also obtained the relative intensities of the levels of Ed=0.890 & 1.054,2.424 & 2.457MeV. 相似文献
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Xu Xiaoji Hu Zhiqiang Guo Junsheng Ma Ruichang Liu Hongye Luo Yixiao Zhang Yuzhao Guo Tianrui Huang Wenxue Xu Lianlian 《中国物理C(英文版)》1994,18(8):680-686
The β-delayed α decay of 20Na was restudied using neon target bombarded by 25 and 35.5 MeV protons.In this experiment a newly developed particle-telescope system including a gas ionization chamber as a thin ΔE detector was used. Two new peaks,one at 0.695 MeV and other at 0.907 MeV, were observed for the first time in the charged particle spectra. Based on particle identification, branching ratio and life time measurement,it is believed that these new peaks result from β-delayed low energy αdecay of 20Na.The decay scheme and the low-lying level scheme of 20Na were thus revised.Its possible astrophysical implications were discussed. 相似文献
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BES Callaboration 《中国物理C(英文版)》2002,26(2):93-99
With 7.8 million produced J/ψ events collected by the BES detector at the BEPC, the decay J/ψ→Σ0Σ0 is analysed. The branching ratio is measured to be BR(J/ψ→Σ0Σ0)=(0.97±0.04±0.24)×10-3. The angular distribution is of the form dN dcosθ=N0(1+α cos2θ) with α value of -0.21±0.27±0.13. 相似文献
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Xie Yuanxiang Xu Shuwei Guo Yingxiang Ma Ruichang Ge Yuanxiu Li Zhankui Wang Chunfang Guo Bin Xing Jianping Zhang Tianmei Zhu Shaofei Xu Wang 《中国物理C(英文版)》1997,21(4):289-291
209Fr has been produced by irradiation of 197Au with 16O from SFC accelarator uia the fusion-evaporation 4n channel.The(EC+β+)decay of 209Fr has been studied by a He-jet tape transport system.The decay scheme is proposed for the first time based on γ-t,X-γ-t,γ-γ-t coincidece and γ-γ delay coincidence measurements,which takes account of 20 observed γ ray.Five members of low-lying states in 209Rn can be explained by the multi-plet [(210Rn2+)(νf5/2)-1].The branching ratio for(EC+β+) decay of 209Fr has been estimated experimentaly to be(3.0±1.5)%. 相似文献
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The basic process of an exotic decay mode namely β-delayed fission is simply introduced. The progress status of the study in the world is essentialized. The observation of β-delayed fission of 228Ac is reported. The radium was radiochemically separated from natural thorium. Thin Ra sources in which 228Ac was got through 228Ra →β-228Ac were prepared for observing fission fragments from β-delayed fission of 228Ac. They exposed to the mica fission track detectors, and measured by an HPGe γ-ray detector. The β-delayed fission events of 228Ac were observed and its β-delayed fission probability was found to be (5±2)×10-12. 相似文献
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楼建玲 李智焕 叶沿林 江栋兴 华辉 李湘庆 张双全 郑涛 葛愉成 孔赞 吕林辉 李琛 卢飞 范凤英 李忠宇 曹中鑫 马立英 Faisal 徐瑚珊 胡正国 王猛 雷相国 段利敏 肖志刚 黄天衡 付芬 章学恒 郑川 余玉洪 涂小林 张亚鹏 杨彦云 张宏斌 唐彬 田育林 欧阳珍 黄美容 徐治国 岳珂 高启 《中国物理 C》2008,32(Z2):41-43
The β-delayed neutron and γ spectra of neutron-rich nucleus 21N using β-γ and β-n coincidence measurements were presented in this paper. Thirteen new neutron groups ranging from 0.28 MeV to 4.98 MeV and with a total branching ratio 88.7±4.2% were observed. One γ transition among the excited states of 21O, and four γ transitions among the excited states of 20O were identified in the β decay chain of 21N. The ungated half-life of 83.8±2.1 ms was also determined for 21N. 相似文献
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WU Xiang-Yao LIU Xiao-Jing GONG Pi-Feng LI Qi-Lang SHI Zong-Hua GUO Yi-Qing 《中国物理C(英文版)》2006,30(11):1048-1052
In this paper, the D0→π-l+νl decay process is studied by applying light-cone QCD sum rules. The form factor of D→π transition is calculated by choosing a correlation function with a chiral current to eliminate the effect caused by the uncertainty of the twist-3 function of the pion. Therefore the calculated result of the form factor is improved, and the branching ratio of the D0→π-l+νl decay process is consistent with the new experimental data. 相似文献
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Previous experimental results of (EC+β+) decay for the medium-heavy nuclei reported by our group since 1996, including 153Er, 157Yb, 209Fr, 128Ce, 130Ce, and 128Pr have been briefly summarized. The observed low-lying states in their daughter nuclei have been reviewed in a systematic way and compared with different model calculations. Finally, some questions have been put forward for further study and discussion. 相似文献
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The coupling problem of the three different intermediate processes J/ψ→ωf2(1270),f2→π+π- and J/ψ→b1±(1235)π+,b1±→ωπ± included in the hadronic decay process J/ψ→ωπ+π- is discussed.The consideration of the coupling effect is very important for measuring the parameters of the resonances f2 and b1± and the helicity amplitude ratios of these reactions precisely. 相似文献