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利用同位旋相关的量子分子动力学模型,研究了112Sn+112Sn和124Sn+124Sn两反应系统在不同入射能量、不同碰撞参数、不同势场和不同核子-核子碰撞截面下的粒子发射特征.阐述了发射体系的同位旋对轻粒子产额比的影响.发现轻粒子产额比是同位旋的敏感观测量.另外,还发现中快度区发射的粒子有更高的丰中子程度.同时,轻粒子的比不敏感于核子核子碰撞截面,而敏感于核态方程,这使得从轻粒子比提取同位旋相关的核态方程变成一种可能.
关键词:
同位旋相关的量子分子动力学
同位旋效应
轻粒子产额比 相似文献
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在稀土区奇奇核πh11/2νi13/2转动带中,系统地观测到随转动频率或角动量增加,B(M1)/B(E2)曲线表现出所谓parabola like形状,即在增加到某一转动频率或自旋后,B(M1)/B(E2)比值快速增强。基于推转模型和粒子转子模型关于奇奇核二准粒子转动带磁偶极约化跃迁几率的描述,对稀土区双奇核的这一行为进行了讨论。指出该现象的发生与νi13/2准中子转动顺排特性密切相关。B(M1)/B(E2)比值在接近第二带交叉(即BC准中子对顺排)的较高频率处的增强效果,可以理解为主要来源于带交叉引起的波函数中混合四准粒子成分的结果。通过对B(M1)/B(E2)比值的增强效果发生在较低频率处的分析,对稀土区奇奇核πh11/2νi13/2带角动量耦合图像有了进一步认识。 相似文献
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通过熔合蒸发反应181Ta(16O,5n)192Tl,在入射束流为97 MeV能量下,布居192Tl的高自旋态,更新了192Tl的能级纲图。共增加8条新能级,尝试性地指定了能级自旋,将负宇称晕带的能级推高到23-?。讨论了192Tl与相邻同位素奇奇核194,196,198Tl负宇称晕带的旋称劈裂与反转现象,发现随着中子数增加,196,198Tl在高自旋处出现了旋称反转,其原因可能是由于中子质子相互作用与科里奥利力相互竞争所致。High spin states of 192Tl were populated by the 181Ta(16O, 5n)192Tl heavy ion fusion evaporation reaction at 97 MeV beam energy. A new level scheme with 8 new levels was constructed and the level spins were tentatively assigned. The negative yrast band was extended up to 23-?. Systematics of signature of inversion were also discussed for the negative yrast band of odd-odd Tl istopes. Signature inversion has been found in 196,198Tl with neutron number increasing in these four Tl isotopes, and it is explained by the competition between the strength of n-p interaction and Coriolis force. 相似文献
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Low-lying states of ~(92,93)Nb excited in the reactions induced by the weakly-bound nucleus ~6Li near the Coulomb barrier
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Yi-Feng Lv Jing-Bin Lu Gao-Long Zhang Yi-Heng Wu Cen-Xi Yuan Guan-Jian Fu Guang-Xin Zhang Zhen Huang Ming-Li Wang Shi-Peng Hu Hui-Bin Sun Huan-Qiao Zhang Cheng-Qian Li Ke-Yan Ma Ying-Jun Ma Yun-Zuo Liu D. Testov P. R. John J. J. Valiente-Dobon A. Goasduff M. Siciliano F. Galtarossa F. Recchia D. Mengoni D. Bazzacco 《中国物理C(英文版)》2019,43(10):104102-104102-9
Excited states of odd-odd nucleus ~(92)Nb and odd-A nucleus ~(93)Nb were populated in the 6 Li+ 89 Y reaction with an incident energy of 34 MeV. The processes that produce 92,~(93)Nb and can be measured by a combination of light charged particle and gamma ray measurements are discussed. Twenty new transitions are observed and eight new levels are constructed in ~(92)Nb, and in addition two new transitions are added to the level scheme of ~(93)Nb. Using shell2 model calculations, the low-lying structure of 9 Nb is investigated and compared with the experimental results. 相似文献
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《Physics letters. [Part B]》1987,195(2):111-115
The first calculation in IBFFM for both energy levels and electromagnetic properties is performed for the odd-odd nucleus 134Cs and compared to recent experimental data. 相似文献
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C. J. Lister B. J. Varley W. Fieber J. Heese K. P. Lieb E. K. Warburton J. W. Olness 《Zeitschrift für Physik A Hadrons and Nuclei》1988,329(4):413-427
We report on the first in-beam study of high spin levels in83Y which were established up to 9.0 MeV excitation energy and probable spin of 41/2+ resp. 27/2? by means of the reaction58Ni(28Si, 3p). Ten lifetimes and six lifetime limits in the 10?12–10?9 s range were determined in two recoil distance Doppler shift experiments. The positive parity yrast states form ag 9/2 Coriolis decoupled band with partial alignment, near-rigid rotor moment of inertia and deformationβ 2=0.29. The negative parity yrast band has very similar collective properties; it shows a pronounced band crossing at rotational frequency ?ω≈0.40 MeV which we associate with twoquasiparticleg 9/2 proton alignment. At 2.56 MeV excitation, a second ΔI=1 band starting with 17/2? was found. On the basis of the similarity to85Y and the very weakE2 decay of this state, we suggest that this band has (3qp) configuration with an alignedg 9/2 neutron pair. The lifetimes of the lowest 2+ and 4+ state in84Zr populated in the reaction58Ni (28Si, 2p) were determined to be τ(2)=17.8(11) ps resp. τ(4)=3.5(4) ps. 相似文献
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丰中子核91Y 的高自旋能级结构通过82Se(13C, p3n)91Y 反应被再次研究了。新建立的包含几条关键能级的能级纲图澄清了以前研究中的几点不确定的地方。这几条能级具有Z=38 和N=56 子闭壳打破的特征,这涉及到张量力和自旋-同位旋依赖的中心力。High-spin level structure of the neutron-rich nucleus 91Y has been reinvestigated via the 82Se(13C, p3n)91Y reaction. A newly constructed level scheme including several key levels clarifies the uncertainties in the earlier studies. These levels are characterized by the breaking of the Z = 38 and N =56 subshell closures, which involves in tensor force and the spin-isospin dependent central force. 相似文献
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Experimental data on energy levels of the odd-odd deformed nucleus180Re obtained from radioactive-decay and heavy-ion reaction studies are analysed to deduce spin-parity and configuration assignments
for the six observed rotational bands based on the selection rules for fast beta transitions, criteria for the relative-energy
ordering of the triplet and singlet bandheads, two-particle-plus-rotor model calculations including Coriolis mixing, rotational
energy systematics involving staggering features, and considerations of gyromagnetic ratios, signature splittings and rotational
band alignments. 相似文献
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V. I. Isakov K. I. Erokhina H. Mach B. Fogelberg A. Korgul K. A. Mezilev E. Ramström 《Physics of Atomic Nuclei》2007,70(5):818-826
Detailed theoretical calculations of the properties of the neutron-excess odd-odd nucleus 134Sb are performed by using different theoretical approaches. A comprehensive comparison with the recent experimental data is
performed; this comparison suggests the presence of isomeric states among the low-lying levels of this nucleus. These states
are the twins of the corresponding levels of the odd-odd nucleus 210Bi that is situated near the stability line. The obtained results manifest the similarity of nuclear structure in the region
of the “remote” doubly magic nucleus 132Sn and in the region of the classical stable doubly magic nucleus 208Pb.
The text was submitted by the authors in English. 相似文献
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References: 《理论物理通讯》2007,47(2):303-308
The level density parameter and the back shift energy E1 are determined for nuclei with A-values across the whole periodic table from fits to complete level schemes at low excitation energy near the neutron binding energies.We find that the energy back shift E1 shows complicated behavior and depends on the type of the nucleus,even-even,odd mass,and odd-odd.The spin cut-off factor has also been investigated for nuclei mentioned above.The results arecompared with the previous results and different experimental data on level densities. 相似文献
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S. Brant V. Paar G. Lhersonneau O. W. B. Schult H. Seyfarth K. Sistemich 《Zeitschrift für Physik A Hadrons and Nuclei》1989,334(4):517-518
Extrapolating the Interacting Boson-Model treatment from lighter neighbours to98Y we predict the properties of low-lying states of spherical nature in IBFFM. This odd-odd nucleus which presents one of the rare cases of coexisting spherical and deformed shapes is of fundamental importance for understanding nuclear phase transitions. 相似文献