偶偶No同位素转动性质研究(英文)

通过总Routhian 面计算方法研究了Z = 102 号元素已实验合成的偶偶248-264No同位素的转动性质。计算的基态形变β2,β4 与前人的计算相符。252,245No 两核基态带的转动惯量特征能得到基本再现。偶偶248-264No同位素转动惯量系统上弯的现象可归因于带交叉。研究还表明,推转时质子与中子顺排有强烈竞争,在较轻的No同位素中j_15/2 中子拆对顺排较为优先,而在较重的No 核中i_13/2 质子顺排更加优先。The rotational properties of the synthesized even-even 248-264No isotopes have been investigated by means of total Routhian surface calculations. The calculated ground-state properties (e.g. β2; β4) are in agreement with previous calculations. The behaviors of moment of inertia of 252,254No are well reproduced by our calculations. The systematic upbending in moment of inertia is attributed to band crossing. It is found that the j_15/2 neutron rotation-alignment is preferred for the lighter No isotopes, but the i_13/2 proton alignment is favored in the heavier ones.     

Investigations on Different Decay Modes of Darmstadtium

Physics of Particles and Nuclei Letters - We have studied the competition between different decay modes such as binary, ternary, cluster radioactivity and alpha decay. The competition between...     

Bi同位素链上原子核α衰变性质的理论研究

采用结团模型(clustermodel)计算了从10752Te到292116共443个核素α衰变的半衰期,所得结果与实验值符合得很好,显示了结团模型可以成功地应用于研究原子核α衰变的性质。同时研究了Bi同位素链上奇A核α衰变的半衰期,计算结果与已有的实验值的偏差一般在3倍以内,进而对实验上未知α衰变半衰期的原子核的性质进行了预言。这有助于将来在实验室探测与鉴别这些原子核以及研究它们的α衰变性质。理论与实验的比较将加深人们对原子核结构的认识。     

76Ge的2νββ衰变寿命和矩阵元

利用76Ge的壳模型波函数计算76Ge的2νββ衰变矩阵元和寿命.结果可以与最近观察到的76Ge的2νββ衰变寿命相比拟.进而从最近的0νββ衰变的实验寿命可以算出有效中微子质量上限是0.4eV.     

利用有效液滴模型对超重元素α衰变半衰期的研究

利用有效液滴模型计算了偶偶超重核的α衰变半衰期,计算过程中采用了保持碎片体积守恒的不对称形状描述以及有效惯性系数计算Gamow势垒穿透因子.首先在质子数Z为88—98的区域检验了有效液滴模型,发现计算结果与实验符合得比较好.随后将此模型推广到Z≥100的情况,虽然只用了两个模型参数,计算结果与实验数据符合,说明有效液滴模型是计算偶偶超重核素α衰变半衰期的一个成功模型.     

Alpha Decay of the Neutron-deficient Isotopes 215,216U

The most neutron-deficient isotopes 215;216U were produced in the complete-fusion reaction 180W(40Ar, 4-5n)215,216U. Evaporation residues recoiled from the target were separated in-flight from the primary beam by the gas-filled recoil separator SHANS and subsequently identified on the basis of correlated -decay chains. Two -decaying states were identified in 216U, one for the ground state and the other for the isomeric state with 8+(h9=2f7=2) configuration. The -decay properties for 215;216U and the systematics of 8+ isomeric state in N =124,126 isotones were investigated.     

Investigation of Technivector Mesons Decay

The interaction vertices of the couplings of technivector mesons to the pseudoscalar mesons are derived from effective Lagrangian.We discuss all possible decay modes of neutral vector mesons and compute various decay factors.     

Calculation of η′ Decay Modes Using Chiral Perturbation Theory

In this paper, with the use of Chiral Perturbation theory (χPT), we have studied the η′ decays in to 3π and 2πη, after performing these reactions. The Scattering amplitude and decay width are calculated for different modes up to NLO. The Dalitz plot expansion and parameter fixing for each of them is also calculated. Experimental results are in good agreement with the obtained results. We compare our results with charged and neutral decay parameters with the most recent Particle Data Group results of these observables. At next-to-leading order, our results for decay widths of the charged (neutral) channel are Γ(η′→2πη)=83.6±0.8 (43.0±2.2) keV and Γ(η′→3π)=0.716±0.072 (0.320±0.079) keV. These results are in agreement with several other theoretical determinations and experimental findings.     

Decay Analysis of Ge Isotopes Formed in Reactions Induced by Tightly and Loosely Bound Projectiles

The dynamical cluster-decay model (DCM) is employed to investigate the decay of ^68,70Ge^* compound nuclei formed respectively via tightly (⁴He) and loosely (⁶He) bound projectiles, using ⁶⁴Zn target. The study is carried out over a wide energy range (E_c.m.~5 MeV to 16 MeV) by including the quadrupole deformations (β2i) and optimum orientations (θ_i^opt) of the decaying fragments. The fusion cross-sections, obtained by adding various evaporation channels show nice agreement with the experimental data for ⁴He+⁶⁴Zn reaction. The contribution from competing compound inelastic scattering channel is also analyzed particularly for ⁶⁸Ge^* nucleus at above barrier energies. On the other hand, the decrement in the fusion cross-sections of ⁷⁰Ge^* nuclear system is addressed by presuming that ⁶⁵Zn ER is formed via two different modes:(i) the αn evaporation of ⁷⁰Ge^* nucleus, and (ii) 1n-evaporation of ⁶⁶Zn^* nuclear system, formed via breakup and 2n-transfer channels due to halo structure of the ⁶He projectile. Besides this, the suppression in 2np evaporation cross-sections suggests the contribution of another breakup and transfer process of ⁶He i.e. ⁴He+⁶⁴Zn. The contribution of breakup+transfer channels for ⁶He+⁶⁴Zn reaction is duly addressed by applying relevant energy corrections due to the breakup of " ⁶He" projectile into 2n and ⁴He. In addition to this, the barrier lowering, angular momentum and energy dependence effects are also explored in view of the dynamics of chosen reactions.     

Quasi-Normal Modes and Exponential Energy Decay for the Kerr-de Sitter Black Hole

We provide a rigorous definition of quasi-normal modes for a rotating black hole. They are given by the poles of a certain meromorphic family of operators and agree with the heuristic definition in the physics literature. If the black hole rotates slowly enough, we show that these poles form a discrete subset of \mathbb C{\mathbb C} . As an application we prove that the local energy of linear waves in that background decays exponentially once orthogonality to the zero resonance is imposed.     

Probable Decay Modes at Limits of Nuclear Stability of the Superheavy Nuclei

The modes of decay for the even–even isotopes of superheavy nuclei of Z = 118 and 120 with neutron number 160 ≤ N ≤ 204 are investigated in the framework of the axially deformed relativistic mean field model. The asymmetry parameter η and the relative neutron–proton asymmetry of the surface to the center (R _η ) are estimated from the ground state density distributions of the nucleus. We analyze the resulting asymmetry parameter η and the relative neutron–proton asymmetry R _η of the density play a crucial role in the mode(s) of decay and its half-life. Moreover, the excess neutron richness on the surface, facets a superheavy nucleus for β^? decays.     

超重核292-310122同位素链的α衰变和自发裂变的竞争

基于推广的液滴模型(GLDM) 理论框架,计算了292-310122 同位素链的 衰变和自发裂变的半衰期。计算时的基本输入量为两子核的质量数和电荷数以及反应Q 值。GLDM能很好地描述重核和超重核的 衰变和自发裂变过程。计算结果表明,A < 308 时在同位素链上N = 176~184 的区域α衰变为主要衰变模式。A > 308 时在同位素链上自发裂变为主要衰变模式。308122 是α衰变和自发裂变的分界点,暗示着N = 184 为中子幻数。Based on the framework of the Generalized Liquid Droplet Model (GLDM), alpha decay and spontaneous fission half-lives for 292-310122 isotopes are studied. The calculation of the basic inputs which only need the two fragmentmass numbers, charge numbers and the Q value. GLDM can describe alpha decay and spontaneous fission the nuclei. It is found that the alpha decay is the dominant mode of decay for isotopes with mass number A < 308, and for those with A > 308 spontaneous fission is dominant. The demarcation between alpha decay and spontaneous fission is at 308122, which shows the presence of a spherical neutron shell closure at N = 184.     

弹剩余核衰变模式间竞争及其在ALADIN数据中的呈现

首次分析了ALADIN多重碎裂数据(An(600MeV/u)+Cu实验)中呈现的弹剩余核衰变模式相对产额随bound>的变化规律,它和非完全熔合碎裂模型的理论结果定性一致.实验与理论的衰变模式相对产额图、Dalitz图、Campi图以及理论的热力学温度图,都很好地呈现出弹剩余核的衰变模式随bound>的减小而竞争和转换的过程.     

冲击加载下20钢中弹性前驱波衰减与应力松弛行为实验研究

 通过改变样品厚度，对平面冲击加载下20钢的弹性前驱波的波幅衰减和应力松弛进行了实验研究。采用激光速度干涉测速仪（VISAR）实测了样品后自由面速度历史，采样频率达到1 ns，保证了实验结果的准确性。实验结果显示：Hugoniot弹性极限随着传播距离呈指数衰减，在所研究的样品厚度范围内，Hugoniot弹性极限减小了44%；应力松弛行为和弹性前驱波的上升沿时间也依赖于传播距离；冲击加载的强度对材料动态屈服行为的影响很小。     

Investigation of Even-Even Ru Isotopes in Interacting Boson Model-2

The interacting boson model of Arima, Iachello, and co-workers is applied to the even ruthenium isotopes, ^96 Ru -116Ru. Excitation energies, electromagnetic transition strengths, quadrupole and magnetic dipole moments, and △（E2/M1） mixing ratios have been described systematically. Mixed symmetry states are investigated. It is seen that the properties of low-lying levels in these isotopes, for which the comparison between experiment and theory is possible, can be satisfactorily characterized by the Interacting Boson Model-2.     

Investigation of Even-Even Ru Isotopes in Interacting Boson Model-2

The interacting boson model of Arima, Iachello, and co-workers is applied to the even ruthenium isotopes,96 Ru ～ 116Ru. Excitation energies, electromagnetic transition strengths, quadrupole and magnetic dipole moments, and △(E2/M1) mixing ratios have been described systematically. Mixed symmetry states are investigated. It is seen that the properties of low-lying levels in these isotopes, for which the comparison between experiment and theory is possible,can be satisfactorily characterized by the Interacting Boson Model-2.     

Xe偶－偶同位素低激发态性质的IBM2描述

通过考虑同类核子相干对Ｓρ、Ｄρ间的四极相互作用，在ＩＢＭＺ中对Ｘｅ偶一偶同位素１１６Ｘｅ—１３２Ｘｅ的低激发态能谱和Ｅ２跃过几率进行了理论分析．计算结果有效地改善了ＩＢＭ中这些核的准γ带能谱的Ｓｔａａｓｅｒｉｎｇ现象，较精确地描述了实验观察到的低激发态的性质．     

Strong Interference Luminescence of Mixed Modes in the Neighborhood of the Critical Value of Exciton Decay

Optics and Spectroscopy - The results of a numerical calculation of the dispersion and luminescence spectra of mixed exciton modes of crystals of the CdS ( $${{A}_{{n = 1}}}$$ ) type are analyzed...