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基于Ru(Z=44)丰中子同位素中存在最大三轴形变的理论预言和实验证据,综述了近年来Rh(Z=45),Pd(Z=46),Ag(Z=47),Cd(Z=48)(质子数Z位于Ru,Z=44之上)及Zr(Z=40),Nb(Z=41),Mo(Z=42),Tc(Z=43)(质子数Z位于Ru,Z=44之下)的A～(100～126)丰中子同位素中关于三轴形变的形状变迁和形状共存系统性研究的重要进展。252Cf自发裂变瞬发γ射线γ-γ-γ三重符合、特别是新建立的γ-γ-γ-γ四重符合数据的系统观测和研究,在Ru,Pd,Cd和Nb丰中子同位素中显著扩展或首次观测到了一系列能带,为这个核区原子核形状的研究提供了新的、重要的实验数据。联系此前报道的有关进展,使用PES,TRS,PSM,CCCSM和SCTAC理论模型计算拟合新的实验数据,在该核区沿同中素和同位素链,并随自旋和激发能变化各自由度,跟踪原子核形状渐进变化,获得了新的系统性研究成果,显著扩展和深化了人们对原子核形状变迁和形状共存的认知。对于Ru及其上的Rh(Z=45),Pd(Z=46),Ag(Z=47)和Cd(Z=48)丰中子同位素的研究表明:Rh丰中子核具有比最大值稍小的三轴形变,γ=-28°,并在103–106Rh同位素链上鉴别出了手征对称破缺;在三轴形变核112Ru和114Pd(N=68)中发现了三轴原子核的摆动运动,该摆动运动也可能在114Ru(N=70)中存在;观察到了从具有最大三轴形变的110,112Ru中手征破缺到稍小三轴形变的112,114,116Pd中扰动的手征破缺的过渡;在较软的Ag核中观察到了丰富的谱学结构,在104,105Ag中鉴别出了可能的手征对称破缺,在较重的115,117Ag中提出了趋于三轴形变的γ软度;具有小形变的Cd核的能级结构被解释为准粒子耦合、准转动和软三轴形变;最近的库伦激发的研究提供了Z=50,N=82满壳附近122,124,126Cd核中出现核集体性的实验和理论证据;上述研究成果展现出从Ru中的最大三轴形变(γ=-30°,三轴形变极小增益为0.67 Me V),经具有大三轴形变的Rh核(γ=-28°),到Pd核中的稍小、但稳定于中等自旋到高自旋区的三轴形变(γ～-41°,三轴形变极小增益为0.32 Me V),再经Ag核中的γ软度,最后到具有很小形变、但仍出现集体性质、包括软三轴形变的Cd核的过渡。对于Pd核转动带交叉系统性的研究揭示了其第一带交叉(νh11/2)2中子转动顺排的上行γ驱动,和第二带交叉(πg9/2)2质子转动顺排的下行γ驱动效应,成功地解释了114Pd中的三轴摆动运动,并给出了110-118Pd同位素链中理论早已预言、而比早期理论预言更为完整准确的形状渐进变迁和形状共存的图像。根据该核区的系统研究,发现最大三轴形变出现在112Ru,而在相邻的偶Z(Pd)同位素链,三轴形变极小的中心在114Pd,两者均为N=68。上述系统性研究沿相邻的Ru和Pd偶Z同位素链,在N=68同中素中鉴别出最大三轴形变,均比理论预言的108Ru和110Pd多4个中子。在Z值位于Ru(Z=44)之下的Zr(Z=40),Nb(Z=41),Mo(Z=42)and Tc(Z=43)丰中子同位素中,Y和Zr核具有很强的轴对称四极形变,而在较重的Zr同位素中出现了γ自由度;较重的Nb核(A=104～106)基态具有中等程度的软三轴形变和强四极形变,随着自旋和激发能的增加,过渡到接近于轴对称的强四极形变;而较轻的Nb核(A 103)基态均接近轴对称形状;在Nb同位素链上基态由球形到强四极形变的形状突变发生在100Nb(N=59),在100–106Nb同位素链中基态的软三轴形变随中子数增加而增加;在Nb核中还观察到关于软三轴形变的形状共存;Mo核具有大的三轴形变,观察到了γ振动和手征对称破缺;Tc核具有比最大值稍小的三轴形变,γ=-26°,并观察到了手征对称破缺。质子数Z从41到48的A～(100～126)丰中子同位素,特别是Pd和Nb同位素,呈现出关于三轴形变的过渡特征。
Based on the theoretical predictions and experimental evidence of the maximum triaxial deformation in Ru (Z = 44) abundance isotopes, the effects of Rh (Z = 45), Pd (Z = 46), Ag (Z = 48) (Z = 48), Tc (Z = 43) (proton number Z is located above Ru and Z = 44) (Ru ~ Z = 44)) in the A ~ (100 ~ 126) abundance neutron isotopes of triaxial deformation. 252Cf spontaneous fission instant gamma ray γ-γ-γ triple coincidence, especially the newly established γ-γ-γ-γ quadruple coincidence data system observation and research, abundance of Ru, Pd, Cd and Nb neutron isotope A series of energy bands have been significantly extended or first observed, providing new and important experimental data for the study of nuclear shape in this nuclear region. In connection with previously reported progress, new experimental data were calculated using PES, TRS, PSM, CCCSM, and SCTAC theoretical models, along which the mid- and isotopic chains were varied and varied degrees of freedom with spin and excitation energy , Tracking gradual changes in the shape of the nucleus, obtained new systematic research results, significantly expanded and deepened people’s understanding of the nuclear shape changes and shape coexistence. Studies of abundance neutron isotopes of Pd (Z = 46), Ag (Z = 47) and Cd (Z = 48) for Ru and Rh on it (Z = 45) Smaller trinocular deformation, γ = -28 °, and chiral symmetry breakage was identified on the 103-106Rh isotope chain; three-axial nuclei were found in the triaxial deformable nuclei 112Ru and 114Pd (N = 68) The oscillatory motion, which may also be present at 114 Ru (N = 70), was observed; the chirality of the perturbations in 112, 114, 116Pd from chiral to 110, 112Ru with maximal triaxial deformation was observed Transition; a rich spectrum of structures was observed in the softer Ag core, a possible chiral symmetry break was identified in 104, 105Ag, and a softness of gamma to triaxial densification was proposed in heavier 115, 117Ag ; The energy level structures of Cd nuclei with small deformations are interpreted as quasi-particle coupling, quasi-rotation and soft triaxial deformation; recent Coulomb excitation studies provide nuclei in 122, 124, 126Cd nuclei near Z = 50, N = 82 Collective experimental and theoretical evidence. The above research results show that the maximum triaxial deformation from Ru (γ = -30 °, the triaxial deformation minimum gain of 0.67 MeV) (Γ = -28 °) to a slightly smaller Pd nucleus, but stable to moderate-spin to high-spin-axis triaxial deformations (γ ~ -41 °, triaxial deformation with a minimum gain of 0.32 MeV) , Followed by γ softness in the Ag nucleus, and finally to a transition with a small deformation, but collective properties, including soft triaxial Cd nuclei. Studies on the cross-systematicness of Pd nuclear rotation bands reveal that the upstream γ drive with the first (nh11 / 2) 2 neutron rotation in the first band and the downward (xg9 / 2) 2 proton rotation with the second band cross γ-driving effect, the three-axis wobble motion in 114Pd is successfully explained, and the theory of 110-118Pd isotope chain has long been predicted, but more complete and accurate shape evolution and shape coexistence than the earlier theoretical predictions. Based on a systematic study of the core region, the largest triaxial deformation was found to occur at 112Ru, while in the adjacent even Z (Pd) isotope chains, the center of the triaxial deformation is at a minimum of 114Pd, both N = 68. The above systemic studies identified the largest triaxial deformation in the N = 68 mesogen along adjacent Ru and Pd even Z isotopes, both 4 neutrons more than predicted 108Ru and 110Pd. In the neutron isotopes of Zr (Z = 40), Nb (Z = 41), Mo (Z = 42) and Tc (Z = 43) with Z values located below Ru (Z = 44) Has a strong axisymmetric quadrupole deformation, and in the heavier Zr isotope γ degree of freedom appears; heavier Nb nuclei (A = 104 ~ 106) ground state with moderate soft triaxial deformation and strong tetrapod deformation , With the increase of spin and excitation energy, transition to a strong quadrupole deformation close to the axisymmetric; while the lighter Nb nucleus (A 103) ground state are close to the axisymmetric shape; Nb isotope chain ground state from spherical to strong The quadrupole-shaped shape mutation occurs at 100Nb (N = 59) and the soft triaxial deformation of the ground state in the 100-106Nb isotope chain increases with the increase of the neutron number. The shape of the soft triaxial deformation is also observed in the Nb core Coexistence; Mo core has a large triaxial deformation, observed γ vibration and chiral symmetry breaking; Tc core has a slightly smaller than the maximum triaxial deformation, γ = -26 °, and the chiral symmetry was observed. A ~ (100 ~ 126) abundance isotopes of protons Z from 41 to 48, especially Pd and Nb isotopes, exhibit transitional features with respect to triaxial deformation.