关于B~0→π~-~+■_衰变过程分支比的计算

通过构造适当的关联函数,计算B→π跃迁形状因子fB+π(q2),fBπ(q2)和标量形状因子f0(q2),从而就能研究轻子质量对B0→π-+ν(l=e,μ,τ)衰变过程的影响.首次分别计算B0→π-e+νe,B0→π-μ+νμ,B0→π-τ+ντ衰变过程的分支比,并发现轻子质量me,mμ可以忽略,但重轻子质量mτ不能忽略,它对分支比计算有一定的贡献.把计算结果与最近的实验数据进行比较,发现理论结果与实验数据基本符合.     

关于B0→π-l+～vl衰变过程分支比的计算

通过构造适当的关联函数,计算B→π跃迁形状因子f+Bπ(q2),～fBπ(q2)和标量形状因子f0(q2),从而就能研究轻子质量对B0→π-l+～vl(l=e,μ,τ)衰变过程的影响.首次分别计算B0→π-e+～ve,B0→π-μ+～vμ,B0→π-τ+～vτ衰变过程的分支比,并发现轻子质量me,mμ可以忽略,但重轻子质量mτ不能忽略,它对分支比计算有一定的贡献.把计算结果与最近的实验数据进行比较,发现理论结果与实验数据基本符合.     

A capacitance servo control plunger for accurate lifetime measurement

The recoil distance Doppler shift method has been widely used in the study of nuclear structure to determine the level lifetime and absolute transition probabilities.A capacitance servo control plunger based on this method has been successfully developed by the Nuclear Structure Group of the China Institute of Atomic Energy.Three microscopes were employed to check the parallelism and can therefore guarantee a delicate measurement of the distance between the target and the stopper.This new plunger made a successful performance in the test experiment and the measured lifetime of the 2~+→0~+ transition in ~(78)Kr is in agreement with the previous value.     

关于B0→π－l+ν l衰变过程分支比的计算

通过构造适当的关联函数,计算B→π跃迁形状因子f⁺_Bπ(q²),f _{Bπ(q²)和标量形状因子f⁰(q²),从而就能研究轻子质量对B⁰→π}     

New high spin level scheme of 87Sr

High spin states of the odd-A ⁸⁷Sr were populated by the fusion-evaporation reaction ⁸²Se(⁹Be, 4n) ⁸⁷Sr at a beam energy of 46 MeV. Excited levels of ⁸⁷Sr have been extended up to an excitation energy of 7.4 MeV at spin 31/2ħ. The coupling of a g_9/2 neutron hole to the yrast states of the ⁸⁸Sr core can account for the low-lying states in ⁸⁷Sr. The structure of the higher spin states is discussed by analogy with those of the neighboring odd-A N=49 isotones and possible configurations are proposed.     

关于B0→π－l+ν l衰变过程分支比的计算

通过构造适当的关联函数,计算B→π跃迁形状因子f⁺_Bπ(q²),f _{Bπ(q²)和标量形状因子f⁰(q²),从而就能研究轻子质量对B⁰→π ^{关键词： B介子半轻衰变 形状因子 分支比}}     

Multi-quasiparticle excitations and the impact of the high-j intruder orbital in the N=51^93 Mo nucleus

The level structures of 93 Mo are investigated using Large Scale Shell Model calculations,and reasonable agreement is obtained between the experimental and calculated values.The calculated results show that the lower-lying states are mainly dominated by proton excitations from the If5/2,2 p3/2,and 2 p1/2 orbitals into the higher orbitals across the Z=38 or Z=40 subshell closure.For the higher-spin states,multi-particle excitations,including the excitation of 2 d5/2 neutrons across the N=56 subshell closure into the high-j intruder 1 h11/2 orbital,are essential.Moreover,the previously unknown spin-parity assignments of the six higher excited states in 93 Mo are inferred from the shell model calculations.     

用量子理论方法研究C60双缝衍射

目前,已有大量的实验和理论对各种粒子的衍射现象进行了深入的研究.我们用量子理论新方法研究C60分子的双缝衍射,从薛定谔方程和基尔霍夫定律出发求得到C60分子的双缝衍射波函数,与实验数据比较我们发现:在考虑C60分子的双缝衍射中退相干机制对衍射图样的影响后所得的结果与实验符合较好.