摘要
由于在轻核中质子与中子处于同一壳,当用相互作用玻色子模型(IBM)描述轻核时,必须引入同位旋.这时 IBM 就叫 IBM 4,系统的对称群为U_(36).它有七条群链,其中群链U_36(?)U_6(sd)×U_6(ST)(?)SU_3(sd)×SU_3(S)×SU_3(T)(?)SU_3(sdS)×SU_3(T)(?)O_3(J)×O_3(T)叫强耦合 SU(3)极限。由于 E2跃迁算符 T(E2)q 是由群 U_(36),V_6(sd),SU_3(sd),SU_3(s)与 SU_3(s dS)的生成元构成的,故不必构造出强耦合 SU(3)极限的波函数,利用 Elliott 波函数妒φ((λμ)KJM)就可以得到 E2跃迁.
Because protons and neutrons in light nuclei fill the same shell,it is necessary to introduce isospin when the light nuclei are described by the interacting boson model(IBM).Thus IBM is called (?)BM4 and the symmetry group of this system is U(36).There are seven group chains,in which the group chain U(36)(?)U_6(sd)×U_6(ST)(?)SU_3(sd)×SU_3(S)×SU_3(T)(?)U_3(sdS)× SU_3(T)(?)O_3(J)×O_3(T)is called the strong coupling SU(3)limit.The E2 transition operator T (E2)_q is composed of the generators of U(36),U_6(sd),(sd),SU_3(S)and SU_3(sdS),so the E2 transition can be obtained by using the Elliott wave-function Ψ((λ_μ)KJM)instead of calculating the wave-function of the strong coupling,SU(3)limit.
