0νββ and 2νββ nuclear matrix elements, quasiparticle random-phase approximation, and isospin symmetry restoration
0νββ and 2νββ nuclear matrix elements, quasiparticle random-phase approximation, and isospin symmetry restoration
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DOI：
10.1103/physrevc.87.045501
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发表时间：
2013-02
影响因子：
3.1
通讯作者：
F. vSimkovic;V. Rodin;A. Faessler;P. Vogel
中科院分区：
文献类型：
--
作者：
F. vSimkovic;V. Rodin;A. Faessler;P. Vogel
在准粒子无规相位近似（QRPA）中，我们实现了同位旋对称性的部分恢复，从而满足了2νββ费米矩阵元M^（2ν）_F为零的要求，这与以前的方法不同。这是通过将粒子-粒子质子-中子相互作用的重整化参数g_pp分成等矢量和等oscillation部分来实现的。等矢量参数g^（T=1）_（pp）需要被选择为基本上等于配对常数g_pair，因此不需要新的参数。对于0νββ衰变，费米矩阵元M^（0ν）_F基本上减少，而全矩阵元M^（0ν）减少约10%。我们认为，这种更一致的方法应该使用从现在开始在质子-中子QRPA和类似的方法
Within the quasiparticle random-phase approximation (QRPA) we achieve partial restoration of the isospin symmetry and hence fulfillment of the requirement that the 2νββ Fermi matrix element M^(2ν)_F vanishes, as it should, unlike in the previous version of the method. This is accomplished by separating the renormalization parameter g_pp of the particle-particle proton-neutron interaction into isovector and isoscalar parts. The isovector parameter g^(T=1)_(pp) needs to be chosen to be essentially equal to the pairing constant g_pair, so no new parameter is needed. For the 0νββ decay the Fermi matrix element M^(0ν)_F is substantially reduced, while the full matrix element M^(0ν) is reduced by ≈10%. We argue that this more consistent approach should be used from now on in the proton-neutron QRPA and in analogous methods