arXivDaily arXiv每日学术速递 周一至周五更新
北美退伍军人节(Veterans Day),12 日无更新
arXiv 1702.00044nucl-th
收藏

考虑准粒子-振动耦合的核自旋-同位旋激发的相对论方法

Relativistic approach to nuclear spin-isospin excitations including quasiparticle-vibration coupling

Caroline Robin, Elena Litvinova

摘要:

在质子-中子相对论准粒子时间阻塞近似(pn-RQTBA)框架下研究了稳定核和奇异核的自旋-同位旋响应。该方法基于协变密度泛函理论,扩展了质子-中子相对论准粒子无规相近似(pn-RQRPA),考虑了单个准粒子与集体核振动的耦合.在电荷交换通道中,这种耦合在质子和中子准粒子之间产生了依赖于时间的有效相互作用。这种相互作用的粒子-空穴分量增加了静态的π介子和ρ介子交换,而粒子-粒子分量提供了微观和一致的质子-中子配对相互作用。我们发现,这样的动力学效应诱导的Gamow-Teller过渡强度,这是重要的更好的协议与实验测量和准确的描述$β$ -衰变率的碎片和传播。新的进展包括单核子与双魔核中的同位旋翻转振动的耦合。我们发现,这些声子可以有一个不可忽略的影响$β$衰减半衰期和“淬火”的强度。

英文摘要:

The spin-isospin response of stable and exotic nuclei is investigated in the framework of the proton-neutron relativistic quasiparticle time-blocking approximation (pn-RQTBA). Based on the Covariant Density Functional Theory, this method extends the proton-neutron Relativistic Quasiparticle Random-Phase Approximation (pn-RQRPA) by including the coupling between single quasiparticles and collective nuclear vibrations. In the charge-exchange channel, this coupling generates a time-dependent effective interaction between proton and neutron quasiparticles. The particle-hole component of this interaction adds to the static pion and rho-meson exchange, while the particle-particle component provides a microscopic and consistent proton-neutron pairing interaction. We find that such dynamical effects induce fragmentation and spreading of the Gamow-Teller transition strength which are important for a better agreement with the experimental measurements and for an accurate description of $β$-decay rates. The new developments include the coupling of single nucleons to isospin-flip vibrations in doubly-magic nuclei. We find that these phonons can have a non-negligible effect on $β$-decay half-lives and "quenching" of the strength.

机构、总结、中文摘要均由AI分析而来,可能存在错误,请以论文正文为准。

↑