有两个主要的原因,缺乏的实用理论剥离到共振态,可以使用的实验组:数值问题的DWBA矩阵元素的收敛时,包括全过渡运营商,目前还不清楚什么光谱信息可以从迁移反应填充的共振态的分析。本文件的目的是解决这两个问题。发展了氘核剥离理论,它是基于后连续离散耦合通道(CDCC)形式,超越了DWBA和反应理论的表面积分公式[A. S. Kadyrov等人,Ann. Phys. { \bf 324},1516(2009)]。首先,形式主义是发展的DWBA,然后扩展到CDCC形式主义,这是本工作的最终目标。CDCC波函数不仅考虑了初始弹性$d+ A$通道,而且考虑了它与DWBA中缺少的氘破裂通道$p + n + A$的耦合。剥离到束缚态和共振都包括在内。在后CDCC形式中解决了剥离到共振态的收敛问题。反应振幅的参数化方面的约化宽度振幅(ANC),逆能级矩阵,边界条件和通道半径,这是相同的参数,在传统的$R$矩阵方法中使用。对于剥离到共振态的多能级,考虑了单通道和双通道的情况。该理论提供了一个一致的工具来分析这两个二元共振反应和氘核剥离在相同的参数。
英文摘要:
There are two main reasons for absence of the practical theory of stripping to resonance states which could be used by experimental groups: numerical problem of the convergence of the DWBA matrix element when the full transition operator is included and it is unclear what spectroscopic information can be extracted from the analysis of transfer reactions populating the resonance states. The purpose of this paper is to address both questions. The theory of the deuteron stripping is developed, which is based on the post continuum discretized coupled channels (CDCC) formalism going beyond of the DWBA and surface integral formulation of the reaction theory [A. S. Kadyrov et al., Ann. Phys. {\bf 324}, 1516 (2009)]. First, the formalism is developed for the DWBA and then extended to the CDCC formalism, which is ultimate goal of this work. The CDCC wave function takes into account not only the initial elastic $d+ A$ channel but also its coupling to the deuteron breakup channel $p + n + A$ missing in the DWBA. Stripping to both bound states and resonances are included. The convergence problem for stripping to resonance states is solved in the post CDCC formalism. The reaction amplitude is parametrized in terms of the reduced width amplitudes (ANCs), inverse level matrix, boundary condition and channel radius, that is the same parameters which are used in the conventional $R$-matrix method. For stripping to resonance states many-level, one and two-channel cases are considered. The theory provides a consistent tool to analyze both binary resonant reactions and deuteron stripping in terms of the same parameters.
Spin asymmetry and GDH sum rule for real and virtual photons for the deuteron
给出了氘核自旋不对称性的一个明确的计算方法和相应的GDH求和规则,包括衰变、单π介子和双π介子以及η介子的产生。对于GDH积分,在衰变通道和介子产生通道之间发现了一个大的抵消。此外,第一个结果的贡献的衰变通道的广义GDH积分在恒定的四动量转移揭示了占主导地位的等矢量M1过渡到$^1$ S $_0$ -状态附近的阈值导致在负的贡献与最小值周围的$Q^2\approx 0.2$ FM $^{-2}$这是由核子异常等矢量磁矩。
The generalized Gerasimov-Drell-Hearn sum rule for deuteron electrodisintegration
本文用显式积分法计算了氘核电致衰变$d(e,e')np$的广义Gerasimov-Drell-Hearn求和规则$I^{GDH}_{γ^*d}(Q^2)$作为平方四动量转移$Q^2$的函数。计算是基于一个传统的非相对论框架,使用一个现实的$NN$势,并包括介子交换流,等压位形和领先的相对论性条款的贡献。实现了良好的收敛。显著的特点是一个深负的最小值,$I_{γ^* d}^{GDH}=-9.5$ mb,在低$Q^2\approx 0.2$ fm $^{-2}$,这是几乎完全由核子等矢量异常磁矩贡献的磁偶极子过渡到$^1S_0$状态。高于$Q^2=20$ fm $^{-2}$,积分$I^{GDH}_{γ^*}(Q^2)$迅速接近零。
Integral relations and the adiabatic expansion method for 1+2 reactions above the breakup threshold: Helium trimers with soft-core potentials
在\cite{bar09,rom11}中引入的积分关系形式主义,旨在描述1+ $N$反应,在这里扩展到碰撞能量高于阈值的目标分裂。这两个关系式是完全通用的,在这项工作中,它们被用来与绝热膨胀法一起描述1+2反应。中子-氘核分裂,基准计算是可用的,作为一个测试的方法。研究了$^4$ He原子和$^4$ He $_2$二聚体在破裂阈值以上的s波碰撞以及使用软核二体势加短程三体力的可能性。与以前的计算三体复合和碰撞解离率的比较将显示。