当前位置: X-MOL 学术Phys. Rev. C › 论文详情
Our official English website, www.x-mol.net, welcomes your feedback! (Note: you will need to create a separate account there.)
Scattering matrix pole expansions for complex wave numbers inR-matrix theory
Physical Review C ( IF 3.2 ) Pub Date : 2021-06-14 , DOI: 10.1103/physrevc.103.064609
Pablo Ducru , Benoit Forget , Vladimir Sobes , Gerald Hale , Mark Paris

In this followup article to Ducru et al. [Phys. Rev. C 103, 064608 (2021)], we establish new results on scattering matrix pole expansions for complex wave numbers in R-matrix theory. In the past, two branches of theoretical formalisms emerged to describe the scattering matrix in nuclear physics: R-matrix theory and pole expansions. The two have been quite isolated from one another. Recently, our study of Brune's alternative parametrization of R-matrix theory has shown the need to extend the scattering matrix (and the underlying R-matrix operators) to complex wave numbers. Two competing ways of doing so have emerged from a historical ambiguity in the definitions of the shift S and penetration P functions: the legacy Lane and Thomas's “force closure” approach versus analytic continuation (which is the standard in mathematical physics). The R-matrix community has not yet come to a consensus as to which to adopt for evaluations in standard nuclear data libraries, such as ENDF. In this article, we argue in favor of analytic continuation of R-matrix operators. We bridge R-matrix theory with the Humblet-Rosenfeld pole expansions, and discover new properties of the Siegert-Humblet radioactive poles and widths, including their invariance properties to changes in channel radii ac. We then show that analytic continuation of R-matrix operators preserves important physical and mathematical properties of the scattering matrix—canceling spurious poles and guaranteeing generalized unitarity—while still being able to close channels below thresholds.

中文翻译:

R-矩阵理论中复波数的散射矩阵极点展开

在这篇 Ducru等人的后续文章中[物理。Rev. C 103 , 064608 (2021)],我们建立了复杂波数的散射矩阵极点扩展的新结果电阻-矩阵理论。过去,出现了两个理论形式的分支来描述核物理中的散射矩阵:电阻-矩阵理论和极点扩展。两人已经相当疏远了。最近,我们对 Brune 的替代参数化的研究电阻- 矩阵理论表明需要扩展散射矩阵(以及底层的 电阻-矩阵运算符)到复数波数。由于转变定义的历史模糊性,出现了两种相互竞争的方法 和渗透 函数:遗留的 Lane 和 Thomas 的“力闭合”方法与解析延拓(这是数学物理学中的标准)。这电阻-matrix 社区尚未就标准核数据库(如 ENDF)中的评估采用哪种方法达成共识。在本文中,我们主张支持分析延续电阻- 矩阵运算符。我们搭桥电阻- 矩阵理论与 Humblet-Rosenfeld 极点扩展,并发现 Siegert-Humblet 放射性极点和宽度的新特性,包括它们对通道半径变化的不变性 一种C. 然后我们证明了电阻-matrix 算子保留了散射矩阵的重要物理和数学特性——消除杂散极点并保证广义单一性——同时仍然能够关闭低于阈值的通道。
更新日期:2021-06-15
down
wechat
bug