{"title":"Breakup Amplitudes from the Pseudostate Extension of the Coupled-Reaction-Channels Method","authors":"","doi":"10.1007/s00601-024-01886-5","DOIUrl":null,"url":null,"abstract":"<h3>Abstract</h3> <p>A pseudochannel extension of the coupled-reaction-channel (CRC) ansatz had been used in earlier work to simulate the effect of the breakup channel on the rearrangement amplitudes. Comparisons with benchmark results on model systems established that rearrangement amplitudes and total breakup probability could be obtained accurately. However, achieving the same level of accuracy with respect to the state-to-state breakup amplitudes had eluded the earlier attempts that used global bases to generate the pseudo states. With the global bases it is difficult to control the spectrum of pseudostate energies and to obtain an optimal distribution of these pseudo-levels. In the present work, local bases in momentum space of the type used in Finite Element methods are employed. Pseudostates are generated using a local interpolation basis in the relative momentum of the two-body subsystem. Local nature of such a basis allows us to control the density of two-body pseudostates by simply adjusting the distribution of the grid points. In the present work, it is demonstrated that breakup amplitudes can be extracted quantitatively using pseudostates generated from a basis of local piecewise quadratic interpolation polynomials. For a local-potential s-wave model of the <span> <span>\\(\\textrm{n}+\\textrm{d}\\)</span> </span> scattering, state-to-state breakup amplitudes obtained from the present approach are compared with the benchmark results available in the literature. Results further confirm that pseudostate-extended CRC method is a viable and efficient approach for three-particle scattering.</p>","PeriodicalId":556,"journal":{"name":"Few-Body Systems","volume":null,"pages":null},"PeriodicalIF":1.7000,"publicationDate":"2024-03-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":"0","resultStr":null,"platform":"Semanticscholar","paperid":null,"PeriodicalName":"Few-Body Systems","FirstCategoryId":"101","ListUrlMain":"https://doi.org/10.1007/s00601-024-01886-5","RegionNum":4,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":null,"EPubDate":"","PubModel":"","JCR":"Q2","JCRName":"PHYSICS, MULTIDISCIPLINARY","Score":null,"Total":0}
引用次数: 0
Abstract
A pseudochannel extension of the coupled-reaction-channel (CRC) ansatz had been used in earlier work to simulate the effect of the breakup channel on the rearrangement amplitudes. Comparisons with benchmark results on model systems established that rearrangement amplitudes and total breakup probability could be obtained accurately. However, achieving the same level of accuracy with respect to the state-to-state breakup amplitudes had eluded the earlier attempts that used global bases to generate the pseudo states. With the global bases it is difficult to control the spectrum of pseudostate energies and to obtain an optimal distribution of these pseudo-levels. In the present work, local bases in momentum space of the type used in Finite Element methods are employed. Pseudostates are generated using a local interpolation basis in the relative momentum of the two-body subsystem. Local nature of such a basis allows us to control the density of two-body pseudostates by simply adjusting the distribution of the grid points. In the present work, it is demonstrated that breakup amplitudes can be extracted quantitatively using pseudostates generated from a basis of local piecewise quadratic interpolation polynomials. For a local-potential s-wave model of the \(\textrm{n}+\textrm{d}\) scattering, state-to-state breakup amplitudes obtained from the present approach are compared with the benchmark results available in the literature. Results further confirm that pseudostate-extended CRC method is a viable and efficient approach for three-particle scattering.
期刊介绍:
The journal Few-Body Systems presents original research work – experimental, theoretical and computational – investigating the behavior of any classical or quantum system consisting of a small number of well-defined constituent structures. The focus is on the research methods, properties, and results characteristic of few-body systems. Examples of few-body systems range from few-quark states, light nuclear and hadronic systems; few-electron atomic systems and small molecules; and specific systems in condensed matter and surface physics (such as quantum dots and highly correlated trapped systems), up to and including large-scale celestial structures.
Systems for which an equivalent one-body description is available or can be designed, and large systems for which specific many-body methods are needed are outside the scope of the journal.
The journal is devoted to the publication of all aspects of few-body systems research and applications. While concentrating on few-body systems well-suited to rigorous solutions, the journal also encourages interdisciplinary contributions that foster common approaches and insights, introduce and benchmark the use of novel tools (e.g. machine learning) and develop relevant applications (e.g. few-body aspects in quantum technologies).