Efficient calculation for the quasiparticle random-phase approximation matrix

TL;DR

This paper introduces an efficient numerical method using the finite amplitude method (FAM) to evaluate the QRPA matrix, enabling faster calculations of nuclear excitations and pairing modes, with applications demonstrated on tin and lead isotopes.

Contribution

The paper presents a novel, efficient FAM-based technique for calculating the QRPA matrix, improving computational speed and applicability for large-scale nuclear structure studies.

Findings

Validated the method with monopole excitation calculations in 120Sn.

Analyzed neutron-pair-transfer modes in neutron-rich Pb isotopes.

Discussed computational strategies for large-scale applications.

Abstract

We present an efficient numerical technique to evaluate the matrix of the (quasiparticle)-random-phase approximation, using the finite amplitude method (FAM). The method is tested in calculation of monopole excitations in 120Sn, compared with result obtained with the former iterative FAM. The neutron-pair-transfer modes are calculated with the present method and their character change in neutron-rich Pb isotopes is discussed. Computational aspects of different FAM approaches are also discussed for future applications to a large-scale computation.