Lorentz Integral Transform for Inclusive and Exclusive Cross Sections with the Lanczos Method

TL;DR

This paper introduces a reformulation of the Lorentz Integral Transform method using the Lanczos algorithm, significantly reducing computational time while maintaining accuracy, enabling ab initio calculations for larger nuclear systems.

Contribution

The paper presents a novel Lanczos-based reformulation of the LIT method, improving efficiency and extending applicability to larger nuclei with full final state interactions.

Findings

CPU time reduced by two orders of magnitude

Excellent agreement with conventional LIT results

Enables ab initio calculations for nuclei with A ≥ 6

Abstract

The Lorentz Integral Transform (LIT) method is reformulated via the Lanczos algorithm both for inclusive and exclusive reactions. The new technique is tested for the total photoabsorption cross section of 3H and 4He. Due to the rapid convergence of the algorithm one has a decrease in cpu time by two orders of magnitude, but at the same time an excellent agreement with the results of a conventional LIT calculation. The present work opens up the possibility of ab initio calculations for inclusive and exclusive processes for A greater equal 6 with inclusion of complete final state interactions.