A Number-Conserving Theory for Nuclear Pairing

TL;DR

This paper introduces a microscopic, number-conserving nuclear pairing theory based on the generalized density matrix formalism, which is computationally efficient and valid across all pairing strengths, including below the BCS critical point.

Contribution

It presents a new nuclear pairing theory that conserves particle number exactly and is computationally comparable to BCS, applicable at any pairing strength.

Findings

Conserves exact particle number in nuclear pairing.

Applicable at arbitrary pairing strengths, including below BCS critical.

Analytical equations similar in simplicity to BCS theory.

Abstract

A microscopic theory for nuclear pairing is proposed through the generalized density matrix formalism. The analytical equations are as simple as that of the BCS theory, and could be solved within a similar computer time. The current theory conserves the exact particle number, and is valid at arbitrary pairing strength (including those below the BCS critical strength). These are the two main advantages over the conventional BCS theory. The theory is also of interests to other mesoscopic systems.