Relativistic spectral function of nucleon in hot nuclear matter

TL;DR

This paper calculates the relativistic spectral function of nucleons in hot nuclear matter, highlighting the importance of both unitary and Landau cuts in the spectral function, and contrasting with non-relativistic approaches.

Contribution

It provides a relativistic calculation of the nucleon spectral function at finite temperature, emphasizing the significance of both cuts often neglected in previous studies.

Findings

Both unitary and Landau cuts significantly affect the spectral function.

Relativistic spectral function differs from non-relativistic approximations.

The imaginary parts of one-loop graphs are linked to physical discontinuities.

Abstract

We present a simple calculation of the nucleon self-energy in nuclear matter at finite temperature in a relativistic framework, using the real time thermal field theory. The imaginary parts of one-loop graphs are identified with discontinuities across the unitary and the Landau cuts. We find that in general both the cuts contribute significantly to the spectral function in the region of (virtual) nucleon mass usually considered, even though the unitary cut is ignored in the literature. Also our relativistic spectral function differs from the one in non-relativistic approximation, used in some earlier calculations.