The Wigner function and short-range correlations in the deuteron

TL;DR

This paper uses the Wigner function to analyze short-range correlations in the deuteron, revealing quantum interference effects between low- and high-momentum components.

Contribution

It introduces a phase-space approach with the Wigner function to study short-range correlations in the deuteron, including effects of different nuclear interactions.

Findings

High-momentum shoulder indicates short-range correlations.

Oscillations in the Wigner function relate to interference effects.

Short-range correlations are quantum-mechanical interference phenomena.

Abstract

$\textbf{Background:}$ The deuteron shows the essential features of short-range correlations found in all nuclei. Experimental observables related to short-range correlations are connected with the high-momentum components of one- and two-body momentum distributions. An intuitive understanding of short-range correlations is provided by the suppression of the two-body density in coordinate space at small distances. $\textbf{Purpose:}$ The Wigner function provides a quasi-probability distribution in phase-space that allows to investigate short-range correlations as a function of distance and relative momentum in a unified picture. $\textbf{Method:}$ The Wigner function for the deuteron is calculated for bare and SRG evolved AV8' and N3LO interactions and investigated as a function of distance, relative momentum and angular orientation. Partial momentum and coordinate space distributions are obtained by integrating over parts of phase space. $\textbf{Results:}$ The Wigner function shows a pronounced low-momentum peak that is not affected by short-range correlations and a high-momentum shoulder at small distances that reflects short-range correlations. Oscillations of the Wigner function are related to interference of low- and high-momentum components. $\textbf{Conclusions:}$ Short-range correlations are a truly quantum-mechanical phenomenon caused by interference of low- and high-momentum components in the wave function.