Short-range correlation physics at low RG resolution

TL;DR

This paper demonstrates how renormalization group (RG) evolution to low resolution reinterprets short-range correlation (SRC) physics in nuclei, shifting the focus from wave functions to reaction operators, and reconciles different experimental pictures.

Contribution

It shows how SRC phenomena at high RG resolution can be understood at low resolution using simple operators and local-density approximations, unifying different nuclear physics perspectives.

Findings

SRC features are identifiable at low RG resolution with simple two-body operators.

Experimental SRC effects follow from nucleon-nucleon interaction properties like the tensor force.

RG evolution allows wave-function simplification without losing physical accuracy.

Abstract

Recent experiments have succeeded in isolating processes for which short-range correlation (SRC) physics is dominant and well accounted for by SRC phenomenology. But an alternative and compelling picture emerges from renormalization group (RG) evolution to low RG resolution. At high RG resolution, SRCs are identified as components in the nuclear wave function with relative pair momenta greater than the Fermi momentum. Scale separation results in wave-function factorization that can be exploited with phenomenologies such as the generalized contact formalism or the low-order correlation operator approximation. Evolution to lower resolution shifts SRC physics from nuclear structure to the reaction operators without changing the measured observables. We show how the features of SRC phenomenology manifested at high RG resolution are cleanly identified at low RG resolution using simple two-body operators and local-density approximations with uncorrelated wave functions, all of which can be systematically generalized. We verify that the experimental consequences to date follow directly at low resolution from well-established properties of nucleon-nucleon interactions such as the tensor force. Thus the RG reconciles the contrasting pictures of the same experiment and shows how to get correct results using wave functions without SRC components. Our demonstration has implications for the analysis of knock-out reactions for which SRC physics is not cleanly isolated.