The EMC Effect and Short-Range Correlations

TL;DR

This paper reviews the EMC effect and short-range correlations in nuclei, highlighting a correlation between the EMC ratio slope and SRC scale factor, and predicts increased proton contributions in asymmetric nuclei.

Contribution

It introduces a new interpretation linking nucleon virtuality to medium modifications and predicts enhanced proton effects in large asymmetric nuclei based on recent SRC observations.

Findings

Correlation between EMC ratio slope and SRC scale factor observed.

High momentum components reduce mean field contributions.

Proton contributions increase in large A asymmetric nuclei.

Abstract

We overview the progress made in studies of EMC and short range correlation (SRC) effects with the special emphasis given to the recent observation of the correlation between the slope of the EMC ratio at Bjorken x<1 and the scale factor of the same ratio at x>1 that measures the strength of the SRCs in nuclei. This correlation may indicate the larger modification of nucleons with higher momentum thus making the nucleon virtuality as the most relevant parameter of medium modifications. To check this conjecture we study the implication of several properties of high momentum component of the nuclear wave function on the characteristics of EMC effect. We observe two main reasons for the EMC-SRC correlation: first, the decrease of the contribution from the nuclear mean field due to the increase, with A, the fraction of the high momentum component of nuclear wave function. Second, the increase of the medium modification of nucleons in SRC. Our main prediction however is the increase of the proton contribution to the EMC effect for large A asymmetric nuclei. This prediction is based on the recent observation of the strong dominance of pn SRCs in the high momentum component of nuclear wave function. Our preliminary calculation based on this prediction of the excess of energetic and modified protons in large A nuclei describes reasonably well the main features of the observed EMC-SRC correlation.