Analysis of the contribution of the quantum anomaly energy to the proton mass

TL;DR

This paper systematically analyzes the quantum anomalous energy's contribution to proton mass using models fitted to recent experimental data, finding it to be a small but quantifiable effect around 3.5%.

Contribution

It provides the first extraction of the QAE contribution distribution with energy based on two theoretical models fitted to recent experimental data.

Findings

QAE contribution to proton mass is approximately 3.5%.

Effective Pomeron and two-gluon exchange models fit the data well.

The energy distribution of QAE contribution is characterized for the first time.

Abstract

Inspired by the recent Hall C and GlueX measurements of $J/\psi$ photoproduction, a systematic analysis of the contribution of quantum anomalous energy (QAE) to the proton mass is carried out under the framework of the vector meson dominance model. The results show that the effective Pomeron model and the parametrized two gluon exchange model can explain the cross section of $J/\psi$ photoproduction well. Based on the predicted cross section values given by the two models, the distribution of the QAE contribution with the energy is extracted for the first time. Finally, the average value of the QAE contribution is estimated to be (3.50$\pm$0.70)$\%$, which suggests that the QAE contribution to the proton mass is small. Accordingly, we compared this result with those of other groups and explored the causes for the differences.