Analytical description of the proton’s mass components in QCD

Establish an analytical, self-consistent description within quantum chromodynamics of the proton’s internal mass decomposition into quark kinetic energy, gluon field energy, quark mass contributions generated by the Higgs mechanism, and trace-anomaly terms, in order to precisely quantify each component’s share of the proton mass.

Background

In assessing how baryonic matter contributes to screening in scalar–tensor theories, the authors emphasize that only the fraction of baryon mass arising from Higgs-generated quark masses should directly contribute to screening, whereas the dominant gluon binding energy is scale-invariant and expected to decouple. Consequently, a precise decomposition of the proton mass into its quark and gluon components is needed to quantify the baryonic screening contribution.

The paper reviews existing estimates obtained from chiral perturbation theory and lattice QCD, which currently yield differing fractions for the quark mass contribution to the proton mass. This uncertainty motivates the explicit open problem of establishing an analytical description of the proton’s components, which would refine constraints on screening mechanisms that depend sensitively on the Higgs-sourced mass fraction.