Origin of hadron mass from gravitational D-form factor and neutron star measurements

Clarifying the origin of hadron mass is one of the fundamental problems in particle physics, relevant from hadronic scales to astrophysical observations. At low energies, this issue is reflected in the decomposition of the hadron mass into chiral-variant and -invariant components. In this letter, we propose a method to extract the chiral invariant mass from the gravitational D -form factor under the assumption of the lightest-sigma meson dominance. Focusing on the nucleon, we show that a sizable chiral invariant mass reduces the magnitude of the D-form factor and brings the result closer to lattice QCD data. The preferred value of the chiral invariant mass lies within the range discussed in recent neutron star studies.