Speaker
Description
In low-energy effective descriptions of QCD, the nucleon mass can be decomposed into chiral-variant and chiral-invariant components. However, their respective quantitative contributions have not yet been fully clarified. In this study, we investigate the chiral-invariant mass through nucleon gravitational form factors, focusing in particular on the D-form factor under the assumption of lightest-sigma-meson dominance. Using the parity doublet model, in which the nucleon and its negative-parity chiral partner ($N^*$) are introduced together with a chiral-invariant mass term, we show that a sizable chiral-invariant mass reduces the magnitude of the nucleon D-form factor. This brings the theoretical prediction into better agreement with lattice QCD data.