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arXiv · 2608.30434

Meson gravitational D-form factors and symmetry breaking in low-energy QCD

Mamiya Kawaguchi·Kazuhiro Tanaka·Mitsuru Tanaka
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Abstract

We investigate meson gravitational D-form factors in the three-flavor linear sigma model and their connection to symmetry breaking in low-energy QCD. Within the scalar meson dominance picture, we examine the scalar meson exchange contributions and their relation to meson masses through scalar-meson couplings. In the three-flavor symmetric limit, we first derive analytical expressions for the D-form factors of pseudoscalar and scalar mesons. In the chiral limit, the forward-limit value of the octet pseudoscalar D-form factor is fixed to $-1$, whereas the $U(1)_A$ anomaly generates additional contributions to the singlet pseudoscalar and scalar-meson D-form factors. For realistic flavor breaking, the interaction introduced to reproduce the scalar-meson mass hierarchy below $1$ GeV significantly affects the scalar-meson D-form factors. We further compare the linear sigma model results with those obtained from a chiral perturbation theory Lagrangian including a dilatonic scalar field and show that their differences are governed by the canonical mass dimensions of the interaction terms contributing to meson mass generation. These results indicate that meson D-form factors provide sensitive probes of symmetry-breaking structures in low-energy hadron physics.

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Mamiya Kawaguchi, Kazuhiro Tanaka, Mitsuru Tanaka. 2026-08-31. Meson gravitational D-form factors and symmetry breaking in low-energy QCD. https://arxiv.org/abs/2608.30434

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