Glimpse into the pion gravitational form factor

We provide a novel approach to calculate the gravitational form factor of pion under the ladder approximation of the Bethe-Salpeter equation, with contact interactions. Central to this approach is a symmetry-preserving treatment of the dressed pi pi amplitude, which shows explicitly the contributions from intrinsic quarks and bound states, the latter being necessary to produce the D -term of pion in the soft-pion limit. The approach we provide in this work can be applied to many processes of physical significance.

Automated summary

We present a novel approach to calculate the gravitational form factor of pion using the ladder approximation of the Bethe-Salpeter equation with contact interactions. A key aspect of this approach is the symmetry-preserving treatment of the dressed pi pi amplitude, which reveals the contributions from intrinsic quarks and bound states, the latter being essential for the D-term of pion in the soft-pion limit. The method we propose in this study can be applied to numerous processes of significance in physics.