D-term and structure of point-like and composed spin-0 particles

Understand

This work deals with form factors of the energy-momentum tensor (EMT) of spin-0 particles and the unknown particle property D-term related to the EMT, and is divided into three parts.

• The first part explores free, weakly and strongly interacting theories to study EMT form factors with the following findings.
• (i) The free Klein-Gordon theory predicts for the D-term D = -1.
• (ii) Even infinitesimally small interactions can drastically impact D.