Speaker
Description
The electromagnetic form factors of the nucleon have been widely used for exhibiting how the charge and magnetization distributions are spatially distributed inside a nucleon in the Breit frame. Similarly, the Energy-Momentum-Tensor form factors (i.e. gravitational form factors, GFFs) characterize the mechanical properties, such as the three-dimensional distributions of mass, angular momentum, pressure, and shear-force densities inside particles.
In this talk, I will first briefly introduce GFFs for particles with different spins and their interpretations in the Breit frame. I will also mention current experimental measurements or lattice QCD calculations on GFFs. Next, I will present our recent studies on Delta GFFs, N-Delta transitional GFFs, and one-pion graviproduction FFs using the chiral perturbation theory (ChPT) in curved spacetime.
Since the validity of the definitions of local densities in the Breit frame has been questioned, a new definition using sharply localized wave packet states is proposed, and I will demonstrate its application to spin-3/2 systems. The long-range behaviors of the densities under our newly proposed definition are obtained with the ChPT results for Delta GFFs.
