Relativistic energy-momentum tensor distributions in a polarized nucleon

We study in detail the relativistic distributions of energy, longitudinal momentum, longitudinal energy flux, and axial momentum flux inside nucleons based on the quantum phase-space formalism. Similar to recent studies on the electromagnetic current, we include the effects of the nucleon polarization and show that the latter are essential for understanding how the Breit frame distributions transform under a longitudinal Lorentz boost. We also explicitly demonstrate that, in the infinite-momentum frame, these distributions allow one to recover not only the "good"but also the "bad"components of the light-front energy-momentum tensor distributions.