1+1D hadrons minimize their biparton Renyi free energy

We use a variational method to calculate the spectrum and the parton distribution function of ground state hadrons of various gauge theories in 1 + 1 dimensions. The template functions in our method minimize a free-energy functional defined as a combination of free-valence partons' kinetic energy on the light cone and the Renyi entanglement entropy of biparton subsystems. Our results show that hadrons in these theories minimize the proposed free energy. The success of this technique motivates applying it to confining gauge theories in higher dimensions.