Asymptotic-freedom and massive glueballs in a qubit-regularized SU(2) gauge theory

Abstract: We argue that a simple qubit-regularized $\mathrm{SU}(2)$ lattice gauge theory on a plaquette chain serves as a pseudo-one-dimensional toy model for Yang-Mills theory in three spatial dimensions. We map the chain Hamiltonian to the Transverse Field Ising Model in a uniform magnetic field and demonstrate that it can be tuned to a continuum limit in which the short-distance physics is governed by the asymptotically free Ising conformal field theory describing free Majorana fermions, while the long-distance regime contains massive excitations of the $E_8$ quantum field theory that can be interpreted as one-dimensional analogues of glueballs. Furthermore, we find $\sqrtσ/m_1 = 0.1763(5)$ where $σ$ is the string tension between two static quarks and $m_1$ is the mass of the lightest glueball.