Critical behavior of the 2d scalar theory: resumming the ${\mathrm{N}}^8\mathrm{LO}$ perturbative mass gap

Gustavo O. Heymans, Marcus Benghi Pinto

We apply the optimized perturbation theory (OPT) to resum the perturbative series describing the mass gap of the bidimensional ${\varphi }^4$ theory in the ${\mathbb{Z}}_2$ symmetric phase. A…