Integrable quantum field theories with supergroup symmetries: the OSP(1/2) case Original Research Article

As a step to understand general patterns of integrability in 1+1 quantum field theories with supergroup symmetry, we study in details the case of OSP(1/2). Our results include the solutions of natural generalizations of models with ordinary group symmetry: the UOSP(1/2)k WZW model with a current–current perturbation, the UOSP(1/2) principal chiral model, and the UOSP(1/2)⊗UOSP(1/2)/UOSP(1/2) coset models perturbed by the adjoint. Graded parafermions are also discussed. A pattern peculiar to supergroups is the emergence of another class of models, whose simplest representative is the OSP(1/2)/OSP(0/2) sigma model, where the (non unitary) orthosymplectic symmetry is realized non-linearly (and can be spontaneously broken). For most models, we provide an integrable lattice realization. We show in particular that integrable osp(1/2) spin chains with integer spin flow to UOSP(1/2) WZW models in the continuum limit, hence providing what is to our knowledge the first physical realization of a super WZW model.