%0 Journal Article
%T Particle Content of the Nonlinear Sigma Model with Theta-Term: a Lattice Model Investigation
%A L. Campos Venuti
%A C. Degli Esposti Boschi
%A E. Ercolessi
%A F. Ortolani
%A G. Morandi
%A S. Pasini
%A M. Roncaglia
%J Statistics
%D 2004
%I arXiv
%R 10.1088/1742-5468/2005/02/L02004
%X Using new as well as known results on dimerized quantum spin chains with frustration, we are able to infer some properties on the low-energy spectrum of the O(3) Nonlinear Sigma Model with a topological theta-term. In particular, for sufficiently strong coupling, we find a range of values of theta where a singlet bound state is stable under the triplet continuum. On the basis of these results, we propose a new renormalization group flow diagram for the Nonlinear Sigma Model with theta-term.
%U http://arxiv.org/abs/cond-mat/0412446v2