Description of the heterotic string solutions in the M model

We continue the study of heterotic non-Abelian Bogomolny-Prasad-Sommerfield (BPS) saturated flux tubes (strings). Previously, such solutions were obtained in U(N) gauge theories: N=2 supersymmetric QCD deformed by superpotential terms μA2 breaking N=2 supersymmetry down to N=1. In these models one cannot consider the limit μ→ which would eliminate adjoint fields: the bulk theory develops a Higgs branch; the emergence of massless particles in the bulk precludes one from taking the limit μ→. This drawback is absent in the M model where the matter sector includes additional "meson" fields M introduced in a special way. We generalize our previous results to the M model, derive the heterotic string [the string world-sheet theory is a heterotic N=(0,2) sigma model, with the CP(N-1) target space for bosonic fields and an extra right-handed fermion coupled to the fermion fields of the N=(2,2) CP(N-1) model], and then explicitly obtain all relevant zero modes. This allows us to relate parameters of the microscopic M model to those of the world-sheet theory. The limit μ→ is perfectly smooth. Thus, the full-blown and fully analyzed heterotic string emerges, for the first time, in the N=1 theory with no adjoint fields. The fate of the confined monopoles is discussed.