title: Solution of a model of self-avoiding walks with multiple monomers per site on the Bethe lattice.
abstract: We solve a model of self-avoiding walks with up to two monomers per site on the Bethe lattice. This model, inspired in the Domb-Joyce model, was recently proposed to describe the collapse transition observed in interacting polymers [J. Krawczyk, Phys. Rev. Lett. 96, 240603 (2006)]. When immediate self-reversals are allowed (reversion-allowed model), the solution displays a phase diagram with a polymerized phase and a nonpolymerized phase, separated by a phase transition which is of first order for a nonvanishing statistical weight of doubly occupied sites. If the configurations are restricted forbidding immediate self-reversals (reversion-forbidden model), a richer phase diagram with two distinct polymerized phases is found, displaying a tricritical point and a critical end point.
authors.affiliation: Facultad de Matemática, Astronomía y Física, Universidad Nacional de Córdoba, Córdoba, RA5000, Argentina. serra@famaf.unc.edu.ar
authors.forename: Pablo
authors.initials: P
authors.lastname: Serra
authors.forename: Jürgen F
authors.initials: JF
authors.lastname: Stilck