title: Stable charged cosmic strings.
abstract: We study the quantum stabilization of a cosmic string by a heavy fermion doublet in a reduced version of the standard model. We show that charged strings, obtained by populating fermionic bound state levels, become stable if the electroweak bosons are coupled to a fermion that is less than twice as heavy as the top quark. This result suggests that extraordinarily large fermion masses or unrealistic couplings are not required to bind a cosmic string in the standard model. Numerically we find the most favorable string profile to be a simple trough in the Higgs vacuum expectation value of radius ≈10(-18)  m. The vacuum remains stable in our model, because neutral strings are not energetically favored.
authors.affiliation: Physics Department, Stellenbosch University, Matieland 7602, South Africa.
authors.forename: H
authors.initials: H
authors.lastname: Weigel
authors.forename: M
authors.initials: M
authors.lastname: Quandt
authors.forename: N
authors.initials: N
authors.lastname: Graham