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 electro--weak 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 vev of radius $\approx 10^{-18}\mathrm{m}$. The vacuum remains stable in our model, because neutral strings are not energetically favored.

5 pages, 3 figures, version to be published in Phys. Rev. Lett

References in corpus (4)

• Remarkable coincidence for the top Yukawa coupling and an approximately massless bound state
• Multi-fermion states for heavy fermions bound via Higgs exchange
• Quantum Energies of Strings in a 2+1 Dimensional Gauge Theory
• Quantum stabilization of Z-strings, a status report on D=3+1 dimensions

Cited by in corpus (1)

• Fermion Energies in the Background of a Cosmic String