Decay of Nambu-Goto Cosmic String Loops via Coupling to a Massive Kalb-Ramond Field

Abstract

We study the dynamics of Nambu-Goto cosmic string loops coupled to a massive Kalb-Ramond field. This coupling provides a framework for describing the interaction between the cosmic string and the gauge field. Within this setup, we compute the energy flux associated with the radiation of massive Kalb-Ramond modes from oscillating string loops. For loops featuring kinks, we find that the decay time scales with the square of the loop length. In contrast, loops with cusps exhibit a decay time proportional to 3/2 times the loop length. The results are in good agreement with field-theoretic simulations of Nambu-Goto-like loops in the Abelian-Higgs model, supporting the validity of the calculation.