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.