A window for cosmic strings

Abstract Particle emission, in addition to gravitational radiation from cosmic string loops, affects the resulting loop distribution and hence corresponding observational consequences of strings. Here we focus on two models which loops length ? are produced infinite network with a given power-law. For both find that, due particle production, Stochastic Gravitational Wave Background (SGWB) is cut off outside region parameter space probed by any current or planned GW experiment. Therefore present constraints LIGO-Virgo-Kagra (LVK) collaboration still hold. However for one these models, if fraction ?????(10 -3 ) particles cascades into ? -rays, backreaction scale follows Polchinski-Rocha model, then tension tightly constrained below measurements Diffuse -Ray Background, above SGWB. With reasonable assumptions, joint constraint set possible observables reduces available this model narrow band. Future upgrades LVK will either rule out detect