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arXiv · 0911.2655

Cosmic Rays from Cosmic Strings with Condensates

Tanmay Vachaspati
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Abstract

We re-visit the production of cosmic rays by cusps on cosmic strings. If a scalar field (``Higgs'') has a linear interaction with the string world-sheet, such as would occur if there is a bosonic condensate on the string, cusps on string loops emit narrow beams of very high energy Higgses which then decay to give a flux of ultra high energy cosmic rays. The ultra-high energy flux and the gamma to proton ratio agree with observations if the string scale is $\sim 10^{13}$ GeV. The diffuse gamma ray and proton fluxes are well below current bounds. Strings that are {\it lighter} and have linear interactions with scalars produce an excess of direct and diffuse cosmic rays and are ruled out by observations, while heavier strings ($\sim 10^{15}$ GeV) are constrained by their gravitational signatures. This leaves a narrow window of parameter space for the existence of cosmic strings with bosonic condensates.

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Tanmay Vachaspati. 2009-11-13. Cosmic Rays from Cosmic Strings with Condensates. https://doi.org/10.1103/physrevd.81.043531

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