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Neutrinos as Source of Ultra High Energy Cosmic Rays in Extra Dimensions

Ashok Goyal·Abhinav Gupta·Namit Mahajan
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Abstract

If the neutrinos are to be identified with the primary source of ultra-high energy cosmic rays(UHECR), their interaction on relic neutrinos is of great importance in understanding their long intergalactic journey. In theories with large compact dimensions, the exchange of a tower of massive spin-2 gravitons (Kaluza-Klein excitations) gives extra contribution to $ν\barν \longrightarrow f\bar{f}$ and $γγ$ processes along with the opening of a new channel for the neutrinos to annihilate with the relic cosmic neutrino background $ν\barν \longrightarrow G_{kk}$ to produce bulk gravitons in the extra dimensions. This will affect their attenuation. We compute the contribution of these Kaluza-Klein excitations to the above processes and find that for parameters of the theory constrained by supernova cooling, the contribution does indeed become the dominant contribution above $\sqrt{s} \simeq 300$ GeV.

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Ashok Goyal, Abhinav Gupta, Namit Mahajan. 2000-09-20. Neutrinos as Source of Ultra High Energy Cosmic Rays in Extra Dimensions. https://doi.org/10.1103/physrevd.63.043003

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