Direct Detection of Kaluza-Klein Particles in Neutrino Telescopes

TL;DR

This paper explores the potential for neutrino telescopes to detect Kaluza-Klein particles predicted by theories with extra dimensions, focusing on the production and detection rates of long-lived NLKPs from high-energy neutrino interactions.

Contribution

It introduces a novel detection method for KK particles via neutrino interactions in Earth, analyzing expected event rates and detection feasibility.

Findings

Potential detection rate of hundreds of NLKP events per year.

Detection feasibility depends on NLKP mass and neutrino flux.

Long-lived NLKPs could be observable in current neutrino telescopes.

Abstract

In theories with universal extra dimensions (UEDs), all standard model fields propagate in the bulk and the lightest state of the first Kaluza-Klein (KK) level can be made stable by imposing a Z2 parity. We consider a framework where the lightest KK particle (LKP) is a neutral, extremely weakly interacting particle such as the first KK excitation of the graviton, while the next-to-lightest KK particle (NLKP) is the first KK mode of a charged right-handed lepton. In such a scenario, due to its very small couplings to the LKP, the NLKP is long-lived. We investigate the production of these particles from the interaction of high energy neutrinos with nucleons in the Earth, and determine the rate of NLKP events in neutrino telescopes. Using the Waxman-Bahcall limit for the neutrino flux, we find that the rate can be as large as a few hundreds events a year for realistic values of the NLKP mass.