Ongoing magnetic monopole searches with IceCube

The IceCube collaboration has instrumented a cubic kilometer of ice with $5160$ photo-multipliers. While mainly developed to detect Cherenkov light, any visible light can be used to detect particles within the ice. Magnetic monopoles are hypothetical particles predicted by many theories that extend the Standard model of Particle Physics. They are carriers of a single elementary magnetic charge. For this particle, different light production mechanisms dominate from direct Cherenkov light at highly relativistic velocities $\left(>0.76\,c\right)$, indirect Cherenkov light at mildly relativistic velocities $\left(\approx 0.5\,c \textrm{ to } 0.76\,c\right)$, luminescence light at low relativistic velocities $\left( \gtrsim 0.1\,c \textrm{ to } 0.5\,c\right)$, as well as catalysis of proton decay at non relativistic velocities $\left(\lesssim 0.1\,c\right)$. For each of this speed ranges, searches for magnetic monopoles at the IceCube experiment are either in progress or they have already set the world's best limits on the flux of magnetic monopoles. A summary of these searches will be presented, outlining already existing results as well as methods used by the currently conducted searches.Comment: Conference proceedings from 6th International Conference on New Frontiers in Physics (ICNFP 2017) from August 17th to 29th of 2017 at the Conference Center of the Orthodox Academy of Creta (OAC) in Kolymbari (Crete), Greece, 8 pages, 8 figure

IceCube Search for Earth-traversing ultra-high energy Neutrinos

The search for ultra-high energy neutrinos is more than half a century old. While the hunt for these neutrinos has led to major leaps in neutrino physics, including the detection of astrophysical neutrinos, neutrinos at the EeV energy scale remain undetected. Proposed strategies for the future have mostly been focused on direct detection of the first neutrino interaction, or the decay shower of the resulting charged particle. Here we present an analysis that uses, for the first time, an indirect detection strategy for EeV neutrinos. We focus on tau neutrinos that have traversed Earth, and show that they reach the IceCube detector, unabsorbed, at energies greater than 100 TeV for most trajectories. This opens up the search for ultra-high energy neutrinos to the entire sky. We use ten years of IceCube data to perform an analysis that looks for secondary neutrinos in the northern sky, and highlight the promise such a strategy can have in the next generation of experiments when combined with direct detection techniques

Posteriori analysis on IceCube double pulse tau neutrino candidates

The IceCube Neutrino Observatory at the South Pole detects Cherenkov light emitted by charged secondary particles created by primary neutrino interactions. Double pulse waveforms can arise from charged current interactions of astrophysical tau neutrinos with nucleons in the ice and the subsequent decay of tau leptons. The previous 8-year tau double pulse analysis found three tau neutrino candidate events. Among them, the most promising one observed in 2014 is located very near the dust layer in the middle of the detector. A posterior analysis on this event will be presented in this paper, using a new ice model treatment with continuously varying nuisance parameters to do the targeted Monte Carlo re-simulation for tau and other background neutrino ensembles. The impact of different ice models on the expected signal and background statistics will also be discussed