Direction Reconstruction for the Radio Neutrino Observatory Greenland (RNO-G)

Abstract

The Radio Neutrino Observatory Greenland (RNO-G) is planned to be the first large-scale implementation of the in-ice radio detection technique. It targets astrophysical as well as cosmogenic neutrinos with energies above 10 PeV. The deep component of a single RNO-G station consists of three strings with antennas to capture horizontal as well as vertical polarization. This contribution shows a model-based approach to reconstruct the arrival direction of the neutrinos with an RNO-G station. The timing of the waveforms is used to reconstruct the vertex position. The shape and amplitude of the waveform are used to reconstruct the viewing angle. Together with the signal polarization it will add up to the neutrino arrival direction. We present the method used and the achieved angular resolution using the deep component of an RNO-G station.

The ultra-high-energy neutrino-nucleon cross section: measurement forecasts for an era of cosmic EeV-neutrino discovery

“…Each detector stations measures enough information to determine the shower energy and neutrino arrival direction; see, e.g., Refs. [182,[196][197][198][199][200].…”

“…The index-of-refraction profile is known well enough to achieve sub-degree precision on the signal direction, as tested in measurements at the South Pole [208]. The viewing angle can typically be reconstructed to within 1 • [197,200,210]. The dominant uncertainty on the direction comes from the measurement of the signal polar--1.0 -0.…”

“…ization [197,208,210]. Polarization is generally measured better in shallow detector components because their orthogonal LPDA pairs provide equal sensitivity to both polarization states.…”

“…The ability to measure the viewing angle and to combine all individual measurements to estimate the arrival direction was quantified in simulation studies using the forward folding technique [81,197,199,210] and deep neural networks [182,212]. The best resolution of the direction was obtained with a shallow detector station with a 68% quantile of 3 • , which translates into an uncertainty of the zenith angle of σ θz = 2 • .…”

Rapporteur ICRC 2021: Neutrinos and Muons

“…KM3NeT will likely reach sub-degree resolution for single cascades [31], and IceCube has, for example, reported on checks of the pointing accuracy using the shadow of the moon, starting to resolve the rim of the moon [32]. While likely not competitive in angular pointing, predictions of the angular resolution of in-ice radio arrays are starting to be more concrete [33,34] (see also Figure 4), which will be useful to evaluate physics cases of the upcoming and proposed in-ice radio arrays and get the theory community thinking of particular models to test in the highest energy range.…”