Searching for ${\nu }_{\mu }\to {\nu }_{\tau }$ Oscillations with Extragalactic Neutrinos

Abstract

We propose a novel approach for studying ${\nu }_{\mu }\to {\nu }_{\tau }$ oscillations with extragalactic neutrinos. Active Galactic Nuclei and Gamma Ray Bursts are believed to be sources of ultrahigh energy muon neutrinos. With distances of 100 Mpc or more, they provide an unusually long baseline for possible detection of ${\nu }_{\mu }\to {\nu }_{\tau }$ with mixing parameters $\Delta m^2$ down to $10^{-17}$eV${}^2$, many orders of magnitude below the current accelerator experiments. By solving the coupled transport equations, we show that high-energy ${\nu }_{\tau }$'s, as they propagate through the earth, cascade down in energy, producing the enhancement of the incoming ${\nu }_{\tau }$ flux in the low energy region, in contrast to the high-energy ${\nu }_{\mu }$'s, which get absorbed. For an AGN quasar model we find the ${\nu }_{\tau }$ flux to be a factor of 2 to 2.5 larger than the incoming flux in the energy range between $10^2$ GeV and $10^4$ GeV, while for a GRB fireball model, the enhancement is 10%-27% in the same energy range and for zero nadir angle. This enhancement decreases with larger nadir angle, thus providing a novel way to search for ${\nu }_{\tau }$ appearance by measuring the angular dependence of the muons. To illustrate how the cascade effect and the ${\nu }_{\tau }$ final flux depend on the steepness of the incoming ${\nu }_{\tau }$, we show the energy and angular distributions for several generic cases of the incoming tau neutrino flux, $F_{\nu }^0\sim E^{-n}$ for n=1,2 and 3.6. We show that for the incoming flux that is not too steep, the signal for the appearance of high-energy ${\nu }_{\tau }$ is the enhanced production of lower energy $\mu$ and their distinctive angular dependence, due to the contribution from the $\tau$ decay into $\mu$ just below the detector.

11 pages, including 4 color figures

References in corpus (10)

• Evidence for oscillation of atmospheric neutrinos
• Neutrino Interactions at Ultrahigh Energies
• Measurement of a small atmospheric ${\nu }_{\mu }/{\nu }_e$ ratio
• Study of the atmospheric neutrino flux in the multi-GeV energy range
• Measurement of the atmospheric neutrino-induced upgoing muon flux using MACRO
• Measurement of the solar neutrino energy spectrum using neutrino-electron scattering
• Tau Neutrino Appearance with a 1000 Megaparsec Baseline
• Measurement of the flux and zenith-angle distribution of upward through-going muons in Kamiokande II+III
• Tau neutrino fluxes from atmospheric charm
• Neutrino Propagation Through Matter

Cited by in corpus (34)

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• Cosmology and Astrophysics of Minimal Dark Matter
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• Physics Reach of High-Energy and High-Statistics IceCube Atmospheric Neutrino Data
• Spectral analysis of the high-energy IceCube neutrinos
• On the flavor composition of the high-energy neutrino events in IceCube
• Neutrino cross sections at high energies and the future observations of ultrahigh-energy cosmic rays
• Probing the LSND scale and four neutrino scenarios with a neutrino telescope
• Prompt atmospheric neutrino fluxes: perturbative QCD models and nuclear effects
• Identifying Galactic PeVatrons with Neutrinos
• Tau Neutrinos Underground: Signals of ${\nu }_{\mu }\to {\nu }_{\tau }$ Oscillations with Extragalactic Neutrinos
• Snowmass White Paper: Beyond the Standard Model effects on Neutrino Flavor
• Non-standard interactions with high-energy atmospheric neutrinos at IceCube
• High Energy Neutrinos from Gamma Ray Bursts: Event Rates in Neutrino Telescopes
• High-energy neutrino attenuation in the Earth and its associated uncertainties
• Tracing very high energy neutrinos from cosmological distances in ice
• Secondary Neutrinos from Tau Neutrino Interactions in Earth
• Oscillating Neutrinos from the Galactic Center
• Extreme Energy nu_tau Propagation Through the Earth
• A Search for UHE Tau Neutrinos with IceCube
• The Oscillation Probability of GeV Solar Neutrinos of All Active Species
• Neutrino propagation in the Earth and emerging charged leptons with $\text{nuPyProp}$
• Anomalous ANITA air shower events and tau decays
• Signatures of cosmic tau-neutrinos
• High Energy Neutrino Signals of Four Neutrino Mixing
• Tau Appearance from High-Energy Neutrino Interactions
• Neutrino conversions in cosmological gamma-ray burst fireballs
• On the transport equations of cosmic neutrinos passing through Earth and secondary nu_mu fluxes
• High-energy neutrino oscillations in absorbing matter
• The Appearance of Tau Neutrinos from a Gamma Ray Burst
• The Passage of Ultrarelativistic Neutralinos through Matter
• Matter effects on neutrino oscillations in gravitational and magnetic fields
• Effects of Majorana Physics on the UHE ${\nu }_{\tau }$ Flux Traversing the Earth