Speaker
Description
IceCube has made measurements of diffuse astrophysical neutrino flux for all flavors up to PeV scales. The high energy (TeV-PeV) IceCube cascade sample is particularly effective at selecting electron and tau neutrinos. We present the results of Single Power Law (SPL) and Broken Power Law (BPL) flux measurements based on 11 years of cascade data. From this cascade sample, we identify high energy (~ 100 TeV) tau neutrinos by detecting a double-cascade signature produced by a charged-current neutrino interaction and the subsequent decay of the tau lepton. A Boosted Decision Tree (BDT), is employed to search for the double cascade signature achieving a significantly improved signal-to-background ratio (9:1) compared to previous analyses based on simple selection cuts. Our simulated double-cascade sample yields a high tau-neutrino purity (~90%) and good reconstruction quality (weighted mean error for reconstructed tau decay length ~ 4m). We present sensitivities for a maximum likelihood fit of the flavor composition and constraints on the astrophysical neutrino flavor ratios using this sample in combination with IceCube’s northern muon neutrino-induced track sample.
| Collaboration(s) | IceCube Collaboration |
|---|
