Deep Core muon neutrino rate and anisotropy by mixing and CPT violation

Abstract

Neutrinos are allowed to mix and to oscillate among their flavor. Muon and tau in particular oscillate at largest values. Last Minos experiment claimed MINOS Collaboration [12] possible difference among their matter and anti-matter masses, leading to a first violation of the most believed CPT symmetry. Isotropically born atmospheric muon neutrino at E ν μ ≃ 20 – 80 GeV , while upgoing, they might be partially suppressed by mixing in analogy to historical SuperKamiokande muon neutrino disappearance into tau, leading to large-scale anisotropy signals. Here, we show an independent muon rate foreseen in Deep Core based on observed SK signals extrapolated to Deep Core mass and its surrounding. Our rate prediction partially differ from previous ones. The ν μ , ν ̄ μ disappearance into ν τ , ν ̄ τ is leading to a μ , μ ̄ anisotropy in vertical upgoing muon track: in particular along channel 3–5 we expect a huge rate (nearly ten thousand of events) of neutral current events, charged current electron and inclined crossing muons. Moreover, at channel 6–9 we expect a severe suppression of the rate due to muon disappearance (in CPT conserved frame). A CPT violation may induce a suppression of vertical upgoing tracks because of larger ν ̄ μ reduction for E ν ̄ μ ≥ 35 GeV , corresponding to channel 9–10, and an amplified rate of events between channels 4–5–6.