Energy spectra, altitude profiles, and charge ratios of atmospheric muons

Abstract

We present a new measurement of air shower muons made during atmospheric ascent of the High Energy Antimatter Telescope balloon experiment. The muon charge ratio µ + /µ − is presented as a function of atmospheric depth in the momentum interval 0.3-0.9 GeV/c. The differential µ − momentum spectra are presented between 0.3 and ∼50 GeV/c at atmospheric depths between 13 and 960 g/cm 2 . We compare our measurements with other recent data and with Monte Carlo calculations of the same type as those used in predicting atmospheric neutrino fluxes. We find that our measured µ − fluxes are smaller than the predictions by as much as 70% at shallow atmospheric depths, by ∼20% at the depth of shower maximum, and are in good agreement with the predictions at greater depths. We explore the consequences of this on the question of atmospheric neutrino production.

Cp-Violation in Neutrino Oscillations and L/E Flatness of the E-Like Event Ratio at Super-Kamiokande

“…The constraints (16)(17)(18)(19), after some algebraic manipulations, reduce to: (23) We find no non-trivial solution that satisfies this set of equations. However, a limit of the second case to be considered next does yield a non CP violating mixing matrix and reproduces the results given in Ref.…”