Measurement of the flux of atmospheric muons with the CAPRICE94 apparatus

TL;DR

This paper reports new measurements of atmospheric muon fluxes across a range of momenta and depths, providing data crucial for validating neutrino flux models and understanding neutrino anomalies.

Contribution

It presents the first detailed momentum spectra of atmospheric muons at various depths from the CAPRICE94 balloon experiment, including latitude-dependent effects.

Findings

Good agreement with previous high-momentum measurements.

Latitude-dependent geomagnetic effects observed below 1 GeV/c.

Data supports improved atmospheric neutrino flux calculations.

Abstract

A new measurement of the momentum spectra of both positive and negative muons as function of atmospheric depth was made by the balloon-borne experiment CAPRICE94. The data were collected during ground runs in Lynn Lake on the 19-20th of July 1994 and during the balloon flight on the 8-9th of August 1994. We present results that cover the momentum intervals 0.3-40 GeV/c for negative muons and 0.3-2 GeV/c for positive muons, for atmospheric depths from 3.3 to 1000 g/cm**2, respectively. Good agreement is found with previous measurements for high momenta, while at momenta below 1 GeV/c we find latitude dependent geomagnetic effects. These measurements are important cross-checks for the simulations carried out to calculate the atmospheric neutrino fluxes and to understand the observed atmospheric neutrino anomaly.