Angular distribution of low momentum atmospheric muons at ground level

Abstract

We report measurements of the angular distributions of low momentum atmospheric muons at 38 m above sea level for zenith angles $\theta$ between -60 and 60 degrees in the south-north direction. The muon detection was performed with two NaI(Tl) scintillation detectors mounted in coincidence. An adjustable lead thickness placed between the detectors allowed to select muons with a minimal momentum ranging from 0.3 to 0.9 GeV$/$c. The integrated and the differential muon flux were determined by analyzing the deposited energy spectra in the scintillators backed up by a Geant4 simulation of the experimental setup. The results are consistent with the ${\cos }^n(\theta )$ distribution in good agreement with the literature. These data contribute to fill the gap in the geomagnetic cutoff rigidity interval 8~GV$<P_c<$14~GV where no similar measurements were performed before. We found that $n=1.88-0.12P_{\mu }^c$ in this domain of muon momenta cutoff $P_{\mu }^c$<1 GeV$/$c. The present measurements are useful for many muon studies requiring an accurate integrated flux.

References in corpus (8)

• Discovery of a big void in Khufu's Pyramid by observation of cosmic-ray muons
• Atmospheric Muon Flux at Sea Level, Underground, and Underwater
• Calibration of the Super-Kamiokande Detector
• Nuclear Waste Imaging and Spent Fuel Verification by Muon Tomography
• Zenith distribution and flux of atmospheric muons measured with the 5-line ANTARES detector
• A Simple Parameterization of the Cosmic-Ray Muon Momentum Spectra at the Surface as a Function of Zenith Angle
• Measurement of Cosmic Muon angular distribution and vertical integrated flux by 2m$\times$2m RPC stack at IICHEP-Madurai
• Biological implications of high-energy cosmic ray induced muon flux in the extragalactic shock model