Measurement of the momentum dependence of atmospheric muon vertical intensity at ground level in Tunisia

Angular distribution of low momentum atmospheric muons at ground level

“…The higher Φ I (0 • ) value of [33] is only due to the high altitude of the measurement. As expected, the present measurements of Φ I (0 • ) are compatible with the values reported in our previous work [18], as can be seen in figure 5. They are also coherent with the values reported in the literature when their variation as a function of P c , P c µ and the altitude is considered.…”

“…The three flux are compatible with each other within statistical uncertainties and the difference between the extreme values remains lower than the quoted systematic uncertainties. They are also compatible with the integral flux determined in our previous work [18] (Φ I = 67.55 ± 2.06 +1.36 −2.71 ) at the same lead thickness, but where the inter detector distance was 81 cm. This comparison, as well as the relatively good χ 2 /ndf (about 1.4 in average) of the fits for all the experimental JCAP04(2023)025 spectra, suggests that Geant4-CRY modeling of the background and muon spectra is quite realistic.…”

“…However, the linear expression of n reproduces better the experimental data and should be used for the applications requiring an accurate knowledge of the muon integral flux. One can see from figure 6 that the CRY Monte-Carlo simulation model overestimates the n exponent by more than 10% even if it reproduces globally the energy [18] and angular distributions in figure 5. This can be explained by the flat atmosphere model used in CRY which overestimates the muon path length for large zenith angles and thus underestimates the corresponding muon flux.…”

“…This uncertainty of the calibration at high deposited energies introduces a systematic uncertainty on N µ which is evaluated by studying the variation of N µ and the χ 2 of the fit when changing the calibration coefficient inside a confidence interval. More details on the determination of N µ and its systematic uncertainty can be found in our previous work [18].…”

“…In this paper, we report the zenith angle distributions of low energy (< 1 GeV) atmospheric muons in Tunisia (region of Monastir: 35.76 N, 10.81 E) at sea level corresponding to a geomagnetic cutoff rigidity P c =9.6 GV [17]. To our knowledge, the only published muon flux data in the region of North Africa concern the vertical muon intensities that we measured in a recent work in the same location [18]. The results reported herein constitute then the first measurements of atmospheric muon angular distributions at sea level in this region of the world and for a geomagnetic cutoff rigidity close to 10 GV.…”