Variation with Zenith Angle of the Integral Intensity of Muons near Sea Level

Abstract

The integral intensity of the cosmic ray muon flux (>0.28 GeV/c) near sea level has been measured in the zenith angle range 75-90", Very few other experimental measurements have been made in this range. The present results agree closely with the predictions of a current theoretical model except at very large zenith angles, where the measured intensities are somewhat higher than predicted.On a mesure l'intensite totale du flux de muons (~0 . 2 8 GeVlc) dans le rayonnement cosmique au niveau de la mer, pour des angles au zenith allant de 75" a 90". I1 existe tres peu de mesures experimentales dans cette region. Les resultats obtenus sont tres pres des predictions d'un modele thkoriquecourant sauf pour des angles au d n i t h tres grands oli les intensites mesurees sont un peu superieures aux valeurs predites.

Measurements of integrated muon intensity at large zenith angles

“…4. Comparison of calculated values with data [1,4,5,7,8] shows a reasonable agreement. In works [2] and [6], the intensity is somewhat higher than measured in [1] or calculated by (2).…”

“…Regions of threshold energies and zenith angles accessible for DECOR and analyzed in this work are shown by the dashed areas in Fig. 1 - [2] - [3] - [4] - [5] - [6] - [7] - [8] …”

Atmospheric muons: experimental aspects

“…It is also shown if the experiment has been used by other reviews, namely "B" (Bugaev et al, 1998), "H&T" (Hebbeker and Timmermans, 2002) and in the Particle Data Group "PDG" (Nakamura et al, 2010). For H&T we report also the final normalization Flint et al (1972), Jakeman (1956), Wilson (1959), Gettert et al (1993), Dmitrieva et al (2006), Crokes and Rastin (1972). of material crossed by the particle in such detectors increases with increase of zenith angle, so the threshold energy for multidirectional muon telescopes depends on θ. A compilation of measurements of the muon flux at latitudes between 52 and 56 • as a function of the zenith angle by different experiments is reported in Fig.…”

“…The points are normalized assuming p T = 0.35 GeV/c. The points correspond (from top to bottom): Flint et al (1972), Jakeman (1956), Wilson (1959), Gettert et al (1993), Dmitrieva et al (2006), Crokes and Rastin (1972).…”

Atmospheric muons: experimental aspects

“…For muon momenta above 10 GeV and altitudes H less than ∼ 1000 m the vertical muon flux can be parameterized as I µ (H) = I µ (0)e −H/L(p) , where L(p) = 4900 + 750p is a scale factor (in meters) which depends on muon momentum, p (measured in GeV/c). [38], [47], [55], [41], [35], [29].…”