Study of muons from ultrahigh energy cosmic ray air showers measured with the Telescope Array experiment

(Telescope Array Collaboration)

Research output: Contribution to journalArticle

7 Citations (Scopus)

Abstract

One of the uncertainties in the interpretation of ultrahigh energy cosmic ray data comes from the hadronic interaction models used for air shower Monte Carlo (MC) simulations. The number of muons observed at the ground from ultrahigh energy cosmic ray-induced air showers is expected to depend upon the hadronic interaction model. One may therefore test the hadronic interaction models by comparing the measured number of muons with the MC prediction. In this paper, we present the results of studies of muon densities in ultrahigh energy extensive air showers obtained by analyzing the signal of surface detector stations which should have high muon purity. The muon purity of a station will depend on both the inclination of the shower and the relative position of the station. In seven years' data from the Telescope Array experiment, we find that the number of particles observed for signals with an expected muon purity of ∼65% at a lateral distance of 2000 m from the shower core is 1.72±0.10(stat)±0.37(syst) times larger than the MC prediction value using the QGSJET II-03 model for proton-induced showers. A similar effect is also seen in comparisons with other hadronic models such as QGSJET II-04, which shows a 1.67±0.10±0.36 excess. We also studied the dependence of these excesses on lateral distances and found a slower decrease of the lateral distribution of muons in the data as compared to the MC, causing larger discrepancy at larger lateral distances.

Original languageEnglish
Article number022002
JournalPhysical Review D
Volume98
Issue number2
DOIs
Publication statusPublished - 2018 Jul 15

Fingerprint

cosmic ray showers
muons
cosmic rays
telescopes
showers
purity
stations
energy
interactions
predictions
inclination
protons
detectors
simulation

All Science Journal Classification (ASJC) codes

  • Physics and Astronomy (miscellaneous)

Cite this

@article{d7ec3aa2f3ed485c86aa3ee857d4d245,
title = "Study of muons from ultrahigh energy cosmic ray air showers measured with the Telescope Array experiment",
abstract = "One of the uncertainties in the interpretation of ultrahigh energy cosmic ray data comes from the hadronic interaction models used for air shower Monte Carlo (MC) simulations. The number of muons observed at the ground from ultrahigh energy cosmic ray-induced air showers is expected to depend upon the hadronic interaction model. One may therefore test the hadronic interaction models by comparing the measured number of muons with the MC prediction. In this paper, we present the results of studies of muon densities in ultrahigh energy extensive air showers obtained by analyzing the signal of surface detector stations which should have high muon purity. The muon purity of a station will depend on both the inclination of the shower and the relative position of the station. In seven years' data from the Telescope Array experiment, we find that the number of particles observed for signals with an expected muon purity of ∼65{\%} at a lateral distance of 2000 m from the shower core is 1.72±0.10(stat)±0.37(syst) times larger than the MC prediction value using the QGSJET II-03 model for proton-induced showers. A similar effect is also seen in comparisons with other hadronic models such as QGSJET II-04, which shows a 1.67±0.10±0.36 excess. We also studied the dependence of these excesses on lateral distances and found a slower decrease of the lateral distribution of muons in the data as compared to the MC, causing larger discrepancy at larger lateral distances.",
author = "{(Telescope Array Collaboration)} and Abbasi, {R. U.} and M. Abe and T. Abu-Zayyad and M. Allen and R. Azuma and E. Barcikowski and Belz, {J. W.} and Bergman, {D. R.} and Blake, {S. A.} and R. Cady and Cheon, {B. G.} and J. Chiba and M. Chikawa and {Di Matteo}, A. and T. Fujii and K. Fujita and M. Fukushima and G. Furlich and T. Goto and W. Hanlon and M. Hayashi and Y. Hayashi and N. Hayashida and K. Hibino and K. Honda and D. Ikeda and N. Inoue and T. Ishii and R. Ishimori and H. Ito and D. Ivanov and Jeong, {H. M.} and S. Jeong and Jui, {C. C.H.} and K. Kadota and F. Kakimoto and O. Kalashev and K. Kasahara and H. Kawai and S. Kawakami and S. Kawana and K. Kawata and E. Kido and Kim, {H. B.} and Kim, {J. H.} and Kim, {J. H.} and S. Kishigami and S. Kitamura and Y. Kitamura and Youngjoon Kwon",
year = "2018",
month = "7",
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doi = "10.1103/PhysRevD.98.022002",
language = "English",
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journal = "Physical Review D",
issn = "2470-0010",
publisher = "American Physical Society",
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Study of muons from ultrahigh energy cosmic ray air showers measured with the Telescope Array experiment. / (Telescope Array Collaboration).

In: Physical Review D, Vol. 98, No. 2, 022002, 15.07.2018.

Research output: Contribution to journalArticle

TY - JOUR

T1 - Study of muons from ultrahigh energy cosmic ray air showers measured with the Telescope Array experiment

AU - (Telescope Array Collaboration)

AU - Abbasi, R. U.

AU - Abe, M.

AU - Abu-Zayyad, T.

AU - Allen, M.

AU - Azuma, R.

AU - Barcikowski, E.

AU - Belz, J. W.

AU - Bergman, D. R.

AU - Blake, S. A.

AU - Cady, R.

AU - Cheon, B. G.

AU - Chiba, J.

AU - Chikawa, M.

AU - Di Matteo, A.

AU - Fujii, T.

AU - Fujita, K.

AU - Fukushima, M.

AU - Furlich, G.

AU - Goto, T.

AU - Hanlon, W.

AU - Hayashi, M.

AU - Hayashi, Y.

AU - Hayashida, N.

AU - Hibino, K.

AU - Honda, K.

AU - Ikeda, D.

AU - Inoue, N.

AU - Ishii, T.

AU - Ishimori, R.

AU - Ito, H.

AU - Ivanov, D.

AU - Jeong, H. M.

AU - Jeong, S.

AU - Jui, C. C.H.

AU - Kadota, K.

AU - Kakimoto, F.

AU - Kalashev, O.

AU - Kasahara, K.

AU - Kawai, H.

AU - Kawakami, S.

AU - Kawana, S.

AU - Kawata, K.

AU - Kido, E.

AU - Kim, H. B.

AU - Kim, J. H.

AU - Kim, J. H.

AU - Kishigami, S.

AU - Kitamura, S.

AU - Kitamura, Y.

AU - Kwon, Youngjoon

PY - 2018/7/15

Y1 - 2018/7/15

N2 - One of the uncertainties in the interpretation of ultrahigh energy cosmic ray data comes from the hadronic interaction models used for air shower Monte Carlo (MC) simulations. The number of muons observed at the ground from ultrahigh energy cosmic ray-induced air showers is expected to depend upon the hadronic interaction model. One may therefore test the hadronic interaction models by comparing the measured number of muons with the MC prediction. In this paper, we present the results of studies of muon densities in ultrahigh energy extensive air showers obtained by analyzing the signal of surface detector stations which should have high muon purity. The muon purity of a station will depend on both the inclination of the shower and the relative position of the station. In seven years' data from the Telescope Array experiment, we find that the number of particles observed for signals with an expected muon purity of ∼65% at a lateral distance of 2000 m from the shower core is 1.72±0.10(stat)±0.37(syst) times larger than the MC prediction value using the QGSJET II-03 model for proton-induced showers. A similar effect is also seen in comparisons with other hadronic models such as QGSJET II-04, which shows a 1.67±0.10±0.36 excess. We also studied the dependence of these excesses on lateral distances and found a slower decrease of the lateral distribution of muons in the data as compared to the MC, causing larger discrepancy at larger lateral distances.

AB - One of the uncertainties in the interpretation of ultrahigh energy cosmic ray data comes from the hadronic interaction models used for air shower Monte Carlo (MC) simulations. The number of muons observed at the ground from ultrahigh energy cosmic ray-induced air showers is expected to depend upon the hadronic interaction model. One may therefore test the hadronic interaction models by comparing the measured number of muons with the MC prediction. In this paper, we present the results of studies of muon densities in ultrahigh energy extensive air showers obtained by analyzing the signal of surface detector stations which should have high muon purity. The muon purity of a station will depend on both the inclination of the shower and the relative position of the station. In seven years' data from the Telescope Array experiment, we find that the number of particles observed for signals with an expected muon purity of ∼65% at a lateral distance of 2000 m from the shower core is 1.72±0.10(stat)±0.37(syst) times larger than the MC prediction value using the QGSJET II-03 model for proton-induced showers. A similar effect is also seen in comparisons with other hadronic models such as QGSJET II-04, which shows a 1.67±0.10±0.36 excess. We also studied the dependence of these excesses on lateral distances and found a slower decrease of the lateral distribution of muons in the data as compared to the MC, causing larger discrepancy at larger lateral distances.

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UR - http://www.scopus.com/inward/citedby.url?scp=85051104508&partnerID=8YFLogxK

U2 - 10.1103/PhysRevD.98.022002

DO - 10.1103/PhysRevD.98.022002

M3 - Article

VL - 98

JO - Physical Review D

JF - Physical Review D

SN - 2470-0010

IS - 2

M1 - 022002

ER -