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Title: Measurement of the atmospheric muon charge ratio at TeV energies with MINOS

Abstract

The 5.4 kton MINOS far detector has been taking charge-separated cosmic ray muon data since the beginning of August, 2003 at a depth of 2070 m.w.e. in the Soudan Underground Laboratory, Minnesota, USA. The data with both forward and reversed magnetic field running configurations were combined to minimize systematic errors in the determination of the underground muon charge ratio. When averaged, two independent analyses find the charge ratio underground to be N{sub {mu}}+/N{sub {mu}}-=1.374{+-}0.004(stat)-0.010{sup +0.012}(sys). Using the map of the Soudan rock overburden, the muon momenta as measured underground were projected to the corresponding values at the surface in the energy range 1-7 TeV. Within this range of energies at the surface, the MINOS data are consistent with the charge ratio being energy independent at the 2 standard deviation level. When the MINOS results are compared with measurements at lower energies, a clear rise in the charge ratio in the energy range 0.3-1.0 TeV is apparent. A qualitative model shows that the rise is consistent with an increasing contribution of kaon decays to the muon charge ratio.

Authors:
; ; ; ; ; ; ; ; ; ; ;
Publication Date:
Research Org.:
Fermi National Accelerator Lab. (FNAL), Batavia, IL (United States)
Sponsoring Org.:
USDOE
OSTI Identifier:
917102
Report Number(s):
FERMILAB-PUB-07-134-E
Journal ID: ISSN 0022-3727; JPAPBE; arXiv eprint number arXiv:0705.3815; TRN: US0804451
DOE Contract Number:
AC02-07CH11359
Resource Type:
Journal Article
Resource Relation:
Journal Name: Phys.Rev.D76:052003,2007; Journal Volume: 76
Country of Publication:
United States
Language:
English
Subject:
72 PHYSICS OF ELEMENTARY PARTICLES AND FIELDS; ENERGY RANGE; KAONS; MAGNETIC FIELDS; MINUS-PLUS RATIO; MUONS; OVERBURDEN; Experiment-HEP

Citation Formats

Adamson, P., Andreopoulos, C., Arms, K.E., Armstrong, R., Auty, D.J., Avvakumov, S., Ayres, D.S., Baller, B., Barish, B., Barnes, P.D., Jr., Barr, G., and /Fermilab /University Coll. London /Rutherford /Minnesota U. /Indiana U. /Sussex U. /Stanford U., Phys. Dept. /Argonne /Caltech /LLNL, Livermore /Oxford U. Measurement of the atmospheric muon charge ratio at TeV energies with MINOS. United States: N. p., 2007. Web. doi:10.1103/PhysRevD.76.052003.
Adamson, P., Andreopoulos, C., Arms, K.E., Armstrong, R., Auty, D.J., Avvakumov, S., Ayres, D.S., Baller, B., Barish, B., Barnes, P.D., Jr., Barr, G., & /Fermilab /University Coll. London /Rutherford /Minnesota U. /Indiana U. /Sussex U. /Stanford U., Phys. Dept. /Argonne /Caltech /LLNL, Livermore /Oxford U. Measurement of the atmospheric muon charge ratio at TeV energies with MINOS. United States. doi:10.1103/PhysRevD.76.052003.
Adamson, P., Andreopoulos, C., Arms, K.E., Armstrong, R., Auty, D.J., Avvakumov, S., Ayres, D.S., Baller, B., Barish, B., Barnes, P.D., Jr., Barr, G., and /Fermilab /University Coll. London /Rutherford /Minnesota U. /Indiana U. /Sussex U. /Stanford U., Phys. Dept. /Argonne /Caltech /LLNL, Livermore /Oxford U. Tue . "Measurement of the atmospheric muon charge ratio at TeV energies with MINOS". United States. doi:10.1103/PhysRevD.76.052003. https://www.osti.gov/servlets/purl/917102.
@article{osti_917102,
title = {Measurement of the atmospheric muon charge ratio at TeV energies with MINOS},
author = {Adamson, P. and Andreopoulos, C. and Arms, K.E. and Armstrong, R. and Auty, D.J. and Avvakumov, S. and Ayres, D.S. and Baller, B. and Barish, B. and Barnes, P.D., Jr. and Barr, G. and /Fermilab /University Coll. London /Rutherford /Minnesota U. /Indiana U. /Sussex U. /Stanford U., Phys. Dept. /Argonne /Caltech /LLNL, Livermore /Oxford U.},
abstractNote = {The 5.4 kton MINOS far detector has been taking charge-separated cosmic ray muon data since the beginning of August, 2003 at a depth of 2070 m.w.e. in the Soudan Underground Laboratory, Minnesota, USA. The data with both forward and reversed magnetic field running configurations were combined to minimize systematic errors in the determination of the underground muon charge ratio. When averaged, two independent analyses find the charge ratio underground to be N{sub {mu}}+/N{sub {mu}}-=1.374{+-}0.004(stat)-0.010{sup +0.012}(sys). Using the map of the Soudan rock overburden, the muon momenta as measured underground were projected to the corresponding values at the surface in the energy range 1-7 TeV. Within this range of energies at the surface, the MINOS data are consistent with the charge ratio being energy independent at the 2 standard deviation level. When the MINOS results are compared with measurements at lower energies, a clear rise in the charge ratio in the energy range 0.3-1.0 TeV is apparent. A qualitative model shows that the rise is consistent with an increasing contribution of kaon decays to the muon charge ratio.},
doi = {10.1103/PhysRevD.76.052003},
journal = {Phys.Rev.D76:052003,2007},
number = ,
volume = 76,
place = {United States},
year = {Tue May 01 00:00:00 EDT 2007},
month = {Tue May 01 00:00:00 EDT 2007}
}
  • The 5.4 kton MINOS far detector has been taking charge-separated cosmic ray muon data since the beginning of August, 2003 at a depth of 2070 m.w.e. in the Soudan Underground Laboratory, Minnesota, USA. The data with both forward and reversed magnetic field running configurations were combined to minimize systematic errors in the determination of the underground muon charge ratio. When averaged, two independent analyses find the charge ratio underground to be N{sub {mu}{sup +}}/N{sub {mu}{sup -}}=1.374{+-}0.004(stat){sub -0.010}{sup +0.012}(sys). Using the map of the Soudan rock overburden, the muon momenta as measured underground were projected to the corresponding values at themore » surface in the energy range 1-7 TeV. Within this range of energies at the surface, the MINOS data are consistent with the charge ratio being energy independent at the 2 standard deviation level. When the MINOS results are compared with measurements at lower energies, a clear rise in the charge ratio in the energy range 0.3-1.0 TeV is apparent. A qualitative model shows that the rise is consistent with an increasing contribution of kaon decays to the muon charge ratio.« less
  • The magnetized MINOS Near Detector, at a depth of 225 mwe, is used to measure the atmospheric muon charge ratio. The ratio of observed positive to negative atmospheric muon rates, using 301 days of data, is measured to be 1.266{+-}0.001(stat){sub -0.014}{sup +0.015}(syst). This measurement is consistent with previous results from other shallow underground detectors and is 0.108{+-}0.019(stat+syst) lower than the measurement at the functionally identical MINOS Far Detector at a depth of 2070 mwe. This increase in charge ratio as a function of depth is consistent with an increase in the fraction of muons arising from kaon decay for increasingmore » muon surface energies.« less
  • Cited by 14
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  • The charge ratio, R μ = N μ+/N μ-, for cosmogenic multiple-muon events observed at an underground depth of 2070 mwe has been measured using the magnetized MINOS Far Detector. The multiple-muon events, recorded nearly continuously from August 2003 until April 2012, comprise two independent data sets imaged with opposite magnetic field polarities, the comparison of which allows the systematic uncertainties of the measurement to be minimized. The multiple-muon charge ratio is determined to be R μ = 1.104±0.006(stat)more » $$+0.009\atop{-0.010}$$(syst). As a result, this measurement complements previous determinations of single-muon and multiple-muon charge ratios at underground sites and serves to constrain models of cosmic-ray interactions at TeV energies.« less