Observation of muon intensity variations by season with the MINOS far detector

P. Adamson , C. Andreopoulos , K. E. Arms , R. Armstrong , D. J. Auty , D. S. Ayres , C. Backhouse , J. Barnett , G. Barr , W. L. Barrett , B. R. Becker , M. Bishai , A. Blake , B. Bock , G. J. Bock , D. J. Boehnlein , D. Bogert , C. Bower , S. Cavanaugh , J. D. Chapman , D. Cherdack , S. Childress , B. C. Choudhary , J. H. Cobb , S. J. Coleman , D. Cronin-Hennessy , A. J. Culling , I. Z. Danko , J. K. de Jong , N. E. Devenish , M. V. Diwan , M. Dorman , C. O. Escobar , J. J. Evans , E. Falk , G. J. Feldman , T. H. Fields , M. V. Frohne , H. R. Gallagher , A. Godley , M. C. Goodman , P. Gouffon , R. Gran , E. W. Grashorn , K. Grzelak , A. Habig , D. Harris , P. G. Harris , J. Hartnell , R. Hatcher , K. Heller , A. Himmel , A. Holin , J. Hylen , G. M. Irwin , Z. Isvan , D. E. Jaffe , C. James , D. Jensen , T. Kafka , S. M. S. Kasahara , G. Koizumi , S. Kopp , M. Kordosky , K. Korman , D. J. Koskinen , Z. Krahn , A. Kreymer , K. Lang , J. Ling , P. J. Litchfield , L. Loiacono , Philippe Lucas , J. Ma , W. A. Mann , M. L. Marshak , J. S. Marshall , N. Mayer , A. M. Mcgowan , R. Mehdiyev , J. R. Meier , M. D. Messier , C. J. Metelko , D. G. Michael , W. H. Miller , S. R. Mishra , J. Mitchell , C. D. Moore , J. Morfín , L. Mualem , S. Mufson , J. Musser , D. Naples , J. K. Nelson , H. B. Newman , R. J. Nichol , T. C. Nicholls , J. P. Ochoa-Ricoux , W. P. Oliver , T. Osiecki , R. Ospanov , S. Osprey , J. Paley , R. B. Patterson , T. Patzak (1) , G. Pawloski , G. F. Pearce , E. A. Peterson , R. Pittam , R. K. Plunkett , A. Rahaman , R. A. Rameika , T. M. Raufer , B. Rebel , J. Reichenbacher , P. A. Rodrigues , C. Rosenfeld , H. A. Rubin , V. A. Ryabov , M. C. Sanchez , N. Saoulidou , J. Schneps , P. Schreiner , P. Shanahan , W. Smart , C. Smith , A. Sousa , B. Speakman , P. Stamoulis , M. Strait , N. Tagg , R. L. Talaga , J. Thomas , M. A. Thomson , J. L. Thron , G. Tinti , R. Toner , V. A. Tsarev , G. Tzanakos , J. Urheim , P. Vahle , B. Viren , M. Watabe , A. Weber , R. C. Webb , N. West , C. White , L. Whitehead , S. G. Wojcicki , D. M. Wright , T. Yang , M. Zois , K. Zhang , R. Zwaska

1 APC - Neutrinos

The temperature of the upper atmosphere affects the height of primary cosmic ray interactions and the production of high-energy cosmic ray muons which can be detected deep underground. The MINOS far detector at Soudan, MN, has collected over 67×106 cosmic ray induced muons. The underground muon rate measured over a period of five years exhibits a 4% peak-to-peak seasonal variation which is highly correlated with the temperature in the upper atmosphere. The coefficient, αT, relating changes in the muon rate to changes in atmospheric temperature was found to be αT=0.873±0.009(stat)±0.010(syst). Pions and kaons in the primary hadronic interactions of cosmic rays in the atmosphere contribute differently to αT due to the different masses and lifetimes. This allows the measured value of αT to be interpreted as a measurement of the K/π ratio for Ep≳7TeV of 0.12-0.05+0.07, consistent with the expectation from collider experiments.

Mots clés: cosmic ray detectors; Neutrino; muon; pion; and other elementary particle detectors; Cosmic rays; Background radiations

Domaines: Physique des Hautes Energies - Expérience [hep-ex]; Instrumentation et méthodes pour l'astrophysique [astro-ph.IM]; Instrumentation et méthodes pour l'astrophysique [astro-ph.IM]

P. Adamson, C. Andreopoulos, K. E. Arms, R. Armstrong, D. J. Auty, et al.. Observation of muon intensity variations by season with the MINOS far detector. Physical Review D, 2010, 81, pp.12001. ⟨10.1103/PHYSREVD.81.012001⟩. ⟨in2p3-00704723⟩