Showing papers by "Mcd Sanchez published in 2007"
TL;DR: The MINOS far detector has been taking charge-separated cosmic ray muon data since the beginning of August 2003 at a depth of 2070 mwe 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 as discussed by the authors.
Abstract: The 54 kton MINOS far detector has been taking charge-separated cosmic ray muon data since the beginning of August, 2003 at a depth of 2070 mwe 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-mu(+)/N-mu(-)=1374 +/- 0004(stat)(-0010)(+0012)(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 03-10 TeV is apparent A qualitative model shows that the rise is consistent with an increasing contribution of kaon decays to the muon charge ratio
62 citations
TL;DR: In this paper, the authors found 140 neutrino-induced muons in 854.24 live days in the MINOS far detector and found the ratio of the total number of negative to positive muons.
Abstract: We found 140 neutrino-induced muons in 854.24 live days in the MINOS far detector. We looked for evidence of neutrino disappearance in this data set by computing the ratio of the number of low momentum muons to the sum of the number of high momentum and unknown momentum muons for both data and Monte Carlo expectation in the absence of neutrino oscillations. The ratio of data and Monte Carlo ratios is consistent with an oscillation signal. A fit to the data for the oscillation parameters excludes the null oscillation hypothesis at the 94% confidence level. We separated the muons by charge sign in both the data and Monte Carlo events and found the ratio of the total number of negative to positive muons in both samples. The ratio of those ratios is a test of CPT conservation. The result is consistent with CPT conservation.
25 citations