Showing papers by "T. Durkin published in 2007"
15 Oct 2007
TL;DR: In this article, the authors measured the velocity of a similar to 3 GeV neutrino beam by comparing detection times at the near and far detectors of the MINOS experiment, separated by 734 km.
Abstract: The velocity of a similar to 3 GeV neutrino beam is measured by comparing detection times at the near and far detectors of the MINOS experiment, separated by 734 km. A total of 473 far detector neutrino events was used to measure (nu - c)/c=5.1 +/- 2.9 x 10(-5) (at 68% C.L.). By correlating the measured energies of 258 charged-current neutrino events to their arrival times at the far detector, a limit is imposed on the neutrino mass of m(nu)50 MeV/c(2) (99% C.L.).
180 citations
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
01 Nov 2007
TL;DR: ZEPLIN-III as mentioned in this paper is a direct dark-matter search instrument using liquid xenon as a target, and both the scintillation light and the ionisation charge are measured.
Abstract: ZEPLIN-III is a direct dark-matter search instrument using liquid xenon as a target.Both the scintillation light and the ionisation charge are measured.The instrument has been built and it is currently being testing in a surface laboratory.We present results from some of the initial testing, including design thermal control system verification, photomultiplier calibration (including spectral measurements with 60 keV photons from 241Am) and two-phase operation showing simultaneous measurement of scintillation and charge and position reconstruction.
1 citations
01 Jan 2007
TL;DR: The first underground data run of the ZEPLIN-II experiment has set a limit on the nuclear recoil rate in the two-phase xenon detector for direct dark matter searches as mentioned in this paper.
Abstract: The first underground data run of the ZEPLIN-II experiment has set a limit on the nuclear recoil rate in the two-phase xenon detector for direct dark matter searches. In this Letter the results from this run are converted into the limits on spin-dependent WIMP-proton and WIMP-neutron cross-sections. The minimum of the curve for WIMP-neutron cross-section corresponds to 7 × 10 −2 pb at a WIMP mass of around 65 GeV.