109 research outputs found

    Transantiago: On the Development of Public Transit in Large Cities

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    Institute of Transport and Logistics Studies. Faculty of Economics and Business. The University of Sydne

    Heterotic type IIA duality with fluxes - towards the complete story

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    In this paper we study the heterotic type IIA duality when fluxes are turned on. We show that many of the known fluxes are dual to each other and claim that certain fluxes on the heterotic side require that the type IIA picture is lifted to M or even F-theory compactifications with geometric fluxes.Comment: 31 pages, references adde

    A Letter of Intent to Build a MiniBooNE Near Detector: BooNE

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    There is accumulating evidence for a difference between neutrino and antineutrino oscillations at the 1\sim 1 eV2^2 scale. The MiniBooNE experiment observes an unexplained excess of electron-like events at low energies in neutrino mode, which may be due, for example, to either a neutral current radiative interaction, sterile neutrino decay, or to neutrino oscillations involving sterile neutrinos and which may be related to the LSND signal. No excess of electron-like events (0.5±7.8±8.7-0.5 \pm 7.8 \pm 8.7), however, is observed so far at low energies in antineutrino mode. Furthermore, global 3+1 and 3+2 sterile neutrino fits to the world neutrino and antineutrino data suggest a difference between neutrinos and antineutrinos with significant (sin22θμμ35\sin^22\theta_{\mu \mu} \sim 35%) νˉμ\bar \nu_\mu disappearance. In order to test whether the low-energy excess is due to neutrino oscillations and whether there is a difference between νμ\nu_\mu and νˉμ\bar \nu_\mu disappearance, we propose building a second MiniBooNE detector at (or moving the existing MiniBooNE detector to) a distance of 200\sim 200 m from the Booster Neutrino Beam (BNB) production target. With identical detectors at different distances, most of the systematic errors will cancel when taking a ratio of events in the two detectors, as the neutrino flux varies as 1/r21/r^2 to a calculable approximation. This will allow sensitive tests of oscillations for both νe\nu_e and νˉe\bar \nu_e appearance and νμ\nu_\mu and νˉμ\bar \nu_\mu disappearance. Furthermore, a comparison between oscillations in neutrino mode and antineutrino mode will allow a sensitive search for CP and CPT violation in the lepton sector at short baseline (Δm2>0.1\Delta m^2 > 0.1 eV2^2).Comment: 43 pages, 40 figure

    Towards Minkowski Vacua in Type II String Compactifications

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    We study the vacuum structure of compactifications of type II string theories on orientifolds with SU(3)xSU(3) structure. We argue that generalised geometry enables us to treat these non-geometric compactifications using a supergravity analysis in a way very similar to geometric compactifications. We find supersymmetric Minkowski vacua with all the moduli stabilised at weak string coupling and all the tadpole conditions satisfied. Generically the value of the moduli fields in the vacuum is parametrically controlled and can be taken to arbitrarily large values.Comment: 33 pages; v2 minor corrections, references added, version to appear in JHE

    Measurement of the neutrino component of an anti-neutrino beam observed by a non-magnetized detector

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    Two independent methods are employed to measure the neutrino flux of the anti-neutrino-mode beam observed by the MiniBooNE detector. The first method compares data to simulated event rates in a high purity \numu induced charged-current single \pip (CC1\pip) sample while the second exploits the difference between the angular distributions of muons created in \numu and \numub charged-current quasi-elastic (CCQE) interactions. The results from both analyses indicate the prediction of the neutrino flux component of the pre-dominately anti-neutrino beam is over-estimated - the CC1\pip analysis indicates the predicted \numu flux should be scaled by 0.76±0.110.76 \pm 0.11, while the CCQE angular fit yields 0.65±0.230.65 \pm 0.23. The energy spectrum of the flux prediction is checked by repeating the analyses in bins of reconstructed neutrino energy, and the results show that the spectral shape is well modeled. These analyses are a demonstration of techniques for measuring the neutrino contamination of anti-neutrino beams observed by future non-magnetized detectors.Comment: 15 pages, 7 figures, published in Physical Review D, latest version reflects changes from referee comment

    First Measurement of Monoenergetic Muon Neutrino Charged Current Interactions

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    We report the first measurement of monoenergetic muon neutrino charged current interactions. MiniBooNE has isolated 236 MeV muon neutrino events originating from charged kaon decay at rest (K+μ+νμK^+ \rightarrow \mu^+ \nu_\mu) at the NuMI beamline absorber. These signal νμ\nu_\mu-carbon events are distinguished from primarily pion decay in flight νμ\nu_\mu and νμ\overline{\nu}_\mu backgrounds produced at the target station and decay pipe using their arrival time and reconstructed muon energy. The significance of the signal observation is at the 3.9σ\sigma level. The muon kinetic energy, neutrino-nucleus energy transfer (ω=EνEμ\omega=E_\nu-E_\mu), and total cross section for these events is extracted. This result is the first known-energy, weak-interaction-only probe of the nucleus to yield a measurement of ω\omega using neutrinos, a quantity thus far only accessible through electron scattering.Comment: 6 pages, 4 figure
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