The Main Injector Neutrino Oscillation Search (MINOS) experiment uses an acceleratorproduced neutrino beam to perform precision measurements of the neutrino oscillation parameters in the "atmospheric neutrino" sector associated with muon neutrino disappearance. This long-baseline experiment measures neutrino interactions in Fermilab's NuMI neutrino beam with a near detector at Fermilab and again 735 km downstream with a far detector in the Soudan Underground Laboratory in northern Minnesota. The two detectors are magnetized steel-scintillator tracking calorimeters. They are designed to be as similar as possible in order to ensure that differences in detector response have minimal impact on the comparisons of event rates, energy spectra and topologies that are essential to MINOS measurements of oscillation parameters. The design, construction, calibration and performance of the far and near detectors are described in this paper.

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Large-angle pp elastic and quasielastic (p,2p) scattering have been simultaneously observed in hydrogen and each of several nuclear targets (Li, C, Al, Cu, Pb) at incident proton momenta of 6, 10, and 12 GeV/c. The nuclear transparency is the ratio of such a cross section in a nucleus to the free pp cross section. The transparency of aluminum increases with incident momentum by more than a factor of 2 from 6 to 9.5 GeV/c and falls significantly between 9.5 and 12 GeV/c. This occurs in a region where the free-proton nucleon-absorption cross section exhibits little energy dependence. QCD predicts an increase in transparency with energy.PACS numbers: 13.75. Cs, 12.38.Qk, 13.85.Dz, 25.40.Ve This Letter describes the first results from a program of study at the Brookhaven National Laboratory Alternating-Gradient Synchrotron which investigates the effects of "color transparency." Quasielastic pp scattering from each of several nuclei is compared to pp elastic scattering in hydrogen at three energies. These data are analyzed with a simple model in which the quasielastic cross section is assumed to factor into the product of three terms, a single-particle nuclear momentum distribution, a free pp cross section, and a factor T which we refer to as the transparency of the nucleus. In the absence of Fermi motion the transparency would beData are presented for pp elastic and quasielastic scattering near 90° cm. (center of mass) at incident proton energies of 6, 10, and 12 GeV/c, corresponding to t [(four-momentum transfer) 2 ] of -4.8, -8.5, and -10.4 GeV 2 .The cross section (da/dt) for pp elastic scattering at large transverse momentum and at fixed cm. angle is characterized by an s [(center-of-mass energy) 2 ] dependence which oscillates around the nominal s~] 0 form predicted by the dimensional scaling law of Brodsky and Farrar. l The form of this energy dependence can be related to the probability of finding protons with all of their quarks confined to a region of space which is proportional to 1A/7. This implies that for large s these initial-and final-state protons are very small.It has been pointed out by Mueller 2 and others that small protons which participate in such processes are characterized by color-charge and color-field distributions confined to ever smaller dimensions as s increases. In high-/ quasielastic scattering this implies that the cross section for soft initial-and final-state interactions with other nucleons in the nucleus will vanish as the energy scale increases. It has thus been predicted that at high energy the transparency of nuclei should approach unity. This is in sharp contrast to a more conventional Glauber picture 3 of absorption in which the transparency would be expected to be energy independent.The apparatus consists of a large-angle magnetic spectrometer with a 4.5° aperture. 4 Large proportional chambers measure the trajectories of recoil tracks opposite the spectrometer. When configured for incident momentum of 10 GeV/c, the spectrometer has Ap/p = 1% and A0 = 1 mr and the recoil-...

The MINOS CollaborationArgonne -Athens -Caltech -Chicago -Dubna -Fermilab -Harvard IHEP-Beijing -Indiana -ITEP-Moscow -Lebedev Livermore VCL-London Minnesota -Oxford -Pittsburgh -Protvino -Rutherford -Stanford -SussexTexas A&M -Texas-Austin -Tufts -Western Washington - Executive summaryThe MINOS (Main Injector Neutrino Oscillation Search) experiment is designed to search for neutrino oscillations with a sensitivity significantly greater than has been achieved to date. The phenomenon of neutrino oscillations, whose existence has not been proven convincingly so far, allows neutrinos of one "flavor" (type) to slowly transform themselves into another flavor, and then back again to the original flavor, as they propagate through space or matter.The MINOS experiment is optimized to explore the region of neutrino oscillation "para meter space" (values of the !:l.m 2 and sin 2 29 parameters) suggested by previous investigations of atmospheric neutrinos: the Kamiokande, 1MB, Super-Kamiokande and Soudan 2 experi ments. The study of oscillations in this region with a neutrino beam from the Main Injector requires measurements of the beam after a very long flight path. This in turn requires an intense neutrino beam and a massive detector in order to have an adequate event rate at a great distance from the source.We propose to enhance significantly the physics capabilities of the MINOS experiment by the addition of a Hybrid Emulsion Detector at Soudan, capable of unambigous identification of the neutrino flavor. Recent developments in emulsion experiments make such a detector possible, although significant technological challenges must be overcome. We propose to initiate an R&D effort to identify major potential problems and to develop practical solutions to them.In addition to this primary motivation for this R&D work, we note that the strong and growing interest in studies of neutrino oscillations using neutrino beams from future muon storage rings provides another potential application. These beams will offer significantly higher intensities, albeit of mixed 1I1J-and lie, beams. In order to take full advantage of these beams for neutrino oscillation studies it will be necessary that the detector be capable of determination of the flavor of the final state lepton, and the lepton's charge in a significant fraction of the interactions. At present, an emulsion detector in an external magnetic field appears best suited to offer such capabilities. The R&D effort discussed here will be an important step towards a design of such a future detector. This document is organized as follows:• Chapter 1 summarizes the physics motivation for the proposed emulsion detector,• Chapter 2 briefly reviews the status of the emulsion technology and its aplication to particle physics experiments,• Chapter 3 discusses design considerations for an emulsion detector,• Chapter 4 describes some of the details of a possible detector as well as results from the work up to date,• Chapter 5 outlines the proposed R&D program and summarizes the resources req...