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Incoming energy crucial for your physics result , but only badly known (~50%) Beam composition not fully known Beam

The Impossible Experiment. Incoming energy crucial for your physics result , but only badly known (~50%) Beam composition not fully known Beam diameter ~ 0.5 m at its source Beamline ~ 300 – 1000 km Beam diameter ~ 600 m at the detector Cross sections ~ 10 -11 mb

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Incoming energy crucial for your physics result , but only badly known (~50%) Beam composition not fully known Beam

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  1. The Impossible Experiment Incomingenergycrucialforyourphysicsresult, but onlybadlyknown (~50%) Beam composition not fullyknown Beam diameter ~ 0.5 m atitssource Beamline ~ 300 – 1000 km Beam diameter ~ 600 m atthedetector Cross sections ~ 10-11mb Only a smallpartofthe final stateknown Winter Park 2011

  2. Long Baseline Experiments Soudan Mine, Nova 770 km Homestake Mine Dusel 1300 km T2K: JPARC-Kamioka ~ 300 km, OPERA: CERN –Gran Sasso ~730 km Winter Park 2011

  3. Long baselineexperiments M. Wascko Winter Park 2011

  4. Neutrino oscillationsearch • neutrinooscillations: probabilityfor 2 flavors: • Crucialparameter: neutrinoenergyE Need to understand ‚classical‘ hadronicinteractions Flux: obtained from Event-Generators for hadronic production and subsequentweak decay Energy must be reconstructed from hadronic final state Winter Park 2011

  5. Neutrino nucleoncrosssection QE R+ ‚ DIS ¼ N N' 10-38cm² = 10-11mb P. Lipari, Nucl. Phys. Proc. Suppl. 112, 274 (2002) QE isusedfor energy reconstruction Winter Park 2011

  6. Quasielastic scattering W, Z • axial form factors • FAFPandFA(0) via PCAC • dipoleansatzfor FA with • MA= 1GeV: Winter Park 2011

  7. Axial FormfactoroftheNucleon • neutrinodataagreewithelectro-pionprod. data MA¼ 1.02 GeVworldaverageMA¼ 1.07 GeVworldaverage Winter Park 2011

  8. Axial FormfactoroftheNucleon • Recent Data give significantly larger values for MA • Onedifference: all olddatauseH (orD) astarget • all newdatausenuclei (C, O, Fe) astarget MiniBooNE (2010):MA = 1.35 GeV Winter Park 2011

  9. MA Problem Winter Park 2011 Old neutrinoexperimentsusedHandDastargets All modern experimentsuse heavy nuclei Quasielasticscatteringkinematicsisusedtoreconstructneutrinoenergy also in oscillationexperiments Problem toidentify QE on nucleartargets

  10. QE Identification Need eventgeneratortoreducedatatotrue QE event Winter Park 2011

  11. GiBUUtransport • whatisGiBUU? semiclassical coupled channels transport model • general information (and code available): http://theorie.physik.uni-giessen.de/GiBUU/ • GiBUU describes (within the same unified theory and code) • heavy ion reactions, particle production and flow • Pion, proton and antiproton induced reactions • low and high energy photon and electron induced reactions • neutrino induced reactions ……..using the same physics input! And the same code! Winter Park 2011

  12. CC nucleon knockout: nm56Fe  m- N X w FSI w/o FSI Dramatic FSI Effect E = 1 GeV Winter Park 2011

  13. DetectorTypes: QE Identification Cerenkov detector (MiniBooNE, K2K 1kt) measured Tracking detector (Sci-BooNE, K2K, SciFi) Toohigh QE: misidentifies about 20%, pion-inducedfakes measured QE identificationis clean, but 30% of total QE crosssectionis missed Winter Park 2011

  14. DetectorSensitivities: T2K T2K has different detectortypes: Tracking forneardetector Cherenkov forfardetector NearDetectorseesonlyabout 50% of all QE events Winter Park 2011

  15. EnergyReconstructionandDetectorThresholds Energyreconstruction sensitive tothedetectorpionthresholds Winter Park 2011

  16. Energyreconstruction via CCQE RmsenergydeviationsS ~15% energyuncertaintyfrom quasifreeqekinematicsalone ~21% uncertaintyfor Cerenkov detectors, error growswithneutrinoenergy ~16% uncertaintyfor trackingdetectors Errors in reconstructedºenergies larger thanexpected Winter Park 2011

  17. Energyreconstruction via CCQE Energyuncertaintiesaffectmixingmasses, Event identificationaffectsmixingangles Winter Park 2011

  18. ±CPwith LBNE Uncertaintiesattheoscillationmaximum due todetector as large asdependence on CP violatingphase Wilson, LBNE workshop Event reconstructionhampersdeterminationof CP violatingphase Winter Park 2011

  19. Physics Summary • Experiments have to rely heavily on event-generators to identify QE events needed for energy reconstruction • Quasielastic scattering events contain admixtures of Delta excitations •  excitations affect nucleon knockout, contaminate QE experiments • Energy reconstruction good up to 15 – 20%. Combined error from near and far detectors ~ 20 – 30%. Experiments want 5%! Challenge for event generators! • Extraction of axial mass (1 GeV) strongly affected by nuclear structure (RPA correlations), difficult to get both absolute height and slope. Winter Park 2011

  20. Need for Low EnergyNuclearPhysics in Neutrino Physics • Low-EnergyNuclearPhysics • determinesresponse • ofnucleitoneutrinos • Need excellenteventgenerators • Toextract fundamental science Winter Park 2011

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