The Neutrino Flux At MiniBooNE.

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The Neutrino Flux At MiniBooNE.
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The BooNE Collaboration

• Y. Liu, I. Stancu
• University of Alabama, Tuscaloosa, AL 35487
• S. Koutsoliotas
• Bucknell University, Lewisburg, PA 17837
• E. Hawker, R. A. Johnson, J. L. Raaf
• University of Cincinnati, Cincinnati, OH 45221
• T. Hart, R. H. Nelson, E. D. Zimmerman
• University of Colorado, Boulder, CO 80309
• A. A. Aguilar-Arevalo, L. Bugel, J. M. Conrad,
• J. Formaggio, J. Link, J. Monroe, D. Schmitz,
• M. H. Shaevitz, M. Sorel, G. P. Zeller
• Columbia University, Nevis Labs, Irvington, NY
  10533
• D. Smith

• D. Cox, A. Green, H. Meyer, R. Tayloe
• Indiana University, Bloomington, IN 47405
• G. T. Garvey, C. Green, W. C. Louis, G. A.
  McGregor,
• S. McKenney, G. B. Mills, V. Sandberg, B. Sapp,
• R. Schirato, N. Walbridge, R. Van de Water, D. H.
  White
• Los Alamos National Laboratory, Los Alamos, NM
  87545
• R. Imlay, W. Metcalf, M. Sung, M. O. Wascko
• Louisiana State University, Baton Rouge, LA 70803
• J. Cao, Y. Liu, B. P. Roe
• University of Michigan, Ann Arbor, MI 48109
• A. O. Bazarko, P. D. Meyers, R. B. Patterson,
• F. C. Shoemaker, H. A. Tanaka
• Princeton University, Princeton, NJ 08544

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MiniBooNE Overview
The FNAL Booster delivers 8 GeV protons to the
MiniBooNE beamline. The protons hit a beryllium
target producing pions and kaons. The magnetic
horn focuses the secondary particles towards the
detector. The mesons decay, and the neutrinos
fly to the detector.

• Signal from pm nm then nm ne which
  produces e- in the detector.

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Meson Production in the Target

• Sanford-Wang parameterizations (pions)
• Cho Fit.
• K2K Fit.
• JAM Fit (MiniBooNE internal).
• MARS Monte Carlo (pions and kaons).
• GFLUKA Monte Carlo (pions and kaons).

MARS does not store neutral kaons and so these
are constructed from K using the GFLUKA K0L/K
yield ratio.
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Sanford-Wang Parameterization

• Empirical parameterization with 8 free
  parameters

where Pp is the momentum of the pion. Pp is the
momentum of the proton. Tp is the production
angle of the pion in the lab frame. c1-8 are the
parameters determined by fitting to available
data.
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Detector Pion Acceptance
momentum
angle
MARS production model used.
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S-W Fit Results
MiniBooNE fit (Jocelyn Monroe, Columbia
University) used the following data Vorontsov,198
3. Cho, 1971. Marmer, 1969. Dekkers, 1964
(subset).
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Vorontsov 1983.
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Cho 1971.
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Marmer 1969.
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Dekkers 1964.
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Beamline Modeling

• GEANT 4 Monte Carlo used for beam simulations.
• Meson productions models from external sources
  (MARS, GFLUKA, S-W etc.) are implemented within
  G4.
• GEANT 4 implementation principally by Michel
  Sorel, Columbia University.
• Neutrino flux which intersects the detector is
  boosted by redecaying mesons.

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GEANT 4 Geometry
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Horn Field Simulation

• Horn provides a 7 increase in the flux and it is
  therefore necessary to check the motion of
  charged particles in its magnetic field.
• Horn field was mapped during testing 300
  positions between inner and outer conductor were
  mapped.
• G4 results have been checked, and agree, with a
  standalone calculation based on the CERNLIB
  routine DRKNYS (numerical integration routine).

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G4 Neutrino Flux Predictions
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E910 Data

• Data taken on Au, Cu, Pb, U and Be.
• Be data taken at momenta of 17.5, 12.3 and
  6.4GeV.
• About 1M events at 12.3GeV.
• Unfortunately only about 5k events at 6.4GeV.
• Currently analyzing 12.3 and 6.4GeV data.
• Initial Sanford-Wang parameterization results
  look encouraging.

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HARP (PS214) Data
Secondary particle production from 8 GeV protons
on an actual MiniBooNE target has been measured
at HARP.
Over 5 million interactions have been
recorded. Analysis of data has started.
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Detector Response

• NUANCE Monte Carlo used to model particle
  production in the MiniBooNE detector.
• BooDetMC used to simulate detector response
  (GEANT 3 based).
• Uncertainties associated with each of these.

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CC ?µ Quasi-elastic data

• Abundance 40.
• Simple topology.
• Kinematics give E? and Q2 from Eµ and Tµ.

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preliminary
CC ?µ Quasi-elastic
Selection based on PMT hit topology and timing.
Variables combined in a Fisher discriminant,
yielding 88 purity in remaining dataset. Data
and MC relatively normalized.
Yellow band Monte Carlo with current uncertaintie
s from

• flux prediction.
• sCCQE
• optical properties.

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preliminary
CC ?µ Quasi-elastic
CC ?µ energy resolution.
lt10 for E?gt800 MeV
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Resistive Wall Monitor
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Utilizing RWM Timing
The goal is to combine the RWM bunch timing with
the reconstructed event time in the detector to
identify different classes of events.

• Given that
• all mesons do not travel at the same speed.
• prompt detection of interaction does not always
  occur.

The timing distributions of events with respect
to the beam may vary for different event samples.
Intrinsic smearing and resolutions may be a
problem to achieve powerful discrimination.
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The RF Bucket Structure
unofficial

• t1 and t2 are the midpoints to adjacent buckets.

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Muon Sample Example
unofficial
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Conclusions

• Lots of work ongoing on the neutrino beam
  simulation.
• Shape agreement between data and MC is
  reasonable.
• E910 and especially HARP data should provide an
  accurate description of target meson production.

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n Flux at the Detector
preliminary
Pion contribution from JAM S-W parameterization.
MARS/GFLUKA for kaon contribution.