MiniBooNE: Status and Plans.

1
MiniBooNEStatus and Plans.
2
Talk Outline

• Motivation for MiniBooNE.
• The MiniBooNE experiment
• Description.
• Current status.
• First cosmic ray data.
• Conclusions.

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LSND and KARMEN
Signal above background 87.922.46.0
events Oscillation probability
(0.2640.0670.045)
KARMEN 2 partially excludes LSND region.
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The Current Situation
LSND and KARMEN 2
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So Whats the Problem?

• Results from solar and atmospheric neutrino
  experiments indicate neutrino oscillations and
  give values of Dm2.
• A neutrino model with only 3 active flavours
  cannot accommodate all the Dm2 values.
• Either one or more of the experiments is wrong,
  or something is wrong with the 3 flavour neutrino
  oscillation model.

and it wouldnt be the first time.
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So Whats the Problem?

• The LSND result should be checked.

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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. Church, C. Green, G. J. VanDalen
• University of California, Riverside, CA 92521
• E. Hawker, R. A. Johnson, J. L. Raaf, N.
  Suwonjandee
• University of Cincinnati, Cincinnati, OH 45221
• T. Hart, E. D. Zimmerman
• University of Colorado, Boulder, CO 80309
• L. Bugel, J. M. Conrad, J. Formaggio, J. Link,
• J. Monroe, M. H. Shaevitz, M. Sorel
• Columbia University, Nevis Labs, Irvington, NY
  10533

• D. C. Cox, A. Green, S. McKenney, H. O. Meyer, R.
  Tayloe
• Indiana University, Bloomington, IN 47405
• G. T. Garvey, W. C. Louis, G. A. McGregor, G. B.
  Mills,
• E. Quealy, V. Sandberg, B. Sapp,
• R. Schirato, 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
• O. Bazarko, P. D. Meyers, R. B. Patterson,
• F. C. Shoemaker, H. A. Tanaka
• Princeton University, Princeton, NJ 08544

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Enter MiniBooNE
The Booster Neutrino Experiment
Proposed summer 1997. The goal to confirm, or
exclude, the LSND result and extend the explored
oscillation parameter space.

• High statistics 10 LSND.
• Different systematics beam energy 10 LSND,
  event signatures and backgrounds different.
• Anticipated gt5s significance over entire LSND
  region.

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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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The FNAL Booster

• an accelerator in its 30s!

Built to deliver 8 GeV protons to the Main Ring.
It now supplies the Main Injector, and will soon
also supply the MiniBooNE beamline.

• Run II and MiniBooNE require
• 5.7Hz beam _at_ 51012 ppp (5Hz to MiniBooNE).
• 7.5Hz power equipment capability.
• This corresponds to 51020 protons per year to
  MiniBooNE.

• The Booster must run at record intensity to meet
  these goals.

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The MiniBooNE Beamline

• The 8 GeV beamline is complete, and protons have
  been successfully transported to the target area.

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The Target and Horn
The horn focuses secondary particles produced in
the Be target using a torroidal magnetic
field. 170kA for 140msec _at_ 5Hz.

• Tested to 10 million pulses.

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The MiniBooNE Detector

• 12 m diameter detector.
• 250,000 gallons of mineral oil.
• Optically isolated inner region with 1280 8"
  PMTs, giving 10 coverage.
• Outer veto region of 240 8" PMTs.

• Currently taking cosmic ray and calibration data.

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n Flux at the Detector

• Non-negligible intrinsic ne background this will
  be measured.

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Beam Backgrounds
Secondary particle production from 8 GeV protons
on an actual MiniBooNE target will be measured at
HARP.
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Beam Backgrounds
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Event Signatures
Hit pattern from Cerenkov light used to determine
event type.
ideal ring

• mis-ID backgrounds when
• muons scatter excessively.
• rings from pion decay overlap, or only one ring
  is produced.

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Some Events
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Muon Decay Candidate
Each frame is 25 ns with 10 ns steps.
Charge (Size)
Time (Colour)
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Michel Events
Fit lifetime of 2.12 0.05 msec. Expect 2.13
msec with 8 m- capture on carbon.
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Hit Time Distribution
Michel electrons can be used to determine PMT
timing resolution and scintillation time constant.
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Calibration Underway
Laser flasks provide PMT charge and timing
calibration and a means to monitor the oil
attenuation length in situ.
Muon tracker above detector and 7 optically
isolated scintillator cubes in the detector
provide cross checks for energy estimation and
reconstruction algorithms.
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Expected ne Signal
from 1021 protons on target (2 years).
500,000 nmC charged current events.
Approximate numbers.
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MiniBooNE Sensitivity
MiniBooNE should be able to cover the entire LSND
region in two years.
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Conclusions

• Milestones
• May 3rd - detector full of oil.
• June 26th - first beam delivered to target
  position.
• Any day! - first beam on target.
• Full beam / horn / detector commissioning to
  follow.

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MiniBooNEStatus and Plans.