T2K Overview for Rochester Neutrino Group

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T2K Overview for Rochester Neutrino Group

• Kevin McFarland1 November 2006

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Neutrino OscillationsThe Big Picture
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Status of Neutrino Oscillations

• Atmospheric (Super-K, K2K) andSolar (SNO,
  KAMLAND) neutrinooscillation signatures are
  wellestablished

sin22?gt 0.92 ?m2(1.6
3.9)10-3eV2
Super-K
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Status of Neutrino Oscillations

• Atmospheric (Super-K, K2K) andSolar (SNO,
  KAMLAND) neutrinooscillation signatures are
  wellestablished

KAMLAND
SNO
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Why Study Oscillations? Qualitative Questions

• The questions facing us now are fundamental, and
  not simply a matter of measuring oscillations
  better
• Examples
• Are there more than three neutrinos?
• What is the hierarchy of masses?
• Can neutrinos contribute significantly to the
  mass of the universe?
• Is there CP violation in neutrino mixings?

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Three Generation Mixing

• Note the new mixing in middle, and the phase, d

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Are Two Paths Open to Us?

• If CHOOZ mixing, q13, is small, but not too
  small, there is an interesting possibility
• At atmospheric L/E,

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Implication of two paths

• Two amplitudes
• If both small,but not too small,both can
  contribute equally
• Relative phase, d, between them can lead toCP
  violation (neutrinos and anti-neutrinos differ)
  in oscillations!

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Importance of Precision P(nm?ne) at Superbeams

• Conventional superbeams and reactors will be
  our next windows into q13, d

• Studying this transition in neutrinos and
  anti-neutrinos gives us q and d as well as sign
  of dm23 (mass hierarchy)
• Reactors only measure q
• Comparing multiple precise measurements is
  necessary

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Our Groups Strategy
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T2K
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Basics of T2K

• Tunable off-axis beam from 0.8MW J-PARC source to
  Super-K
• beam and nm backgrounds are kept below 1 for ne
  signal
• 2200 nm events/yr (w/o osc.)

d0, no matter effects
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The T2K 280m Detector
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US Contribution to 280m Detector The P0D

• Active scintillator detector for 280m (near)
  detector for p0 reconstruction (P0D)
• Youll be shocked to learn it looks a lot like
  MINERvA
• We will work on parts (scintillator extrusions,
  WLS fibers, optical connectors) weve already
  worked on for MINERvA

white scintillator, mesh water, red lead
foil
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T2K US B280 Proposal

• The T2K B280 (beamline and 280m detector)
  submitted a proposal to DOE-HEP for construction
• Also presented to NUSAG
• Have received FY06 RD funds for engineering and
  component development
• P0D modules (P0Dules, my bad) are a Colorado
  State-Rochester-Stony Brook collaboration
• The P0D is a 2.7M detector
• Construction will dovetail into end of MINERvA
• For Rochester, we want to keep factories going,
  do only minimal RD specific to T2K (MINERvA
  designs)

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Our Piece of the P0D
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Rochester P0D Responsibilities

• Scintillator
• this means little except negotiating with the lab
  to produce scintillator. We will handle ordering
  of materials and shipping of bars from FNAL.
• Scanner
• we are charged with producing a scanner similar
  to the MINERvA scanner. Source and DAQ provided
  by others.
• Fiber
• many responsibilities QC, polishing, shipping,
  etc.

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How is P0D Different from MINERvA?

• Photosensor is a pixelated photodiode run in
  Geiger mode (MPPC)
• high gain, 106
• high dark noise, 1 MHz single PEs
• typical sensitive area is small, 1mm2
• number of pixels 103. Since each pixel fires
  once per event (on/off mode), there is a
  non-linearity.
• But device is compact sits on bar, no clear
  fiber.

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How is P0D Different from MINERvA? (contd)

• Fiber
• is smaller in diameter to match MPPC (1mm)
• Y-11 has better light yield? concentration not
  tested.
• mirror far end through Al mirror vacuum
  deposition in Lab 7 (same as MINERvA)
• ends in WLS fiber with a single fiber ferrule
  which mates into a connector holding the MPPC
• Scanner
• P0Dules are smaller (2.5m on a side, square)
• stationary trundle table slides under
  bedframe

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Status

• We have acquired (borrowed) a fiber polisher from
  U Washington which can be used to polish the
  ferrules
• leave it here (Lab G?) or send to Rochester?
• Scintillator SOW proceeding
• Need (soon) to order fiber samples and scan
• Dan has single MPPC (can get more) which we will
  try to integrate into scanner
• No work (just talk) on mapper yet.
• Schedules are still fluid, so I dont have
  concrete deadlines for many of these items.