STATUS OF THE

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STATUS OF THE INDIA-BASED NEUTRINO OBSERVATORY
(INO) PROPOSAL
Naba K Mondal Tata Institute of Fundamental
Research Mumbai, India
WIN05, Delphi, Greece, 6-11 June, 2005
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Celebrating 40 years of atmospheric neutrino
detection
Physics Letters 18, (1965) 196, dated 15th Aug
1965
Atmospheric neutrino detector at Kolar Gold
Field 1965
PRL 15, (1965), 429, dated 30th Aug. 1965
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KGF
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KGF Continued
KGF Proton Decay Experiment
KGF collaboration contributed immensely to the
cosmic ray and particle physics. The KGF mine
was closed in early 90s
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Current India-based Neutrino Observatory
initiative
Goal A large mass detector with charge
identification capability

• Two phase approach

R D and Construction Phase I Physics
studies, Detector R D, Site survey, Human
resource development Phase II Construction of
the detector
Operation of the Detector Phase I Physics with
Atmospheric Neutrinos Phase II Physics with
Neutrino beam from a factory
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Physics using atmospheric neutrinos during Phase I

• Reconfirm atmospheric neutrino oscillation
• Improved measurement of oscillation parameters
• Search for potential matter effect in neutrino
  oscillation
• Determining the sign of Dm223 using matter effect
• Discrimination between nm ? nt and nm ? ns
  oscillation
• Probing CP and CPT violation
• Constraining long range leptonic forces
• Ultra high energy neutrinos and muons

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Physics with Neutrino beam from NUFACT Phase II

• Determination of q13
• Sign of Dm223
• Probing CP violation in leptonic sector
• Matter effect in nm ? nt oscillation

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Physics Studies

• Matter Effect and Sign of Dm223
• D.Indumathi M.V.N.Murthy, Phys Rev. D71,
  013001, (2005), hep-ph/0407336
• R.Gandhi, P.Ghoshal,S.Goswami, P.Mehta and S.Uma
  Sankar,
• Phys.ReV.Lett 94, 051801 (2005),
  hep-ph/0411252
• CPT violation
• A.Datta, R.Gandhi, P.Mehta, S.Uma Sankar Phys.
  Lett B 597, 356 (2004), hep-ph/0312027
• Constraining long range leptonic forces
• A.S.Joshipura and S.Mohanty, Phys Lett B584, 103
  (2004), PRL preprint, October 2004

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Disappearance of Vs. L/E
The disappearance probability can be measured
with a single detector and two equal sources
1 - sin2 (2Q) sin2 (1.27 Dm2 L/E)
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Matter Effect
R. Gandhi et al PRL 94, 051801, 2005
Total no. of nm charge current events
Neglecting D21
Where
For positive D31 resonance occurs When r and E
are such that AD31cos2q13 condition is satisfied
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Pme
For negative D31 no resonence occurs for
neutrinos, but it occurs for anti-neutrinos
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Matter Effect Contd
For energies much below the resonance energy A ltlt
D31 and D31m D31.. Thus the first term is
essentially Pmtvac and second and third terms
are negligible. As one approach the resonance,
q13m approaches p/4. This leads to cos2qm13
decreasing sharply and sin2qm13 increase
sharply. However if we are in the neighbourhood
of a vacuum peak then the effect of the decrease
of the first term is stronger than the effect of
the increase of the second term.
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Matter Effect Contd
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Matter Effect Contd
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Matter Effect Sign of D31 from event rate
m-
m
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Sign of Dm232 from matter induced asymmetry
d32 gt 0 d32 lt 0
The neutrino and anti-neutrino up/down event
ratios are different from each other as well as
different with direct and inverted mass
hierarchies.
Q13 5,7,9,11
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nm? nt vs nm? ns
nm?nt events will give rise to excess of muon
less events. There will be excess of upgoing
muonless events.
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CPT Violation
The expression for survival probability for the
case of CPTV 2-flavour oscillations
and
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Sign of
Number of wrong-sign muon Events as a function of
d32
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Choice of Neutrino Source and Detector

• Neutrino Source
• Need to cover a large L/E range
• Large L range
• Large En Range
• Use Atmospheric neutrinos as source
• Detector Choice
• Should have large target mass ( 50-100 kT)
• Good tracking and Energy resolution ( tracking
  calorimeter)
• Good directionality ( lt 1 nsec time resolution
  )
• Charge identification
• Ease of construction
• Modularity
• Complimentarity with other existing and proposed
  detectors
• Use magnetised iron as target mass and RPC as
  active detector medium

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INO Detector Concept
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The Magnet
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ICAL Detector Specifications
No of modules 3
Module dimension 16 m X 16 m X 12 m
Detector dimension 48 m X 16 m X 12 m
No of layers 140
Iron plate thickness 6 cm
Gap for RPC trays 2.5 cm
Magnetic field 1.3 Tesla
RPC unit dimension 2 m X 2 m
Readout strip width 3 cm
No. of RPCs/Road/Layer 8
No. of Roads/Layer/Module 8
No. of RPC units/Layer 192
Total no of RPC units 27000
No of Electronic channels 3.6 X 106
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RPC R D

• Built RPCs of different sizes
• 30 cm X 30 cm
• 120 cm X 90 cm

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RPC Efficiencies and Timing
RPC working in Streamer mode
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RPC in Avalanche mode
CMS bakelite RPC 73 cm X 42.5 cm
120 cm X 90 cm Glass RPC Built at TIFR
CMS RPC on test stand
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Performance in Avalanche mode
Efficiency plots of RPCs in Avalanche mode
Noise Rates of RPCs operating in Avalanche mode
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Detector Simulation

• Used NUANCE Neutrino Event Generator
• Generate atmospheric neutrino events inside INO
  detector
• Used Atmospheric Neutrino Flux of Honda et. al.
• GEANT detector simulation package
• Simulate the detector response for the neutrino
  event
• Generated 5 years of simulated data equivalent to
  5 years of running the experiment.
• Analysed oscillation data at two levels
• Using NUANCE output and kinematic resolution
  function
• Using full detector simulation
• Obtained preliminary results so far. Detailed
  simulation is underway.

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Results using NUANCE
n
m
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Possible INO sites

• PUSHEP (Pykara Ultimate Stage Hydro Electric
  Project) in South India
• or
• RAMMAM Hydro Electric Project Site

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PUSHEP
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Location of Rammam
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Underground Cavern
Layout of the Underground Cavern
Experimental Hall
Size of the experimental hall 150 m X 22 m X 30 m
Parking Storage
Access tunnel
Experimental Hall
Electronics
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Documentation produced so far
Presented to Indian Funding Agencies on 1st May,
2005
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Summary

• A large magnetised detector of 50-100 Kton is
  needed to achieve some of the very exciting
  physics goals using atmospheric neutrinos.
• A case for such a detector was highlighted
  earlier by the Monolith Collaboration.
• Physics case for such a detector is strong as
  evident from recent publications.
• It will complement the existing and planned
  water cherenkov detectors.
• Can be used as a far detector during neutrino
  factory era.
• We have started a very active R D work towards
  building such a detector.
• Looking for participation from international
  neutrino community.