Transcript R&D towards huge liquid argon detectors for nucleon

R&D towards Huge Liquid Argon
Detectors for Nucleon Decay, Neutrino
Astrophysics and CP-violation in the
Lepton Sector
T.Maruyama (KEK)
2009/07/22
NuFact09 at Chicago
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Physics motivation
• Giant LAr TPC is a good candidate to do
neutrino physics and proton decay
– to increase signal eff. / to reduce background
using excellent tracking performance.
– to have good energy resolution.
• Possibility to use for Neutrino Factory
– with magnetic field. High temperature superconducting magnet could be a good candidate
to use. (e.g. high temperature superconducting, see LAr TPC talk at NuFact05 by A.Rubbia)
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Example of Physics Scenario
νeSpectrum
sin22θ13=0.03,Normal Hierarchy
•Cover Oscillation 1st and 2nd Maximum
•Neutrino Run Only 5 Years×1.66 MW
•100kt Liq. Ar TPC
-Good Energy Resolution
-Good e/π０discrimination
•Keeping Reasonable Statistics
δ=0°
δ=90°
δ=180°
δ=270°
CP Measurement Potential
3s
Okinoshima
Beam νe
Background
658km
0.8deg. Off-axis
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NP08, arXiv:0804.2111
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Example2; LAGUNA (+EUROnu) project
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Concept of the LAr TPC
readout
GEM
Gas Argon

Double phase
5kV/cm
Ionization selectron signal


Liquid Ar
1 kV/cm

Ionization electrons

Electric
Field
Cherenkov light


~5x104e/cm MIP
3D track reconstruction as a
TPC
drift velocity is ~mm/μs with
~kV/cm electric field
LAr purity affects the
attenuation of the drift electrons.
No amplification inside LAr
Diffusion of the drift electrons is
about 3mm after 20m drift
nm charged current event
Charged particle
Closed
Scintillation light
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dewar
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charged current event
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A. Bueno, et.al.,, hep-ph/0701101
Introduction for LAr TPC R&D
• There are several LAr R&D efforts around the
world.
– US has remarkable progresses, especially,
ArgoNEUT, MicroBoone and material test-stand.
The former two will be covered by Maddalena
Antonello later (WG2).
– We think the charge readout (e.g. single and
double phase readout) is an important R&D item
to proceed. We’d like to show the new result on
the readout from ETHZ-KEK collaboration.
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Proposed Strategy @ Fermilab
0.5x0.5x1.0 m3 0.3 ton
Data: ~2011-2012
See talk by Maddalena
Antonello
170 ton
1-5 kton
2009/07/22
Data: ~2015-2016
100>M>5
7
1<N<20 NuFact09 atR.Chicago
Rameika, Project X Workshop, January 2008
Neutrino candidate
Pixel size = (4.0 x 4.0 x 0.3) mm3
50cm
p
m
100cm
Neutrino candidate in ArgoNeuT
(ref. J.Spitz talk at FNAL user’s meeting on 4-Jun-2009)
Large energy deposition
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Quest for the Origin of Matter Dominated Universe
One of the Main Subject of the
KEK Roadmap
Ｔ２Ｋ
(２００９~)
Discovery of
the ne Appearance
Neutrino
Intensity Improvement
Huge Detector R&D
Establish
Huge Detector Construction of
Huge Detector
Technology
v
Water Cherenkov
2009/07/22
Discovery of
Lepton CP Violation
Proton Decay
Liquid Ar ＴＰＣ
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Pros and Cons of Water Cherenkov and
Liquid Argon Huge detector
Water Cherenkov
Liquid Argon
Pros
• matured technique
• 50 kton detector has been
working for more than 10
years
• Easier to build huge and
massive detector
• Possible to have excellent
tracking performance, and it
has directly impact to ne
appearance or proton decays
search.
Cons
• Cherenkov threshold is high
for Kaons, protons, massive
particles.
• electrons / pi0 separation is
relatively bad compared to
LAr TPC
• There are lots of R&D items
to attack to achieve 100 kton
level detector. -> therefore, I
have this talk
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Towards Huge LAr TPCs
There are several proposals towards Huge LAr TPCs
with different approaches:
• a modulable or a scalable detector for a total LAr mass
of 50-100 kton
• evacuable or non-evacuable dewar -> evacuation
guarantees the good purity.
• detect ionization charge in LAr without amplification or
with amplification -> affects signal to noise ratio, etc.
see later comments.
Goal; Keep good physics performance with reasonable total
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cast
for building.
Items to be Proven toward Huge Detector
• Technical Feasibility for Huge Detector (these are
important for technology choice)
– Establish realistic maximum drift distance
•
•
•
•
Tightness of LNG (Liquid Natural Gas) type tank.
Purification from non-evacuated large volume.
Possible drift high voltage, and effect of the bubble inside the tank
Ionization signal distortion for long drift, dE/dx
– Use of passive insulation (thermal uniformity, stability, …)
– Scaling up of purification capacity
– Pre-cooling, flushing
• Physics Performance
– Define tolerable charge signal distortion , dE/dx resolution
– MC study needed (reconstruction,…)
– Proof with Beam is necessary
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• Calorimetry (energy reconstruction, electric field dependence,
energy scale, etc should be investigated with electron/muon beam)
• Charged pions (hadron interaction in medium, electric field
dependence)
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Items to be Proven toward Huge Detector (2)
• Signal-to-noise ratio is one of main issues in liquid argon TPC
– minimum ionizing track is releasing about 3 fC or about 17'000
electrons per 3 mm readout pitch, and dQ/dt decreases with drift
length because of diffusion also attenuation due to impurities reduces
further number of electrons
• problems for large detectors;
– need very good charge preamplifier (expensive) and noise must be
kept low in charge preamplifier depends on capacitive load at input
typically 100-200 pF
– it increases when wires are longer ---> longer wires ---> more noise
– also environmental noise (computers, DAQ, clocks etc...) is bad
– drift length is limited by attenuation and diffusion
therefore our approach is to do new R&D on charge readout
method on small scale setup
prototype before trying to simply extrapolate existing technol
ogy to large detectors NuFact09 at Chicago
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Results from small prototypes
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Small setup to test double phase detector (ETHZ)
Level
meters
HV connector
Signal cable
LEM (Large Electron Multiplier) is a thick
macroscopic GEM
Signal plane
30 kV feedthrough
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Readout;
Anode; 6mm pitch Cu plane.
LEM; 6mm pitch separated.
TPB coated
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arXiv:0811.3384
Typical cosmic muon track
Typical cosmic ray muon event:
charge signals and related light signal.
Proportional light:
produced by
electron in high
extraction field in
the gas
Scintillation light:
primary light due to
muon crossing LAr
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dQ/dx distribution
Distribution of the energy loss per unit path length (dQ/dx).
Charge on the anode is corrected for the drifting e- lifetime.
Gauss-convolved Landau
function is fitted:
MP ≈ 83 fC/cm
s ≈ 14 fC/cm
resolution ≈ 17%
26kV/cm
For LEM
(Gain10
Operation)
S/N = 80 / 1
They succeeded to have
one week operation
as a long run stability test.
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Operation with LEMs in liquid
LEM-TPC can be operated with the LEMs completely immersed in
LAr without charge amplification.
This shows that LEM can be used as a readout even inside Lar.
Proof of LEMs transparency
Gain = 1
Anode
electrodes
LEM
electrodes
S/N ≈ 80/5
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Anode electrodes LEM
electrodes
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Liquid Argon TPC R&D (KEK)
• 10L Liquid Argon
Hydrosorb
(H2O filter)
LAr
Turbo Pump
GAr
Scroll Pump
Oxysorb
(O2 filter)
Test
Chamber
LAr Open Bath
Anode
teststand was set
up at KEK.
- Gas Argon is
liquefied after
purification.
- Test chamber
is evacuated
and baked
before liquefaction.
Grid
Inside chamber
Field
shaper
Cathode
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• 4 channel strip
was used for read
out. (anode plane)
• Field shapers and
grid plane are prepared.
• Sensitive area is
~ 9x9x5cm3 19
First cosmic ray track at KEK (single phase)
•
•
Open Bath trigger1
–
–
trigger2
Anode 1
Grid
Trigger counters was set to measure
cosmic ray track.
We see the cosmic ray signal using
the TPC (oscilloscope signal is shown
below).
2
3
Signal timing is as expected.
First cosmic ray track at KEK
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Trigger 1
(2cmx20cm
X5mm(t))
Cathode
Trigger
2
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(2cmx20cmx5mm)
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2 Phase TPC with GEM
(KEK)
• REPIC thick GEM
– 400 mm thickness
– 300 mmf hole
– 700 mm pitch
• GEM – Anode distance = 3 mm
• Nominal voltage
– Cathode -9kV, Ext Grid -2.5kV
– GEM DV=-1.8 kV and lower V = -300V
•
•
Sensitive area: 9x9x4.5 cm
Cathode: 9x9 cm copper plate
•
Anode：9x2.2 cm copper plates
– 4 ch readout
•
Extraction Grid
– 100 mm SUS wire
– 5 mm pitch (1D)
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Cosmic Track (double phase)
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250L test and 3 ton purging test
• 250L (right) and 3 ton (left)
– 250L; Test-beam (e/g at Japan)
– Purification test without evacuation.
• At first, we purge the air using GAr
• Then purify the gas
• Can we obtain ppm level gas
without evacuation?
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Summary
• LAr TPC is a very important candidate for next
generation neutrino physics and proton decay.
• There are many R&D items to achieve;
–
–
–
–
–
–
Tank/Vessel (incl. Purity without evacuation)
Possible high voltage for drift
Ionization signal distortion.
Scaling up of purification capacity
Good electronics and number of channels
Physics performance
• One solution to achieve the good signal-to-noise
ratio even with attenuation is to use 2-phase
TPC. Some results are shown here.
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backups
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Readout electronics (ETHZ/CAEN)
Custom made front-end charge preamp + shaper
2 channel per chip
rise time 0.6 ms, fall time 2 ms
Inspired by C. Boiano et al. IEEE
Trans. Nucl. Sci. 52 (2004) 1931
In collaboration with CAEN, ADC and DAQ system development
• 12 bit 2.5 MS/s flash ADC.
• Programmable FPGA.
• Channel-by-channel trigger
and global “trigger alert”.
• 256 channel crate.
• Chainable optical link.
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ETHZ setup overview
Input purification cartridge
Purification circuit
Detector
HV supply
External bath
Readout
electronics
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Vacuum
pumps
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Argon purification (ETHZ)
Two purification stages
Input LAr purification:
• Custom made cartridge for LAr
purification at detector input.
GAr purification circuit:
• Heating resistors evaporate
LAr in the detector.
• A metal bellow pump pushes
GAr into a flow meter and SAES
getter (~48h to recirculate 1
volume).
• Purified GAr condensates into
the detector volume.
Filling procedure:
• The detector vessel is evacuated to 10-6 mbar.
• The detector is filled with pure GAr (99.9999%) @ 1 bar.
• The external bath is filled, the detector cooled down while
recirculating GAr through SAES getter.
• The detector is filled with LAr through custom made cartridge.
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Double stage LEM with anode
LEM1
Anode
LEM2
10x10 cm2
6 mm strips
2009/07/22
• Produced by standard PCB methods.
• Double-sided copper-clad FR4 plates.
• Precision holes by drilling.
• Thickness: 1.6 mm.
• Amplification hole diameter: 500 mm.
• Distance between centers of neighbouring holes: 800 mm.
• Segmented anode and
LEM2 top plane: 2x16 strips 6 mm wide.
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Operation in pure gas argon (ETHZ)
Pure argon gas operation, room temperature, 1.2 bar
55Fe
(full peak)
~5.9 keV 6.9 kBq
29.3% FWHM
55Fe
and 109Cd sources positioned
below the cathode grid
Deposited energy is proportional to
the sum of the involved strips
Both anode and LEM signals can
be used for the energy evaluation
55Fe
(escape peak)
~2.9 keV 6.9 kBq
42% FWHM
109Cd
~22.3 keV 0.5 kBq
24.7% FWHM
• The gain is measured from 109Cd
peak.
• The electric field is calculated as
the ratio of DV across the LEM and
the LEM thickness.
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Readout Electronics (KEK)
• Preamp
–
–
–
–
–
Short pulse
Charge amp
AMPTEK A250
Gain: 1 V/pC
Rise time few ns
Decay time 300 ms
4ms
Long pulse 40 ms
• Postamp
–
–
–
–
NIM shaper amp
Hoshin N012
Gain 1.0
Time constant 0.5 ms
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40ms
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Vacuum (KEK)
• Dry scroll pump
– Variant SH110
•
• Molecular turbo pump
– Pfeiffer HiPace80
– Directly mounted on chamber
• Vacuum level
– Baking @90oC for few days
• 2x10-4 Pa
– Main source of outgassing
• HV feedthrough
– 2x2x40cm Araldite bar
• w/o feedthrough 3x10-5 Pa
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Purification, Recirculation (KEK)
• Oxysorb, Hydrosorb
– Air Liquide “Small Cartridge”
– Specification
• < 1 ppm input Gas purity
• < 5 ppb Oxygen
• < 20 ppb Water
• Recirculation system
– Gas -> Gas recirculation
• No heater inside chamber
• No heat exchanger
– Initial filling and recirculation share the
same filter
– EMP (Enomoto Micro Pump)
• Diaphragm pump
• MX808-ST
• 25L/min
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Purity Monitor
• Xenon flash lamp
– Hamamatsu
– Quartz window
• Optical fiber, feedthrough
– Ocean Optics
– good UV transmission
• Photo cathode
– Cathode copper plate
• Readout
– Anode signal only
– Signal yield is stable within
few% over few hours NuFact09 at Chicago
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GEM test using Ar Gas (KEK)
• Established the purity
monitor signal with gas
Argon (~1.2 atm)
• GEM sparks at HV > 1000V
• Signal pulse height w/o
GEM was ~100mV
600V
– Gain = 1 at ~ 700V
800V
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Operation in double phase
Charge multiplication occurs in argon vapour: 87 K,
1 bar, ~3.4 denser than at STP.
Radioactive
sources were
not suitable for
cryogenic
operation.
Anode
electrodes
LEM
electrodes
LEM electrodes
Anode electrodes
• Gain ~10
• Raw images
• S/N ≈ 800/10
E (kV/cm)
Anode LEM2
2.1
LEM2
~26
LEM2 LEM1
1.5
LEM1
~26
Drift
0.7
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Tracking
•
•
Analyze
oscilloscope
waveform
Ch4
Ch3
Ch2
Ch1
Drift time > z pos.
Single track event
Anode plane
Multi-track event
Cathode plane
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Double Phase Detector
•
•
•
Without Multiplication
Sensitive area: 9x9x4.5 cm
Cathode: 9x9 cm copper plate
•
Anode：9x2.2 cm copper plates
– 4 ch readout
•
Field Shaper (SUS)
– 9x9 cm x0.8 mm
– 8 mm distance (5th is grid)
•
Extraction Grid
– 100 mm SUS wire
– 5 mm pitch (1D)
•
Shielding Grid
– 100 mm SUS wire
– 5 mm pitch (2D mesh)
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Anode
Shielding Grid
Extraction Grid (Gas)
Extraction Grid (Liquid)
Field
shapers
Cathode
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3ton purging test
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Towards large LAr TPCs
Starting from ICARUS (1985), several proposals
towards large LAr TPCs:
 LANNDD 2001
 GLACIER 2003
 FLARE 2004
 MODULAR 2007
…with different approaches:
• a modular or a scalable detector for a total LAr mass
of 50-100 kton
• evacuable or non-evacuable dewar
• detect ionization charge in LAr without amplification or
with amplification
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ICARUS
MODULAR
LANNDD
A LINE OF LIQUID ARGON TPC DETECTORS
SCALABLE IN MASS FROM 200 TONS TO 100
KTONS
David B. Cline 1, Fabrizio Raffaelli 2 and Franco
Sergiampietri 1,2
1 UCLA
2
Pisa,
FLARE
GLACIER
Bartoszek Eng. - Duke - Indiana - Fermilab LSU - MSU -Osaka - Pisa - Pittsburgh - Princeton –
Silesia – South Carolina - Texas A&M Tufts - UCLA - Warsaw University INS Warsaw - Washington - York-Toronto
2009/07/22
ETHZ, Bern U., Granada U., INP Krakow, INR
Moscow, IPN Lyon, Sheffield U., Southampton U.,
US Katowice, UPS Warszawa, UW Warszawa, UW
Wroclaw
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LANNDD
A scalable detector with an evacuable dewar and ionization
charge detection without amplification
D.B. Cline, F. Raffaelli, F. Sergiampietri,
JINST 1, T09001, 2006
n=3, ~5 kton
2009/07/22
 Drift paths up to 5 m
 Evacuable dewar with the possibility of
checking its tightness
 Use of stainless steel for the inner vessel and
for cathodes, wire chamber frames and shaping
electrodes
 UHV standards for any device in contact with
the argon
 Vacuum insulation, together with the use of
superinsulation jacket around the cold vessel, to
reduce running costs
 A continuous (not segmented) active LAr volume
(high fiducial volume) contained in a cryostat
based in a multi-cell mechanical structure
 This solution allows a cubic shape composed by n3
cells, 5m×5m×5m in size each
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MODULAR
A modular detector with a non-evacuable dewar and ionization
charge detection without amplification
B. Baibussinov et al., arXiv:0704.1422 [hep-ph]
Geometry of an ICARUS-T600 half-module (T300) “cloned” into a larger
detector scaled by a factor 8/3 = 2.66: the cross sectional area of the
planes is 8 x 8 m2 rather than 3 x 3 m2. The length of such a detector is 50
meters.
Perlite insulation
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 2 modules of 5 kton each with common
insulation
 1.5 m thickness of perlite, corresponding
to ~ 4 W/m2 thermal loss
 wires at 0°, ±60°
 0° wires split in two, 25 m long, sections
 6 mm wire pitch, to compensate for the
increase capacitance of the longer wires
Low conductivity foam glass light
NuFact09
at Chicago
bricks for the bottom
support
layer
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FLARE
50 kton LAr
Fermilab-Proposal-0942, Aug. 2004
hep-ex/0408121
30 m
A scalable detector with a non-evacuable
dewar and ionization charge detection
without amplification
40 m
LNG style tank: CB&I
standard design for double
wall and double roof vessel
 Thermal insulation
• 1.2 m thick layer of perlite
• boil-off rate of 0.05%/day (25 ton/day)
• a cryogenic system is necessary in order to re-liquefy this gas mass
 Wire planes
• 3 m drift distance, 5 mm wire spacing
• large wire planes, with the largest of 30x40 m2
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LArTPC @ Fermilab
A scalable detector with a non-evacuable
dewar and ionization charge detection
without amplification
LNG style tank
A 5 ton detector is a cylinder 5 meters high with diameter 1 meter.
A 5 kton detector is a cylinder 17 meters high with diameter 17 meters
1 meter
Field grid
17 meters
Field grid
wire panel
2009/07/22
cellular design for wire
planes
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ne  nm oscillation probability
P(n e n m )  sin 213T1   sin 213 (T2  T3 )   T4
2
2
2

sin
(1  A)D 
2
T1  sin  23
(1  A) 2
Atmospheric
sin( AD) sin (1  A)D 
T2  sin  CP sin 212 sin 2 23 sin D
A
(1  A)
sin( AD) sin (1  A)D 
T3  cos  CP sin 212 sin 2 23 cos D
A
(1  A)
2
sin
[ AD]
2
2
T4  cos  23 sin 212
A2
2
Dm21

 0.03
2
2009/07/22
A.Bueno
Dmet31al
2 2GF ne E
Dm L
A
DNP08
 NuFact09
2
(@Mito) at
on Chicago
Mar-6-2008 Dm
4E
31
2
31
Interference
Solor
Interference term
plays important
46
role!!
Parameters for oscillation
Dm312 = 2.5x10-3 eV2 <normal hierarchy>
 Dm212 = 8.2x10-5 eV2
 23 = p/4
 12 = 0.573
 r = 2.8 g/cm3 for matter effects
(all parameters are same as PRD 76,
093002 (2007))
 These parameters are assumed to be well
determined, thus free parameters are only
13 and CP.

2009/07/22
A.Bueno
et al
NP08NuFact09
(@Mito) at
on Chicago
Mar-6-2008
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