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Andr Rubbia, ETH/ Z rich, 11/2/01
The ICARUS Project
André RubbiaETH Zürich
8th-10th February, 2001
SNOW in Uppsala
ItalyAquila, LNGS, Milano, Padova, Pavia, Pisa, Torino
ChinaIHEP
SwitzerlandETH/Zurich
USAUCLA
CERN
PolandKatowice, Krakow, Warszawa,
Wroclaw
André Rubbia, ETH/Zürich, ICARUS Collaboration, 11/2/01
The IC
AR
US
Collaboration
André Rubbia, ETH/Zürich, ICARUS Collaboration, 11/2/01
Neutrino and rare process physics✯ The performance of a neutrino detector is proportional
to its total mass and also to its geometricalgranularity with which the events can be reconstructed.
�Atmospheric neutrinos:− ≈1000 atm CC events / year
− ≈≈≈≈5 ντ CC /year from oscillations
�Solar neutrinos:
− 17500××××f8B solar neutrinos / year @ E > 5 MeV
�Neutrinos from CERN (CNGS):
−13600 νµ CC per 4.5×1019 pots @ L = 730 km
�Neutrino factory:
− 1200 νµ CC per 1020 µ @ L = 7400 km
�Number of targets for nucleon stability:
− 3 × 1033 nucleons ⇒ ττττp (1032 years) > 6 ×××× T(yr) ×××× εεεε @ 90 C.L.
What we get for 5 ktons:What we get for 5 ktons:
γγγγνννν
A bonus!
André Rubbia, ETH/Zürich, ICARUS Collaboration, 11/2/01
ICARUS liquid argon imaging TPC (I)✯ The LAr TPC technique is based on the fact that ionization electrons can drift
over large distances (meters) in a volume of purified liquid Argon under a strongelectric field. If a proper readout system is realized (i.e. a set of fine pitch wiregrids) it is possible to realize a massive "electronic bubble chamber", with superb3-D imaging.
40 cm
40 c
mW
ires
Drift
"Bubble" size ≈ 3 x 3 x 0.2 mm3
Energy depositionmeasured for eachpoint
André Rubbia, ETH/Zürich, ICARUS Collaboration, 11/2/01
✯ Detect electrons produced by ionizing tracks crossing the LAr
v–
v+
+
–
Ionizing track
V
i0
Ed
d
d
p
Ionizing track
1st Induction wire / Screen grid
2nd Induction wire grid (x view)
Collection wire grid (y view)
e-
Char
ge
Drift timeA
B
C
Signals induced
Char
ge
Drift timeA B
C
Drift
Electron-ion pairs are producedElectrons give the main contribution tothe induced current due to the much larger mobility
I0 = e(v+ + v-)/d
A set of wires at the end of the drift give a sampling of the trackNo charge multiplication occurs near the wires Ë electrons can be used to induce signals on subsequent wires planes with
different orientations ⇒ 3D imaging
E = 500 V/cm
ICARUS liquid argon imaging TPC (II)
André Rubbia, ETH/Zürich, ICARUS Collaboration, 11/2/01
ICARUS liquid argon imaging TPC (III)Detector is continuously sensitive, thus allowing to easily
simultaneously collect atmospheric, CNGS and other rare events...
Time -- drift
Rea
l eve
nt fr
om 1
5 to
n
André Rubbia, ETH/Zürich, ICARUS Collaboration, 11/2/01
CERN ν-beam
νµ + n → µ − + p
128
read
out w
ires
2.54
mm
wire
pitc
h
ICARUS-CERN-Milano
(Chamber located in front of NOMAD detector)
collection view time (400 ns/sample)46 cm max. drift distance
Neutrino event in 50 liter LAr TPC (1998)
André Rubbia, ETH/Zürich, ICARUS Collaboration, 11/2/01
ICARUS: a graded strategy
✔ After several years of R&D and prototyping, the ICARUS collaboration is nowrealizing the first 600 ton module, which will be installed at Gran Sasso in theyear 2001.
Small-scaleprototypes 15 ton
T600
→ Air Liquide for Cryostat and Argon purification
→ BREME Tecnica for internal detector mechanics
→ CAEN for readout electronics
Cooperation with specialized industries:
We are here!
Lab activities:
2x300 tonT1400 (?)
≈≈≈≈4x300 tonor 1x1400 ton
André Rubbia, ETH/Zürich, ICARUS Collaboration, 11/2/01
ICARUS 15 ton (10m 3) prototype (1999-2000)
✯ A major step of the R&D program hasbeen the construction and operation ofa 10m3 prototype
� Test of the cryostat technology
� Test of the “ variable-geometry ” wire
chamber
� Test of the liquid phase purification
system
� Test of trigger via scintillation light
� Large scale test of final readout
electronics
T15 installation @ LNGS (Hall di Montaggio)
➜ First operation of a 15 ton LAr massas an actual “detector”
André Rubbia, ETH/Zürich, ICARUS Collaboration, 11/2/01
Cryostat
Cryo. pump
LN2 exchanger
Control
André Rubbia, ETH/Zürich, ICARUS Collaboration, 11/2/01
Cooling 15 ton prototype March ‘99
✖Confirmation of thefunctionality of the variablegeometry mechanics
100
1000
-50 0 50 100 150 200 250
Lifetime evolution
Life
time
(µµµµ s
)
Elapsed Time (hours)
Pump OFF
Pump ON
✖The electrons lifetime, afterabout 4 days of recirculation, wasbetween 2 ms to 3 ms.
LAr purityTemperature / Wire stretching
André Rubbia, ETH/Zürich, ICARUS Collaboration, 11/2/01
Top View
Lateral View
Internal Volumes Layout
Imaging region (35 cm drift)
External trigger
cathode
wires
André Rubbia, ETH/Zürich, ICARUS Collaboration, 11/2/01
• Just after LAr filling: τ ~ 100µs, according to expectations based on residual leak
rates ( 10-5 mbar/s).
• In a few days of LAr pump operation: τ > 2 ms
Slow ττττ degradation (GAr recirculation off)
Electron Lifetime Measurements
André Rubbia, ETH/Zürich, ICARUS Collaboration, 11/2/01
Tracks in 15 ton prototype
Drift
Wire
s
40 cm
76 c
m
DriftW
ires
10m3 Moduleat LNGS
Cosmic Ray tracksrecorded during the10 m3 operation
André Rubbia, ETH/Zürich, ICARUS Collaboration, 11/2/01
The ICARUS T600 module
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Number of independent containers = 2Single container Internal Dimensions: Length = 19.6 m , Width = 3.9 m , Height = 4.2 mTotal (cold) Internal Volume = 534 m Sensitive LAr mass = 476 ton
Number of wires chambers = 4Readout planes / chamber = 3 at 0° , ± 60° from horizontalMaximum drift = 1.5 mOperating field = 500 V / cmMaximum drift time ≈ 1 msWires pitch = 3 mmTotal number of channels = 58368
2 independent aluminum containerseach one transportable inside the GS Laboratory
External insulation layer (400 mm)
LN2 cooling circuit
Signal feedthroughs
HV feedthroughs
Under construction
3
André Rubbia, ETH/Zürich, ICARUS Collaboration, 11/2/01
T600 assembly schedule
✯ Completed site preparation in Pavia for the T600 cryostat (Nov 1999 )➜ “clean room”, “assembly island”, floor, ...
✯ Delivery of the 1st cryostat by AirLiquide (Feb 2000)➜ Successful vacuum tightness and mechanical stress tests
✯ Beginning of assembly of the internal detector mechanics (Mar 2000)
✯ Completion of assembly and positioning of inner detector frames (Jul 2000 )
✯ Installation of 30000 wires + signal cables (Jul 2000-Oct 2000 )
✯ Delivery of the 2nd cryostat of AirLiquide (Aug 2000 )➜ Successful vacuum tightness and mechanical stress tests
✯ Installation of scintillation light and all slow control devices (Jul 2000-Dec2000)
✯ H.V. and field electrodes system installation (Oct 2000- Jan 2001 )
✯ Installation of the 48 electronic racks on top of dewar (Dec 2000-ongoing )✯ Installation of external heat insulation (for both dewars) and LAr and LN 2
cryogenic circuits (Dec 2000-Jan 2001 )
✯ Semi-module now ready to be sealed.
André Rubbia, ETH/Zürich, ICARUS Collaboration, 11/2/01
First half-module delivery in Pavia (Feb 29, 2000)
André Rubbia, ETH/Zürich, ICARUS Collaboration, 11/2/01
Cryostat
Assembly of the T600 internal detector (Mar-Jul 2000)
Dirtyobserver
Cleanworkers
Internaldetector
André Rubbia, ETH/Zürich, ICARUS Collaboration, 11/2/01
Second half-module during the vacuum test (Jul 2000)
André Rubbia, ETH/Zürich, ICARUS Collaboration, 11/2/01
Vacuum curve
1.00E-05
1.00E-04
1.00E-03
1.00E-02
1.00E-01
1.00E+00
1.00E+01
1.00E+02
1.00E+03
1.00E+04
0.01000 0.10000 1.00000 10.00000 100.00000
Pumping Time (hr )
Ab
solu
te
pre
ssu
re
(mb
ar)
Primary Vacuum (speed = 72 m 3/ h r )
Turbomolecular pumping (speed = 2000 lt/sec)
Vacuum Tests - Second half-module
André Rubbia, ETH/Zürich, ICARUS Collaboration, 11/2/01
Walls Displacement s
- 3 5
- 3 0
- 2 5
- 2 0
- 1 5
- 1 0
- 5
0
5
1 0
1 5
0.00E+00 2.00E+02 4.00E+02 6.00E+02 8.00E+02 1.00E+03 1.20E+03 1.40E+03 1.60E+03
Absolute Pressure (mbar)
Dis
pla
cem
en
t (m
m)
D1 (mm)D2 (mm)D3 (mm)D4 (mm)D5 (mm)D6 (mm)D7 (mm)D8 (mm)D9 (mm)
Dewar behaviour under inner pressure change
overpressure
vacuum
André Rubbia, ETH/Zürich, ICARUS Collaboration, 11/2/01
Second half-module (delivered Aug 2000)
Thermal floor
Thermal insulation panels
André Rubbia, ETH/Zürich, ICARUS Collaboration, 11/2/01
Nomex honeycombpanels (heat insulation)
Dewar
Readoutelectronics
André Rubbia, ETH/Zürich, ICARUS Collaboration, 11/2/01
Installation slow control devices (Jul 2000)
Wire stretchingsensor
André Rubbia, ETH/Zürich, ICARUS Collaboration, 11/2/01
Wire installation in T
600 internaldetector (Jul-O
ct 2000)
André Rubbia, ETH/Zürich, ICARUS Collaboration, 11/2/01
and one PMT
The three wire planes at 0°,±60° (wire pitch = 3mm)
André Rubbia, ETH/Zürich, ICARUS Collaboration, 11/2/01
Wires crossing the spacers (wire pitch = 3mm)
André Rubbia, ETH/Zürich, ICARUS Collaboration, 11/2/01
Wire ChamberSide A
Wire ChamberSide B
Drift distance1.5 m
T600 - Completed Internal Detector view
André Rubbia, ETH/Zürich, ICARUS Collaboration, 11/2/01
Drift distance1.5 m
Hor
izon
tal w
ires
read
out c
able
s–75kVRace-track
E
Drift H.V. and field electrodes system
André Rubbia, ETH/Zürich, ICARUS Collaboration, 11/2/01
Slow control system and scintillation light detection✯ Several instrumentation , most of it custom designed to work at LAr temperature in high
purity environment, has been built tested and installed:
➜ LAr Purity monitors
➜ High precision LAr level meters
➜ Position meters for the wires tensioning springs and for the container walls
➜ Temperature probes
✯ Detection of LAr scintillation light (VUV λ=128 nm, attenuation length in LAr ≈90cm,
1÷2×104 γ per MeV deposited)
➜ Provide help for triggering and T0 measurement .
➜ Bare PMT’s immersed in LAr with wavelength shifter deposited on the glass window
– Test and qualification of PMT at LAr temperature:8 inches EMI PMTs with special treatedbialkali photocathode to work at cryogenic temperature.
– Choice of most efficient wavelength shifter (TPB = TetraPhenylButadiene), depositionmethod (spray), aging properties, pollution of LAr, etc.
André Rubbia, ETH/Zürich, ICARUS Collaboration, 11/2/01
Position meter PMT
Purity Monitors
Wires before tensioning
Slow control sensor (behind wire planes)
André Rubbia, ETH/Zürich, ICARUS Collaboration, 11/2/01
8” PMT coated with TPB
Scintillation light collection(in total 20 PMTs on detector walls)
André Rubbia, ETH/Zürich, ICARUS Collaboration, 11/2/01
André Rubbia, ETH/Zürich, ICARUS Collaboration, 11/2/01
chimneys
Electronicrack
Readout electronic installation on top of dewar (Dec 2000-now)
André Rubbia, ETH/Zürich, ICARUS Collaboration, 11/2/01
Readout electronic installation on top of dewar (Dec 2000-now)
Digital
Analog
André Rubbia, ETH/Zürich, ICARUS Collaboration, 11/2/01
Man-hole (after sealing, the only way to get inside!)
André Rubbia, ETH/Zürich, ICARUS Collaboration, 11/2/01
✯ The ICARUS T600 detector
➜ has a physics program of its own, immediately relevant for neutrino oscillationphysics: solar+SN neutrinos, atmospheric neutrinos
➜ Though with limited statistics, due its relatively small mass, compared to the standardfor underground detectors set by the operating SuperKamiokande.
✯ However, the T600 should also be considered as one more step towards largerdetector masses.
➜ solving technical issues associated with actual operation of a large mass LAr devicein an underground site (LNGS Tunnel).
➜ fully establish the imaging, PID, calorimetric energy reconstruction capabilities ofREAL events, during steady detector operations
➜ In situ proof of actual physics performance of this novel detector technique, inparticular measurement of backgrounds, extrapolable to larger mass detectors
✯ Physics issues for both present and future LAr detectors: Atmospheric ννννSolar+SN ννννCNGS+Nufactory ννννp decay
Perspectives of ICARUS
André Rubbia, ETH/Zürich, ICARUS Collaboration, 11/2/01
Proposed setup ICARUS 5kt in LNGS Hall B
ICARUS T600
Two possible options:A) ≈8 x T600B) 4 x T1400 (better for physics)
André Rubbia, ETH/Zürich, ICARUS Collaboration, 11/2/01
Muon bending measurement
L
8 m
µ
✯ We consider a design in which the muon escaping theliquid Argon is bent by a magnetized piece of iron
B=2.0 T, L�iron� = 2.5 m�
0
25
50
75
100
125
150
175
200
5 10 15 20 25 30 35 40µ momentum (GeV)
An
gle
(m
rad
)
Angle due to bending in magnetic field�
Angle due to multiple scattering�
B = 2 Tesla, L = 2.5 m
Bθ
The bending angle θθθθ is measured withthe tracks observed in two
subsequent liquid argon module
Bending in field
Multiple scattering
16 m
∆∆∆∆p/p ≈≈≈≈ 25%
Charge confusion: ~10-4
André Rubbia, ETH/Zürich, ICARUS Collaboration, 11/2/01
The νννν oscillation framework: Three flavor mixing!
P P PCP CP( ) ( ) ( )ν ν ν ν ν να β α β α β→ = → ± →/ /
P JCP jk jkj k
= −>∑δαβ αβ4 2Re sin ∆
∆∆
jkjkm L
E=
1 27 2.
ννν
ννν
µ
τ
µ µ µ
τ τ τ
e e e eU U U
U U U
U U U
=
1 2 3
1 2 3
1 2 3
1
2
3
∆∆∆∆m2jk in eV2, L in km,
E in GeV
Weak eigenstates
Mass eigenstates
ν1
ν2
ν3νµ
ντ
νe
P JCP jk jk jkj k
/ />
= ∑4 Im sin cos αβ ∆ ∆
J U U U Ujk k k j jαβ α β α β= * *
CP-conservingCP-violating
Mixing strength
Oscillatory pattern
(—) (—) (—) (—) (—) (—)
In general, the oscillation pattern may be complicated and involve a combination of transitions to
ννννe, ννννµµµµ, ννννττττ and by symmetry with quark sector it is natural to expect CP violation at some level.
André Rubbia, ETH/Zürich, ICARUS Collaboration, 11/2/01
Three family oscillations
Ue3➨ Parameterization la CKM :
∆m232 ≈ ∆m2
31≈3x10–3 eV2, θ23≈45°Atmospheric anomaly:
Solar deficit: ∆m212, θ12 , θ23
➨ Current standard mass and mixing assignment:
P P( ) ( )?
ν ν ν να β α β→ ≠ →}
δ≠0?
θ13 (small)
ν νµ τ→
ν νµ τe → /
ν νµ → e ν ντe →
André Rubbia, ETH/Zürich, ICARUS Collaboration, 11/2/01
3 flavor mixing analysis of SuperKamiokande
K. Nakamura, NUFACT00, Monterey(USA), May 2000
PRELIMINARY
Atmospheric neutrinosanalysis
André Rubbia, ETH/Zürich, ICARUS Collaboration, 11/2/01
Solar neutrinos
M.B. Smy, NOON2000, Tokyo(Japan), Dec 2000No smoking gun ?
André Rubbia, ETH/Zürich, ICARUS Collaboration, 11/2/01
�Atmospheric neutrinos�Improvements over existing detection technique
—Detection down to production thresholds—Complete event final state reconstruction—Identification all neutrino flavors—Identification of neutral currents
�Excellent resolution on L/E reconstruction
�Direct ττττ appearance search
�Neutrinos from CERN�Search for ννννµ →→→→ ννννττττ
�Search for ννννµ →→→→ ννννe
�Solar neutrinos�Energy threshold: 5 MeV�Large statistics, high precision measurements�Experimental signal ν νe ee e+ → +νe Ar e K+ → +40 40 *
Absorption Elastic
ICARUS physics potential (I)
∆m232, θ23
∆m212
∆m232, θ23 , θ13
∆m212, θ12
André Rubbia, ETH/Zürich, ICARUS Collaboration, 11/2/01
�Proton decay�Large variety of decay modes accessible
⇒⇒⇒⇒ study branching ratios free of systematics
�Background free searches⇒⇒⇒⇒ linear gain in sensitivity with exposure
�Neutrinos “factory”�Precise measurement of ∆∆∆∆m2
23, ΘΘΘΘ23, ΘΘΘΘ13
�Matter effects, sign of ∆∆∆∆m223
� First observation of ννννe →→→→ ννννττττ
�CP violation
ICARUS physics potential (II)
∆m232, θ23 , θ13
∆m232>0 or ∆m2
32<0 ?
Unitarity of mixing matrix
δ≠0 ?
mm
Mheavyν
?
=}
Physics at Unificationscales?
André Rubbia, ETH/Zürich, ICARUS Collaboration, 11/2/01
Solar neutrinos detection in ICARUS
❖ Two reactions can be measured independently:
ν νx xe e+ → +− − νe Ar K e+ → + −40 40 *
Elastic scattering onatomic electron
νννν absorption onArgon nuclei
❖ Signature:❖ Primary electron track❖ Absorption: surrounded by low energy secondary tracks (40K*de-
excitation).❖ Prototype setup: electron track visible down to kinetic T=150 KeV❖ Electron track threshold = 5 MeV (needed to reduce background
contribution and to establish the e- direction in elastic scattering).❖ Sensitive to 8B component of the solar spectrum.
André Rubbia, ETH/Zürich, ICARUS Collaboration, 11/2/01
Radioactive source: 6 MeV γγγγ’s
André Rubbia, ETH/Zürich, ICARUS Collaboration, 11/2/01
André Rubbia, ETH/Zürich, ICARUS Collaboration, 11/2/01
Signal selection
✯ Elastic events:➜ Angular distribution of the electron
peaked in the solar ν direction:
✯ Absorption events:➜ Electron track directions can be
considered isotropically distributed
α = 25˚
ε = 72%
The off-line selection can be done in terms of the energyof the main electron and the correlation betweenmultiplicity and energy of the associated tracks.
André Rubbia, ETH/Zürich, ICARUS Collaboration, 11/2/01
Solar νννν’s background events
Naturalradioactivity
Spontaneous fission orSpontaneous fission or((αα ,n) reactions,n) reactions
Captures in the detectorCaptures in the detector((4040Ar, Ar, 2727Al, Al, 5656Fe,…)Fe,…)
n flux γγγγ-rays e-
energies inenergies in
the the 88B rangeB range
Y(cm)�
X(c
m)�
n/cm2/s capt/cm2/s
Y(cm)
X(c
m)
Neutronshield
(Full FLUKAsimulation)
≈7400 captures/year in500 ton fiducial ≈150 /year with Ee>5 MeV
André Rubbia, ETH/Zürich, ICARUS Collaboration, 11/2/01
Solar neutrino rates and sensitivity
Events per year for a 600ton detector
Te (MeV) Neutrons
0.0 7400
1.0 3404
2.0 1554
3.0 696
4.0 318
5.0 144
6.0 66
7.0 30
8.0 13
Events/year
Elastic channel Background
2126
Absorption channels Background
759 26
470 ton fiducial, allcuts imposed
RN N
N N
EStheoryES
ABStheoryABS≡
/
/
ES=elastic scattering
ABS=absorption events
ν νx xe e+ → +− −
νe Ar K e+ → + −40 40 *
∆R R kt yr kt yr kt yr/ %( ), %( ), %( )≈ × × ×7 1 5 2 4 4
10 10 10 10 10-4 -3 -2 -1 0
10
10
10
10
10
10
10
10
10
10
10
-11
-10
-9
-8
-7
-6
-5
-4
-3
-2
-1
0.950.98
0.98
0.990.99
0.99
0.99
0.99
1
1.08
1.08
1.08
1.08
1.2
1.3
1.51.92.2
5
10
20
57
MS
W -
LO
W
JustSo
MSW - SMA
MS
W -
LM
A
sin2 2 θ
∆ m
2 (eV
)2
(a)
André Rubbia, ETH/Zürich, ICARUS Collaboration, 11/2/01
Supernova neutrinos detection in ICARUS
✯ ICARUS can detect neutrinos coming from stellar collapses in ourGalaxy via 2 processes:
➜ Elastic scattering(flavor independent)
➜ Absorption on argon
ν νx xe e+ → +− −
νe Ar K e+ → + −40 40 *
Expected events from a stellarcollapse occurred at 10 kpc
600 ton 5 kton 30 kton
8 70 400
Nv = ×8 1057
André Rubbia, ETH/Zürich, ICARUS Collaboration, 11/2/01
Atmospheric neutrinos
π,Kµ
e
Earth
µ�
µ�
p,He,...
p,He,...
νµ
νµ
hadronic cascade + decays
almost isotropic source(geomagnetic effects)
0.4 < Eν < 1 GeV at Gran Sasso
0.02
0.025
0.03
0.035
0.04
0.045
0.05
0.055
-1 -0.5 0 0.5 1
3 dim
1 dim
cosθ
ν/cm
2 /sec
/sr/
GeV
νµ 0.02
0.025
0.03
0.035
0.04
0.045
0.05
0.055
-1 -0.5 0 0.5 1
3 dim
1 dim
cosθ
νµ-
0.01
0.0125
0.015
0.0175
0.02
0.0225
0.025
0.0275
0.03
-1 -0.5 0 0.5 1
3 dim
1 dim
cosθ
ν/cm
2 /sec
/sr/
GeV
νe 0.008
0.01
0.012
0.014
0.016
0.018
0.02
0.022
0.024
-1 -0.5 0 0.5 1
3 dim
1 dim
cosθ
νe-
Simulation based on FLUKA interaction and transport code(extensively benchmarking against data)3D representation of Earth and atmosphereGeomagnetic effects includedAll relevant physics taken into account: energy losses, polarized decays
André Rubbia, ETH/Zürich, ICARUS Collaboration, 11/2/01
90 cm
90 c
m Eν = 370 MeV
Pµ = 250 MeV
Tp = 90 MeVµ
p
Atmospheric ννννµµµµ CC
e
(simulated event)
Atmospheric v’s
ννννµ Q-el. interaction
André Rubbia, ETH/Zürich, ICARUS Collaboration, 11/2/01
100 cm
90 c
m
Eν = 450 MeV
Pe = 200 MeV
Tp = 240 MeVp
e
Atmospheric v
ννννe quasielastic interaction
(simulated event)
Atmospheric ννννe CC
André Rubbia, ETH/Zürich, ICARUS Collaboration, 11/2/01
Events/year
NUX �σν/E�ν , isoscalar�
0
0.2
0.4
0.6
0.8
1
1.2
10-2
10-1
1 10 102
Eν (GeV)
σ/E
TotalQEDISCharm
Atmospheric neutrino rates (5 kt x year)(nux)
Nuclear effectsfully embedded in FLUKAnuclear model
André Rubbia, ETH/Zürich, ICARUS Collaboration, 11/2/01
0�
50�
100�
150�
200�
250�
300�
350�
400�
-1� -0.5� 0� 0.5� 1�
Mean�
RMS�
-0.3652E-01�
0.3098�
((L/E)�MC�-(L/E)�meas�)/(L/E)�MC�
Eve
nts
(arb
itrar
y un
its)�
0�
100�
200�
300�
400�
500�
600�
700�
800�
-1� -0.5� 0� 0.5� 1�
Mean�
RMS�
-0.4069E-01�
0.2875�
((L/E)�MC�-(L/E)�meas�)/(L/E)�MC�
Eve
nts
(arb
itrar
y un
its)�
L/E distribution
✯ Oscillation parameters:➜ ∆∆∆∆m2
32 = 3.5 x 10-3 eV2
➜ sin 2 2ΘΘΘΘ23 = 0.9
➜ sin 2 2ΘΘΘΘ13 = 0.1
✯ Electron sample can be usedas a reference for nooscillation case
0�
10�
20�
30�
40�
50�
60�
0� 0.5� 1� 1.5� 2� 2.5� 3� 3.5� 4�Log�10�(L/E)�
Eve
nts
for
25 k
ton
x ye
ar�
0�
20�
40�
60�
80�
100�
120�
140�
0� 0.5� 1� 1.5� 2� 2.5� 3� 3.5� 4�Log�10�(L/E)�
Eve
nts
for
25 k
ton
x ye
ar�
Electrons
Muons
25 kt yearP mL
E( ) sin sin .ν ν θα β→ =
2 2 22 1 27∆
∆( / ) %L E RMS ≈ 30
André Rubbia, ETH/Zürich, ICARUS Collaboration, 11/2/01
CNGS neutrino beam
CERN Gran Sasso
CERN Neutrino Beam in the Direction of Gran Sasso
earth
Distance = 732 Km
Earth
radi
us =
638
0 Km 10.5 km below ground Planned beam commissioning: May 2005
CERN 98-02 - INFN-AE/98-05CERN-SL/99-034(DI) - INFN/AE-99/05
The expected νe and ντ contamination of the CNGS beam are of the
order of 10–2 and 10–7 respect to the dominant νµ.
ννννττττ? ννννe?
ννννµµµµ
André Rubbia, ETH/Zürich, ICARUS Collaboration, 11/2/01
✯ Primary protons: 400 GeV; 4x2.3x10 13 p/cycle; 26.4 s/cycle✯ Pots per year: 4.5x1019 pots “shared”; 200x0.75 days/year
✯ Optimized for
✯ 7.6x1019 pots/yr “dedicated”CERN 98-02 - INFN-AE/98-05; CERN-SL/99-034(DI) - INFN/AE-99/05
CNGS event rates
νµ CC events events spectrum@LNGS
νννν ττττ CC
eve
nt
rate
s
N E E E dECCτ ν νφ σ
µ τ∝ × −∫ ( ) ( ) 2
No
osci
llatio
ns
André Rubbia, ETH/Zürich, ICARUS Collaboration, 11/2/01
CNGS events in 5 kton, 4 years running
θθθθ23 = 45°, θθθθ13 = 7°
André Rubbia, ETH/Zürich, ICARUS Collaboration, 11/2/01
eννBr ≈ 18%
ττττ→→→→ννννµµµµ→→→→ ννννττττCharged current (CC)
ννννττττ++++N→→→→ττττ+jet;
Charged current (CC)ννννe++++N→→→→e+jet
ννννµµµµ →→→→ννννττττ oscillations (I)
Background:
✯ Analysis of the electron sample
➜ Exploit the small intrinsic νe contamination of the beam
(0.8% of νµ CC)
➜ Exploit the unique e/π0 separation
470 νeCC
∆m eV2 3 23 5 10= × −. 110 events
Statistical excess visible before cuts ⇒⇒⇒⇒ this is the main reason for performingthis experiment at long baseline !
⇒
André Rubbia, ETH/Zürich, ICARUS Collaboration, 11/2/01
ννννµµµµ →→→→ννννττττ oscillations (II)
0
5
10
15
20
25
30
35
40
0 5 10 15 20 25 30 35 40
νe� + �ντ CC�νe� CC�ντ CC�
Evisible (GeV)
Eve
nts
/20k
ton
x y
ear
Reconstructed energy
νe CC
signal
✯ Reconstructed visibleenergy spectrum of electronevents clearly evidencesexcess from oscillations intotau neutrino
André Rubbia, ETH/Zürich, ICARUS Collaboration, 11/2/01
ννννµµµµ →→→→ννννττττ oscillations (III)
νe CC 0
2
4
6
8
10
12
14
16
18
20
0 0.5 1 1.5 2 2.5 3
νe� + �ντ CC�νe� CC�ντ CC�
Missing PT (GeV)
Eve
nts/
20kt
on x
yea
r
Transverse missing PT
✯ Kinematical selection in order to enhanceS/B ratio
✯ Can be tuned “a posteriori”depending on the actual ∆m2
✯ For example, with cuts listed below,reduction of background by factor 100 fora signal efficiency 33%
André Rubbia, ETH/Zürich, ICARUS Collaboration, 11/2/01
e/ππππ0 discrimination
electron ππππ0
0�
0.0005�
0.001�
0.0015�
0.002�
0.0025�
0� 5� 10� 15� 20� 25� 30� 35� 40� 45� 50�0�
0.0005�
0.001�
0.0015�
0.002�
0.0025�
0� 5� 10� 15� 20� 25� 30� 35� 40� 45� 50�
Wire number Wire number
GeV
GeV
Single m.i.p. Double m.i.p.
e ee
Wire pitch = 3 mm ¯ 0 .02 X0
0
50
100
150
200
250
300
0.0 0.2 0.4 0.6 0.8 1.0 1.2 1.4 1.6 1.8 2.0
Ent
ries/
0.02
MeV
(ar
bitr
ary
norm
aliz
atio
n)
Energy deposited (MeV)
Single electrons vs Dalitz pairs20 wires
pitch = 3 mm
Dalitz pairs>99% with Edep > 1MeV
single electrons91.4% with Edep < 1MeV
¯10cm
Combined rejection: dE/dx +photon converted within 3 cmof vertex: > 500
André Rubbia, ETH/Zürich, ICARUS Collaboration, 11/2/01
L = 732 Km �∆m�2� = 3.5 x 10�-3� eV�2� �Θ23� = 45�o� �Θ13� = 7�o�
10-1
1
10
10 2
10 3
0 2 4 6 8 10 12 14Elepton (GeV)
Eve
nts/
20kt
on x
yea
r
All�
νe� CC�
Oscillated �νµ→ �νe�
Oscillated �νµ �→ �ντ
NC�
νe� CC + Oscillated �νµ �→ �ντ
ICANOE at CNGS
Evis < 20 GeV
ννννe CC versus νννν NC discrimination (I)
L = 732 Km �∆m�2� = 3.5 x 10�-3� eV�2� �Θ23� = 45�o� �Θ13� = 7�o�
10
10 2
10 3
0 2 4 6 8 10 12 14Elepton (GeV)
Eve
nts/
20kt
on x
yea
r
All�
νe� CC�
Oscillated �νµ→ �νe�
Oscillated �νµ �→ �ντ
NC�
νe� CC + Oscillated �νµ �→ �ντ
ICANOE at CNGS
Evis < 20 GeV
γ converting within 3 cm (10 samples) from primary vertexconsidered as electron candidate
NC
NO dE/dxinformation used
dE/dx information usedSingle vs double m.i.p.algorithm provides >500rejection factor
André Rubbia, ETH/Zürich, ICARUS Collaboration, 11/2/01
L = 732 Km �∆m�2� = 3.5 x 10�-3� eV�2� �Θ23� = 45�o� �Θ13� = 7�o�
1
10
10 2
10 3
10 4
0 0.5 1 1.5 2 2.5 3Missing PT (GeV)
Eve
nts/
20kt
on x
yea
r
All�
νe� CC�
Oscillated �νµ→ �νe�
Oscillated �νµ �→ �ντ
NC�
νe� CC + Oscillated �νµ �→ �ντ
ICANOE at CNGS
Evis < 20 GeV and Ee > 1 GeVQlep > 0.3 GeV
L = 732 Km �∆m�2� = 3.5 x 10�-3� eV�2� �Θ23� = 45�o� �Θ13� = 7�o�
10-1
1
10
10 2
10 3
0 0.5 1 1.5 2 2.5 3Missing PT (GeV)
Eve
nts/
20kt
on x
yea
r
All�
νe� CC�
Oscillated �νµ→ �νe�
Oscillated �νµ �→ �ντ
NC�
νe� CC + Oscillated �νµ �→ �ντ
ICANOE at CNGS
Evis < 20 GeV and Ee > 1 GeVQlep > 0.3 GeV
ννννe CC versus νννν NC discrimination (II)
Additional discrimination powerprovided by event kinematics
NC rejection
NO dE/dx information used dE/dx information used
André Rubbia, ETH/Zürich, ICARUS Collaboration, 11/2/01
∆∆∆∆m232=3.5x10–3 eV2; sin22θθθθ23 = 1
Search for θθθθ13≠≠≠≠0
ICANOE4 years
P e( ) sin sinν ν θ θµ → = 213
223
2322 ∆
P( ) cos sinν ν θ θµ τ→ = 413
223
2322 ∆
André Rubbia, ETH/Zürich, ICARUS Collaboration, 11/2/01
0
10
20
30
40
50
60
70
0 5 10 15 20 25 30 35 40Evisible (GeV)
Eve
nts
/20k
ton
x y
ear
νe� CC + oscillated �νµνe� CC�Oscillated �νµ→ �νe�
Oscillated �νµ �→ �ντνe� CC + Oscillated �νµ �→ �ντ
L = 732 Km �∆m�2� = 3.5 x 10�-3� eV�2� �Θ23� = 45�o� �Θ13� = 7�o�
0
10
20
30
40
50
60
70
0 0.5 1 1.5 2 2.5 3Missing PT (GeV)
Eve
nts
/20k
ton
x y
ear
νe� CC + oscillated �νµνe� CC�Oscillated �νµ→ �νe�
Oscillated �νµ �→ �ντνe� CC + Oscillated �νµ �→ �ντ
ICANOE at CNGS
Evis < 20 GeV and Ee > 1 GeV
Transverse missing PTTotal visible energy
P e( ) sin sinν ν θ θµ → = 213
223
2322 ∆P( ) cos sinν ν θ θµ τ→ = 4
132
232
322 ∆
∆∆∆∆m232=3.5x10–3 eV2; sin22θθθθ23 = 1 ; sin22θθθθ13 = 0.05
André Rubbia, ETH/Zürich, ICARUS Collaboration, 11/2/01
10-4
10-3
10-2
10-1
10-3
10-2
10-1
1
↔νµ νe90% allowed
χ2 min
+ 4.6
νµ → ντ included, Θ23 = π/4
CHOOZ
sin2 2Θ13
∆m2 23
(eV
2 )Sensitivity to θθθθ13 in three family-mixing
Ο Sensitivity to νµ → νe
oscillations inpresence of νµ → ντ
(three family mixing)
Ο Factor 5 improvementon sin22θ13 at ∆m2 =3x10–3 eV2
Ο Almost two-orders ofmagnitudeimprovement overexisting limit at high∆m2
André Rubbia, ETH/Zürich, ICARUS Collaboration, 11/2/01
Nucleon decay search
Thanks to excellenttracking and particle
id capabilities
LAr unique tool for
Extremely efficientbackground rejection
High detection efficiency
Bias-free, fully exclusivechannel searches!
p→→→→e+ ππππ0000 decayp→→→→ννννK+ decay n→→→→ννννK0 decay
André Rubbia, ETH/Zürich, ICARUS Collaboration, 11/2/01 Exposure: 1000 kton x year
p→→→→e+ ππππ0 decay kinematics
0
20
40
60
80
100
0 0.2 0.4 0.6 0.8
π0 absorbed
π0 detected
Total Momentum (GeV)
N /
20 M
eV
0
100
200
300
400
500
0.4 0.6 0.8 1
π0 absorbed
π0 detected
Measured Energy (GeV)
N /
20 M
eV
≈45% π0 absorbed in Ar nucleus
Nuclear effects: pion absorption and rescattering included(FLUKA)
André Rubbia, ETH/Zürich, ICARUS Collaboration, 11/2/01 Exposure: 1000 kton x year
p→→→→K+νννν decay kinematics
At least we see the kaon!
André Rubbia, ETH/Zürich, ICARUS Collaboration, 11/2/01
Proton decay: expected backgrounds vs channel
ICARUS Proton Decay: Expected Backgrounds
1
10
10 2
10 3
1 10 102
103
p → e+ π0
p → e+ (π0)
p → K+ ν–
p → µ- π+ K+
p → e+ π+ π-
p → e+ π+ (π-)
p → e+ (π+ π-)
p → π+ ν–
p → µ+ π0
p → µ+ (π0)
Exposure (kTons × year)
Exp
ecte
d B
ackg
roun
ds (
# ev
ents
)
Channel # Bkg. events
( 1kTon × year )
p → e+ π0 0.002p → e+ (π0) 2.099
p → K+ ν–
0.001p → µ- π+ K+ 0.001p → e+ π+ π- 0.025
p → e+ π+ (π-) 1.257p → e+ (π+ π-) 5.945
p → π+ ν–
0.552p → µ+ π0 0.015
p → µ+ (π0) 5.829
p→e+π0
p→K+ν
p→e+X
1 Mton x yr
Extremely good exclusivesignal signatures
⇒ Excellent backgroundrejection
Discovery with a singleevent!
Nuclear effects in backgrounds: fullyembedded in FLUKA nuclear model
André Rubbia, ETH/Zürich, ICARUS Collaboration, 11/2/01
Sensitivity vs exposureICARUS: Limits on Proton Decay
1031
1032
1033
1034
1035
1 10 102
103
p → e+ π0
p → e+ (π0)
p → K+ ν–
p → µ- π+ K+
p → e+ π+ π-
p → e+ π+ (π-)
p → e+ (π+ π-)
p → π+ ν–
p → µ+ π0
p → µ+ (π0)
Exposure (kTons × year)
τ p/B
upp
er li
mit
at 9
0% C
L (
year
s)
Channel Efficiency (%) # Bkg. events
( 1kTon × year )p → e+ π0 37.5 0.002
p → e+ (π0) 14.15 2.099p → K+ ν
–97.15 0.001
p → µ- π+ K+ 99.2 0.001p → e+ π+ π- 22.4 0.025
p → e+ π+ (π-) 29.15 1.257p → e+ (π+ π-) 14.45 5.945
p → π+ ν–
39.75 0.552p → µ+ π0 40.95 0.015
p → µ+ (π0) 18.25 5.829
Nuclear effects in signal: fully embeddedin FLUKA nuclear model
p→e+π0
p→K+ν
Extremely good exclusivesignal signatures
⇒ Excellent backgroundrejection
Discovery with a singleevent!
1034
1035
10 kton x yr
André Rubbia, ETH/Zürich, ICARUS Collaboration, 11/2/01
Exposure needed to reach PDG limit
Given our poor knowledge of the physics at the GUT scale, weneed to look for all possible channels, in unbiased, free of
background searches.
André Rubbia, ETH/Zürich, ICARUS Collaboration, 11/2/01
µ− →e− νeνµνµ→νe→e− appearance
νµ disappearance
νµ→ντ→τ− appearance
νe disappearance
νe→ νµ→µ+ appearance
νe→ ντ→τ+ appearance
Plus their charge conjugates with µ+
beam
Neutrino factory
Ideal detector should be able tomeasure 12 different processes
�Detect: µ+, µ−, e, NC, τ
�Various baselines
�Various muon energies
O(1021) µ required
André Rubbia, ETH/Zürich, ICARUS Collaboration, 11/2/01
E�µ = 30 GeV, L = 7400 km, 10�20� �µ-� decays�
0
20
40
60
80
100
120
0 5 10 15 20 25 30 35 40Evisible (GeV)
dN/d
Eν (
ν e C
C e
vent
s/1.
6GeV
per
10
kton
)
Anti-�νe�+ �νe�+ �ντ CC�Anti-�νe� CC�νe� CC�ντ CC�
E�µ = 30 GeV, L = 7400 km, 10�20� �µ-� decays�
0
10
20
30
40
50
60
0 5 10 15 20 25 30 35 40Evisible (GeV)
dN/d
Eν (
ν µ C
C e
vent
s/1.
6GeV
per
10
kton
)
νµ + �ντ CC + background�νµ CC�ντ CC�Background�
E�µ = 30 GeV, L = 7400 km, 10�20� �µ-� decays�
0
20
40
60
80
100
0 5 10 15 20 25 30 35 40Evisible (GeV)
dN/d
Eν (
ν ev
ents
/1.6
GeV
per
10
kton
)
ν NC + �ντ CC�ν NC�ντ CC�
E�µ = 30 GeV, L = 7400 km, 10�21� �µ+ � decays�
0
20
40
60
80
100
120
140
160
180
0 5 10 15 20 25 30 35 40Evisible (GeV)
dN/d
Eν (
ν µ C
C e
vent
s/1.
6GeV
per
10
kton
)
νµ + �ντ CC + background�
νµ CC�
ντ CC�
Background�
Event classes
Right sign µ
Wrong sign µ
ElectronsNC-like
Combining all classes⇒ (over-constrained) sensitivity to all oscillations!
André Rubbia, ETH/Zürich, ICARUS Collaboration, 11/2/01
Expected sensitivity to θθθθ13 at a neutrino factory
NuFact: Eµ=30 GeV, L = 7400 km�
10-4
10-3
10-2
10-6 10-5 10-4 10-3 10-2 10-1 1sin2 2Θ13
∆m2 23
(eV
2 )
90% ALLOWED
SUPER-K ALLOWED
2 x 1020 µ(background)
2 x 1020 µ
(no background)
2 x 1021 µ(no background)
2 x 1021 µ(background)
4 years CNGS + atm
✯ Very long baseline:L=7400 km
✯ Search for wrong-signmuons
Ο Strongly depends onbackground level forwrong-sign muons
Ο Might be the only way tomeasure θ13
André Rubbia, ETH/Zürich, ICARUS Collaboration, 11/2/01
Conclusion
✯ The ICARUS T600, based on the novel ICARUS technique, is now almost ready.
✯ Given the past record with previous prototypes, we are confident that also the
T600 will come into operation smoothly…
➜We hope to present the first 20 m long tracks with 3 mm granularity
soon!
➜ It will demonstrate that the technique , even on such large scales, is now
mature .
✯ Then, the first T600 Module should be installed into the Gran Sasso tunnel.
✯ Operation inside tunnel in the course of next year (2002) should allow an
appropriate scaling up for the increase of the mass
✯ The technology, once it is scaled to the “right” size , will become a powerful
tool in particle physics, in particular in order to explore neutrino oscillations from
both accelerator and non-accelerator beams and proton decay.