1. Physics with the ICARUS T1800 detector
Jan Kisiel Institute of Physics, University of Silesia, Katowice, Poland
(on behalf of the ICARUS collaboration)
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2. 25 INSTITUTIONS, 150 PHYSICISTS
Icarus Collaboration
L’Aquila, LNGS,
Milano, Napoli,
Padova, Pavia,
Pisa, LNF
ETHZ
Katowice Krakow
Warsaw, Wroclaw
INR
UCLA
CIEMAT
Granada
IHEP
25 INSTITUTIONS, 150 PHYSICISTS
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3. Scheme of presentation
Status of the ICARUS detector
T1800: some numbers
T1800: physics program
- nucleon decay
- atmospheric neutrinos
- CNGS neutrinos
- supernova neutrinos
Summary
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4. considered in this talk
ICARUS Detector
T1800 (T600 + T1200)
considered in this talk
T600 tested
Pavia, 2001
T600
T1200
ICARUS T3000
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5. Status of the ICARUS detector
2001: successful test of the T300 module in Pavia (100 days of data taking, ~29000 triggers on tape, different topologies: long (up 18 m !) muon tracks, hadronic and EM interactions, muon bundles,… µ+ e+
18 m
1.5 m
Cathode
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6. Status of the ICARUS detector
2004: two T300 modules (composing T600) delivered to LNGS,
Construction of next two T600 modules (composing T1200) is now at starting point,
T1800: T600 (1 year of running) +T1800 (4 years of running) considered in this talk.
NuFact05, Frascati,

7. NuFact05, Frascati,

8. T1800: some numbers
T600 - the instrumented volume: m3, t of LAr, with drift length = 1.5m
T1200 – the instrumented volume: m3, t of LAr, with drift length = 3.0m
Energy resolution:
For electrons, Ee < 50MeV:
from the measurement of the Michel ρ parameter in µ decay)
For photons (the π0 mass reconstruction) – analysis in progress
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9. Nucleon decay:
Full event simulation with FLUKA: Fermi motion of the nucleon inside the Ar nuclei, and nuclear effects due to the scattering or absorption of the decay products inside the parent nucleus are included
Atmospheric neutrinos background evaluation based on a sample corresponding to a 100kton x 1year exposure
Signal/background extraction: sequence of topological and kinematical (total energy, momentum and invariant mass) cuts
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10. Nucleon decay – summary table
For the channel
limit is from hep-ex/ (SK), for the rest
from PDG’2004.
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11. Nucleon decay:
In all exclusive channels the background is much below 1event/kton/year → discovery capability of nucleon decay with the observation of a single event
SuperKamiokande limits for channels: p→π+ν and n→e-K+ can be improved with the exposure less than one year
The ICARUS T1800 detector has the capability to improve the present limits for several channels of nucleon decay with an exposure of few years
NuFact05, Frascati,

12. Atmospheric neutrino
Studies of atmospheric neutrinos proved the neutrino oscillations and have established mixing parameters of the 2-3 sector of the lepton mixing matrix (Super-Kamiokande), however the precision comes mostly from the systematics, not from the event statistics
Sub-GeV νe events, after solar neutrino and KAMLAND results, are of particular interest: thanks to interferences with the 1-2 mixing sector, low energy νe oscillations should appear at some level, even for sin2θ13=0
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13. Atmospheric neutrino
LAr technique allows to observe all neutrino flavors and both CC and NC events, with reconstruction of complicated event topologies, down to a very low kinematical threshold → for the first time for pe<100MeV/c
A more precise measurement of the Sub-GeV νe could be the best possible tool to measure θ23:
→ first important insight from ICARUS,
→ statistical significance from the next generation of LAr detectors
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14. Atmospheric neutrino: simulation parameters
Improved ICARUS simulation:
→ FLUKA+NUX, 3-flavor neutrino oscillation, including matter effects (F.Vissani)
→ neutrino oscillation parameters:
Δm122= eV2
Δm232=(1.5) 2.5 (3.4) 10-3 eV2
sin22θ12=0.825
sin22θ13=0.140
sin22θ23=1.0
δCP=0
exposure: 6.36 kton yr (1 yr T yrs T1800)
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15. Atmospheric neutrinos: event selection
Separation energy:
ICARUS: Sub-GeV → Evisible < 1 GeV
Multi-GeV → Evisible > 1 GeV
Super-Kamiokande: 1.33 GeV
Kinetic energy threshold:
ICARUS: 10 MeV for electrons and muons
Super-Kamiokande: 100 MeV for electrons
120 MeV for single-ring muons
600 MeV for multi-ring muons
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16. Atmospheric neutrinos: # of expected events
contained events for a 6.36 kton yr exposure
200 events
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17. Atmospheric neutrinos: expected result
1σ statistical uncertainty (dotted lines) achievable with the expected number of Sub-GeV e-like events in T1800 assuming fit to a flat distribution
15% excess level (red line) found by the Super-Kamiokande Coll. in their comparison of data with MC
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18. CNGS neutrinos: νµ and νe spectra
new simulation with updated beam parameters
shared beam mode operation: pot/year, with possible upgrade of 50%
beam contaminations:
νe~0.6%, ντ<10-6 (clean ντ appearance)
possibility of νµ→ νe search thought the CNGS beam is not optimized for such search
νµ and νe energy spectra
with parent particles
at the Gran Sasso site
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19. CNGS: νµ→ντ – signal vs background
Main part of the background
Flux contamination
jet
jet
conservation
Also contribute to background:
from Dalitz
decays
misidentification as …
jet
jet
„missing”
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20. CNGS: νµ→ντ – expected results
CL for the νµ→ντ oscillation
discovery as a function of
ICARUS exposure.
number of νµ→ ντ events and bkgd
for T600(1 yr) + T1800(4 yr)
obtained with sin22θ23=1
(in parenthesis for the 50% upgraded beam intensity)
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21. Supernova neutrinos:
Assumptions: mean energies 11MeV, 16MeV and 25MeV for electron neutrino, antineutrino and νµ/τ respectively; and the same luminosity for all neutrino flavors,
Number of expected SN neutrino events in ICARUS T1800 for inverted (normal) mass hierarchy and small value of θ13
NuFact05, Frascati,

22. Supernova neutrinos: T1800 sensitivity
global sensitivity
(all reactions)
up to ~ 1Mly
distance
sensitivity to the SN
direction (elastic
events only)
up to galactic SNs
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23. Summary:
T1800 has capability to improve the current limits for several channels of nucleon decay
T1800 allows for almost free from experimental systematics investigation of SubGeV atmospheric neutrinos
T1800 has discovery capability for ντ appearance and can explore the νµ→ντ oscillation
T1800 can detect SN explosion up to 1Mly distance
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