Physics with the ICARUS T1800 detector Jan Kisiel Institute of Physics, University of Silesia, Katowice, Poland kisielj@us.edu.pl (on behalf of the ICARUS collaboration) http://www.cern.ch/icarus/ NuFact05, Frascati, 21-26.06.2005

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 NuFact05, Frascati, 21-26.06.2005

Scheme of presentation Status of the ICARUS detector T1800: some numbers T1800: physics program - nucleon decay - atmospheric neutrinos - CNGS neutrinos - supernova neutrinos Summary NuFact05, Frascati, 21-26.06.2005

considered in this talk ICARUS Detector T1800 (T600 + T1200) considered in this talk T600 tested Pavia, 2001 T600 T1200 ICARUS T3000 NuFact05, Frascati, 21-26.06.2005

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 NuFact05, Frascati, 21-26.06.2005

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, 21-26.06.2005

NuFact05, Frascati, 21-26.06.2005

T1800: some numbers T600 - the instrumented volume: 340.35m3, 476.5 t of LAr, with drift length = 1.5m T1200 – the instrumented volume: 710.51m3, 994.5 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 NuFact05, Frascati, 21-26.06.2005

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 NuFact05, Frascati, 21-26.06.2005

Nucleon decay – summary table For the channel limit is from hep-ex/0502026 (SK), for the rest from PDG’2004. NuFact05, Frascati, 21-26.06.2005

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, 21-26.06.2005

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 NuFact05, Frascati, 21-26.06.2005

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 NuFact05, Frascati, 21-26.06.2005

Atmospheric neutrino: simulation parameters Improved ICARUS simulation: → FLUKA+NUX, 3-flavor neutrino oscillation, including matter effects (F.Vissani) → neutrino oscillation parameters: Δm122=8.3 10-5 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 T600 + 4 yrs T1800) NuFact05, Frascati, 21-26.06.2005

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 NuFact05, Frascati, 21-26.06.2005

Atmospheric neutrinos: # of expected events contained events for a 6.36 kton yr exposure 200 events NuFact05, Frascati, 21-26.06.2005

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 NuFact05, Frascati, 21-26.06.2005

CNGS neutrinos: νµ and νe spectra new simulation with updated beam parameters shared beam mode operation: 4.5 1019pot/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 NuFact05, Frascati, 21-26.06.2005

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” NuFact05, Frascati, 21-26.06.2005

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) NuFact05, Frascati, 21-26.06.2005

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, 21-26.06.2005

Supernova neutrinos: T1800 sensitivity global sensitivity (all reactions) up to ~ 1Mly distance sensitivity to the SN direction (elastic events only) up to galactic SNs NuFact05, Frascati, 21-26.06.2005

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 NuFact05, Frascati, 21-26.06.2005