Performance of the ICARUS T600 detector CIPANP 2003 Conference on the Intersections of Particle and Nuclear Physics New York City May 19-24, 2003 Sergio Navas University of Granada, Spain Sergio Navas (U. Granada), 23/05/03 CIPANP03 (NY) 1
Minimum ionizing track: 88000 electron-ion pairs per cm After recombination @ 500 V/cm: 55000 pairs/cm e - e - e - Ar + Ar + Ar + Ar + Ar + - Drift of electrons: v - e - e - e - Trajectory of ionizing particle e - Ar + Ar + Ar + Ar + Ar + e - + Drift of ions: v + E-field.v + <<v - 1.6 mm/µs @ 500 V/cm Sergio Navas (U. Granada), 23/05/03 CIPANP03 (NY) 2
µ Cathode Detection technique LAr used as `target` and `detector` Anode: multiplane readout 3 wire planes at 0 and ± 60 deg Wire separation = 3 mm e e e e e E E e e e Wire planes E = 500 V/cm Argon (87K) 3 m 3 m Collection Induction 1 Induction 2 ( transparent ) Sergio Navas (U. Granada), 23/05/03 CIPANP03 (NY) 3
Drift Coordinate Drift Coordinate Wire Coordinate 1 m Multiple plane readout of T600 Run 969, Evt.50 (Right chamber) Collection 0.9 m "Bubble" size 3 3 0.2 mm 3 1 m Wire Coordinate (wire number) 2.2 m Drift Coordinate (time) Induction 2 0.9 m Induction 1 1.3 m Wire Coordinate... Can reconstruct 3D images! Sergio Navas (U. Granada), 23/05/03 CIPANP03 (NY) 4
Argon purity Free electrons can attach to impurities like Oxygen for instance To drift over long distances, the liquid argon must be very pure: < 0.1 ppb Oxygen-equivalent < 5 m drift e- e-? 10 m drift! 50 litre prototype data Sergio Navas (U. Granada), 23/05/03 CIPANP03 (NY) 5
ICARUS physics programme 1 3 tons, 50 l (lab.activities) Phase I : ( starts in 2003 ) 600 ton ICARUS detector Observation of atmospheric neutrinos and proton-decay / solar ν studies. 15 ton T600 2 T1200 past present future (2005) far future? "Modularity" and "Scaling up" in mass?? 1 Phase II : ( starts 2005 ) 3000 ton ICARUS detector Continue observation of atmospheric neutrinos and solar/p-decay studies Detection of artificial neutrino beam from CERN T600 2 T600 2 T600 Summer '01: first technical run of 300 ton detector (Pavia) November '01: proposal to CLONE T1200 modules to reach the desired mass (2005-2006 3000 tons). March '02: allocation of LNGS entire Hall B for ICARUS 2002: continue planning for installation of T600 in LNGS 2003: detector installation in Gran Sasso INFN Comm. II has approved the T3000 scientific programme and the design of successive T1200 modules. ICARUS approved as CERN-experiment and inserted on the CNGS programme (31/March/03). Built and tested Fully funded requested Sergio Navas (U. Granada), 23/05/03 CIPANP03 (NY) 6
ICARUS T300 cryostat Τ300 300.000 kg of L.Ar Sergio Navas (U. Granada), 23/05/03 CIPANP03 (NY) 7
View of the inner detector Readout electronics Cryostat (half-module) 4 m 4 m 20 m Sergio Navas (U. Granada), 23/05/03 CIPANP03 (NY) 8
Slow control sensors (behind wire planes) Wires Purity Monitors Position meter PMT Sergio Navas (U. Granada), 23/05/03 CIPANP03 (NY) 9
Long tracks + Bremstrahlung 17 m 1,5 m Run 975, Event 140 Collection Left Run 975, Event 93 Collection Left 1 m 17 m Sergio Navas (U. Granada), 23/05/03 CIPANP03 (NY) 10
7 m Shower 1,7 m Run 975, Event 157 Collection Right 1,8 m Run 961, Event 16 Collection Right Sergio Navas (U. Granada), 23/05/03 CIPANP03 (NY) 11 4,3 m
Reconstruction : hadronic events 2,7 m 2,3 m 1,4 m Run 308, Event 160 Collection Left 1,3 m Run 308, Event 160 Induction1 Left Interaction vertex! Sergio Navas (U. Granada), 23/05/03 CIPANP03 (NY) 12
Single wire performance Hit fitting empirical function f(t) = B + A e 1 + e t - T 0 τ 2 t - T 0 τ 1 τ 1 τ 2 B = baseline A = amplitude τ 1, τ 2 = rise and fall time T 0 = peak position B A T 0 Reconstructed de/dx T600 Signal Sergio Navas (U. Granada), 23/05/03 CIPANP03 (NY) 13
Muon decay Collection Left 25 cm.e Run 960, Event 4 Induction2 Left.e.µ 89 cm 85 cm.µ 154 cm 4 hits on this wire Sergio Navas (U. Granada), 23/05/03 CIPANP03 (NY) 14
Reconstruction : muon decay µ + [AB] e + [BC] µ+ e+ Induction 2 view Collection view µ+ e+ Run 939 Event 95 Sergio Navas (U. Granada), 23/05/03 CIPANP03 (NY) 15
Michel electrons Muon decay probability dp dx 1 N x 2 3 1 x 2 3 N = normalización x = E/E max E max = 52.8 MeV 4x 3 3 m e E max 1 x x 1 2 f x Michel parameter ρ = 0.72 ± 0.20 ± 0.10 (SM: 0.75) Sergio Navas (U. Granada), 23/05/03 CIPANP03 (NY) 16 (stat) (sys)
$ Free electron drift velocity Argon Purity : Drift electron lifetime in T600 Scanning of v d covering low and high electric field regions µ # #!" (*) %'& V d = 1.56 mm / µs @ 0.5 kv/cm 960 µs to drift 1.5 m 2400 time samples (0.4 µs / sample) full drift Two independent and complementar methods to measure the LAr purity: The Purity Monitors : array of dedicated devices that provide on-line information on a fixed position of the chamber (punctual measurement). Muon tracks : off-line analysis measuring the collected charge atenuation from crossing muon tracks (average measurement). Sergio Navas (U. Granada), 23/05/03 CIPANP03 (NY) 17
A vast physics program....hep-ex/0103008 Atmospheric neutrinos T3000 Supernova neutrinos Solar neutrinos p e + +π 0 Nucleon stability Long Baseline neutrinos Sergio Navas (U. Granada), 23/05/03 CIPANP03 (NY) 18
90 cm, + 2 0. 1 / - 90 cm ICARUS will provide Atmospheric neutrino events An observation of atmospheric neutrino events with very high quality An unbiased, mostly systematic free, observation of atmospheric neutrino events CC/NC separation, clean e/µ discrimination, all final states accessible, excellent e/π 0 separation, particle identification (p/k/π) for slow particles An excellent reconstruction of incoming neutrino properties (energy and direction) (simulated ν µ quasi-elastic interaction) (simulated ν e quasi-elastic interaction) About 100 events of this quality in 1 year of T600 running µ 90 cm 100 cm E ν = 370 MeV T p = 90 MeV P µ = 250 MeV E ν = 450 MeV T p = 240 MeV P e = 200 MeV Sergio Navas (U. Granada), 23/05/03 CIPANP03 (NY) 19
Atmospheric neutrino rates Detection of single recoil proton or multi-prongs final states will provide a precise determination of the incoming neutrino energy Events can be fully reconstructed up to kinematics production threshold (50% of the predicted rate has P lepton < 400 MeV/c) fundamental contrubution to the understanding of the low energy part of the atmospheric neutrino spectrum C7> A B 6@?> < = ;: 9: 8 67 354 Simulation based on FLUKA interaction and transport code, 3D representation of Earth and atmosphere, Geomagnetic effects included, All relevant physics taken into account: energy losses, polarized decays Sergio Navas (U. Granada), 23/05/03 CIPANP03 (NY) 20
Rates for upward/downward events For a 2 kton x year exposure, we expect to measure a significant deficit of upward-going muon-like events Sergio Navas (U. Granada), 23/05/03 CIPANP03 (NY) 21
U VKP NO G I H P a Z WXYZ bd a Z Z ] WXYZ q r s t u v p w o m n CNGS neutrino beam EP M T P S N EG H QMRE M F MNF O JLK G D*EFG _e [\^] dxc b Z] _`] [\^] _e [[d cx] l jk a ] _hi [[] fgd ν µ 730 km 400 GeV/c SPS proton beam 4.5 10 19 protons per year (graphite target) Two magnetic horns focus 35 and 50 GeV/c mesons 30 mrad acceptance 1 km decay tunnel 732 km baseline for neutrino oscillations CNGS beam ν e and ν τ contaminations in the order of 10-2 and 10-7 relative to the main ν µ component ν τ ν ν µ CC : study online the beam profile and normalization ν τ CC : search for ν µ ν τ oscillations (with a sensitivity at least similar to OPERA); ν e CC : search for ν µ ν e oscillations; NC events: search for ν µ ν s oscillations or exotic models Sergio Navas (U. Granada), 23/05/03 CIPANP03 (NY) 22
CNGS - tau appearance experiment The expected ν e and ν τ contamination of the CNGS neutrino beam in absence of oscillations is in the order of 10-2 and 10-7 relative to the main ν µ component ν e / ν µ = 0.8 % ν µ / ν µ = 2.1 % ν e / ν µ = 0.07 % Detector configuration 5 T600 modules Active LAr: 2.35 ktons 5 years of CNGS running Shared mode 4.5 x 10 19 p.o.t./year 280 ν τ CC expected for m 2 23=3 x 10-3 ev 2 and maximal mixing Process ν µ CC ν µ CC ν e CC ν e CC ν NC ν NC ν τ CC, m 2 (ev 2 ) Expected Rates 32600 10600 1 x 10-3 31 2 x 10-3 3 x 10-3 125 280 5 x 10-3 750 Sergio Navas (U. Granada), 23/05/03 CIPANP03 (NY) 23 652 262 17 243
ν µ ν τ Background: Charged current (CC) (Br 18%) ν e + Ar e + jet Charged current (CC) ν µ ν τ oscillations ν τ + Αr τ + jet ; τ ν τ ν e e m 2 32 = 3 10-3 ev 2 49 evts 262 evts Reconstructed visible energy spectrum of electron events clearly evidences excess from oscillations into tau neutrino ν e background ν τ signal Lnλ Sergio Navas (U. Granada), 23/05/03 CIPANP03 (NY) 24
ν µ ν τ appearance search summary T600+2 x T1200 modules (2.35 kton active LAr, 1.5 kton fiducial) 5 year CNGS shared running (2.25 10 20 p.o.t.) Super-Kamiokande: 1.6 < m 2 < 4.0 at 90% C.L. Several decay channels exploited (golden channel = electron) (low) backgrounds measured in situ (control samples) High sensitivity to signal; oscillation parameters determination Sergio Navas (U. Granada), 23/05/03 CIPANP03 (NY) 25
ƒ ~ z } œ š ν µ ν e appearance: search for θ 13 0 The confirmation that ν µ ν τ will be an important milestone, but The measurement of a non-vanishing θ 13 would open the door to search for CP-violation in the leptonic sector The search for excess of electrons, on top of electronic tau decays, takes advantage of good e/π 0 separation in ICARUS. The search is limited by statistics, needs more intensity at low energy... m 2 32 = 3.5 10-3 ev 2 ; sin 2 2θ 23 = 1 {z x y ~ z ~L { Ž Œ Š ˆ P cos 4 13 sin 2 2 23 2 m 32 Sergio Navas (U. Granada), 23/05/03 CIPANP03 (NY) 26 P Ÿž e sin 2 2 13 sin 2 m 2 32, θ 23, θ 13 23 2 m 32
± «Sensitivity to θ 13 in three family mixing ª L ¾½ ¼ ³ º» ¹ µ ² ³ Sensitivity assuming both ν µ ν τ and ν µ ν e at the same m 2 (three family mixing) 30 5.sin 2 2θ 13 > 2 10-2 for m 2 32 = 3 10-3 ev 2 Sergio Navas (U. Granada), 23/05/03 CIPANP03 (NY) 27
SUMMARY It has been demonstrated that L.Ar imaging technology has come to maturity. Very massive detector volumes, of relevance for non-accelerator physics, can be constructed at a reasonable cost. Performance is very close to the one of traditional bubble chambers, with the added advantages of being continuously sensitive and to permit accurate calorimetric measurements. T600 + 2 T1200 = 3000 ktons in 2005 vast physics programme in the domain of: Atmospheric neutrinos New detection technique Proton decay The best background conditions Solar and supernovae neutrinos Flavor discrimination via ES&CC channels CNGS neutrinos Search for ν µ ν τ and ν µ ν e flavor appearance 18 1.5 m 2 The T600 test in Pavia has provided the tools and the knowledge to start physics analysis as soon as the T600 is commissioned at LNGS... we expect to produce first relevant results in neutrino physics within one year of T600 data taking. Sergio Navas (U. Granada), 23/05/03 CIPANP03 (NY) 28