Introduction Experimental procedure Beam characteristics and systematic

1. “q13” at CNGS D.Duchesneau LAPP, Annecy • Introduction • Experimental procedure • Beam characteristics and systematic • OPERA and ICARUS performances • Conclusion GDR Neutrino Lyon, September 20th 2005

2. Mesure de q13 Pour les projets de Long Baseline: Dans le vide négligeable en LBL pour L/E< max. atm. Auquel doit s’ajouter les effets de matière: P(nmne ) augmente pour la hiérarchie normale et diminue pour la hiérarchie inverse Attention:les effets dus à q13 et à d sont indissociables avec une simple mesure de P(nmne )  paramètres sont corrélés

3. nm  ne search: at CNGS • CNGS beam is ‘off-peak’: 732km, <E> = 17 GeV • P4 term dominates over P3: sensitivity on q13 has a different dependence on dCP • P4 changes sign with Dm312 : sensitivity depends of mass hierarchy m2 > 0 m2 < 0 This hierarchy dependence is not there for the ‘on peak’ projects. Matter effect is small.

4. nm  ne search: at CNGS Experimental method: • signal: look for an excess of low energy ne CC events Background: • ne beam contamination: higher visible energy • oscillation nm  nt , tentne : missing Pt, kink in long decays • nm NC events with p0 identified as electrons, +CC where m is not identified: missing Pt, e/g separation, low energy electrons Requirements: • knowledge of the neand nm fluxes, beam spectra. • particle identification, reconstructed event properties, event topologies

5. CNGS: beam optimized for nt appearance For1 year of CNGS operationin shared mode: “Off-peak”: 200 days/year ; e = 55% 4.5 x 1019 pot/year  CC / kton 2900  NC / kton 875 < E > ( GeV ) 17  /  2.1 % tprompt negligible ForDm2=2.4x10-3 and maximal mixing expect16 nt CC/kton/yearat Gran Sasso OPERA: ~ 30 evts/day

6. CNGS Beam energy spectra at Gran Sasso • ne sources: • m+gnm e+ne • K+gp0 e+ne • K0gp-e+ne nm ne m+ mainly from m+ decay p+ K0 K+ K+ ne http://www.mi.infn.it/~psala/Icarus/cngs.html Event rate normalized to 1019 pot and 1kton (e + e) /  ~ 0.85 %

7. Neutrino beam systematics: Total normalisation uncertainty for both nm and ne ~ 4 % • p and K production at the target: 3.8 % • Particle reinteraction along the beam line: 1.1 % • Proton beam position+optics: 0.8 % Uncertainties on n fluxes ne nm Uncertainty on nm/ne : large cancellation due to p origin of both flavours ~3.1% nm/ne derived from previous measurements and studies with WANF experiments Ref: A. Ferrari et al. hep-ph/0501283

8. OPERA in Gran Sasso (Hall C) n 8cm 12.5cm 206 336 lead emulsion bricks target mass: 1.8 ktons 1st SM 2nd SM ~ 10 m ~ 10 m ~20 m

9. 5 cm 5X0 ( ~ ½ brick) 1 mm Emulsion bricks: TEST experiment at CERN PS • Electron Identification • Method based on shower identification and on MCS of the track (e and p losses different) • ee ~ 90 % , • Energy measurement • count the number of track segments into a cone of 50 mrad along the electron track • Resolution @ few GeV Excellent capabilities for te decays and search for nm ne appearance

10. nm  ne search: OPERA and ICARUS similar method Events Events nm ne nm ne ne beam ne beam nm nt nm nt NC NC Visible Energy (GeV) sin22q13 Missing pT (GeV) • Kinematical cuts (OPERA): • Eelectron> 1GeV • Visible Energy < 20 GeV • Missing Pt < 1.5 GeV Assume no CP and no matter effect: P(nm -> nt)= cos4q13 sin22q23 sin2(1.27 Dm2 L/E) P(nm -> ne)= sin2q23sin22q13 sin2(1.27 Dm2 L/E) • take into account electron event from nm  nt , tentne OPERA Both oscillations distort Evis at low energy Fit oscillation components simultaneously sin22q13 use Evis, PTmiss, Eel

11. nm  neexpected signal and background Dm223 (eV2) Preliminary 4.50 1019 pot/yr 6.76 1019 pot/yr sin22q13 5 years: 2.25x1020 pot syst. on the ne contamination up to 5% OPERA sensitivity to q13 Limits at 90% CL for m2 = 2.5x10-3 eV2 full mixing Ref: Komatsu et al. J. Phys. G29 (2003) 443.

12. q13 sensitivity as a function of pot’s OPERA sin22q13 as a function of the pots Ref: P. Migliozzi, NuFact05

13. T1200 Unit (two T600 superimposed) T1200 Unit (two T600 superimposed) First Unit T600 + Auxiliary Equipment ≈ 95 m Not yet included in infrastructure design but ultimate goal: T3000+muon spectrometer money available for tendering of cryostats, inner mechanics and readout electronics: Should be completed by end of 2007 transported to LNGS: to be installed in 2005 Should be completed by autumn 2006 ICARUS in Gran Sasso (Hall B) gradual mass increase Cloning T600 module to reach a sensitive mass of 2.35ktons n Situation before june 2005 Numbers quoted: 1 year of T600 + 4 years of T1800

14. Detector performance: Shower 176 cm 434 cm Pictures from T600 technical run: EM and hadronic showers are identified and fully sampled Total energy obtained from charge integration Excellent calorimeter with very good E resolution EM showers: 265 cm 142 cm Hadronic showers: Hadronic interaction Run 308, Event 160 Collection Left

15. nm  ne search: ICARUS T1800 Evis spectra Δm223=2.5 10 -3 eV2 Sin2(2θ13)= 0.14 (CHOOZ limit) 25 oscillated events Fit 2 oscillation components simultaneously sin22q13 use Evis, PTmiss, PTel Ref: ICARUS document SPSC-2002-027 + private communication

16. nm  ne search: Expected sensitivity to q13 Limits at 90% CL for m2 = 2.5x10-3 eV2 full mixing ICARUS T1800 90% confidence level Full = CNGS std. 1y t600 +4y t1800 Dashed = CNGS x 1.5 5% systematic error on background

17. nm  ne search: at CNGS expected signal and background 5 years: 2.25x1020 pot OPERA ICARUS T1800 m2 = 2.5x10-3 eV2

18. Conclusions • nm  ne : • high detector capabilities to explore this channel • q13 limit down to 70 • sensistivity onq13with a dependence ondCPdifferent from T2K Beam systematics < 5% Sensitivity completely dominated by statistics More refined studies to perform: include CP violation , matter effect, full simulation CNGS beam: on schedule  expect to start in June 2006 OPERA: construction and installation is progressing  should be ready to record n events in 2006 ICARUS: successful demonstration of the principle withT600 Hall B: T600 in 2006 + T1200 ………

19. ICARUS project: Realization of a 600+1200 ton LAr TPC at LNGS main goal: Detect CNGS neutrinos for a  appearance search in the parameter region of atmospheric neutrino oscillations (CNGS2 experiment). ……. Private communication with Andre Recent event: The INFN President has recently communicated to the ICARUS Collaboration the intention not to allocate the 20 MEuro for the T1200 construction. One motivation is the anticipated delay of the T1200 construction and commissioning for CNGS physics. Given the INFN role of main funding agency this implies "de facto” the phasing-out of the CNGS2 program. At the same time, INFN encouraged the Collaboration to proceed along with the proposal of a future program focused on the realization of a large mass (~5 kton) LAR TPC based on a single tank, monolithic-design to be possibly installed in the LNGS territory, as a scalable test module in view of a larger mass facility, in particularly meant for proton decay searches. In the case of a sensible proposal, the above mentioned 20 MEuro contribution could be likely reassigned for the funding of the new project. In parallel, INFN welcomes and intends to support the commissioning of the existing T600 module (already at LNGS) to mainly act as a demonstrator of the technique in view of future implementations. Remarks: - No official communication of the INFN decision has been forwarded yet to the SPS and LNGS scientific committees, regulating the execution of the CNGS2 experiment. - The ICARUS Collaboration (and in particular the Italian INFN groups) has not yet defined a follow-up strategy.

21. The End

22. sensitivity vs dCP m2 < 0 m2 > 0 There are dCP valuesfor which the sensitivityon q13 is even betterthan the one computedin the 2-flavor approximation (dCP=0).

23. Mesure de q13 Pour les projets de Long Baseline: Dans le vide négligeable en LBL sur max. atm. Auquel doit s’ajouter les effets de matière: P(nmne ) augmente pour la hiérarchie normale et diminue pour la hiérarchie inverse Attention:les effets dus à q13 et à d sont indissociables avec une simple mesure de P(nmne )  paramètres sont corrélés

24. On peak  Off peak P. Migliozzi and F. Terranova hep-ph/0302274 On/off peak

25. O1 O1 O2 O3 O3 O2 O4 O4 On peak  Off peak • On-peak • O1 (leading term) and O2 (~sin ) • are dominant • at high energy and larger distances • larger matter effects  sign(m231) • Off-peak • O1 (leading term) and 03 (~cos) • O3 is CP even or odd under • m231 -m231transformation

26. T1800 configuration

27. T600 in Hall B: March 2005

28. ICARUS:nm  nt search other channel: t rntwith r- p-po main background: nm NC  missing pt use isolation criteria: QT nm nt p- nm QT nm QT ptot ptot T1800 detector(1 year 0.47 kton+4 years 1.4 ktonactive LAr) 5 years: 2.25x1020 pot

29. nm  ne Events nm ne Dm223 (eV2) Preliminary ne beam nm nt NC 4.50 1019 pot/yr Visible Energy (GeV) 6.76 1019 pot/yr sin22q13 Similar approach in both experiments OPERA Both oscillations distort Evis at low energy Fit oscillation components simultaneously use Evis, PTmiss, Eel sin22q13 sensitivity to q13 syst. ne contamination up to 10% Limits at 90% CL for m2 = 2.5x10-3 eV2 full mixing

30. nm  ne search: at CNGS in the 3 flavour n oscillation framework AssumingDm122 << Dm232= Dm132 = Dm2, P(nm -> nt)= cos4q13 sin22q23 sin2(1.27 Dm2 L/E) P(nm -> ne)= sin2q23sin22q13 sin2(1.27 Dm2 L/E) subleading transition • look for an excess of ne CC events and take into account nm  nt , tentne expected signal and background 5 years: 2.25x1020 pot OPERA