Exploring Neutrino Appearance with NOvA: Long Baseline Particle Physics Experiment

1. NOnA NuMI Off-axis ne Appearance Dan Cronin-Hennessy University of Minnesota Nov 1, 2006 DPF/JPS

2. Outline • Brief overview of NOnA • The lepton mixing matrix and NOnA goals • Details of NOnA • Site • Beam • Detectors • Physics reach • Summary

3. Overview • NOnA is optimized for measuring ne appearance. - The goal is to improve MINOS’s nmne reach by approximately an order of magnitude. • The NOnA far detector • - Current plan for a 20 kT far detector • - “totally active” liquid-scintillator detector • - 810 km baseline • - 12 km off the NuMI beamline axis (Ash River, MN likely) • The uniqueness of NOnA is the long baseline • - required for determining mass ordering

4. Matter Effects

5. Matter Effects

6. Ambiguity p+ Klong CP Violation p- p+ MATTER Matter Effects p-

7. NOnA’s Potential Impact on Lepton Mixing sin22q13 In vacuum Dm232 andsin22q23 nmnmfrom same experiment. Dm232 precision measurement ~10-4 eV2. sin22q23 ~ 2% Mass Ordering Depends on sign of mass difference. ( ~30% effect for NOnA!). Can access by running both n and anti-n beams. CPV in quark sector from CKM matrix well constrained. Far short in magnitude to explain baryogenesis. CPV in lepton sector is most likely a long term goal. CP Violation

8. Off-Axis Beam • Narrow energy distribution. • Higher intensity at optimal energy. • Suppressed high energy tail (reduces NC contamination)

9. Far Detector Site • “Sophisticated” Site Selection Algorithm • Walk along beam to Canadian border. • Walk 14 mrad off-axis • Walk toward Fermilab until first road appears. • *Ambiguity resolved by terrain • *This procedure yields a baseline that is optimal for the beam energy (particularly when recent MINOS results are included). • *This procedure maximizes are sensitivity to the mass ordering. 810 km

10. Tracker Muon System Calorimeter Far Detector ~90 • 20 kT “Totally Active” liquid- scintillator detector. • Cells are made from 16-cell rigid PVC extrusions (32-cell modules). • 1 Plane = 12 extrusions • 31 Planes are grouped into a block. • Detector constructed in block units. • 1300 planes • Face is 15.7 m square

11. Near Detector Near detector will be placed off-axis in MINOS access tunnel. Will be capable of moving along tunnel. * measure different components of background.

12. Detector Technology (~20,000) Inexpensive Design Extruded PVC Module - utilizes existing manufacturing infrastructure - current focused on increasing reflectivity Liquid scintillator filled cells. WLS fiber - 0.7 mm diameter - looped end (“perfect” reflector) - readout both ends on one side Avalanche Photodiode - Hamamatsu multi-pixel - 85% QE

13. 48 ft Novel aspect of NOnA is the challenge of achieving sufficient light output at a length scale of 15 m. *Light collection efficiency demonstrated. *Sufficiently low noise from APD operating -15o C. *Attenuated spectrum matches well APD response curve. *First tests completed with existing extrusion die. *> 20 pe demonstrated for current design Light output results 3-cell full-length prototype (April 2005)

14. Simulated NOnA Events Signal nepe-pp+ En=2.5 GeV Background nmnm-np+p0 En=2.8 GeV Physics results to follow are based on full reconstruction Raw hits are used to construct physics objects Likelihood function developed to distinguish signal and background. Likelihood cut chosen to maximize FOM. Blind hand scan analyses show room for improvement in current reconstruction. Possible FOM gains of order 20%.

15. PID Performance and Resolution Energy resolution Electron and muon separation 0.10/E0.5 Electrons Muons Type Efficiency For 100 events Signal 0.23 86 CC nm7.1x10-4 1 NC nm1.3x10-3 6 Beam ne6.6x10-2 7

16. Assumed Schedule • CD1 completed (April 2006): Recommendation to approve. • CD2 (Mar 2007): TDR in progress. • Occupancy of FD (Mar 2010) • Beam exists: Data taking begins when ~20% of Detector Complete

17. Proton Plan • FY10: Down time to convert Main Injector to 1MW source • Coversion of Recycler and Accumulator into proton stackers • Construction of Booster-Accumulator and Accumulator- • Recycler transfer lines. • FY11: 44 weeks @ .4MW to .7 MW • FY12: 38 weeks @ .7MW to 1MW • Beyond FY12: 44 weeks @ 1MW • Assumptions • Accelerator uptime .85 • Average relative to peak: .90 • NuMI uptime: .90 • Six year run after completion of construction. • Protons on target: 60.3x1020

18. 3 sigma sensitivity to q13 Physics projections based on 1)run plan 2) proton beam & 3) detector parameters that were presented on previous slides.

19. Parameters Consistent with a 1% and 4% nmne oscillation probability

20. Resolution of the mass hierarchy Establishing CP violation requires resolving mass ordering since the matter effects contribute an apparent CP violation. Resolving the mass ordering provides information for interpreting future neutrino double beta decay results. Window to very high energy scales - new physics. (e.g. GUT generally favor normal ordering).

21. Supernova Current NOnA design includes 3 meter overburden Purpose is to reduce contamination from the EM component of cosmic interactions. Fringe benefit is greater sensitivity to galactic SN.

22. Summary • NOnA provides highest sensitivity to sin22q13 compared to other near-term planned experiments. • NOnA exploits existing NuMI beam. • It will provide the required information for planning future more ambitious n-physics projects. • It is unique for its capabilities in resolving the mass ordering. • It has some sensitivity to CP violation. • - depends on size of sin22q13.

23. Proton Plan • 0.4 MW while collider runs • 0.7 MW after collider shoutdown • 1.2MW upgrade • Proton Driver possible but not included in sensitivities presented today. • POT: 60.3x1020 • Details • 2006 Shutdown Maximum Booster rep. rate increases from 7.5Hz->9Hz Main Injector Improvements will allow studies of full 2+9 operation Assume beam loss in Main Injector limits us to 2+5 as standard operation. • 2007 Shutdown Installation of half of Booster correctors will allow increased throughput Collimation and RF Improvements in the Main Injector will allow operational slip stacking (2+9) operation to NuMI • 2008 Shutdown With the installation of last Booster correctors and improved gamma-t magnets, all Proton Plan projects complete.

24. Backup