1. Gary Feldman P5 Meeting 21 February 2008 0 The NO A Experiment P5 Meeting SLAC 21 February 2008 Gary Feldman

2. Gary Feldman P5 Meeting 21 February 2008 1 What is NO A? NO A is a second-generation experiment on the NuMI beamline, which is optimized for the detection of   e oscillations. It will give an order of magnitude improvement over MINOS in measurements of e appearance and  disappearance. NO A is a “totally active” tracking liquid scintillator calorimeter, sited off-axis to take advantage of a narrow- band beam. The NO A project also includes accelerator upgrades to bring the beam power from 400 kW to 700 kW. NO A’s unique feature is its long baseline, which gives it sensitivity to the neutrino mass ordering. NO A is complementary to both T2K and Daya Bay.

3. Gary Feldman P5 Meeting 21 February 2008 2 NO A Site The Ash River site is the furthest available site from Fermilab along the NuMI beamline. This maximizes NO A’s sensitivity to the mass ordering.

4. Gary Feldman P5 Meeting 21 February 2008 3 NO A Basic Detector Element Liquid scintillator in a 4 cm wide, 6 cm deep, 15.7 m long, highly reflective PVC cell. Light is collected in a U-shaped 0.7 mm wavelength-shifting fiber, both ends of which terminate in a pixel of a 32-pixel avalanche photodiode (APD). The APD has peak quantum efficiency of 85%. It will be run at a gain of 100. It must be cooled to -15 o C and requires a very low noise amplifier.

5. Gary Feldman P5 Meeting 21 February 2008 4 Far Detector There are 1003 planes, for a total mass of 15 kT. There is enough room in the building for 18 kT, which can be built if we can preserve half of our contingency. The detector can start taking data as soon as blocks are filled and the electronics connected. An admirer The cells are made from 32-cell extrusions. 12 extrusion modules make up a plane. The planes alternate horizontal and vertical.

6. Gary Feldman P5 Meeting 21 February 2008 5 NO A Timeline May 20021st Workshop Jun 2002Letter of Intent Mar 2004Proposal to the Fermilab PAC Mar 2005Revised Proposal to the PAC Apr 2005Fermilab Stage 1 Approval Nov 2005CD-0 Granted Feb 2006Recommended by NuSAG Oct 2006Recommended by P5 May 2007CD-1 Granted Oct 2007Passed CD-2/3a Review May 2008CD-2/3a Granted Nov 2008CD-3b Granted Apr 2009Start of Construction Jun 2011Far Detector Building Beneficial Occupancy Aug 20121st 2.5 kT of the Far Detector Online Jan 2014Full Far Detector Online

7. Gary Feldman P5 Meeting 21 February 2008 6 Funding Profiles With this profile, we could advance the schedule by 10 months.

8. Gary Feldman P5 Meeting 21 February 2008 7 Reactor vs. Accelerator Peter explained the physics of neutrino oscillations well, so I need not repeat it. However, I would like to expand on a couple of points. Reactor and accelerator experiments do not measure the same thing. Reactors are sensitive to sin 2 (2  13 ), while accelerators are sensitive to sin 2 (  23 ) sin 2 (2  13 ). If  23 ≠  /4, these quantities can be quite different. The good news is that a comparison of NO A and Daya Bay can break this ambiguity and determine whether 3 couples more to  or .

9. Gary Feldman P5 Meeting 21 February 2008 8 95% CL Resolution of the  23 Ambiguity The ambiguity can be resolved in the region below and to the right of the curves. The sensitivity depends on the mass ordering, , and the sign of the ambiguity itself. The curves repre- sent an average over these parameters.

10. Gary Feldman P5 Meeting 21 February 2008 9 Measurement of sin 2 (2  23 ) This calculation uses NO A’s excellent energy resolution on  CC events. It is a parameterized calculation, which needs to be redone with a full reconstruction.

11. Gary Feldman P5 Meeting 21 February 2008 10 Sensitivity to sin 2 (2  13 ) ≠ 0

12. Gary Feldman P5 Meeting 21 February 2008 11 Parameters Consistent with a 2%   e Oscillation Probability

13. Gary Feldman P5 Meeting 21 February 2008 12 Strategy for Determining the Mass Ordering If the CP-violating term goes in the same direction as the matter effect, then there is no ambiguity and NO A can determine the mass ordering by itself, given sufficient integrated beam. If the CP-violating term goes in the opposite direction as the matter effect, then there is an inherent ambiguity and NO A cannot determine the mass ordering by itself. But it can be determined, in principle, by comparing NO A and T2K. If the neutrino oscillation probability is larger in NO A than in T2K, it is the normal mass ordering; if the opposite, it is the inverted mass ordering.

14. Gary Feldman P5 Meeting 21 February 2008 13 95% CL Resolution of the Mass Ordering NO A Alone Normal OrderingInverted Ordering

15. Gary Feldman P5 Meeting 21 February 2008 14 Combining Data with T2K When it is useful to combine data with T2K, I will assume that T2K will only run a neutrino beam because This is what they have proposed to do. They have less incentive to run antineutrinos since  They have too short a baseline to get information on the mass ordering.  The antineutrino rates at T2K energies are relatively somewhat lower than at NO A energies.  The complementarity between the two experiments is better statistically if T2K runs only neutrinos since it consists of comparing like runs — neutrinos to neutrinos or antineutrinos to antineutrinos.

16. Gary Feldman P5 Meeting 21 February 2008 15 95% CL Resolution of the Mass Ordering NO A Plus T2K Normal OrderingInverted Ordering

17. Gary Feldman P5 Meeting 21 February 2008 16  vs.  13 Contours: Best Possible 

18. Gary Feldman P5 Meeting 21 February 2008 17  vs.  13 Contours: Worst Possible  T2K and NO A Alone Profiles, not limits

19. Gary Feldman P5 Meeting 21 February 2008 18  vs.  13 Contours: Worst Possible  T2K and NO A Combined

20. Gary Feldman P5 Meeting 21 February 2008 19 Conclusions I Due to its long baseline and ease of running antineutrinos, NO A will produce important results unavailable from any other experiment in its time frame. It is complementary to both T2K and Daya Bay. What was to become NO A had its first workshop in May 2002. It has now passed all of its reviews and is ready to start construction in the spring of 2009, assuming funding will be available. All of the other major US neutrino accelerator initiatives being discussed today are in the workshop phase.

21. Gary Feldman P5 Meeting 21 February 2008 20 Conclusions II NO A will be the anchor of the US accelerator neutrino program. In addition to its unique physics contributions, It will provide the incentive to increase the NuMI beam power from 400 to 700 kW, and then to either 1.2 MW (SNuMI) or 2.3 MW (Project X), depending on available funding. It will provide a base detector, allowing the necessary liquid argon prototype, LAr5, to double the capacity of NuMI program. It will provide the continuity necessary to keep the program running smoothly, e.g. training experimental and accelerator physicists.

22. Gary Feldman P5 Meeting 21 February 2008 21 Backup Slides

23. Gary Feldman P5 Meeting 21 February 2008 22 What NO A Can Do If … sin 2 (2  13 )  0.1 Determine the mass ordering for half of the  space at the 1-3  level; combining with T2K, determine the mass ordering for the other half of the  range at 1-2  level. Exclude about half of the  space at the 1-2  level. Combining with Daya Bay, determine whether 3 couples more strongly to  or  at the 2  level if sin 2 (2  23 ) < 0.97.

24. Gary Feldman P5 Meeting 21 February 2008 23 What NO A Can Do If … sin 2 (2  13 )  0.06 Determine the mass ordering for half of the  space at the 1-2  level; combining with T2K, determine the mass ordering for the other half of the  range at 1-2  level. Exclude about half of the  space at the 1-2  level. Combining with Daya Bay, determine whether 3 couples more strongly to  or  at the 2  level if sin 2 (2  23 ) < 0.94.

25. Gary Feldman P5 Meeting 21 February 2008 24 What NO A Can Do If … sin 2 (2  13 )  0.03 Determine the mass ordering for a quarter of the  space at the 1  level. Exclude about half of the  space at the 1-2  level.

26. Gary Feldman P5 Meeting 21 February 2008 25 What NO A Can Do If … sin 2 (2  13 )  0.01 See a signal at the 1-3  level, confirming weak signals seen in other experiments.

27. Gary Feldman P5 Meeting 21 February 2008 26 What We Know and What We Don’t Know Don’t know Know to some extent O. Mena and S. Parke, hep-ph/0312131

28. Gary Feldman P5 Meeting 21 February 2008 27 NO A Near Detector 4.1 m 2.9 m 14.4 m Veto region Target region Shower containment region Muon catcher 1 m iron 209 T 126 T totally active 23 T fiducial The Near Detector will be placed in a cavern off of the MINOS access tunnel on the same off axis line as the far detector.

29. Gary Feldman P5 Meeting 21 February 2008 28 Event Quality Longitudinal sampling is 0.15 X0, which gives excellent  -e separation. A 2-GeV muon is 60 planes long.

30. Gary Feldman P5 Meeting 21 February 2008 29 e CC event e p  e - p  + E =2.5GeV E e =1.9GeV E p =1.1GeV E  =0.2GeV

31. Gary Feldman P5 Meeting 21 February 2008 30 Background NC event  N   p  o E =10.6 GeV E p =1.04GeV E  o =1.97GeV