1. Gary Feldman P5 Meeting 21 February 2008 0
The NOnA Experiment
P5 Meeting
SLAC
21 February 2008
Gary Feldman
Gary Feldman P5 Meeting February

2. Gary Feldman P5 Meeting 21 February 2008 1
What is NOnA?
NOnA is a second-generation experiment on the NuMI beamline, which is optimized for the detection of nm  ne oscillations.
It will give an order of magnitude improvement over MINOS in measurements of ne appearance and nm disappearance.
NOnA is a “totally active” tracking liquid scintillator calorimeter, sited off-axis to take advantage of a narrow-band beam.
The NOnA project also includes accelerator upgrades to bring the beam power from 400 kW to 700 kW.
NOnA’s unique feature is its long baseline, which gives it sensitivity to the neutrino mass ordering.
NOnA is complementary to both T2K and Daya Bay.
Gary Feldman P5 Meeting February

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NOnA Site
The Ash River site is the furthest
available site from Fermilab along
the NuMI beamline. This maximizes
NOnA’s sensitivity to the mass
ordering.
Gary Feldman P5 Meeting February

4. NOnA 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 It must be
cooled to -15oC and requires a very low noise amplifier.
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Far Detector
The cells are made from 32-cell extrusions.
12 extrusion modules make up a plane. The planes alternate horizontal and vertical.
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
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NOnA Timeline
May st Workshop
Jun Letter of Intent
Mar Proposal to the Fermilab PAC
Mar Revised Proposal to the PAC
Apr Fermilab Stage 1 Approval
Nov CD-0 Granted
Feb Recommended by NuSAG
Oct Recommended by P5
May CD-1 Granted
Oct Passed CD-2/3a Review
May CD-2/3a Granted
Nov CD-3b Granted
Apr Start of Construction
Jun Far Detector Building Beneficial Occupancy
Aug st 2.5 kT of the Far Detector Online
Jan Full Far Detector Online
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Funding Profiles
With this profile, we could advance the schedule by 10 months.
Gary Feldman P5 Meeting February

8. 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 sin2(2q13), while accelerators are sensitive to sin2(q23) sin2(2q13). If q23 ≠ p/4, these quantities can be quite different.
The good news is that a comparison of NOnA and Daya Bay can break this ambiguity and determine whether n3 couples more to nm or nt.
Gary Feldman P5 Meeting February

9. 95% CL Resolution of the q23 Ambiguity
The ambiguity can be resolved in the region below and to the right of the curves.
The sensitivity depends on the mass ordering, d, and the sign of the ambiguity itself. The curves repre-sent an average over these parameters.
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Measurement of sin2(2q23)
This calculation uses NOnA’s excellent energy resolution on nm CC events.
It is a parameterized calculation, which needs to be redone with a full reconstruction.
Gary Feldman P5 Meeting February

11. Sensitivity to sin2(2q13) ≠ 0
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12. Parameters Consistent with a 2% nm  ne Oscillation Probability
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13. 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 NOnA 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 NOnA cannot determine the mass ordering by itself. But it can be determined, in principle, by comparing NOnA and T2K.
If the neutrino oscillation probability is larger in NOnA than in T2K, it is the normal mass ordering; if the opposite, it is the inverted mass ordering.
Gary Feldman P5 Meeting February

14. 95% CL Resolution of the Mass Ordering NOnA Alone
Normal Ordering
Inverted Ordering
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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 NOnA 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.
Gary Feldman P5 Meeting February

16. 95% CL Resolution of the Mass Ordering NOnA Plus T2K
Normal Ordering
Inverted Ordering
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17. d vs. q13 Contours: Best Possible d
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18. vs. q13 Contours: Worst Possible d T2K and NOnA Alone
Profiles,
not limits
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19. d vs. q13 Contours: Worst Possible d T2K and NOnA Combined
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Conclusions I
Due to its long baseline and ease of running antineutrinos, NOnA 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 NOnA had its first workshop in May 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.
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Conclusions II
NOnA 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.
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Backup Slides
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What NOnA Can Do If …
sin2(2q13)  0.1
Determine the mass ordering for half of the d space at the 1-3 s level; combining with T2K, determine the mass ordering for the other half of the d range at 1-2 s level.
Exclude about half of the d space at the 1-2 s level.
Combining with Daya Bay, determine whether n3 couples more strongly to nm or nt at the 2 s level if sin2(2q23) < 0.97.
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What NOnA Can Do If …
sin2(2q13)  0.06
Determine the mass ordering for half of the d space at the 1-2 s level; combining with T2K, determine the mass ordering for the other half of the d range at 1-2 s level.
Exclude about half of the d space at the 1-2 s level.
Combining with Daya Bay, determine whether n3 couples more strongly to nm or nt at the 2 s level if sin2(2q23) < 0.94.
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What NOnA Can Do If …
sin2(2q13)  0.03
Determine the mass ordering for a quarter of the d space at the 1 s level.
Exclude about half of the d space at the 1-2 s level.
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What NOnA Can Do If …
sin2(2q13)  0.01
See a signal at the 1-3 s level, confirming weak signals seen in other experiments.
Gary Feldman P5 Meeting February

27. What We Know and What We Don’t Know
Know to some
extent
Don’t know
O. Mena and S. Parke, hep-ph/
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NOnA Near Detector
14.4 m
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.
4.1 m
209 T
126 T totally active
23 T fiducial
Muon catcher
1 m iron
Shower containment region
Target region
2.9 m
Veto region
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Event Quality
Longitudinal sampling is 0.15 X0, which gives excellent m-e separation.
A 2-GeV muon is 60 planes long.
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ne CC event
epe-p+
E=2.5GeV
Ee=1.9GeV
Ep=1.1GeV
E=0.2GeV
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Background NC event
Npo
E=10.6 GeV
Ep=1.04GeV
Eo =1.97GeV
Gary Feldman P5 Meeting February