Existing and future long-baseline neutrino oscillation experiments Mark Messier Indiana University The 9th ICFA Seminar 28 October 2008 SLAC 1
3rd oscillation maximum 2nd oscillation maximum 1st oscillation maximum Fermilab to DUSEL NOvA MINOS OPERA T2K K2K Long baseline experiments P = sin 2 (2θ) sin 2 ( 1.27 m 2 L[km] ) E[GeV] 2
Conventional neutrino beams Past, current, and near-future long baseline facilities use conventional neutrino beams. Given name super-beams once beam power approaches 1 MW Typical composition (neutrino focus): 93% νμ graphic shows case of NuMI beam 5% νμ 1%νe+νe Channels available: νμ νμ, νμ νμ νμ ντ, νμ ντ νμ νe, νμ νe 3
Conventional neutrino beams!"#$%&'()*"+,)-(."%)&')/0)!" #!!" $!!!" $#!!" %!!!" %#!!" &'(")*+",-./"0./1",-./"0./1"/2"34567" 890'":)';" (+'<" =)0,9'">?+?+@" '2A3B",./.&CC'9" =%=" '2,?" '2,?">D'2,?"C/EFD@" 'GH)" +'2,?" IJCK3L6"M" 8'*+" A%=" plot after A. Marchionni 4
58 νμ QE candidate events K2K Experiment (1999-2004) L = 250 km E = 0.3-1.8 GeV 1x10 20 POT delivered m 2 =2.8 +0.5 0.6 10 3 ev 2 [68% C.L.] 5
The MINOS Experiment MINOS: Main Injector Neutrino Oscillation Search Neutrino beam produced using 120 GeV protons from Fermilab Main Injector (NuMI) Two functionally identical detectors separated by 735 km: 1 kt near detector on Fermilab site to measure composition and energy spectrum of beam 5.4 kt far detector in Soudan underground laboratory to measure effects of neutrino oscillation 6
MINOS Far Detector 5.4 kt. Magnetized steel/ scintillator sandwich L = 735 km 7
Event topologies in MINOS E ν = E shower + P µ σ = 55% E[GeV] σ = 6% using range σ = 10% using curvature 8
5.33 e20 total POT Run 1 1.27E20 POT hep-ex/0607088 hep-ex/07110769 Run 2 3.36E20 POT hep-ex/08062237 Run 3 Special runs including high energy running 0.15E20 POT MINOS Running Increase due to slip-stacking in Main Injector. Able to fill MI with 11 booster turns instead of 9. Depending on mode of operation this is an increase of 30% to 80% bringing intensity to between 230 kw to 315 kw 9
MINOS Neutrino Spectra 25 50 MINOS Near Detector Low energy beam (x2) 150 MINOS Far Detector POT 16 Events / GeV / 10 20 40 15 30 10 20 105 High energy beam Tuned MC Fluka05 MC Events / GeV 100 50 Far detector data No oscillations Best oscillation fit NC background 0 0 5 10 15 20 30 50 Reconstructed neutrino energy (GeV) 0 0 5 10 15 20 30 50 Reconstructed neutrino energy (GeV) 10
4 4.0 3.5!3 "10 ) 2 ev!3 (10 2 #m 3 3.0 2.5 2 2.0 1.5 MINOS best oscillation fit MINOS 90% Super!K 90% MINOS 68% Super!K L/E 90% MINOS 2006 90% K2K 90% 1.01 0.6 0.7 0.8 0.9 1 sin 2 (2!) MINOS muon neutrino oscillation result m 2 =2.43 ± 0.13(5.3%) 10 3 ev 2 sin 2 2θ > 0.90 (90%C.L.) 11
MINOS: Tests of non-oscillation models Ratio to null hypothesis 1.5 1 MINOS data 0.5 Best oscillation fit Best decay fit Best decoherence fit 0 0 5 10 15 20 30 50 Reconstructed neutrino energy (GeV) Test against neutrino decay P (ν µ ν µ )= decoherence ( sin 2 θ + cos 2 θ exp( αl 2E ) P (ν µ ν µ )=1 1 2 sin2 (2θ) ) 2 ( ) 1 exp µ2 L 2E Neither of these models produce oscillations and hence can be used to quantify the significance of the dip in the event rates at 2 GeV. neutrino decay disfavored by 3.7σ decoherence disfavored by 5.7σ 12
MINOS: Systematic uncertainties 13
MINOS Neutralcurrent measurement Select events with NC-like topologies in near and far detector to search of active neutrino disappearance Rates at FD match expectation Confirms oscillation model Implies non-zero νe +ντ flux at far detector Limits the fraction of νμ that could have oscillated to νs rather than ντ Events/GeV 3 Events/ GeV 300 Near Detector Data 200 10100 Monte Carlo Expectation Expected! µ -CC Background 500 10 20 30 E Far reco (GeV) Detector Data 40 = 0 30 20 10! 13! 13 = 0.21, # = 3"/2 $ µ -CC Background &m sin 2 32 2 = 2.43 % (2! 23 ) = 1-3 2 4 10 ev /c f s < 0.68 (90% C.L.) 0 0 5 10 15 20 25 30 E reco (GeV) 14
MINOS Electron Neutrino Appearance Far detector spectrum blinded. With current exposure, we expect 12 signal events over 42 background events for oscillations at the CHOOZ limit. 15
Future MINOS Running In planning for the future, MINOS can choose to run in several configurations: Neutrinos or anti-neutrinos? Low energy or high energy? Inputs to this discussion: 1. The sin 2 2θ and Δm 2 measurements are likely to remain statistically limited for any reasonable exposure 2. MINOS is likely the last magnetized long baseline experiment which will run for a very long time. Measurements using anti-neutrinos and/or high energies probe more speculative physics (CPT violation, non-standard interactions) but are likely the last opportunity to explore them for quite some time. 3. Electron neutrino appearance: If MINOS has a signal when the box is opened we will continue to pursue it 4. MINOS will likely get some exposure to different beam configurations as part of the MINERvA and NOvA programs The future scenarios committee inside MINOS has been tasked with exploring these possibilities 16
CNGS Neutrino Beam CERN Geneva Mont-Blanc Monte-Emilius Piemonte Alessandria Emilia-Romagna Monte-Maggiorasca Monte-Prato Monte-Giovo 11.4km 732km neutrino beam Toscana Firenze Arezzo Perugia Umbria Laboratory of Gran Sasso 5km 0 50km 17
CNGS Neutrino Beam: Optimized for ντ 8.24E17 POT Integrated POT 1.58E17 POT/day Designed to deliver 4.5e19 POT/year 2900 νμ CC events/kt/year 14 ντ CC events/kt/year 20 SEP 2007 24 OCT 2007 Summary of 2007 running 18
The OPERA Detector ν brick/scintillator planes 10c 8c 12.5c plastic base 200 µm thick 1 mm ν τ Pb emulsion layers (44 µm thick) Instrumented dipole magnet (1.53 T) 1.35 kt target mass Recorded 29 CC and 9 NC events in 2007 run 19
First OPERA Event P µ =7.8 GeV ν µ CC ν µ µ - n Hadronic shower γ e compatible π 0 2 γ : π 0 mass: 110 ± 30 MeV 1 cm γ e 20
Discovery probability (%) 0 20 40 60 80 100 Tau Neutrino Observation OPERA Discovery probability vs. Δm 2 1.35 kt x 5 years x 4.5E19 POT/year Main backgrounds are: charm production and decay hadron re-interactions in lead large-angle muon scattering in lead 4-σ evidence 3-σ evidence Minos 2008 90% CL SK 90% CL (L/E analysis) 0.05 0.1 0.15 0.2 0.25 0.3 0.35 21
OPERA Sensitivity to θ13 Assuming 5% uncertainty in νe backgrounds, Δm 2 =2.5x10-3 ev 2, OPERA can reach sin 2 2θ13 = 0.06 at 90% C.L. in 5 years 22
2008 CNGS Run New run started on 18 June 2008. Reached 1E19 POT on October 1st. Produced >160 events in OPERA already Run will continue through November: 2.28E19 POT Should be enough running to produce first detected tau event 23
K2K νμ νe Signal Background 1 seen event over expected background of 1.7 sin 2 2θ13<0.26 at 90% C.L. 24
How to go beyond K2K s νμ νe search? The T2K and NOvA experiments intend to push x26 beyond K2K and x10 beyond MINOS/OPERA in the search for νμ νe Higher power. K2K: ~5 kw, T2K 770 kw, NOvA: 700 kw Go off-axis to achieve a narrow band neutrino beam Puts more neutrino flux at oscillation maximum Reduces backgrounds from high energy NC feeddown Better near detectors: Reduce 30% uncertainty in backgrounds to 10-5% 25
T2K: Tokai-to-Kamioka 26
The J-PARC Facility J-PARC January 2008 The ND280 Pit Neutrino Beamline Running at 750 kw 2.5 o offaxis: 1600 νμ CC events/ 22.5 kton/year Stage 1: 0.75 MW 3 GeV RCS 27
T2K: Electron neutrino appearance 28
T2K: Muon neutrino disappearance High statistics allows precise measurement of muon neutrino disappearance Non-QE backgrounds fill in dip region. Requires good handle on these backgrounds from near detector measurements 29
The T2K Near Detector Suite Off-axis detector at 280 m Goal is to make precise measurements of neutrino-h2o cross-sections Tracking using fine grain scintillator and gas TPC s contained in UA1 magnet. π 0 detector for calibration of background. Surrounded by EM calorimeter and down stream muon ranger INGRID: On axis at 280 m. Modules of iron/scintillator. Used for beam monitoring and direction measurement. 37 m 30
T2K Schedule J-PARC Linac commissioned at 181 MeV in January 2007 3 GeV RCS fully commissioned operating at 200 kw Main ring: Beam has been captured. Soon will be able to accelerate to 30 GeV. Ready for first neutrino beam in April 2009. Super-Kamiokande PMT coverage fully restored (40%) Electronics upgrade complete Near detectors INGRID will be ready for beam in April 2009 ND280m installed during summer 2009. Operating in fall 2009 First T2K results in 2010 31
The NOvA Experiment NOvA is a second generation experiment on the NuMI beamline which is optimized for the detection of νμ νe and νμ νe oscillations NOvA is: An upgrade of the NuMI beam intensity from 400 kw to 700 kw A 15 kt totally active tracking liquid scintillator calorimeter sited 14 mrad off the NuMI beam axis at a distance of 810 km A 215 ton near detector identical to the far detector sited 14 mrad off the NuMI beam axis at a distance of 1 km 20 cm 2.5 GeV νe + p 1.9 GeV e - + 1.1 GeV p + 0.2 GeV π + 20 cm MIPs MIPs 32
Single NOvA extrusion being attached to vacuum lifting fixture for gluing and assembly at Argonne Laboratory Stack of NOvA far detector extrusions ready to be loaded on truck bound for University of Minnesota for assembly and to Argonne for assembly of construction prototype 33
NOvA Far Detector Location Ash River, MN 810 km from Fermilab Medium Energy Tune ν CC events / kt / 1E21 POT / 0.2 GeV μ 80 60 40 20 on-axis 7 mrad off-axis 14 mrad off-axis 21 mrad off-axis 0 0 2 4 6 8 10 E ν (GeV) 34
excerpted from US Particle Physics: Scientific Opportunities. A Strategic Plan for the Next Ten Years. Report of the Particle Physics Project Prioritization Panel, May 2008 35
1) What is the value of θ13? NOvA searches for electron neutrino appearance down to ~0.01 at 90% CL excerpted from US Particle Physics: Scientific Opportunities. A Strategic Plan for the Next Ten Years. Report of the Particle Physics Project Prioritization Panel, May 2008 36
2) Do neutrino oscillations violate CP? NOvA provides the first look into the CPV parameter space excerpted from US Particle Physics: Scientific Opportunities. A Strategic Plan for the Next Ten Years. Report of the Particle Physics Project Prioritization Panel, May 2008 37
3) What are the relative masses of the three known neutrinos? NOvA s long baseline makes it sensitive to the mass ordering excerpted from US Particle Physics: Scientific Opportunities. A Strategic Plan for the Next Ten Years. Report of the Particle Physics Project Prioritization Panel, May 2008 38
Color code for hits: e μ p π 4) Is θ23 maximal? Because of its excellent energy resolution NOvA can make ~1% measurements of muon neutrino disappearance using quasi-elastic channel. Measurement will be made for both neutrino and anti-neutrino excerpted from US Particle Physics: Scientific Opportunities. A Strategic Plan for the Next Ten Years. Report of the Particle Physics Project Prioritization Panel, May 2008 39
4) Is θ23 maximal? Because of its excellent energy resolution NOvA can make ~1% measurements of muon neutrino disappearance using quasi-elastic channel. Measurement will be made for both neutrino and anti-neutrino excerpted from US Particle Physics: Scientific Opportunities. A Strategic Plan for the Next Ten Years. Report of the Particle Physics Project Prioritization Panel, May 2008 40
5) Are neutrinos their own antiparticles? Avignonee, Elliott, Engel, arxiv:0708.1033 If NOvA establishes inverted hierarchy and next generation of 0νββ experiments see nothing, then it is very likely that neutrinos are Dirac particles excerpted from US Particle Physics: Scientific Opportunities. A Strategic Plan for the Next Ten Years. Report of the Particle Physics Project Prioritization Panel, May 2008 41
6)...supernova within our galaxy? ~15min of data With typical ~10s supernova signal 10ms time bins 3m OVERBURDEN NOvA would see burst of 5000 events for a supernova at the center of the galaxy excerpted from US Particle Physics: Scientific Opportunities. A Strategic Plan for the Next Ten Years. Report of the Particle Physics Project Prioritization Panel, May 2008 42
8)...beyond the Standard Model...Do sterile neutrinos exist? Reconstructed visible energy for NC sample Events/25kt/39e20POT/bin 1500 1000 500 NC (pure! µ!! " ) NC (23%! µ!! s )! µ CC intrinsic! e! 0 0 1 2 3 4 5 6 Visible Energy [GeV] NOvA s granularity allows for clean neutral-current measurements facilitating searches for sterile neutrinos excerpted from US Particle Physics: Scientific Opportunities. A Strategic Plan for the Next Ten Years. Report of the Particle Physics Project Prioritization Panel, May 2008 43
Schedule NOvA passed its Department of Energy, Office of Science CD2/3a. Ready to start civil construction at far site in March 2008 FY2008 omnibus budget passed by Congress in December of 2007 zeroed funding for NOvA in FY08. Formally closed the project office, but we able to make some progress with small amount of FY07 carryover and with university groups. FY08 funding required new cost and schedule to be drafted and reviewed. Those reviews passed in April and June of 2008. CD2 signed (15 September) CD3a signed (24 October) Emergency funding bill passed by Congress passed this month. Included $62.5M additional funding for HEP. NOvA is funded at $9.5M for this fiscal year. Project office officially reopened. $9.5M is enough to complete roughly 3/4 of the remaining design and R&D tasks in our schedule. To date we ve obligated $2M. Including anticipated 4 month delay in FY09 Congressional budget process: Start of construction April 2009 First 2.5 kt taking data August 2012 Detector complete January 2014 NOvA construction schedule is driven by funding profile. 44
Neutrino Running Anti-Neutrino Running Combined Backgrounds Signal Backgrounds Signal Background Signal ν µ ν e total ν e ν µ ν e total ν e T2K 10 13 23 100 n/a n/a n/a n/a 23 100 NOvA 6 8 14 75 4 3 7 29 22 104 T2K: 5 years running at 750 kw NOvA: 3 years neutrino + 3 years anti-neutrino at 700 kw NOvA numbers assume maximal θ23 and Δm 2 =0.0024 ev 2. Matter and CPV effects are not included. I presume T2K numbers use similar assumptions. νμ νe rate comparison sin 2 2θ13 = 0.10 45
Combining NOvA and T2K: Mass hierarchy In top portion of plot NOvA resolves the hierarchy by comparing neutrino and antineutrino rates In bottom portion of plot, adding T2K helps as one can compare the oscillation probability for neutrinos at the first maximum with matter effects (NOvA) and without (T2K) 46
T2K and NOvA Combined (as above, higher exposure) 47
Going beyond Next-next steps will likely require More intense beams Larger (and if possible, better) detectors Longer baselines Better understanding Hadron production measurements (NA49, HARP, MIPP, SHINE) Neutrino cross-section measurements (SciBooNE, MINOS near, MINERvA, microboone, T2K near, NOvA near) 48