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Current * Neutrino Oscillation Experiments

Current * Neutrino Oscillation Experiments. PPAP Meeting Birmingham 15 July 2009 Elisabeth Falk University of Sussex. Def. current: running or under construction. Outline. Neutrino-oscillation experiments: what to measure, and how Accelerator-based experiments Reactor experiments

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Current * Neutrino Oscillation Experiments

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  1. Current* Neutrino Oscillation Experiments PPAP Meeting Birmingham 15 July 2009 Elisabeth Falk University of Sussex Def. current: running or under construction

  2. Outline • Neutrino-oscillation experiments:what to measure, and how • Accelerator-based experiments • Reactor experiments • Conclusions and outlook E. Falk, U. of Sussex

  3. What to measure, and how n3 Dm232 n2 Dm212 n1 Neutrino Mixing ne nt nm Unknown CP-violating phase Reactor n (CHOOZ): sin2 2q13< 0.11 @ 90% CL (or q13 <~ 10o) Dm231~Dm232 Atmospheric n + MINOS, K2K: q23= (45 ± 7)o Dm232 = 2.5 x 10-3 eV2 Solar n + KamLAND: q12= (34 ± 3)o Dm212 = 7.6 x 10-5 eV2 E. Falk, U. of Sussex

  4. What to measure, and how Accelerator-Based vs. Reactor Experiments Reactor experiments: q13 only: • Look for disappearance (ne ne) as a fnc of L and E • Near detector to measure unoscillated flux • P (ne ne) independent of d; matter effects small LBL accelerator experiments: sin2q12, Dm232: • Look for disappearance (nm nm) as a fnc of L and E • Near detector to measure unoscillated spectrum q13, δCP, sign(Dm232): • Look for appearance (nm  ne) in nm beam vs. L and E • Near detector to measure background nes (beam + mis-id) • P (nm ne) = f (d, sign(Dm312)) Accelerator-based and reactor experiments complementary ND FD MINOS, T2K, NOnA Double Chooz, Daya Bay, RENO E. Falk, U. of Sussex

  5. What to measure, and how nm spectrum spectrum ratio Unoscillated Oscillated Monte Carlo Monte Carlo Experimental Approach • ne appearance measurements: • Measure ne spectrum at Far Detector • Near Detector to measure background nes (beam + mis-id) • Predict Far Detector background using MC • (nm) disappearance measurements: • Measure unoscillated nm spectrum at Near Detector • Extrapolate using MC • Compare to measured spectrum at Far Detector ~ sin2 2q23 E. Falk, U. of Sussex ~ Dm232

  6. Accelerator-based experiments Neutrino Beam • Protons strike graphite target • Magnetic horns focus secondary p/K • Decay of p/K produces (mostly) muon neutrinos NuMI NuMI E. Falk, U. of Sussex

  7. Accelerator-based experiments Players: MINOS, T2K, NOnA MINOS: • NuMI (Fermilab) to Soudan mine, MN • 735 km baseline • Magnetised sci/steel calorimeters • Taken beam data since 2005 • Two more years of data-taking • Large UK involvement • All ana/working groups have UK co-convener(s) • Made significant h/w & DAQ contributions T2K: • J-PARC (Tokai) to Kamioka mine • 295 km baseline, off-axis • New beam • FD: Super-K (water Cerenkov) • Start data-taking in 2010 • Large UK involvement • ND280 off-axis detector(P0D, ECAL, DAQ, ….) NOnA: • NuMI (Fermilab) to Ash River, MN • 810 km baseline, off axis • Upgrade beam power • “Totally active” tracking liquid sci calorimeters • Start data-taking in 2013 • No UK involvement E. Falk, U. of Sussex

  8. Accelerator-based experiments MINOS nm disappearance Main physics results to date: • nm disappearance:|Δm232|=(2.43 ± 0.13) x 10-3 eV2at 68% C.L. sin2(2θ23) > 0.90 at 90% C.L. • Most precise result for |Δm232| to date • ne appearance: • 1.5s excess (within realms statistical fluctuation): • Normal hierarchy (dCP = 0):sin2(2θ13) < 0.29 (90% C.L.) • Inverted hierarchy (dCP = 0):sin2(2θ13) < 0.42 (90% C.L.) • nm disappearance: • Study 7% nm component • See 1.9s fewer events than CPT-conserving • Neutral-current interaction rate: • Limit on sterile neutrinos:fs < 0.68 (90% C.L.) ne appearance E. Falk, U. of Sussex

  9. Accelerator-based experiments MINOS Future plans: • Update all analyses with more than double the data set • Data in the can (3.2  7E20 POT) • Muon antineutrino running • Switch beam magnetic horns to focus p- • Start in September this year • Make the first direct measurement • Reduce uncertainty on Dm232 by an order of magnitude • nm mode for 2E20 POT, or until July 2010 E. Falk, U. of Sussexß

  10. Accelerator-based experiments T2K • Physics programme: • Phase I: • Discovery/measurement of q13 • D(sin2 2q23) ~ 0.01 (1%)D|Dm232| < 1 x 10-4 eV (a few %) (90% CL) • Potential phase 2: • Search for CP violation • Milestones: • ND suite operational by end of 2009 • Beam power ramped over next few years(2009: 30 kW; 2010: 100 kW; 2011: 300 kW; + “a few years”: 750 kW • Phase 1: total of 5E21 POT E. Falk, U. of Sussex

  11. Accelerator-based experiments NOnA • Significant injection of funds via US stimulus package revived NOnA • Physics programme: • Optimised for ne appearance • An order of magnitude more sensitive than MINOS • Improve sin2 2q23 and |Dm232| by an order of magnitude (compared to MINOS) • Mass hierarchy (sign (Dm232)) • Long baseline: only experiment sensitive to this • Milestones: • 1 May 2009: FD groundbreaking • Autumn 2011: Start of beam upgrades (400 kW  700 kW) • 2013: Data-taking with full FD E. Falk, U. of Sussex

  12. Reactor experiments Measuring q13: ne Disappearance ne ne (nm,t) Nuclear power station Near Detector d = 300 - 400 m Far Detector d = 1 - 1.8 km Present limit from CHOOZ: sin2(213) < 0.15 (90% C.L.) at Dm231 = 2.5 x 10-3 eV2 Dominant source of systematic error in CHOOZ: Reactor neutrino spectrum ~ Cancels out with two detectors E. Falk, U. of Sussex

  13. Reactor experiments The Detectors Example: Double Chooz Outer Veto:Plastic scintillator panels n Target:10 m3 liquid scintillatordoped with 0.1% Gd g Catcher:23 m3 liquid scintillator Buffer:114 m3 mineral oil with~400 PMTs Inner Veto: 90 m3 liquid scintillatorwith 80 PMTs Shielding:15 cm steel Prompt e+ signal Eprompt = En – (Mn – Mp) + me Inverse Beta Decay Delayed n capture on Gd (t ~ 30 ms) with emission of g cascade ( E ~ 8 MeV) E. Falk, U. of Sussex

  14. Reactor experiments Players: Double Chooz, RENO, Daya Bay RENO, Korea Expected sin2213~0.03 250 ton-GWth Double Chooz, France Expected sin2213~0.03 85 ton-GWth Small UK interest(Sussex, no longer funded) Daya Bay, China Expected sin2213~0.01 1400 ton-GWth • Main differences: • Reactor power/no of cores • Configuration cores vs. detectors; no. of detectors • Detector target mass E. Falk, U. of Sussex

  15. Reactor experiments Status and Expected Milestones* Double Chooz RENO Daya Bay N and F tunnelscompleted 2009 2009 2009 Near Hall occupancy ND hall + tunnelconstruction begins ND and FD commissioning First detector complete; start dry run 2010 2010 2010 ND and FD readyfor data-taking FD ready for data-taking Near Hall ready for data-taking 2011 2011 2011 Far Hall ready for data-taking;Ling Ao Hall ready abit earlier sin2 2q13 ~ 0.06 ND ready fordata-taking 2012 2012 2012 2013 2013 2013 sin2 2q13 ~ 0.03 ??? 2014 2014 2014 sin2 2q13 ~ 0.03 sin2 2q13 ~ 0.01 * DC schedule includes my estimated delays – not official, so don’t quote it! RENO, DB official schedules, but at least DB will likely be delayed by a few months E. Falk, U. of Sussex

  16. Comparison of q13 Sensitivities M. Mezzetto, Venice, March 2009 E. Falk, U. of Sussex

  17. Comparison of q13 Sensitivities M. Mezzetto, Venice, March 2009 E. Falk, U. of Sussex

  18. Conclusions and Outlook • Past and present experiments have pinned down q13, Dm212, q23, Dm232 • MINOS recently announced 1.5s result for q13 • T2K and reactor experiments come on-line within ~a year from now • Next 5 years will see sensitivity to sin2 2q13 to ~0.01, plus order of magnitude improvement on q23 and Dm232 • Need combination of different baselines + reactor to resolve q13, δCP, sign (Dm232) • Would be difficult to search for δCP if sin2 2q13 < 0.01 E. Falk, U. of Sussex

  19. Reactor Experiment Howto: Improve on Chooz CHOOZ : Rosc = 1.01 ± 2.8% (stat) ± 2.7% (syst) • Statistics • More powerful reactor (multi-core) • Larger detection volume • Longer exposure • Experimental error: n flux and cross-section uncertainty • Multi-detector • Identical detectors • Reduce inter-detector systematics (normalisation, calibration...) • Background • Improve detector design • Increase overburden • Improve knowledge of background by direct measurement Larger S/B Reach ~1% precision E. Falk, U. Sussex

  20. Double Chooz Systematic Uncertainties n energy, Dt, (distance e+ - n) E. Falk, U. Sussex

  21. Reactor experiments Baselines and Reactor Power Daya Bay RENO Double Chooz P = 8.2 GWth/2 cores L = 1.05 km P = 11.6 GWth/4 cores ~2011: 17.4 GWth/6 cores L ~ 1.8 km P = 16.1 GWth/6 cores L ~ 1.4 km E. Falk, U. of Sussex

  22. Daya Bay and Ling Ao Nuclear Power Plant LingAo II NPP 2.9GW2Under construction (2010) LingAo NPP 2.9GW2 Daya Bay NPP 2.9GW2

  23. Reactor experiments Far (80 t) LA (40 t) DYB (40 t) Daya Bay Run Plan • Istall first two detectors in DB Near Hall within a year from now • Take data (engineering run) while Ling Ao and Far Halls completed • Additional detectors deployed in pairs, one in Ling Ao and one in Far Hall, as they become ready – except last pair • One detector to be moved from Near to Far Hall • Last pair deployed in Near + Far Halls • Run for three years • Publish E. Falk, U. of Sussex

  24. Far (80 t) LA (40 t) DYB (40 t) Daya Bay: Redundancy • Measuring sin2213to 0.01 need to control systematic errors very well. • We believe that the relative (near/far) detector systematic error could be lowered to 0.38%, with near/far cancellation and improved detector design. • Side-by-side calibration: Event rates and spectra in two detectors at the same near site can be compared  How IDENTICAL our detectors are? • Detector swapping: Daya Bay antineutrino detectors are designed to be MOVABLE. All detectors are assembled and filled with liquids at the same place. Detectors at the near sites and the far site can be swapped, although not necessary to reach our designed sensitivity, to cross check the sensitivity and further reduce the systematic errors.

  25. Reactor experiments Comparison of q13 Sensitivities Daya Bay Double Chooz sin22q13 limit ssys= 0.6% Far+Near Detectors ssys= 2.6% Far Detector only 2010 2011 2012 2013 2014 2015 E. Falk, U. of Sussex

  26. Comparison of q13 Sensitivities M. Mezzetto, Venice March 2009 • Assumptions: • DC to start end of 2009; ND 1.5 yrs later • More likely 2nd quarter of 2010 (my estimate) • DB to start mid 2011 • From C. White: Schedule slipping by a few months • T2K: 0.1 MW in 2010; 0.45 MW in 2011; 0.75 MW thereafter • From D. Wark: 0.1 MW in 2010; 0.3 MW in 2011; ramp to 0.75 MW over a few years • MINOS, OPERA: sensitivity as per proposal, scaled by POT E. Falk, U. of Sussex

  27. MINOS Overview • Long baseline Fermilab  735 km  Soudan • Near detector at Fermilab • Measure beam composition, energy spectrum • Far detector in Minnesota • Search for and study oscillations • Test the nmnx oscillation hypothesis • Measure precisely |Dm232| and sin2 (2q23) • Search for sub-dominant nmne oscillations • Sensitive to q13 • Other MINOS physics: • Search for sterile neutrinos, CPT/Lorentz violation • Compare nm, nm oscillations • Studies of cosmic rays and atmospheric neutrinos • Neutrino interaction studies in the Near Detector E. Falk, U. of Sussex

  28. MINOS Muon-Neutrino Disappearance Analysis • Strong energy-dependent spectrum distortion • Spectrum fit with two-flavour oscillation hypothesis • Fit constrained to physical region + includes three largest systematics • Results:|Δm232|=(2.43 ± 0.13) x 10-3 eV2 at 68% C.L. sin2(2θ23) > 0.90 at 90% C.L. PRL 101 131802 (2008) • Most precise measurement of |m232| to date E. Falk, U. of Sussex

  29. MINOS Antimuon-Neutrino Disappearance Analysis • Measure |Δm232|, sin2(2θ23) • Test CPT • FNAL Wine & Cheese three weeks ago • nm CC events are 7% of beam • Mis-ID muon and NC backgrounds relatively larger • As CC analysis, but with extra cuts • Track-length likelihood, charge-sign significance E. Falk, U. of Sussex

  30. If the excess persists If the excess goes away The Future All these analyses have used 3x1020 of the 7x1020 protons-on-target that have been recorded • As of this June’s summer shutdown Over the next year, the analyses will be updated with the increased dataset • Using the blind analysis policy on the new data Graphs below show the θ13 sensitivity for 7x1020 PoT Justin Evans

  31. MINOS Electron-Neutrino Appearance Analysis CC Event • Sub-dominant neutrino oscillations P(νμ→νe) ≈ sin2θ23 sin22θ13 sin2(1.27Δm231L/E) • Also CPv and matter effects: not shown here but included in fit • ANN algorithm to select ne events • Background measured in ND • NC events, high-y nm CC, beam ne, oscillated nt at FD • Data-driven technique: compare horn on/off data • Predict FD background from measured ND background + MC NC Event eCC Event E. Falk, U. of Sussex

  32. MINOS Electron-Neutrino Appearance Analysis • Far Detector spectrum obtained after blind analysis • Expected background:27±5(stat) ± 2(syst) • Contours from Feldman-Cousins method • Fit to number of events • Observed events:37 • Results: • Normal hierarchy (dCP = 0):sin2(2θ13) < 0.29 (90% C.L.) • Inverted hierarchy (dCP = 0):sin2(2θ13) < 0.42 (90% C.L.) • 1.5s excess • Well within realms of statistical fluctuation E. Falk, U. of Sussex

  33. MINOS Neutral Current Analysis • General NC analysis overview: • All active neutrino flavours participate in NC interaction • Mixing to a sterile ν will cause a deficit of NC events in Far Detector • Assume one sterile neutrino and that mixing between νμ, νs and ντ occurs at a single Δm2 • Survival and sterile oscillation probabilities become: (αμ,s = mixing fractions) Simultaneous fit to CC and NC energy spectra yields the fraction of νμ that oscillate to νs: E. Falk, U. of Sussex

  34. MINOS Future Plans • Update all analyses with more than double the data set • Muon antineutrino possibilities • Switch beam magnetic horns to focus p- • MINOS can make the first direct measurement • Reduce uncertainty on Dm232 by an order of magnitude E. Falk, U. of Sussex

  35. T2K Main Measurements: sin2q13 Simulated SK spectrum • Use CCQE: ne + n  e- + p • Main backgrounds: • Beam ne contamination • NC p0 events E. Falk, U. of Sussex

  36. T2K sin22q23 Main Measurements: sin2q23,Dm232 • Use CC quasi-elastic events:nm + n  m- + p • Background from non-CCQE interactions nmdisappearance • Precision prospect:D (sin22q23) ~ 0.01 (1%)D (Dm232) < 1 x 10-4 eV2 (a few %) at 90% C.L. • @ Dm2 ~ 2.5 x 10-3 eV2 Dm322 E. Falk, U. of Sussex

  37. T2K J-PARC Accelerator Complex Protons to 30 GeV on 23/12/08Commissioning is on time Commissioned,in use for material & life science n beam-line componentsCommissioning in progress Commissioned,in use for material & life science E. Falk, U. of Sussex Neutrino Beam Line

  38. T2K Near Detectors at 280 m • On- and off-axis detectors 280 m downstream of target • Understand the neutrino beam before oscillations occur • T2K timeline • Apr 09: Beam-line commissioning 10 days • Summer-autumn 09: Install INGRID & ND280 • Oct 09: Restart beam commissioning • Dec 09-June 10: Physics run • Aim to improve CHOOZ limit ND 280: Off-axis detectors inside UA1 magnet On-axis: INGRID Scintillator/iron modules E. Falk, U. of Sussex

  39. T2K Beam Power Projections April 1, 2009 E. Falk, U. of Sussex

  40. T2K Discovery Potential E. Falk, U. of Sussex

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