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Neutrino oscillation physics with superbeams and neutrino factories

Neutrino oscillation physics with superbeams and neutrino factories. Nu HoRIzons workshop HRI, India February 13-15, 2008 Walter Winter Universität Würzburg. Contents. Will not talk about beta beams! Contents reflect a biased selection of aspects!. Introduction Superbeams

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Neutrino oscillation physics with superbeams and neutrino factories

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  1. Neutrino oscillation physics with superbeams and neutrino factories Nu HoRIzons workshop HRI, India February 13-15, 2008Walter Winter Universität Würzburg

  2. Contents Will not talkabout beta beams!Contents reflecta biased selectionof aspects! • Introduction • Superbeams • What can we expect from 1st generation experiments? • Examples for upgrade options • Neutrino factory • IDS-NF baseline setup 1.0 • Detector requirements/detector optimization • Physics with a very long baseline (to India?) • Requirements for non-standard measurements/physics case for the silver channel? • Summary and conclusions Nu HoRIzons 2008 - Walter Winter

  3. Evolution of q13 discovery limit? • Specific scenario • Bands reflect dependence on dCP GLoBES 2005 (NOvA) (from: FNAL Proton Driver Study) Nu HoRIzons 2008 - Walter Winter

  4. Appearance channels • Antineutrinos: • Magic baseline: • Silver: • Platinum: (Cervera et al. 2000; Freund, Huber, Lindner, 2000; Huber, Winter, 2003;Akhmedov et al, 2004) Nu HoRIzons 2008 - Walter Winter

  5. Superbeams: Concept • Conventional neutrino beams:Neutrino production by pion, kaon decays (obtained from protons hitting a target) • „Super“-beams: T2K, NOvA • Higher target powers O(1 MW) • Larger detectors O(30 kt) • Off-axis technology (for BG suppression, lower E) • „Super“-Superbeams, superbeam upgrades: WBB, T2KK, CERN-Memphys, NuMI*, … • Even higher target powers O(4 MW) • Even larger detectors O(100-500 kt) • On- or off-axis technology • „Super“ pricy For leading atm. params Signal prop. sin22q13 Contamination Nu HoRIzons 2008 - Walter Winter

  6. Running example for beams: MINOS • Measurement of atmosphericparameters with high precision • Flavor conversion ? Fermilab - SoudanL ~ 735 km Beam line Near detector: 980 t Far detector: 5400 t 735 km Nu HoRIzons 2008 - Walter Winter

  7. Perspectives for MH and dCPfor the coming 5 to 10 years? • A mass hierarchy or CP violation measurement will be unlikely or impossible from • Beams+Reactor experiments • Any other source alone (supernova etc.) (from: Huber, Lindner, Rolinec, Schwetz, Winter, 2004) Nu HoRIzons 2008 - Walter Winter

  8. Superbeam upgrades: Examples • Exposure: Detector mass [Mt] xTarget power [MW] xRunning time [107s] • Bands: variation of systematical errors: 2%-5%-10% • Dots: Nominal L • Typical dCP, 3s discovery (Barger, Huber, Marfatia, Winter, hep-ph/0610301, hep-ph/0703029) Nu HoRIzons 2008 - Walter Winter

  9. Luminosity scalings • If q13 found by superbeams: • WBB and T2KKcan measure CPV, MH • NuMI requires Lumi-upgrade (ProjectX?) • Systematics impact least for WBB; best physics concept?

  10. Baseline-OA-OptimizationExample: NuMI-like beam  100kt liquid argon sin22q13 CP violation Mass hierarchy FNAL-DUSELWBB dCP=-p/2 Ash RiverOA,NOvA* ConstraintfromNuMIbeam dCP=+p/2 (Barger, Huber, Marfatia, Winter, 2007) Nu HoRIzons 2008 - Walter Winter

  11. Large q13 case… for the sensitivity to CP violation g=350 beta beamBurguet-Castell et al, 2005 • Superbeam upgrades can easily outperform a „straightforward“ NF • How can one optimize a neutrino factory for large q13? Neutrino factory3000 +7500 km50 kt + 50 kt NuMI beam to 100kt LArTPC FNAL - DUSEL 100kt LArTPC 270kt+270ktWC detector (Barger, Huber, Marfatia, Winter, hep-ph/0703029) Nu HoRIzons 2008 - Walter Winter

  12. Neutrino factory • Ultimate “high precision” instrument!? • Muons decay in straight sections of storage ring • Technical challenges: Target power, muon cooling, charge identification, maybe steep decay tunnels (Geer, 1997; de Rujula, Gavela, Hernandez, 1998; Cervera et al, 2000) Signal prop. sin22q13 For leading atm. params Contamination ISS

  13. NF optimization potential (ISS) (Huber, Lindner, Rolinec, Winter, hep-ph/0606119; b-beam: Burguet-Castell et al, hep-ph/0503021) • Optimized NuFact: Excellent q13 reach for both MH and CPV • But: For sin22q13 ~ 10-2, g=350 beta beam (L=730 km) better Em=20 GeV Em=50 GeV 3s Nu HoRIzons 2008 - Walter Winter

  14. IDS-NF launched at NuFact 07International design study for a neutrino factory • Successor of the International Scoping Study for a „future neutrino factory and superbeam facility“:Physics case made in physics WG report (~368 pp) (arXiv:0710.4947 [hep.ph]) • Initiative from ~ 2007-2012 to present a design report, schedule, cost estimate, risk assessment for a neutrino factory • In Europe: Close connection to „Euronus“ proposal within the FP 07; currently ranked #1, negotiating contract • In the US: „Muon collider task force“How can a neutrino factory be „upgraded“ to a muon collider? Nu HoRIzons 2008 - Walter Winter

  15. IDS-NF baseline setup 1.0 • Two decay rings • Em=25 GeV • 5x1020 useful muon decays per baseline(both polarities!) • Two baselines:~4000 + 7500 km • Two MIND, 50kt each • Currently: MECC at shorter baseline (http://www.hep.ph.ic.ac.uk/ids/) Nu HoRIzons 2008 - Walter Winter

  16. New analysis (diff. Lm) Baseline detector Old analysis/det. IDS-NF baseline setup 1.0 description • 55% E0.5 energy resolution • Detection threshold and backgrounds from new simulation • 2.5% signal uncertainty, 20% BG uncertainty • 5 yr + 5 yr running time • Silver channel: 10 kt Silver from hep-ph/0606119 (Autiero et al MECC) (IDS-NF baseline specification) Nu HoRIzons 2008 - Walter Winter

  17. IDS baseline performancefor discovery… evaluated with GLoBES! 3s Nu HoRIzons 2008 - Walter Winter

  18. Two-baseline optimization revisited Optimum • Sensitivity for all sin22q13>10-3.4 (q13),sin22q13 >10-3.8 (MH, CPV) (5s) for the shown performance indicator • True dCP chosen close to worst case • Robust optimum for ~ 4000 + 7500 km IDS baseline Nu HoRIzons 2008 - Walter Winter (Kopp, Ota, Winter, in prep.)

  19. Consequences for detector locations • Long baseline: L ~ 7000 - 9000 km good choice: CERN-INO? Nu HoRIzons 2008 - Walter Winter

  20. Magic baseline - detector requirements • IDS-NF baseline requires two MINDs as specified • What if • The long baseline detector is smaller? • The CID capabilities do not allow for the specified threshold/backgrounds? Quality moreimportant thanquantity! Nu HoRIzons 2008 - Walter Winter

  21. Large q13: Low-E (low budget?) NuFact • Use magnetized detector with low threshold to allow for lower Em(Bross, Ellis, Geer, Mena, Pascoli, 2007) • Combine with superbeam? – NF-Superbeam: Or use second target? * (Huber, Winter, 2007) Nu HoRIzons 2008 - Walter Winter

  22. Low-E NuFact: CPV comparison Ep=28 GeV500 kt WC • NF-SB (Ep=28 GeV, Em=5 GeV, L=1250 km) can outperform any of the discussed setups except from beta beam • But: Luminosity choice for beta beam arbitrary in this context!Parameters: g=350, L=712 km, 5 yr x 5.8 1018 useful 6He decays/yr, 5 yr x 2.2 1018 useful 18Ne decays/yr (Burguet-Castell et al, 2005) (Huber, Winter, 2007) Nu HoRIzons 2008 - Walter Winter

  23. Physics with a very longneutrino factory baseline CERN-INO???

  24. Precision measurements dCP precision q13 precision 3s dCP dep. (Huber, Lindner, Winter, 2004) (Gandhi, Winter, 2006) Nu HoRIzons 2008 - Walter Winter

  25. Further applications:Matter density measurement Lower mantle density • Idea: Treat r as yet another oscillation parameter to be measured; marginalize oscillation parameters! • Comes „for free“ from very long baseline!? • Two different models: • Measure rRef • Measure rLM(lower mantle density) (Winter, 2005; Minakata, Uchinami, 2006; Gandhi, Winter, 2006) Nu HoRIzons 2008 - Walter Winter

  26. Matter density: Geophysical use? • Example:Plume hypothesis • A precisionmeasurement << 1%could discriminatedifferent geophysicalmodels • Possible selectorof detectorlocations? (Courtillot et al., 2003; see talk from B. Romanowicz, Neutrino geophysics 2005) Nu HoRIzons 2008 - Walter Winter

  27. Results for one-parameter measurement • Assume that only one parameter measured • For large q13, < 1% precision at 3s • Indep. confirmed byMinakata, Uchinami(for one baseline) (Gandhi, Winter, 2006) True d=0 Nu HoRIzons 2008 - Walter Winter

  28. Resolving the q23 degeneracy (Gandhi, Winter, 2006) • 4000 km alone: Problems with degs for intermediate q13 • 7200 km alone: No sensitivity for small q13 • 4000 km + 7200 km: Good for all q13 Similar performanceto Gold+Silver* @ 4000kmMeloni, arXiv:0802.0086 Nu HoRIzons 2008 - Walter Winter

  29. MSW effect sensitivity: even for q13=0! • Solar term:Note thati.e., effect increases with baseline (D ~ L)! 5s (Winter, 2004) Nu HoRIzons 2008 - Walter Winter

  30. Requirements fornew physics searches?

  31. Non-standard neutrino interactions • Consider effective four-point interactions • This leads to a Hamiltonian for n propagation:matter potential: • For antineutrinos: H  H*, aCC  -aCC Weak constraints Nu HoRIzons 2008 - Walter Winter

  32. NSI with magic baseline 3000 km arXiv:0709.1980 • Combing the two baselines reduces the impact of correlations drastically(only real eet assumed!) • Does one still need the silver channel in that case? 7000 km +Disappearance Combined Close to worst case for degeneracies: dCP=3p/2, sin22q13=0.001 (Kopp, Ota, Winter, in prep) Nu HoRIzons 2008 - Walter Winter

  33. Correlations at magic baseline • Including NSI, the magic baseline is not exactly correlation/degeneracy-free • Example: High-E Approximation • aCC ~ E: Standard term drops as 1/E4, NSI-Term as 1/E3 High energies important for NSI! Nu HoRIzons 2008 - Walter Winter

  34. When does the silver channel help? • Silver channel, in principle, very sensitive to eet, ett • Fix golden baselines:Where is the optimalsilver baseline?(Use Silver* (5xSG,3xBG; all hadronic decay channels of the t observed) IDS-NF MECC baseline = Golden 1 (Kitazawa, Sugiyama, Yasuda, 2006) Preliminary (Kopp, Ota, Winter, in prep.) Nu HoRIzons 2008 - Walter Winter

  35. ~ Currentbounds Minimum muon energy? • Higher muon energy helps; low-E NF not an option • Silver channel: Not relevant for IDS baseline; helps for Em ~ 50 GeV IDS baseline Low-E NuFact? Low-E NuFact? High-E version IDS baseline High-E version Preliminary (Kopp, Ota, Winter, in prep.) Nu HoRIzons 2008 - Walter Winter

  36. Two baseline optimization (no silver) • Similar to matter effects (which increase with baseline!), NSI sensitivities want one very long baseline • Absolute sensitivity: Current limits improved by up to three orders of magnitude! Preliminary (Kopp, Ota, Winter, in prep.) Nu HoRIzons 2008 - Walter Winter

  37. New physics searches… and the physics case for nt detection? • Two approaches: • Have specific model, i.e., spectral dependence • Want to do general unitarity checks, i.e., no specific idea about spectral dependence • Two solutions: • Use spectral dependence with model parametersBut: much more statistics in Pem, Pmmthan Pet (cf., NSI example) • Use NC or CCs Ne+Nm+Nt;But for NC: Systematical uncertainties, CC contamination limit to percent levelBut for CC: Initial nm: not possible because of MECC readout rate? Initial ne: platinum CID (showers!), silver statistics again limited to few percent!? • Is the conclusion that there is no physics case for the MECC at L1? (Barger, Geer, Whisnant, 2004) NC: Systematic uncertaintyin NC rate eNC and CC contaminations limit performance; limited tofew percent?

  38. Summary and conclusions • First generation superbeams (or reactor experiments) may find q13; however: no high-CL discovery of CPV, MH  Need upgrades! • Current IDS-NF setup uses two baselines:Does INO match the detector requirements for the far detector? • The physics case for the VL baseline is very robust (a number of applications) • Open question: Do new physics searches require the silver channel? Nu HoRIzons 2008 - Walter Winter

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