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Phenomenology of future LBL experiments … and the context with Euro n WP6

Phenomenology of future LBL experiments … and the context with Euro n WP6. IDS-NF + Euro n plenary meeting at CERN March 25, 2009 Walter Winter Universität Würzburg. TexPoint fonts used in EMF: A A A A A A A A. Contents. Introduction to LBL phenomenology Status of Neutrino factory

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Phenomenology of future LBL experiments … and the context with Euro n WP6

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  1. Phenomenology of future LBL experiments… and the context with Euron WP6 IDS-NF + Euron plenary meeting at CERN March 25, 2009Walter Winter Universität Würzburg TexPoint fonts used in EMF: AAAAAAAA

  2. Contents • Introduction to LBL phenomenology • Status of • Neutrino factory • Superbeams • Beta beams • Current Euron/IDS-NF issues • Performance indicators • Benchmark setups • Optimization/decision: Large versus small q13 • Conclusions This talk:Only standardoscillationphysics

  3. Long baseline phenomenology

  4. Channels of interest • Disappearance for Dm312, q23: nm nmNB: We expand in • Appearance for q13, CPV, MH: • Golden: ne nm (NF/BB) or nm ne(SB)(e.g., De Rujula, Gavela, Hernandez, 1999; Cervera et al, 2000) • Silver: ne nt (NF – low statistics!?)(Donini, Meloni, Migliozzi, 2002; Autiero et al, 2004) • Platinum: nm ne (NF: maybe in low-E NF)(see e.g. ISS physics working group report) • „Discovery“: nm nt (OPERA, NF?)(e.g. Fernandez-Martinez et al, 2007; Donini et al, 2008)Neutral currents for new physics (e.g., Barger, Geer, Whisnant, 2004; MINOS, 2008) D31 = Dm312 L/(4E)

  5. Appearance channels • Antineutrinos: • Magic baseline: • Silver: • Superbeams, Plat.: (Cervera et al. 2000; Freund, Huber, Lindner, 2000; Huber, Winter, 2003; Akhmedov et al, 2004)

  6. Degeneracies Iso-probability curves • CP asymmetry(vacuum) suggests the use of neutrinos and antineutrinos • One discrete deg.remains in (q13,d)-plane(Burguet-Castell et al, 2001) • Additional degeneracies: (Barger, Marfatia, Whisnant, 2001) • Sign-degeneracy (Minakata, Nunokawa, 2001) • Octant degeneracy (Fogli, Lisi, 1996) b-beam, n b-beam, anti-n Best-fit

  7. Degeneracy resolution WBB FNAL-DUSEL, T2KK, NF@long L, … Monochromatic beam, Beta beam with different isotopes, WBB, … T2KK, magic baseline ~ 7500 km, SuperNOvA Neutrino factory, beta beam, Mton WC SB+BB CERN-Frejus, silver/platinum @ NF Reactor, atmospheric, astrophysical, … • Matter effects (sign-degeneracy) – long baseline, high E • Different beam energies or better energy resolution in detector • Second baseline • Good enough statistics • Other channels • Other experimentclasses (many many authors, see e.g. ISS physics WG report)

  8. Status of the neutrino factory

  9. Neutrino factory – IDS-NF (Geer, 1997; de Rujula, Gavela, Hernandez, 1998; Cervera et al, 2000) IDS-NF: • 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 • In the US: „Muon collider task force“ Signal prop. sin22q13 Contamination Muons decay in straight sections of a storage ring ISS

  10. Physics potential • Excellent q13, MH, CPV discovery reaches (IDS-NF, 2008) • About 10% full width error (3s) on log10 (sin22q13) for sin22q13 = 0.001(Gandhi, Winter, hep-ph/0612158, Fig. 6) • About 20-60 degree full width error (3s) on dCPfor sin22q13 = 0.001 (Huber, Lindner, Winter, hep-ph/0412199, Fig. 7)But what does that mean? Cabibbo angle-precision(qC ~ 13 deg.)!Why is that relevant? Can be another feature of nontrivial QLC models:E.g. from specific texture+QLC-type assumptions:(F: model parameter) (Niehage, Winter, arXiv:0804.1546)

  11. Low energy neutrino factory • „Low cost“ version of a neutrino factoryfor moderately large q13: Em ~ 4.12 GeV • Possible through magnetized TASD with low threshold (Geer, Mena, Pascoli, hep-ph/0701258; Bross et al, arXiv:0708.3889)

  12. On near detectors@IDS-NF • Define near detectors including source/detector geometry: • Near detector limit: Beam smaller than detector • Far detector limit: Spectrum similar to FD • Systematics • X-Section (shape) errors (30%) • Flux normalization errors (2.5%) • BG normalization errors (20%) ~ND limit ~FD limit (Tang, Winter, arXiv:0903.3039)

  13. ND: Main results • Need two near detectors, especially for leading atmospheric parameters • Flux monitoring important for CPV (large q13) • Near detectors not relevant for q13 discovery, MH • Systematical errors cancel if two neutrino factory baselines (even without ND) 30% XSec-errors, uncorrelated among all bins Use near detectors (Tang, Winter, arXiv:0903.3039)

  14. Impact of ND+new systematics CP violation, 3s IDS-NF systematicstoo conservative? (Tang, Winter, arXiv:0903.3039)

  15. Low-E versus high-E NuFact • High-E reference: IDS-NF baseline 1.0 • Low-E reference: Bross et al, arXiv:0708.3889, 1023 decays*kt, 2% systematics errors (flux norm, BGs) • High-E NuFact one to two orders of magnitude in q13 better (Tang, Winter, arXiv:0903.3039)

  16. NF: Status and outlook • Characteristics: • Truly international effort • Green-field setup (no specific site) • High-E NuFact: Benchmark setup defined • Will evolve over time • Examples: MECC, Detector masses of far detectors • Open issues:„Low cost“ alternative? Benchmark setup for that? • Euron relationship: Results shared between IDS-NF (physics) and Euron; Funding from Euron

  17. Status of superbeams

  18. Beam/Superbeam setups Characteristics: Possible projects depend on regional boundary conditions(e.g., geography, accelerator infrastructure) Setups:MINOSNOnA (+ upgrades)WBB FNAL-DUSEL… Setups:CNGSCERN SPL-Frejus… Setups:T2KT2HKT2KK…

  19. Superbeam upgrades: Examples 120 GeV protons • Exposure L: Detector mass [Mt] xTarget power [MW] xRunning time [107s] • Bands: variation of systematical errors: 2%-5%-10% • „Typical“ dCP, 3s discovery Nominal exposure (Barger, Huber, Marfatia, Winter, hep-ph/0610301, hep-ph/0703029)

  20. Luminosity scalings • If q13 found by next generation: • WBB and T2KKcan measure CPV, MH • NuMI requires Lumi-upgrade (ProjectX?) • Systematics impact least for WBB; best physics concept? MH for sin22q13 > 0.003

  21. On-axis versus off-axisExample: NuMI-like beam  100kt liquid argon On axis sin22q13 CP violation Mass hierarchy FNAL-DUSELWBB dCP=-p/2 Ash RiverOA,NOvA* ConstraintfromNuMIbeam dCP=+p/2 (Barger et al, hep-ph/0703029) Off-axis technology may not be necessary if the detector is good enough, i.e., has good BG rejection and good energy resolution! WC good enough???

  22. European plan: CERN-MEMPHYS • L=130 km: CERN-Frejus • Interesting in combination with beta beam: Use T-inverted channels (ne nm and nm  ne) to measure CPV • Problem: MH sensitivity, onlycomparable to T2HKConcerns of WP6 communicated to Euron CB in Feb 2008:„[...] It is well known that this setup has good possibilities to observe CP violation, however, due to the short baseline there will be no chance to determine the mass hierarchy. We believe that this is a very important measurement for a future neutrino facility, and will be one of the comparison criteria to be defined within this study. We want to point out very clearly that restricting the SB study only to the CERN-Frejus setup excludes this measurement from the very beginning. […]” 2s LBL+ATM WBB FNAL-DUSEL (average) (Campagne, Maltoni, Mezzetto, Schwetz, hep-ph/0603172)

  23. SB: Status and outlook • Characteristics: • Projects driven by regional interests/boundary conditions • Projects attached to existing accelerator sites (mid term perspective) • Benchmark setups: • Partly defined (such as baselines, detectors etc) • Fuzzy assumptions on proton plans, running times, … (benchmark comparison difficult!) • Relationship to Euron: Only CERN-Frejus setup studied within Euron WP2 • Concern raised by some WP6 members:European setup maybe „dead end“?

  24. Status of beta beams

  25. Original „benchmark“ setup!? (CERN layout; Bouchez, Lindroos, Mezzetto, 2003; Lindroos, 2003; Mezzetto, 2003; Autin et al, 2003) (Zucchelli, 2002) • Key figure (any beta beam):Useful ion decays/year? • Often used “standard values”:3 10186He decays/year1 101818Ne decays/year • Typical g ~ 100 – 150 (for CERN SPS) More recent key modifications: • Higher g(Burguet-Castell et al, hep-ph/0312068) • Different isotope pairs leading to higher neutrino energies (same g) (http://ie.lbl.gov/toi) (C. Rubbia, et al, 2006)

  26. Current status: A variety of ideas • “Classical” beta beams: • “Medium” gamma options (150 < g < ~350) • Alternative to superbeam! Possible at SPS (+ upgrades) • Usually: Water Cherenkov detector (for Ne/He) (Burguet-Castell et al, 2003+2005; Huber et al, 2005; Donini, Fernandez-Martinez, 2006; Coloma et al, 2007; Winter, 2008) • “High” gamma options (g >> 350) • Require large accelerator (Tevatron or LHC-size) • Water Cherenkov detector or TASD or MID? (dep. on g, isotopes) (Burguet-Castell et al, 2003; Huber et al, 2005; Agarwalla et al, 2005, 2006, 2007, 2008, 2008; Donini et al, 2006; Meloni et al, 2008) • Hybrids: • Beta beam + superbeam(CERN-Frejus: see before; Fermilab: see Jansson et al, 2007) • “Isotope cocktail” beta beams (alternating ions)(Donini, Fernandez-Martinez, 2006) • Classical beta beam + Electron capture beam(Bernabeu et al, 2009) • …

  27. Stand-alone European version? • CERN-Gran Sasso or Boulby? • Example: CERN-Boulby, L=1050 km • g=450 (SPS upgrade), 18Ne only! • Red: 1021 usef. ions x kt x yr • Blue: 5x2021 usef. ions x kt x yr Masshierarchy 99% CL Problem: Antineutrino channel missing!(degs only partially resolved by spectrum)More later … 99% CL (Meloni, Mena, Orme, Palomares-Ruiz, Pascoli, arXiv:0802.0255)

  28. BB: Status and outlook • Characteristics: • Mostly European effort (so far) • Partly green-field, mostly CERN-based • Benchmark setup: • Often-used: SPS-based setup, sort of „benchmark“ in the literature (e.g. for useful number of ion decays) • Not up-to-date anymore wrt isotopes, g, useful ion decays etc • Define new benchmark with the necessary requirements for WP4? • Relationship to Euron:Studied within WP4 (mostly source aspects)

  29. Current Euron physics issues (some thoughts)

  30. Performance indicators • Many performance indicators used in literature • What is the best way to present? • Fair comparison of whole parameter space or comparison at specific benchmark points? • WP6 will have to look into this (Pilar) Example:q13 discovery vs q13sensitivity(Huber, Lindner, Schwetz, Winter, in prep.) Preliminary Warning: If particular dCP chosen, any answer canbe obtained!

  31. Benchmark setups: Status • Do we need these? At the end, for a physics comparison, probably … • Can be used to define requirements for reasonable physics output (see, e.g., IDS-NF) • Maybe: More aggressive versus minimal versionExample: ISS Plot • Neutrino factory: • Exists for high-E version • Not yet for low cost version • Superbeam: • Minimal version exists (apart from specific numbers) • More aggressive: Not defined • Beta beam: • Minimal version exists (apart from specific numbers) • More aggressive: Not defined (ISS, arXiv:0710.4947)

  32. Optimization of exps • Small q13:Optimize q13, MH, and CPV discovery reaches in q13 direction • Large q13:Optimize q13, MH, and CPV discovery reaches in (true) dCPdirection~ Precision! • What defines “large q13”? A Double Chooz, Day Bay, T2K, … discovery! Beta beam Optimization for large q13 NuFact T2KK Optimization for small q13 (3s, Dm312=0.0022 eV2)

  33. Large q13 strategy • Assume that we know q13(Ex: Double Chooz) • Minimum wish listeasy to define: • 5s independent confirmation of q13 > 0 • 3s mass hierarchy determination for any (true) dCP • 3s CP violation determination for 80% (true) dCP~ Cabibbo-angle precision as a benchmark! For any (true) q13 in 90% CL D-Chooz allowed range!(use available knowledge on q13 and risk-minimize) • What is the minimal effort (minimal cost) for that? • Use resources wisely! (arXiv:0804.4000; Sim. from hep-ph/0601266; 1.5 yr far det. + 1.5 yr both det.)

  34. Example: Minimal beta beam (arXiv:0804.4000) • Minimal effort = • One baseline only • Minimal g • Minimal luminosity • Any L (green-field!) • Example: Optimize L-g for fixed Lumi: • g as large as 350 may not even be necessary! Sensitivity for entire Double Chooz allowed range! 5yr x 1.1 1018 Ne and 5yr x 2.9 1018 He useful decays

  35. Minimal beta beam at the CERN-SPS? (g fixed to maximum at SPS) (500 kt) CERN-Boulby CERN-Boulby CERN-LNGS CERN-LNGS (arXiv:0809.3890) Conclusions:- CERN-Boulby or CERN-LNGS might be OK at current SPS if ~ 5 times more isotope decays than original benchmark (production ring?)- CERN-Frejus has too short baseline for stand-alone beta beam

  36. Small q13 strategy • Assume that Double Chooz … do not find q13 • Minimum wish list: • 3s-5s discovery of q13 > 0 • 3s mass hierarchy determination • 3s CP violation determination For as small as possible (true) q13 • Two unknowns here: • For what fraction of (true) dCP? One has to make a choice (e.g. max. CP violation, for 80% of all dCP, for 50%, …) • How small q13 is actually good enough? • Minimal effort is a matter of cost! • Maybe the physics case will be defined otherwise? ?

  37. Connection to high-E frontier?

  38. Conclusions • Current status: • Neutrino factory: • Strong collaboration with IDS-NF • High-E benchmark setup defined • „Low cost“ version further studied • Superbeams: • CERN-Frejus anticipated as benchmark • Has too little MH sensitivity, even if combined with atm. data(Issues: low energy, short baseline) • Beta beams: • SPS-based benchmark often used in literature • Probably not sufficient: Define more aggressive version with higher g or more isotope decays (production ring)? • Next steps? • Discuss performance indicators • Discuss if benchmarks needed for WP6 • Connection to global perspective? • …

  39. Backup

  40. Long baseline experiments For leading atm. params Signal prop. sin22q13 Contamination

  41. 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 (https://www.ids-nf.org/)

  42. Two-baseline optim. revisited • Robust optimum for ~ 4000 + 7500 km • Optimization even robust under non-standard physics(dashed curves) (Kopp, Ota, Winter, 2008)

  43. Timescale for q13 discovery? • Assume:Decision on future experiments made after some LHC running and next-generation experiments • Two examples: • ~ 2011: sin22q13 > 0.04? • ~ 2015: sin22q13 > 0.01? D (Huber, Kopp, Lindner, Rolinec, Winter, 2006)

  44. Example: CPV discovery … in (true) sin22q13 and dCP Best performanceclose to max. CPV (dCP = p/2 or 3p/2) Sensitive region as a function of trueq13 anddCP dCP values now stacked for each q13 No CPV discovery ifdCP too close to 0 or p No CPV discovery forall values of dCP 3s Cabibbo-angleprecision for dCP ~ 85%!Fraction 80% (3s) corresponds to Cabibbo-angleprecision at 2sBENCHMARK! Read: If sin22q13=10-3, we expect a discovery for 80% of all values of dCP

  45. Luminosity scaling for fixed L • What is theminimal LSF x g? • (Ne,He):LSF = 1 possible(B,Li):LSF = 1 not sufficient • But: If LSF >= 5:g can be lower for (B,Li) than for (Ne,He), because MH measurement dominates there (requires energy!) (500kt) (100kt) (Winter, arXiv:0804.4000) only g < 150!

  46. Minimal g beta beam (Winter, arXiv:0804.4000)

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