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Performance comparison: Superbeams, Beta beams, Neutrino Factory

Performance comparison: Superbeams, Beta beams, Neutrino Factory. NuFact 2010 TIFR Mumbai, India October 20-25, 2010 Walter Winter Universität Würzburg. TexPoint fonts used in EMF: A A A A A A A A. Contents. Long baseline phenomenology, conceptual comparison

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Performance comparison: Superbeams, Beta beams, Neutrino Factory

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  1. Performance comparison:Superbeams, Beta beams, Neutrino Factory NuFact 2010TIFR Mumbai, India October 20-25, 2010Walter Winter Universität Würzburg TexPoint fonts used in EMF: AAAAAAAA

  2. Contents • Long baseline phenomenology,conceptual comparison • Quantitative performance indicators • Ingredients of the performance comparison • Optimization/status beta beams and NuFact (… affect the performance) • Performance comparison: Example

  3. Introduction/repetition: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 (high-E NF?)(Donini, Meloni, Migliozzi, 2002; Autiero et al, 2004) • Platinum: nm ne (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/NF, n b-beam/NF, anti-n Best-fit

  7. Degeneracy resolution LBNE, T2KK, NF/BB@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 • High statistics • Other channels • Other experimentclasses (many many authors, see e.g. ISS physics WG report, Euronu reports)

  8. Reactor experiments for q13 Identical detectors, L ~ 1-2 km (Mezzetto, Schwetz,2010) Multi-source multi-detector systems, disappearance channel: systematics important! WG 1 session 8! Need to think about systematics in future multi-source-multi detector beam experiments as well? Neutrino Factory: 4 sources (straights), 6-10 detectors? (see, e.g., Giunti, Laveder, Winter, 2009; Tang, Winter, 2009a)

  9. Site-specific versus green-field setups Time? q13 reach?

  10. Site-specific examples Characteristics: Possible projects depend on regional boundary conditions(e.g., geography, accelerator infrastructure) Setups:T2KT2HKT2KK… Setups:CNGSCERN-MEMPHYS… Setups:MINOSNOnA (+ upgrades)LBNE: FNAL-DUSEL… See WG1 session 1+3:OPERA, T2K, NOvA, LBNEMINOS/anomaly?+ new ideas in sessions 6+9

  11. Green-field example: NF … but that does not mean that it wouldn‘t work for specific sites … Can the reddot be realized? (Kopp, Ota, Winter, 2008)

  12. Site-specific NF? (Agarwalla, Huber, Tang, Winter, in prep.) Best CPVbaseline? Red dotcorresponds to JPARC-CJPL-Pyhaselmi or Icicle creek

  13. New physics searches: what are the most interesting cases for us? • If new physics lives at high energies:Describes additions to the SM in a gauge-inv. way! • Interesting dimension six operatorsFermion-mediated  Non-unitarity (NU)Scalar or vector mediated Non-standard int. (NSI)[this form not gauge-invariant; theoretical motivation for large effects not thrilling …] • If new physics at low energies: light SM singlets may mix with neutrinos (sterile neutrinos) n mass d=6, 8, 10, ...: NSI, NU, CLFV, … More in WG 1 session 9:Rodejohann, Blennow, Lopez-Pavon

  14. On light sterile neutrinos • MiniBOONE antineutrino data: LSND re-loaded? • vs. recent cosmology data: 1 eV? 3+1 0.05 eV? ~ 0 eV? 3+1‘ 0.05 eV? 0.03 eV? ~ 0 eV? Need to re-analyze current data??? … more: WG1 session 2(Stancu, Schwetz, Huber, Tang) (Hamann, Hannestad, Raffelt, Tamborra, Wong, 2010)

  15. Comparison – conceptual (1) • Standard oscillation parameters Focus on that part

  16. Comparison – conceptual (2)(includes: new physics requirements?)

  17. Quantitative performance indicators

  18. Most interesting quantities • The value of q13  Three-flavor effects • q13 sensitivity (exclusion limit if no signal) • q13 discovery reach/discovery potential • CP violation  Leptogenesis? • Mass ordering  Lepton flavor structure? • Deviation from tribimaximal mixings? • Deviations q23-p/4 • Deviations sin2q12 – 1/3 • In particular interesting in combination with q13=0! (Pascoli, Petcov, Riotto, hep-ph/0611338) More:WG 1session 5

  19. Example: CPV discovery • Any value of dCP(except for 0 and p)violates CP • Sensitivity to CPV:Exclude CP-conservingsolutions 0 and pfor any choiceof the other oscillationparameters in their allowed ranges

  20. CP violation 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 at 2s( QLC models?) Read: If sin22q13=10-3, we expect a discovery for 80% of all values of dCP

  21. Example: Discovery reaches at NuFact PRELIMINARY (IDS-NF Interim Design Report, in preparation)

  22. A note on precision (potatoes) • Experimentalist‘sfavorite:„Potato plots“( looks like results!) • The mean thing:Precision=shape of potato depends on true values of q13, dCP • The meaner thing: How do I compare the shape of two potatoes? • The meanest thing: SB measure nm ne appearance, BB and NF ne nm • Prefer different dCP • Provocative statement: Can always find a set of (q13, dCP) such that my experiment has the most beautiful potato! • Need to find ways to compare the whole parameter space A. Laing (NF)

  23. On the precision of dCP (from hep-ph/0310307) (from hep-ph/0412199) No info on dCP 90% CL,sin22q13=0.1 3s Some dCP excluded Good at dCP ~ 3p/2 Good at dCP ~ p/2

  24. On the precision of q13 • Bands reflect dependence on true dCP: • Very long baseline(such as to INO) key for q13 precision? NuFact (from hep-ph/0204352) (from hep-ph/0612158)

  25. Ingredients of the (objective?) performance comparison … for future experiments

  26. Key ingredients(from a phenomenologist‘s perspective) • Factors under machinery control(… can be dealt with in objective manner) • Factors under experiment‘s control(… we may take them as „god given“, but we do critically ask questions!) • Factors under theorist‘s control(… factors not under any control?) • Factors under Nature‘s control(… we cannot control)

  27. 1. Machinery control Choose comparable assumptions: • Same oscillation framework • Same oscillation parameters (best-fit) • Same external input (e.g. solar parameters) • Same performance indicators • Same assumptions on matter density • Same marginalization techniques • Same syst. implementation, same c2 • Same simulation/comparison tool?

  28. GLoBES AEDL„Abstract ExperimentDefinition Language“ Define and modifyexperiments User InterfaceC library, reads AEDL files Functionality forexperiment simulation AEDL files GLoBES software(General Long Baseline Experiment Simulator) http://www.mpi-hd.mpg.de/lin/globes/ Application softwarelinked with user interfaceCalculate sensitivities … (Huber, Lindner, Winter, 2004; Huber, Kopp, Lindner, Rolinec, Winter, 2007) Online now: GLoBES 3.1.8 (improved Mac support, new API functions, bug fixes, etc.)

  29. 2. Experiment‘s control Typically information from proposals: • Beam (source) spectrum or geometry • Detector description (efficiencies, backgrounds, energy resolution) • Systematical errors • Potentially: cross sections • Anticipated luminosity (dangerous, often outdated!) • Timescale (very dangerous, always outdated!) • To be understood as target values! Encourage transparency: Provide all information needed for experiment simulationor even collaboration-agreed AEDL file, to allow for new physics etc. tests

  30. 3. Theorist‘s control • Choice of performance indicators and parameters • Systematics implementation (unless specified in detail in proposal) • Luminosity (how to compare apples with pears: protons on target, useful ion decays, useful muon decays?) • Design parameters which can be easily changed in the simulation, such as ions, g (beta beams), L, Em • Two (strong) recommendations: • Do not mix up existing with future experiments • Only compare experiments for which a cost tag exists (i.e., some experimentalists have thought about feasibility and risk in some detail) Caveat: We do not always follow these rules …

  31. 4. Nature‘s control • Example: QE X-secs in different models • Absolute performance depends on X-secs! g=100 beta beam CERN-Frejus Fernandez-Martinez, Meloni, arXiv:1010.2329

  32. Optimization/Status BB and NF (superbeams discussed by P. Huber)

  33. Beta beam benchmark? (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 “target values” (EURISOL):3 10186He decays/year1 101818Ne decays/year • Typical g ~ 100 – 150 (for CERN SPS) Prod.ring? Possible/recent 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)

  34. Current status: A variety of ideas • “Classical” beta beams: • “Medium” gamma options (100 < g < ~350) • Alternative to superbeam! • Possible at SPS (+ upgrades)  use existing infrastructure • 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; Choubey et al, 2009; Fernandez-Martinez, 2009; Peltoniemi, 2009; Coloma et al, 2010) • “High” gamma options (g >> 350) • Require large accelerator (Tevatron or LHC-size) • Water Cherenkov detector or TASD or MIND? (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; Agarwalla, Huber, 2009) • Hybrids: • Beta beam + superbeam(CERN-Frejus; Fermilab: see Jansson et al, 2007) • “Isotope cocktail” beta beams (alternating ions)(Donini, Fernandez-Martinez, 2006) • Classical beta beam + Electron capture beam etc(Bernabeu et al, 2009; Orme, 2009) • … Exp.studied(Euronu) Theorist‘scontrol: g

  35. Isotopes compared (1) • Example: Unoscillated spectrum for CERN-INO • Total flux ~ Nbg2 (forward boost!) (Nb: useful ion decays) (E0 ~ 14 MeV) (E0 ~ 4 MeV) g (from Agarwalla, Choubey, Raychaudhuri, 2006) Peak En ~ g E0 Max. En ~ 2 g E0 (E0 >> me assumed;E0: endpoint energy)

  36. Isotopes compared (2) • Examples for isotopes • Want same neutrino energies(=same X-sections, L, physics):Peak energy ~ g E0, flux ~ Nbg2 Use high g and isotopes with small E0or low g and isotopes with large E0 for same total flux (exact for me/E0 << 1) • Example (table): Nb(B/Li) ~ 12 Nb(He/Ne) , g(He/Ne) ~ 3.5 g(B/Li) • Can only compensated by tremendous luminosity increase! From energy to luminosity limited exp.!

  37. Minimal beta beam at the CERN-SPS? (g fixed to ~ maximum at SPS) (500 kt) CERN-Boulby CERN-Boulby CERN-LNGS CERN-LNGS MH, CPV (80% of dCP) at 3s (arXiv:0809.3890) Conclusions: useful for large q13 if (for B/Li)1. Long enough baseline (CERN-LNGS realistic minimum)2. About factor of five luminosity increase > 1019 useful ion decays/year WARNING: Theoretical studies typically very aggressive in that number!

  38. 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 • Current status: Interim Design Report (end 2010)including details of how costing will be done Signal prop. sin22q13 Contamination ~ 7500 km ~ 4000 km Target: Em ~ 25 GeV, 2.5 1020 usful muon decays/polarity/ring/year = 1021 total

  39. FAQ:What is the very long baseline good for? • Complemenary mesurement (physics): measures q13, MH and matter density only • Insurance against anything (?)which can go wrong: • New physics • Systematics • Luminosity • Unfortunate part of parameter space (degeneracies) • Risk minimizer! Ribeiro et al, 2007

  40. Impact of ND/systematics CP violation, 3s Luminosity or 2nd baseline Two baselines: rel. insensitive to:- Luminosity (scales with statistics)- Cross section uncertainties(bin-to-bin uncorrelated, but correlated between FD) (Jian Tang, WW, arXiv:0903.3039)

  41. Low energy neutrino factory • High luminosity, low Em ~ 4-5 GeV • Possible through magnetized TASD with low threshold • Interesting: ne with CID (Geer, Mena, Pascoli, hep-ph/0701258; Bross et al, arXiv:0708.3889; Fernandez-Martinez et al, arXiv:0911.3776; Tracey Li)

  42. Neutrino factory in stages? Phase III: Baseline (7500km) or det. mass (100 kt) upgrade, 5 years Phase I: Search for q13Em=4.12 GeV, 5 years, 20kt TASD@900km Phase II: Energy upgradeEm=25 GeV, 5 years, 50kt MIND@4000km (Jian Tang, WW, arXiv:0911.5052) If q13 discovered: Use knowledge for baseline optimization of phase II! Use measurement of q13 for upgrade choice of phase III! Yellow error bars:precision on q13 from phase II

  43. Silver/discovery channel • Original idea: use ECC for direct nt detection • Silver: ne nt(Donini, Meloni, Migliozzi, 2002; Autiero et al, 2004) • „Discovery“: nm nt(Donini et al, 2008) • Problem: low statistics at intermediate baseline • More recently: „indirect channels“ • Silver contam. ne nt t- m- vs. ne nm m-(Donini, Gomez Cadenas, Meloni, 2010) • Reconstructed at low E, needs to be taken into account • Disc. contam. nm nt t- m- vs. nm nm m-(Indumathi, Sinha, 2009) • Contaminates atmospheric param. measurements 17% 17%

  44. Silver channel, reloaded? • Low E events carry high E silver information, possibly as clean signal: Does that improve/affect the sensitivity? PRELIMINARY A. Laing et al migration matrices+ Donini et al nt contamination; from Agarwalla, Huber, Tang, Winter, in prep. WG 1 session 6:Sinha, Coloma

  45. Performance comparison:Example Here: Euronu plots;many other versions out there …

  46. Performance comparison Best beta beam:Four ions,all at 1019 usef. decays/year g>350,650 km (500kt water)+7000 km (50kt MIND) Theorists‘ dream? ? + Systematics too conservative?+ Detector re-opt. not included yetCost estimate by NuFact 2012? Generation 3:NuFactBB g>350 ??? Generation 2:LBNET2HKSPLBB100? Probablynot fantastic;cost? Generation 1:Double ChoozDaya BayT2KNOvA Inconstruction willhappen! „Downgraded“NuFact ~high endbeta beam?

  47. Summary • There are conceptual differences among the considered experiment classes: not all parameters can be obtained everywhere • Quantitatively, one can classify into three categories: • Next generation experiments • Superbeam upgrades, beta beam g ~ 100 • Neutrino factory, beta beam g > 350 • The comparison within each category should be done with care; does not say anything about feasibility and cost • Mike says I should not talk about cost; but a reasonable cost estimate (for me) means: someone (experimentalist) has been thinking about feasibility and risk • Does not mean that theorists are not allowed to dream and come up with better implementations …

  48. BACKUP

  49. Performance comparison (2)

  50. 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.)

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