1. POFPA 18 october Alain Blondel Neutrino Factory (and the International Scoping Study (ISS)) mother link http://muonstoragerings.cern.ch (see NUFACT05) ‘ ECFA/CERN studies of a European Neutrino Factory Complex' CERN 2004-002 ECFA/04/230 and Physics with a MMW proton driver (MMW workshop) CERN-SPSC-2004-024 and http://www.hep.ph.ic.ac.uk/iss/

2. POFPA 18 october Alain Blondel Kayser -- EPS05 Accelerator neutrinos are CENTRAL to the future program.

3. POFPA 18 october Alain Blondel

4. 1.An ambitious neutrino programme is a distinct possibility, but it must be well prepared to have a good proposal in time for the big decision period in 2010 (Funding window: 2011-2020) 2. Two avenues have been identified as promising a) SuperBeam + Beta-Beam + Megaton detector (SB+BB+MD) b) Neutrino Factory (NuFact) + magnetic detector The physics abilities of the neutrino factory are (much) superior in particular for flux normalisation but….. « what is the realistic time scale? » 3. (Hardware) cost estimate of a neutrino factory ~1B€ + detectors. This needs to be verifed and ascertained on a localized scenario (CERN, RAL…) and accounting. The cost of a (BB+SB+MD) is not very different Cost/physics performance/feasibility comparison needed

5. POFPA 18 october Alain Blondel -- Neutrino Factory -- CERN layout    e + e   _ interacts giving   oscillates e     interacts giving    WRONG SIGN MUON 10 16 p/ s 1.2 10 14  s =1.2 10 21  yr 3 10 20 e  yr 3 10 20   yr 0.9 10 21  yr

6. POFPA 18 october Alain Blondel Neutrino fluxes  + -> e + e   / e ratio reversed by switching     e   spectra are different No high energy tail. Very well known flux (aim is 10 -3 ) - absolute flux measured from muon current or by  e  ->   e in near expt. -- in race track or triangle ring, muon polarization precesses and averages out (-> calib of energy, energy spread) -- E&   calibration from muon spin precession -- angular divergence: small effect if  < 0.2/  can be monitored similar comments can be made for beta-beam, but not for superbeam.  polarization controls e flux:  + -X> e in forward direction

7. POFPA 18 october Alain Blondel Detector studies so far: Iron calorimeter Magnetized Charge discrimination B = 1 T Fiducial mass = 40 kT cut at 5 GeV muon. Baseline 3500 Km 732 Km 3.5 x 10 7 1.2 x 10 6 5.9 x 10 7 2.4 x 10 6 1.1 x 10 5 1.0 x 10 5  CC e CC  signal (sin 2  13 =0.01) Events for 1 year 2 10 20 muon decays Also: L Arg detector: magnetized ICARUS Wrong sign muons, electrons, taus and NC evts *-> CF e signal at J-PARC =40 Cervera et al Bueno et al old scheme!

8. POFPA 18 october Alain Blondel Studies and plots made so far have been based on this study by Anselmo Cervera, which is optimized for the sensitivity to very low  13. Clearly cuts should be relaxed for large values of  13.

9. POFPA 18 october Alain Blondel Lindner et al newer plot should come out of scoping study – « correlations » are sensitive to assuptions on the solar and atmospheric parameters– what will they be? ……………………………………degeneracies correlations systematics.  beam + SPL3.5 SB+Mton approval date: ~NOvA +PD  km 

10. POFPA 18 october Alain Blondel Mezzetto L=  /2.54 E/  m  l =  /2.54 E/  m  Three family oscillations look at    e oscillation

11. POFPA 18 october Alain Blondel P( e   ) = ¦A¦ 2 +¦S¦ 2 + 2 A S sin  P( e   ) = ¦A¦ 2 +¦S¦ 2 - 2 A S sin   = A CP  sin    solar term… sin  sin (  m 2 12 L/4E) sin   … need large values of sin    m 2 12 (LMA) but *not* large sin 2   … need APPEARANCE … P( e  e ) is time reversal symmetric (reactor s do not work) … can be large (30%) for suppressed channel (one small angle vs two large) at wavelength at which ‘solar’ = ‘atmospheric’ and for e  ,  … asymmetry is opposite for e   and e   P( e   ) - P( e   ) P( e   ) + P( e   ) CP violation

12. POFPA 18 october Alain Blondel T asymmetry for sin  = 1 0.1 0 0.3 0 1010 3030 9090 ! asymmetry is a few % and requires excellent flux normalization (neutrino fact., beta beam or off axis beam with not-too- near near detector ) NOTEs: 1. sensitivity is more or less independent of  13 down to max. asymmetry point 2. This is at first maximum! Sensitivity at low values of  13 is better for short baselines, sensitivity at large values of  13 is better for longer baselines (2d max or 3d max.) 3.sign of asymmetry changes with max. number. error arbitrary scale Maximum Asymmetry 6%

13. POFPA 18 october Alain Blondel Towards a comparison of performances on equal footing CP violation example = A CP  sin    solar term… sin  sin (  m 2 12 L/4E) sin   P( e   ) - P( e   ) P( e   ) + P( e   ) Near detector should give e diff. cross-section*flux BUT:need to know  and  diff. cross-section and detection efficiency with small (relative) systematic errors. interchange role of e and  for superbeam in case of beta-beam one will need a superbeam at the same energy. Will it be possible to measure the required cross sections with the required accuracy at low energies with a WBB? What is the role of the difference in mass between electron and muons? how well can we predict it? In case of sub-GeV superbeam alone how can one deal with this?

14. POFPA 18 october Alain Blondel d  /d  e,e’  E e  E e’  Enegy transfer (GeV) E e =700-1200 MeV Blue: Fermi-gas Green: SP Red: SP+FSI QE  Zeller These are for electron beam. errors are ~5-10% but what happens when a muon mass is involved?

15. POFPA 18 october Alain Blondel A discussion is necessary to establish reasonable systematic errors in measuring the CP or T asymmetry this discussion should include the following questions: 1.what kind of near detector will be needed? 2. how does one measure the cross-section*efficiency of the appearance channel in a beam with only one flavor? (superbeam or beta-beam alone) my guess: these issues will be quite serious at low energies (E ~ few m  ) and gradually become easier at high Energies. Neutrino factory provides all channels in the same beam line/detector

16. POFPA 18 october Alain Blondel CP asymmetries and matter effect compare e   to e   probabilities   is prop. to matter density, positive for neutrinos, negative for antineutrinos HUGE effect for distance around 6000 km!! Resonance around 12 GeV when  m 2 23 cos2  13   = 0

17. POFPA 18 october Alain Blondel CP violation (ctd) Matter effect must be subtracted. One believes this can be done with uncertainty of order 2%. This is potential systematic error for large values of sin 2 2  13 ! However the energy shape of matter effect and CP violation are different  It is important to subtract in bins of measured energy.  knowledge of spectrum is essential here!  low threshold is crucial since matter effect is reduced at low E while CP asymmetry changes sign from 1 st (6 GeV@300km) to 2d max (2 GeV@3000km) 5-10 GeV 10-20 GeV 20-30 GeV 30-40 GeV 40-50 GeV 40 kton L M D 50 GeV nufact 5 yrs 10 21  /yr In fact, 20-30 GeV Is enough! Best distance is 2500-3500 km De Rujula, Gavela, Hernandez

18. POFPA 18 october Alain Blondel NB: This works just as well INO ~7000 km (Magic distance)

19. POFPA 18 october Alain Blondel By 2010 we must know how much these facilities cost and how long they would take to build. 4MW, 1 Mton upgrade of T2K NUFACT with thick magnetized Iron detector in two locations 7000km and 3000 km assume 2% flux error in T2K vs. 5% matter eff. error on nufact and 5 GeV muon thres.

20. 20 Oscillation parameters can be extracted using energy distributions a)right-sign muons b)wrong-sign muons c)electrons/positrons d)positive  -leptons e)negative  -leptons f)no leptons X2 (  + stored and  - stored) Events Bueno, Campanelli, Rubbia; hep-ph/00050007 Simulated distributions for a 10kt LAr detector at L = 7400 km from a 30 GeV nu-factory with 10 21  + decays. E VIS (GeV) Note: e   is specially important (Ambiguity resolution & Unitarity test): Gomez-Cadenas et al.

21. POFPA 18 october Alain Blondel channel at neutrino factory High energy neutrinos at NuFact allow observation of  e   (wrong sign muons with missing energy and P  ). UNIQUE Liquid Argon or OPERA-like detector at 732 or 3000 km (better) Since the sin  dependence has opposite sign with the wrong sign muons, this solves ambiguities that will invariably appear if only wrong sign muons are used. ambiguities with only wrong sign muons (3500 km) equal event number curves muon vs taus associating taus to muons (no efficencies, but only OPERA mass) studies on-going A. Donini et al   

22. POFPA 18 october Alain Blondel e.g. Rigolin, Donini, Meloni

23. POFPA 18 october Alain Blondel Wrong sign muons alone Wrong sign muons and taus Wrong sign muons and taus + previous exp.

24. POFPA 18 october Alain Blondel red vs blue = different baselines dashed vs line = different energy bin (most powerful is around matter resonance @ ~12 GeV) red vs blue = muons and taus

25. POFPA 18 october Alain Blondel Conclusion: Neutrino Factory has many handles on the problem (muon sign + Gold + Silver + different baselines + binning in energy) thanks to high energy! "It could in principle solve many of the clones for    down to 1 0 The most difficult one is the octant clone which will require a dedicated analysis" (Rigolin)

26. POFPA 18 october Alain Blondel 2010 will be a time of major decisions in particle physics LHC will be completed first results will appear ILC  first results from MINOS, OPERA double-CHOOZ might be available. T2K will be starting and very rapidly dominating! It will be time for the next step in neutrino physics! TARGET DATE: 2010 Barry Barish, CERN SPC sept05

27. POFPA 18 october Alain Blondel evolution of sin 2 2  13 sensitivity observation and study of CP violation requires -- all accelerator neutrinos -- high precision in neutrino vs antineutrino normalization -- redundancy. probably out of reach of these experiments  need to go further Mezzetto

28. POFPA 18 october Alain Blondel By 2010 we must know how much these facilities cost and how long they would take to build. 4MW, 1 Mton upgrade of T2K NUFACT with thick magnetized Iron detector in two locations 7000km and 3000 km 2010 assume 2% flux error in T2K vs. 5% matter eff. error on nufact and 5 GeV muon thres.

29. POFPA 18 october Alain Blondel Design study Design study will take place in two phases 1.Scoping study: understand what are the most important parameters of the facility to be studied, what are the critical tests to be performed, and how to organize it. Assemble the team. 2. Design study: proceed to the design study and associated R&D experiments, with the aim to deliver a CDR that a laboratory can chose as its next project. For design study we intend to request EU funding – probable date spring 2007 It will be WORLD WIDE: 1. It is likely that there will be no more than one Megaton detector and/or one Neutrino Factory in the world so we better agree on what we want. 2. Expertise on Neutrino Factory is limited world-wide (mostly in US) 3. Resources e.g. at CERN are also very limited 4. International community meets regularly at NUFACT meetings and is engaged in common projects (R&D experiments) Muon cooling exp. MICE at RAL, Target Experiment nTOF11 at CERN

30. POFPA 18 october Alain Blondel Collaborators of the scoping study : -- ECFA/BENE working groups (incl. CERN) (funded by CARE) -- Japanese Neutrino Factory Collaboration -- US Neutrino Factory and Muon collider Collaboration -- UK Neutrino Factory Collaboration (also part of BENE) -- others (e.g. India INO collaboration, Canada, China, Corea...) objectives:  Evaluate the physics case for a second-generation super-beam, a beta-beam facility and the Neutrino Factory and to present a critical comparison of their performance;  Evaluate the various options for the accelerator complex with a view to defining a baseline set of parameters for the sub-systems that can be taken forward in a subsequent conceptual-design phase;  Evaluate the options for the neutrino detection systems with a view to defining a baseline set of detection systems to be taken forward in a subsequent conceptual-design phase. ~400-500 persons

31. POFPA 18 october Alain Blondel Detectors (NEW!) 1. Water Cherenkov (1000kton) 2. Magnetic sampling detector (100kton) 3. Liquid Argon TPC (100 kton) magnetized Liquid Argon TPC (15kton) 4. Hybrid Emulsion (4 kton) 5. Near detectors (and instrumentation) ( SB,BB or NF ) Physics compare performance of various options on equal footing of parameters and conventions and agreed standards of resolutions, simulation etc. identify tools needed to do so (e.g. Globes upgraded) propose « best values » of baselines, beam energies etc.. Accelerator: -- proton driver (energy, time structure and consequences) -- target and capture (chose target and capture system) -- phase rotation and cooling -- acceleration and storage evaluate economic interplays and risks include a measure of costing and safety assessment Yorikiyo Nagashima Alain Blondel Michael Zisman coordination Peter Dornan + ‘wise men’ Ken Peach Vittorio Palladino(BENE) Steve Geer Yoshitaka Kuno

32. POFPA 18 october Alain Blondel Time scales: NUFACT05 26 June 2005 launch of scoping study CERN 22-24 September 2005 first meeting KEK 23-25 January 2006, RAL 27-29 April 2006 (BENE) (2-6 may meeting on the future of CERN in DESY-Zeuthen) UC Irvine 21-23 August 2006 (just before NUFACT06) NUFACT06 (summer 2006) discussion of results of scoping study September 2006 ISS report 2007 full design study proposal submission to EU as design study. 2010 conclusions of Design Study & CDR NB: This matches well the time scales set up at CERN – participation of CERN is highly desirable to ensure that the choices remain CERN-compatible. This effort is similar to and synergetic with the PAF and POFPA working groups at CERN. NNBB we will try to have an available report at each ISS meeting.

33. POFPA 18 october Alain Blondel Progress The performance plots shown earlier mostly based on 2000-2002 ECFA study. Much progress has been gathered since then. 1.accelerator performance: study II-a (2004): use of RF phase rotation leads to capture of both mu+ and mu- global improvement by factor 4.8 (also reduction of cost to ~1G€ from 1.6)  at 4MW on target, collect 9.6 10 20 muon decays of one sign at a time in a 10 7 s year in a racetrack geometry in triangle geometry each straight gets 2/3 of this number. 2. detector performance:. proposal (Nelson) of a 90 kton (was 40kton) detector with 4 times better granularity. Expect threshold for muons to ~1.5 GeV for similar sign resolution. Cost estimate. Electron ID? Tau detection?. operation of (10 liters) Larg prototype in 0.5 T mag. Field.. tau detectors should be feasible with ~4 times OPERA mass (4 kton)

34. POFPA 18 october Alain Blondel PROGRESS 3.Accelerator R&D A. Target experiment nTOF11 MERIT is approved at CERN (Data taking 2007) B. MICE experiment approved at RAL C. PRISM experiment (low energy muon FFAG) is approved at Osaka D. 2004 study re-evaluated cost of NUFACT

35. POFPA 18 october Alain Blondel Some Highlights of the first Scoping Study meeting CERN 22-24 september 2005 see transparencies at: http://dpnc.unige.ch/users/blondel/ISSatCERN.htm register at http://www.hep.ph.ic.ac.uk/iss/http://www.hep.ph.ic.ac.uk/iss/ 1.first presentation of the preliminary study for the Fréjus underground laboratory 2.presentation of « feasible » 90 kton fine-grained magnetized iron calorimeter for ~200M€ (same cost basis as NOvA) 3.first observation of tracks in the magnetized liquid argon prototype 4.presentation of upgraded performance estimate for the neutrino factory 10 21 muon decays per year per direction! and status of beta-beam study. 5.planning of implementation of all sorts of detectors in a common oscillation program GLOBES 6. performance vs primary proton energy

36. POFPA 18 october Alain Blondel need to add cost of electronics, cavern and water treatment  ~1G€ do we need so many tubes?  R&D for photodetectors!!! Japan-France collaboration collaboration with industry (Photonis) Megaton Water Cherenkov (J.-E. Campagne) + HV, electronics, etc..! the largest single cavern is 4XSK.

37. POFPA 18 october Alain Blondel

38. alternatively could simply add a large magnet to a NOvA-like design! (cost?) Jeff Nelson

39. POFPA 18 october Alain Blondel 10 liters prototype liquid argon TPC has been tested in 0.5 T at ETHZ A. Rubbia

40. POFPA 18 october Alain Blondel $$$$$ … COST … $$$$$ USA, Europe, Japan have each their scheme for Nu-Fact. Only one has been costed, US 'study II' and estimated (2001) ~2B$. The aim of the R&D is also to understand if one could reduce cost in half. Neutrino Factory CAN be done…..but it is too expensive as is. Aim of R&D: ascertain challenges can be met + cut cost in half. + detector: MINOS * 10 = about 300 M€ or M$

41. 41 Why we are optimistic: We are working towards a “World Design Study” with an emphasis on cost reduction. In the previous design ~ ¾ of the cost came from these 3 equally expensive sub-systems. New design has similar performance to Study 2 performance and keeps both  + and  - ! (RF phase rotation) S. Geer: NUFACT 2004: cost can be reduced by at least 1/3 = proton driver + 1 B € ==>the Neutrino Factory is not so far in the future after all… $$$$$ … COST … $$$$$

42. POFPA 18 october Alain Blondel Total Yield of  + and  − Normalised to unit beam power Yields (on a tantalum rod) using MARS15 and GEANT4. Better to include the acceptance of the next part of the front end  protons on heavy target (good for pi-) (-30%)

43. POFPA 18 october Alain Blondel Phase Rotator Transmission (MARS15) Optimum moves down because higher energies produce pions with momenta too high for capture Doubled lines give some idea of stat. errors Somewhat odd behaviour for π + < 3GeV The discontinuity between 3-5 GeV is suspicious as it corresponds to change of model in MARS (there is no real physics reason) HARP data will be available end 2005-early 2006 at 3 GeV/c(2.2 GeV), 5 GeV/c (4.15 GeV), 8 GeV/c (7.1 GeV) optimum 5-10 GeV. Within 30% of optimum: 4-40 GeV

44. POFPA 18 october Alain Blondel Conclusions 1.The Neutrino Factory remains the most powerful tool imagined so far to study neutrino oscillations Unique: High energy e   and  e   transitions at large   has the precision at small   has the sensitivity Much progress can be envisaged in performance wrt early studies. 2. The complex offers many other possibilities (muons!) 3. It is a step towards muon colliders 4. There are good hopes to reduce the cost significantly thus making it an excellent option for CERN in the years 2011-2020 5. Regional and International R&D on components and R&D experiments are being performed by an enthusiastic and motivated community International scoping study underway. 6. Opportunities exist in Europe and CERN: HI proton driver, (CERN), Target experiment @ CERN, Collector @CERN MICE @ RAL

45. POFPA 18 october Alain Blondel 7. need to understand the best synergy between a neutrino programme and the LHC lumi upgrade. 8. I would consider that re-instating a neutrino factory development team at CERN to be a high priority for the 2006-2010 period! 9. there is quite a variety of detectors and experimental (near and far) areas to design, which are well fit to CERN’s Experimental teams compentence. Conclusions:

46. POFPA 18 october Alain Blondel Superbeam+Betabeam option 1.What is the importance of the superbeam in this scheme? T violation? increased sensitivity? have a (known) source of muon neutrinos for reference? 2. At which neutrino energy can one begin to use the event energy distribution? Fermi motion and resolution issues. What is the impact of muon Cherenkov threshold? 3.What is the best distance from the source? What is the effect of changing the beta-beam and superbeam energy? (event rates, backgrounds, ability to use dN/dE ) Should energy remain adjustable after the distance choice? 4, what is the relationship between beta-beam energy vs intensity? 5. What is really the cost of the detector? what PM coverage is needed as function of energy and distance. NB superbeam requires 4 MW proton driver, beta-beam claim to be able to live with 200 kW!

47. POFPA 18 october Alain Blondel Questions for Neutrino Factory experiments: 1.Do we REALLY NEED TWO far locations at two different distances? Muon momentum cut at 4 GeV cuts 2d max info. 2.3000 km  1st osc. max at 6 GeV and 2d max at 2 GeV. Muon momentum cut at 4 GeV cuts 2d max info. Can this be improved? 3.Can we eliminate all degenracies by combination of energy distribution and analysis of different channels (tau, muon, electron, both signs, NC…) 4.what are the systematics on flux control? (CERN YR claims 10 -3 ) 5. optimal muon ENERGY? Cost of study II was 1500M$ + 400M$*E/20