1. Preparation of design study ICL may 2005 Alain Blondel Future Neutrino Oscillation Experiments: Physics studies Towards a comparison of options on equal footing Defining the next steps Aim of this presentation is to trigger discussion The ECFA/BENE Working groups (several 100 authors since 1998) recently published ‘ECFA/CERN studies of a European Neutrino Factory Complex' CERN 2004-002 ECFA/04/230 and Physics with a MMW proton driver (MMW workshop) +The beta beam working group beta-beam and high power target studies within EURISOL DESIGN STUDY (Lindroos + Lettry)

2. Preparation of design study ICL may 2005 Alain Blondel I Questions from JJ Gomez-Cadenas et al.

3. Preparation of design study ICL may 2005 Alain Blondel T2K-II zNeeds a very serious upgrade of proton driver, to 4 MW. It is unclear today how feasible/easy/costly is to do that. zIt requires a MTON class detector. zCannot “move” before T2K-I sees a signal. Building the detector will take 5 years at least. Cannot start before 2020 *), probably zIt is still a conventional beam, affected by the usual systematics on intrinsic background, beam shape and normalization. *) NB(AB) Nakamura said 2023 at NUFACT04 – this is telling of the timescale of such a megaton project.

4. Preparation of design study ICL may 2005 Alain Blondel Beta-Beam zA design based on low gamma has been studied over the last 1-2 years. zA design that uses the CERN SPS has a limit on gamma 150 (He6) and 250 (Ne18/19). zA design based on the Tevatron can reach a gamma of about 500(Ne18/19) zRequires Mton class detector. zIt does not need to wait for T2K-I to start. Experiment could start as early as 2015, about 10 years from now. NB (AB) the time scale is somewhat optimistic here too.

5. Preparation of design study ICL may 2005 Alain Blondel Options Compared (I) Option b and c always much better than option a Option b and c very similar for  13  sensitivity

6. Preparation of design study ICL may 2005 Alain Blondel Neutrino Factory zDesign improving with time, but always challenging zNeeds “only” “conventional” detectors (Minos x 10, Opera x 2-5) zTau *and* muon appearance + energy binning = best tools against degeneracies. zMeasures with great precision atmospheric parameters. Can also measure matter effects what is the realistic time scale? zIt still seems the best neutrino machine around. But what is the realistic time scale?

7. Preparation of design study ICL may 2005 Alain Blondel 3 sigma reach on CP violation (achievable is above the curve) Mezzetto NuFact BuRget et al NB: for large values of  13 the sensitivity of NUFACT depends on precision with which matter effects are understood! (here has 4 GeV thresh and 2% syst. uncertainty)

8. Preparation of design study ICL may 2005 Alain Blondel The Beta-Beam offers an alternative/complement to the Neutrino Factory. Different technology, different systematic errors and different E/L. It needs for ultimate sensitivity 1Mton class detector. such a detector has a great physics potential (proton decay, supernova observatory) of their own, but it is extraordinarily challenging to build It cannot provide by itself measurement of atmospheric parameters, and the lower-gamma options cannot measure matter effects. No tau appearance. A careful assessment of the relative merits of the Beta-Beam versus NUFACT is necessary Conclusions from JJ

9. Preparation of design study ICL may 2005 Alain Blondel The situation as I see it is as follows. In 2011 LHC will be running and paid, and CERN does not have a credible plan. CLIC is not going to happen so soon and the sub-TeV linear collider will probably happen elsewhere. If the sub-TeV linear collider happens, CLIC will not begin seriously until the other one has already been exploited; and If the sub-TeV linear collider does not happen it may mean that CLIC is not worth building either (although it can be rescued in some scenarios). Conclusion: there is a gap at CERN in the years 2011-20XX where my middle estimate for XX is >=20. (very personal) CERN-centric view: The leading contender for filling this gap is a high intensity neutrino programme. Which one? Package 1: neutrino factory + near detectors + far magnetic detectors (LMD, Larg, tau) Package(s) 2: superbeam + beta beam + large water Cherenkov Mton or large Larg

10. Preparation of design study ICL may 2005 Alain Blondel A bit of explanation: Why is it that now we are placing these options as alternative and not in sequence? (  decisions are more painful) A. The time window is limited B. We may not have another shot C. The cost estimate for Neutrino factory has been reduced considerably (and design simplified, and flux doubled) D. The timeline has shifted somewhat Caveats: the fact that either a neutrino factory or a 1 Mton Water Cherenkov is ready to be built in 2011 is highly non-trivial! (not to mention the Large Liquid Argon detector) These aspects of feasibility need demonstration

11. Preparation of design study ICL may 2005 Alain Blondel CERN and… the ‘scoping-study’ for a future accelerator neutrino complex 0. does CERN decide to play a role in ‘scoping study’? 1.who from CERN goes to meeting 6/7 May at ICL? 2.who represents/coordinates CERN efforts on -- accelerator -- detector studies -- phenomenological studies 3.ENCOG? if yes, who is in charge of assembling it? 4. CERN position?

12. Preparation of design study ICL may 2005 Alain Blondel 0. does CERN decide to play a role in ‘scoping study’? A. Yes, CERN will be involved. There are however very limited resources until 2008. CERN will supports the nTOF11 experiment and the CARE and EURISOL studies. +recognised MICE and will provide RF source hardware. 1.who from CERN goes to meeting 6/7 May at ICL? A. Leslie Camillieri will be coming as CERN representative. 2. who represents/coordinates CERN efforts on -- accelerator -- detector studies -- phenomenological studies A. it was felt too early to fill these names, but names will be given. 3.3. ENCOG? if yes, who is in charge of assembling it? A. this is felt to be somewhat premature. 4. CERN position? CERN fully supports the scoping study under the condition that it is performed within the framework of BENE.

13. Preparation of design study ICL may 2005 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

14. Preparation of design study ICL may 2005 Alain Blondel NB: This works just as well

15. Preparation of design study ICL may 2005 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 700 or 3000 km. 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

16. Preparation of design study ICL may 2005 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 effect of changing the beta-beam and superbeam energy at fixed length? On event rates, backgrounds, ability to use dN/dE (is there interest in keeping this parameter variable?) 4, what is the relationship between beta-beam energy vs intensity? 5. What is really the cost of the detector? what coverage is neded as function of energy and distance. NB superbeam requires 4 MW proton driver, beta-beam claim to be able to live with 200 kW!

17. Preparation of design study ICL may 2005 Alain Blondel Regarding the comparisons, in my view we are still missing a lot of pieces: -- A stable realistic setup for NuFact: muon energy, muon fluxes, baselines, golden+golden, golden+silver, Icarus like etc. -- A stable realistic setup for beta beam: optimal gamma, fluxes, baseline -- A detailed study of detector performances. For water we have parameters from SK. For the magnetic detector we should have Minos parameters. For emulsions and liquid argon we should have Opera and Icarus. This topic could be named « build a set of Globes AEDL files describing detector performances in the most accurate possible way ». -- A realistic and accepted set of measured parameters at the time when the future facilities will start. It makes no sense to assume we will not know the precise value of the atmospheric parameters in 10 years from now, it should be agreed the level of precision of the solar parameters after the end of SNO and Kamland (and hopefully Borexino). This topic is far from trivial because additional and new analysis from atmospherics, data for Nova if any etc. could help very much in solving degeneracies. -- A study of performances using the same set of assumptions: systematic errors, degeneracies, ambiguities etc. This can be done already now by using Globes, and I'm consuming my time in trying to use it. From Mauro Mezzetto:

18. Preparation of design study ICL may 2005 Alain Blondel Proposed milestones -- DRAFT A.Blondel 6-5-2005— 04 2005today 6/7 05 2005meeting in London define overall content and planning of DS produce draft report 27 May 2005report to RAL CEO should be delivered to CERN DG/CSO, ECFA (as well and ENCOG?) (ENCOG = European Neutrino Coordination Group need rep from big labs and funding agencies) 21-26 June 2005 NUFACT05 launch 1 st yearly DS will invite ENCOG ? initiate DSreport1 from NUFACT05 scientific content this report is ‘where do we stand’ and ‘list of questions’, should identify critical issues October 2005 DS meeting 2 DSreport1 is produced End 2005 SPL CDR2 Jan/feb 2006 DS meeting 3 June 2006NUFACT06 UCI (Ca, USA) prepare DSreport2 this report is essentially an extended reference book from which first draft of DS proposal can be extracted

19. Preparation of design study ICL may 2005 Alain Blondel October 2006 EU FP7 DS town meeting public presentation of DSreport2 Dsreport2 is input to CERN discussions October 2006 EU FP7 DS call end 2006 CERN foresees to decide on linac4 and on plans for R&D in 2007-2010 March 2007 submission of FP7 DS bid : Neutrino superbeam and factory DS include detector R&D and phys. studies.(SITE?) spring 2007 MICE and target experiment start in April 2007 etc… Summer 2007 NUFACT07(Japan) Summer 2007 FP7 DS bid for Neutrino superbeam and factory DS approved? fall 2007 LHC starts January 2008 EU funding for Neutrino superbeam and factory DS starts?

20. Preparation of design study ICL may 2005 Alain Blondel Summer 2008 NUFACT08 (Geneva?) 2008results from target experiment summer 2009 MICE reports observation of Ionization cooling summer 2009 NUFACT09 (US) Although this is only half way through the FP7 DS, one should produce a report. This could be the NF-CDR or MT-CDR produced as result of WDStudy III 2009 -2010 CERN decides on next large project for years 2011-2020 end 2011 end of FP7 Design study. produce NF-TDR or MT-TDR 2011begin construction?

21. Preparation of design study ICL may 2005 Alain Blondel How to get there? Build the Neutrino Factory as soon as possible Numi/CNGS, Off-Axis Beams, SuperBeams, Beta Beam, Neutrino Factory The Fast TrainThe Slow Train

22. Preparation of design study ICL may 2005 Alain Blondel How to choose? The Fast Train zAdvantages yfastest route x(possibly) ycheapest route x(possibly) zDisadvantages ymoney x(big commitment) ypolitics x(related to money) The Slow Train zAdvantages yincremental x(duplication?) ylower risk x(e.g. if no CPV) zDisadvantages ycosts more x(duplication) ymay never get there x(why measure better?)

23. Preparation of design study ICL may 2005 Alain Blondel

24. Preparation of design study ICL may 2005 Alain Blondel Combination of beta beam with low energy super beam Unique to CERN: need few 100 GeV accelerator (PS + SPS will do!) experience in radioactive beams at ISOLDE many unknowns: what is the duty factor that can be achieved? (needs < 10 -3 ) combines CP and T violation tests e   (  +) (T)    e (  + ) (CP) e   (  -) (T)    e (  - )

25. 25 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 € MAYBE the Neutrino Factory is not so far in the future after all…. $$$$$ … COST … $$$$$

26. Preparation of design study ICL may 2005 Alain Blondel Where will this get us… comparison of reach in the oscillations  right to left: present limit from the CHOOZ experiment, expected sensitivity from the MINOS experiment, CNGS (OPERA+ICARUS) 0.75 MW JHF to super Kamiokande with an off-axis narrow-band beam, Superbeam: 4 MW CERN-SPL to a 400 kton water Cerenkov in Fréjus (J-PARC phase II similar) from a Neutrino Factory with 40 kton large magnetic detector. 0.1 0 1010 2.5 0 5050 13 0 Mezzetto X 5

27. Preparation of design study ICL may 2005 Alain Blondel T asymmetry for sin  = 1 0.1 0 0.3 0 1010 3030 9090 JHFI-SK ! asymmetry is a few % and requires excellent flux normalization (neutrino fact., beta beam or off axis beam with not-too- near near detector ) JHFII-HK neutrino factory NOTE: This is at first maximum! Sensitivity at low values of  13 is better for short baselines, sensitivity at large values of  13 may be better for longer baselines (2d max or 3d max.) This would desserve a more careful analysis!

28. Preparation of design study ICL may 2005 Alain Blondel Slide reserved to collect questions and suggestions from the group on neutrino factory Q

29. Preparation of design study ICL may 2005 Alain Blondel Slide reserved to collect questions and suggestions from the group on super- beam/beta-beam Q

30. Preparation of design study ICL may 2005 Alain Blondel T2K-II Sensitivity to  

31. Preparation of design study ICL may 2005 Alain Blondel BB: Scenarios Option a: SPS-Frejus gamma 60 ( 6 He 2+ )/100 ( 18 Ne 10+ ) Option b: SPS-limit gamma 150/250 at 300 km Option c: Tevatron-Soudan gamma=350/500

32. Preparation of design study ICL may 2005 Alain Blondel Options Compared Option b and c always much better than option a Option b and c very similar for  13  sensitivity Option c sees matter effects

33. Preparation of design study ICL may 2005 Alain Blondel Option c (gamma 500) sees matter effects

34. Preparation of design study ICL may 2005 Alain Blondel Superbeam only Beta-beam only Betabeam + superbeam 3 sigma sensitivity of various options NUFACT

35. Preparation of design study ICL may 2005 Alain Blondel NUFACT Superbeam only Beta-beam only Betabeam + superbeam Upgrade 400kton-> 1 Mton J-PARC HK 540 kton? 3 sigma sensitivity of various options