1. Summary of Nufact-03 Alain Blondel NuFact 03 5th International Workshop on Neutrino Factories & Superbeams Columbia University, New York 5-11 June 2003 Highlights and personnal impressions http://www.cap.bnl.gov/nufact03/

2. Summary of Nufact-03 Alain Blondel first results from miniboone first results from MUSCAT! theta13 prospectives (reactor proposals!) the issue of degeneracies beta beam getting close in performance to neutrino factory?! Nufact: death of bow-tie machine part: MICE strongly recommended – in approval path status of target status of RF cavity studies status of accelerator design FFAG!!!! Cooling ring!!!! to cool or not to cool? cost saving hopes WORLD STUDY III synergies: emphasis on low energy muon and high intensity physics personnal reflexions: Europe’s strengths two avenues for Europe: when should we chose? NUFACT03 Highlights

3. Summary of Nufact-03 Alain Blondel   peak Miniboone

4. Summary of Nufact-03 Alain Blondel MUSCAT an important experiment to re-measure multiple scattering for low Z materials (discrepancies between theories and theory vs expt) engineering run 2000… several teething problems 2. new measurements in spring 2003 at Triumf with many improvements (sci-Fi tracker!) 2003 Physics run all went very well –46M events taken; LH2 as well as solid targets –First look at data: very good; Analysis just starting First results: ENG meeting 9 th July (?)

5. Summary of Nufact-03 Alain Blondel  J Louis  approved (MINOS, OPERA, ICARUS) programme on approval path (J-PARC  SK) will lead to improvement vs CHOOZ by factor 2-3 (MINOS, ICARUS+OPERA with tau optimized beam) by factor 5 specially optimized L.E beam for ICARUS by factor 20 J-PARC  SK what else?

6. Summary of Nufact-03 Alain Blondel  Superbeam possibilities 1.J-PARC  SK (2008 onwards) J-PARC  HK (1 Mton) will not begin excavation before results from J-PARC  SK are obtained 2011? also hopes to increase intensity from 0.7 MW to 4 MW. 2. Off-axis NUMI beam exists with required flexibility detector design in progress – will lead to a LOI in the fall near detector. (how can this be in time to be competitive???) 2’. CNGT: need beam (not CNGS) and detector. Detector viability? (single wall is ‘technologically risky’) + interesting: what is the physics of an off axis at the second osc. max? - no near detector NB similar idea had been put forward by Susuki in 2000 in an immersed super-tanker. both 2 and 2’ are dedicated detectors that can do nothing else as such. (CNGT could be re-deployed as km 3 detector) 3.BNL  homestake mine 4. SPL + beta beam  Frejus a very serious contender iff beta beam can perform as advertised. (almost a neutrino factory!) ecavation could start in 2008 (better get our act together!) the most consistent scheme for a CERN based effort!  support SPL + propose the Fréjus International Laboratory

7. Summary of Nufact-03 Alain Blondel NuMI Off-axis Detector Low Z imaging calorimeter: yGlass RPC or yDrift tubes or yLiquid or solid scintillator Electron ID efficiency ~ 40% while keeping NC background below intrinsic e level Well known and understood detector technologies Primarily the engineering challenge of (cheaply) constructing a very massive detector How massive?? 50 kton detector, 5 years run =>  10% measurement if sin 2 2  13 at the CHOOZ limit, or  3  evidence if sin 2 2  13 factor 10 below the CHOOZ limit (normal hierarchy,  =0), or zFactor 20 improvement of the limit Para

8. Summary of Nufact-03 Alain Blondel NuMI Off-axis 50 kton, 85% eff, 5 years, 4x10 20 pot/y JHF to SK Phase I, 5 years allAfter cutsallAfter cuts   CC (no osc)283486.8107141.8 NC865019.440809.3 Beam e 60431.229211 Signal (  m 2 23 =2.8x 10 -3,      NuMI/JHF) 867.3307.9302123 FOM (S/sqrt(B))40.726.2 Para

9. Summary of Nufact-03 Alain Blondel Determination of mass hierarchy: complementarity of JHF and NuMI Combination of different baselines: NuMI + JHF extends the range of hierarchy discrimination to much lower mixing angles Minakata,Nunokawa, Parke Para

10. Summary of Nufact-03 Alain Blondel BNL  Homestake Super Neutrino Beam 2540 km Homestake BNL 28 GeV protons, 1 MW beam power 500 kT Water Cherenkov detector 5e7 sec of running, Conventional Horn based beam Diwan

11. Summary of Nufact-03 Alain Blondel Advantages of a Very Long Baseline  neutrino oscillations result from the factor sin 2 (  m 32 2 L / 4E) modulating the flux for each flavor (here  disappearance)  the oscillation period is directly proportional to distance and inversely proportional to energy  with a very long baseline actual oscillations are seen in the data as a function of energy  the multiple-node structure of the very long baseline allows the  m 32 2 to be precisely measured by a wavelength rather than an amplitude (reducing systematic errors) Diwan

12. Summary of Nufact-03 Alain Blondel e Appearance Measurements  a direct measurement of the appearance of   e is important; the VLB method competes well with any proposed super beam concept  for values > 0.01, a measurement of sin 2 2  13 can be made (the current experimental limit is 0.12)  for most of the possible range of sin 2 2  13, a good measurement of  13 and the CP-violation parameter  CP can be made by the VLB experimental method Diwan

13. Summary of Nufact-03 Alain Blondel e Appearance Measurements (Cont.)  even if sin 2 2  13 = 0, the current best-fit value of  m 21 2 = 7.3x10 -5 induces a e appearance signal  the size of the e appearance signal above background depends on the value of  m 21 2 ; the figure left indicates the range of possible measured values for the e yields above background for various assumptions of the final value of  m 21 2 Diwan

14. Summary of Nufact-03 Alain Blondel very long baseline proposal (BNL  homestake mine) -- interest: CP violation and sign  m 2 13 from 1st to second peak comparison -- energy dependence helps extracting the physics criticisms: 1.very large mass required to reach decent sensitivity (1/L 2 dependence hurts) 2.possibility of detecting e signal at > 1-2 GeV seriously criticized

15. Summary of Nufact-03 Alain Blondel BETA BEAMS Concept proposed by Piero Zucchelli Produce radioactive ions (ISOL technique) Accelerate them in the CERN accelerator complex up to  of order 100 Store ions in a storage ring with long straight sections aimed at a far detector Advantages strongly focussed neutrino beam due to small Q value of beta decays (quality factor  /Q) very pure flavour composition (   contamination ~ 10 -4 ) perfectly known energy spectrum Baseline scenario studied at CERN (Mats Lindroos and collaborators) Recent progress presented at a special workshop at Moriond Possible synergy between beta beams and EURISOL Updated study of expected performances (Mauro Mezzetto)

16. Summary of Nufact-03 Alain Blondel A new idea for the ion source: using a pulsed ECR source Idea proposed by Pascal Sortais at Moriond workshop Based on experimental work done at Grenoble with Phoenix => High density/high frequency plasmas allow to produce efficiently short bunches (20  s instead of 20 ms) of ions with a high repetition rate (16 Hz) by pulsing the RF and the HV Advantages: Ions are already very well bunched and (hopefully) totally stripped This simplifies considerately the design downstream: Possibility to use a LINAC rather than a cyclotron or a FFAG Multiple turn injection in the storage ring becomes possible (40 turns)

17. Summary of Nufact-03 Alain Blondel New RFQ LINAC 3 PSB Simplification of the injection system P. Sortais, Moriond workshop

18. Summary of Nufact-03 Alain Blondel sin 2  13 0.0003 0.001 0.003

19. Summary of Nufact-03 Alain Blondel    and  measurements using superbeam and betabeam SPL: 2 years in  + 8 years in anti  BETABEAM: 10 years of 6 He AND 18 Ne (Mauro Mezzetto)

20. Summary of Nufact-03 Alain Blondel UPDATED CP sensitivity : domain of 99% CL effect for maximal CP violation

21. Summary of Nufact-03 Alain Blondel Future Measurement of sin 2 2  13 at Nuclear Reactors Jonathan Link Columbia University June 6, 2003 ′03

22. Summary of Nufact-03 Alain Blondel Krasnoyarsk, Russia (hep-ex/0211070) 115m 1000m Completely underground facility was used by the Soviets for weapons production. One ~2 GW reactor Two 50 ton detectors Near detector at 115 meters Far detector at 1000 meters About 60 days of reactor off running per year. ~100 GW·tons (4 years → ~0.02)

23. Summary of Nufact-03 Alain Blondel near far Kashiwazaki, Japan (hep-ph/0211111) 7 Reactors, 24 GW thermal (most powerful site in the world) Three ~8 ton detectors Two near detectors at baselines of 300 to 350 meters One far detector at ~1300 meters ~190 GW·tons See O. Yasuda in WG1 today at 16:00

24. Summary of Nufact-03 Alain Blondel Possible U.S. Sites Top 30 U.S. Sites by Power Performance Most U.S. sites have one or two reactors. One and two reactor sites are conceptually easier: only one baseline. (The experiment can be done at multi- reactor sites.) U.S. two reactor sites are among the best in the world in power performance. ~350 GW·tons (with a 50 ton detector) Many U.S. sites have other favorable qualities such as potential for shielding. The challenge will be getting reactor operators to agree to work with us!

25. Summary of Nufact-03 Alain Blondel What is the Right Way to Make the Measurement? Start with the Systematics and Work Backwards… CHOOZ Systematic Errors, Normalization Near Detector Identical Near and Far Detectors Movable Detectors  Veto and Neutron Shield CHOOZ Background Error BG rate 0.9% Statistics may also be a limiting factor to the sensitivity.

26. Summary of Nufact-03 Alain Blondel Movable Detector Scenario The far detector spends about 10% of the run at the near site where the relative efficiency of the two detectors is measured head-to-head. The detectors must be well underground to reduce the cosmic rate. So the near and far sites need to be connected by a tunnel!

27. Summary of Nufact-03 Alain Blondel Detector Tunnel Wall Larger version of CHOOZ (smaller KamLAND) Homogenous Volume Viewed by PMT’s Gadolinium Loaded, Liquid Scintillator Target Pure Mineral Oil Buffer In the Movable Scenario Rail System for Easy Transport Carries Electronics and Front-end DAQ. Detector Design

28. Summary of Nufact-03 Alain Blondel Systematic Error from Backgrounds At sites with more than one reactor there is no reactor off running, so other ways of measuring the backgrounds are needed. The toughest background comes from fast neutrons created by cosmic  ’s. They can mimic the coincidence signal by striking a proton and then capturing. 1.Build it deeper (hard to do!) 2.Veto  ’s and shield neutrons (effective depth) 3.Measure the recoil proton energy and extrapolate into the signal region. Veto Detectors p n   n

29. Summary of Nufact-03 Alain Blondel Conclusions and Prospects The physics of sin 2 2  13 is interesting and important. An international proto-collaboration has been formed to work towards a proposal by 2005 (and a white paper this fall). The search for a suitable reactor site is underway. Controlling the systematic errors is the key to making this measurement. Reactor sensitivities are comparable off-axis and the two methods are complementary. With a 3 year run, the sensitivity in sin 2 2  13 could reach 0.01 (90% CL) at  m 2 = 2.5×10 -3.

30. Summary of Nufact-03 Alain Blondel Degeneracies

31. Summary of Nufact-03 Alain Blondel JJ and several others: neutrino factory Golden + silver (taus) + likely existing info from superbeam will solve ambiguities.