NuFact 03 5th International Workshop on Neutrino Factories & Superbeams

1. 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. NUFACT03 Highlights 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?

3. Miniboone p0 peak

4. 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 9th July (?)

5. q13 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. q13 • Superbeam possibilities • 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 km3 detector) • 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. NuMI Off-axis Detector Low Z imaging calorimeter: • Glass RPC or • Drift tubes or • Liquid or solid scintillator Electron ID efficiency ~ 40% while keeping NC background below intrinsic ne 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 sin22q13 at the CHOOZ limit, or • 3s evidence if sin22q13 factor 10 below the CHOOZ limit (normal hierarchy, d=0), or • Factor 20 improvement of the limit Para

8. Para

9. 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. BNL  Homestake Super Neutrino Beam Homestake BNL 2540 km 28 GeV protons, 1 MW beam power 500 kT Water Cherenkov detector 5e7 sec of running, Conventional Horn based beam Diwan

11. Advantages of a Very Long Baseline  neutrino oscillations result from the factor sin2(Dm322L / 4E) modulating the n flux for each flavor (here nm 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 Dm322 to be precisely measured by a wavelength rather than an amplitude (reducing systematic errors) Diwan

12. ne Appearance Measurements  a direct measurement of the appearance of nmneis important; the VLB method competes well with any proposed super beam concept  for values > 0.01, a measurement of sin22q13 can be made (the current experimental limit is 0.12)  for most of the possible range of sin22q13, a good measurement of q13and the CP-violation parameter dCP can be made by the VLB experimental method Diwan

13. ne Appearance Measurements (Cont.) even if sin22q13 = 0, the current best-fit value of Dm212 = 7.3x10-5 induces a ne appearance signal  the size of the ne appearance signal above background depends on the value of Dm212; the figure left indicates the range of possible measured values for the ne yields above background for various assumptions of the final value of Dm212 Diwan

14. very long baseline proposal (BNL homestake mine) • -- interest: CP violation and sign Dm213 from 1st to second peak comparison • -- energy dependence helps extracting the physics • criticisms: • very large mass required to reach decent sensitivity (1/L2 dependence hurts) • possibility of detecting ne signal at > 1-2 GeV seriously criticized