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

15. BETA BEAMS • Concept proposed by Piero Zucchelli • Produce radioactive ions (ISOL technique) • Accelerate them in the CERN accelerator complex up to G 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 G/Q) • very pure flavour composition ( n m 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. 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 ms 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. New RFQ LINAC 3 PSB Simplification of the injection system P. Sortais, Moriond workshop

18. sin2 q13 0.0003 0.001 0.003

19.  13and d measurements using superbeam and betabeam SPL: 2 years in nm + 8 years in anti nm BETABEAM: 10 years of 6He AND18Ne (Mauro Mezzetto)

20. UPDATED CP sensitivity : domain of 99% CL effect for maximal CP violation

21. Future Measurement of sin22q13 at Nuclear Reactors Jonathan Link Columbia University June 6, 2003 ′03

22. Krasnoyarsk, Russia (hep-ex/0211070) • 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) Completely underground facility was used by the Soviets for weaponsproduction. 1000m 115m

23. Kashiwazaki, Japan (hep-ph/0211111) • 7 Reactors, 24 GWthermal (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 far near near

24. 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. 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 m Veto and Neutron Shield CHOOZ Background Error BG rate 0.9% Statistics may also be a limiting factor to the sensitivity.

26. 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. Detector Design • 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 Tunnel Wall

28. Systematic Error from Backgrounds Veto Detectors p n n m m 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 m’s. They can mimic the coincidence signal by striking a proton and then capturing. • Build it deeper (hard to do!) • Veto m’s and shield neutrons (effective depth) • Measure the recoil proton energy and extrapolate into the signal region.

29. Conclusions and Prospects • The physics of sin22q13 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 sin22q13 could reach 0.01 (90% CL) at Dm2 = 2.5×10-3.

30. Degeneracies

31. JJ and several others: neutrino factory Golden + silver (taus) + likely existing info from superbeam will solve ambiguities.

32. Neutrino Factory: the Japanese Scenario now more thoroughly simulated based on FFAG physics all the way: low E muons g-2 muons, low energy NuFact, 20 GeV NUFACT… Other notable difference wrt US and EU scheme Energy for capture is higher (0.4 +- 0.2 kinetic GeV) (50 GeV proton source + optimization) SUPPORTED! Ekin Time COOLING is not necessary…. but brings a factor in intensity of >> 2! Japan (Osaka & KEK) are active members of MICE!

33. Muon Physics Programs & Staging Scenario • High Power Proton Driver • Muon g-2 • Pion Capture (MECO) • Muon LFV Physics outcomes at each stage • Muon Factory (PRISM) • Muon LFV • Muon Factory-II (PRISM-II) • Muon EDM • Muon g-2 • Neutrino Factory • Muon Collider

34. NB: a standard cyclotron would be MUCH smaller and inexpensive but would have much smaller acceptance and could not be scaled up to higher energies. Yoshi Mori

35. Yoshi Mori

36. PRISM PRISM ring construction has been approved. PRISM=Phase Rotated Intense Slow Muon source • Specifications • muon intensity: 1011~1012 /sec • central momentum: 67-120 MeV/c • momentum width: 3 % (<--- 30 %） • phase rotation approx 5 M$

37. US MC (Neutrino Factory and Muon Collider collaboration) highlights *** target studies already advertised. mercury jet in beam mercury jet in B field to get both is a problem: where and how????  JHF / Isolde… ***RF studies in magnetic fields Important for MICE (rf noise in spectrometer) Important for NUFACT (cooling channel with high emittance muon beam going through RF while being contained in magnetic field (phase rotation or cooling) studies so far with 800 MHz, construction of 200 MHz cavity now started! nice study of cooling in gas H2 filled cavities. (R. Johnson) *** replace induction linacs with RF phase rotation (Neuffer) (cost saving!) *** cooling rings works (on paper)! main problem : the injection and ejection kicker

38. US MC (Neutrino Factory and Muon Collider collaboration)

39. sizeable improvement in the level of dark current using Be windows

41. Kicker studies (Palmer)

42. TOWARDS WORLD STUDY III Rob Edgecock took initiative (triggered by MUG) to initiate a ‘world study III … trigger is EU FP6 design study request. … all three regions agree to collaborate. Aim is: 1. Design Report by LHC start up. 2. reduce cost of neutrino factory by factor of 2. steering group formed etc….

43. MICE •  Experiment passed International Peer Review Panel successfully • ‘strongly recommends approval’ •  Experiment under funding review in the UK: [10 M£ or 15 M£] • this means we will be going around looking for cryogenics, RF power sources, beam magnets, etc… • RAL management has authorized construction work to begin in the experimental hall at RAL MICE IS HAPPENING!

44. If funding is adequate, the following sequence of events can be envisaged: m - STEP I: 2006 STEP II: summer 2006 STEP III: winter 2007 STEP IV: spring 2007 STEP V: fall 2007 STEP VI: 2008

45. 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?