Alain Blondel Detectors UNO (400kton Water Cherenkov) Liquid Ar TPC (~100kton)

Alain Blondel Far detector in second phase Phase-I: Super-K 22.5kt (50kt) Phase-II: Hyper-K 1,000 kt Candidate site in Kamioka Other major goal: improve proton decay reach limit to the size of large underground Water Cherenkov detectors will be given by the difficulties of excavation. Max width is about meters.=> increase high&length

Alain Blondel SPL neutrino beam * At 2 GeV, K production is very small  Bkg of from e in the beam is small and dominated by muon decay This can be tailored by varying the length of the decay tunnel and reduced to % (all spectrum) * this is a low energy beam ( = 300 MeV ) e  Still work to do to fucus these…

Alain Blondel  /e Background Rejection e/mu separation directly related to granularity of coverage. Limit is around (mu decay in flight) SKII coverage OKOK, less maybe possible

Alain Blondel  reconstruction < 1GeV region CC quasi elastic reaction  + n →  + p -- p ( E , p  )   + n →  + p +  -- p ( E , p  )   Inelastic (BG)  CCqe inelastic  ~80MeV(10%) limited by Femi motion Small BG 5 X smaller for SPL beam SK Full Det. Sim. Energy can be well reconstructed =>Bkg reduction  precise measurement of osc. params  SENSITIVITY SIMILAR TO JHF-> HyperK

Alain Blondel BETA Beam new idea by P. Zucchelli produce 6 He++, store, accelerate (100 GeV/u), store Q= MeV T/2 = s pure anti- e beam at  600 MeV or: pure e beam at  600 MeV oscillation signal: appearance of low energy muons no opposite charge neutrinos=> no need for magnetic detectors little matter effects at these energies water Cerenkov excellent for this too, same as for Superbeam. seems feasible; but cost unknown so far. Critical: duty cycle. A nice *** idea to be followed up! 6 He ++   Li +++ e e 

Alain Blondel Anti-Neutrino Source Consider 6 He ++  6 Li +++ e e - E 0  MeV T/2  s 1. The ion is spinless, and therefore decays at rest are isotropic. 2. It can be produced at high rates, I.e. 5E13 6 He/s 3. The neutrino spectrum is known on the basis of the electron spectrum. DATA and theory: =1.578 MeV =1.937 MeV RMS/ =37% B.M. Rustand and S.L. Ruby, Phys.Rev. 97 (1955) 991 B.W. Ridley Nucl.Phys. 25 (1961) 483

Alain Blondel Neutrino Source Possible neutrino emitter candidate: 18 Ne The same technology used in the production of 6 He is limited in the 18 Ne case to ions/s. Dedicated R&D should increase this figure. Use this intensity as reference. Issues: MgO less refractory, heat dissipation

Alain Blondel Beta Beam (P. Zucchelli) M. Lindroos et al.

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 < ) combines CP and T violation tests e   (  +) (T)    e (  + ) (CP) e   (  -) (T)    e (  - ) Can this work???? theoretical studies now on beta beam + SPL target and horn R&D  design study together with EURISOL

Alain Blondel Superbeam & Beta Beam cost estimates