1. LBL Oscillation Physics @WIN05
H. Minakata (Tokyo Metropolitan U.)

2. n oscillatory behavior has been seen!SK
K2K
KamLAND
WIN05, June 6-11
Hisakazu Minakata

3. What is left #1: q13 (There are 2 ways)
LBL vs. reactor
WIN05, June 6-11
Hisakazu Minakata

4. What is left #2:  mass hierarchy
WIN05, June 6-11
Hisakazu Minakata

5. What is left #3: CP violation
Shoichi Sakata
Ziro Maki
Lepton-quark correspondence ?
Relation to cosmic baryon number?
WIN05, June 6-11
Hisakazu Minakata

6. Closest possibility: J-PARC phase II
T2K phase-I: The unique LBL experiment funded !
JPARC accelerator upgraded to 4MW
Hyper-Kamiokande of 1 Mton (fiducial volume = 0.54 Mton)
WIN05, June 6-11
Hisakazu Minakata

7. There are competitive ideas/plans, e.g.,
NOA
High-gamma beta beam
WIN05, June 6-11
Hisakazu Minakata

8. For me it is natural to think about J-PARC phase II project for many reasons, but it has a serious problem…
WIN05, June 6-11
Hisakazu Minakata

9. A half of the sensitivity region is obscuredO.
WIN05, June 6-11
Hisakazu Minakata

10. Why so much ambiguity by sign(Dm2) degeneracy?
The reason is:
Large d2 - d1 (= p/2 ~ p) in overlapping region of different-sign Dm2 ==>
CPC-CPV confusion
One has to solve sign-degeneracy to determine 
WIN05, June 6-11
Hisakazu Minakata

11. T2KK, or Resolving neutrino mass hierarchy and CP degeneracy by Komioka-Korea twin Hyper-Kamiokande
Based on: M. Ishitsuka, T. Kajita, HM, H. Nunokawa, hep-ph/

12. There are cultural, philosophical, diplomatic, string-theoretical
reasons for T2KK
apart from scientific ones
WIN05, June 6-11
Hisakazu Minakata

13. Korea is booming in Japan ! 韓流ブーム
WIN05, June 6-11
Hisakazu Minakata

14. Korea is booming in Japan continued
WIN05, June 6-11
Hisakazu Minakata

15. Current design of Hyper-Kamiokande contains 2 tanks !
Why don’t you bring one of the 2 tanks to Korea?
WIN05, June 6-11
Hisakazu Minakata

16. Yes, we are the neighbours
Taken from Hagiwara et al.
WIN05, June 6-11
Hisakazu Minakata

17. Sign confusion in Korea is as severe as in Kamioka
WIN05, June 6-11
Hisakazu Minakata

18. Where is the right place?
How different are P’s of 2 degenerate
WIN05, June 6-11
Hisakazu Minakata

19. What is the difference: 1st-1st OM
WIN05, June 6-11
Hisakazu Minakata

20. What is the difference: 1st-2nd OM
Energy dependence far more dynamic at 2nd OM !
WIN05, June 6-11
Hisakazu Minakata

21. high-E(1st-1st OM) vs. low-E(1st-2nd OM)
WIN05, June 6-11
Hisakazu Minakata

22. Spectral information solves degeneracy
WIN05, June 6-11
Hisakazu Minakata

23. T2K(0.54 Mt) vs. T2KK(0.27+0.27 Mt)  WIN05, June 6-11
Hisakazu Minakata

24. T2K(0.54 Mt) vs. T2KK(0.27+0.27 Mt)  WIN05, June 6-11
Hisakazu Minakata

25. T2KK can resolve  mass hierarchy keeping CP sensitivity
thick: 3 thin: 2
WIN05, June 6-11
Hisakazu Minakata

26. Power of 2 identical detectors
Systematic errors cancel between 2 HK !
Modest requirement of 5% systematic errors is enough to guarantee the great sensitivity to CP violation and  mass hierarchy !
WIN05, June 6-11
Hisakazu Minakata

27. Results insensitive to systematic error !
WIN05, June 6-11
Hisakazu Minakata

28. T2KK vs. NOA; mass hierarchy
thick: 3 thin: 2
T2K II
WIN05, June 6-11
Hisakazu Minakata

29. T2KK vs. NOA; CP thick: 3 thin: 2 WIN05, June 6-11
Hisakazu Minakata

30. T2KK vs. super-NOA; mass hierarchy
95% CL dashed/ solid w/o proton D
thick: 3 thin: 2
Mena-Palomares-Ruiz-Pascoli; L2nd=200 km
WIN05, June 6-11
Hisakazu Minakata

31. Conclusion
People started to explore various 2 detector setups for determining CP & mass hierarchy in the context of conventional  superbeam
There are two options; 1st-1st OM and 1st-2nd OM. They differ in  spectral properties => require different strategy
T2KK improves the original T2K II proposal with no extra cost by adding ability to determine mass hierarchy while keeping sensitivity to CP violation
WIN05, June 6-11
Hisakazu Minakata

32. Supplementary sheets
WIN05, June 6-11
Hisakazu Minakata

33. 2 and background 5% errors are assumed WIN05, June 6-11
Hisakazu Minakata

34. Events vs. selections Dm2=2.5x10-3eV2,sin22q13=0.1
workshop
(events / 22.5kt / 5yrs)
nmCC BG
nmNC
beam ne
ne(CC)
Signal
FCFV,
Evis>100
2849
1082
248
290 1R
1313(46%)
277(26%)
114(46%)
243(84%)
e-like
51(1.8%)
219(20%)
111(45%)
240(83%)
no decay-e
15(0.5%)
195(18%)
92(37%)
222(77%)
0.35<Enrec<0.85
2.2(0.1%)
58(5%)
27(11%)
173(60%)
DL<80,M<100,cos<0.9
12±0.8(0.3%)
16±0.4(6%)
122±3(42%)
(stat.)
(stat.)
(stat.)
(old p0 fitter: )
WIN05, June 6-11
Hisakazu Minakata

35. Stability of the results
WIN05, June 6-11
Hisakazu Minakata