Precision measurement of mixing angles and CP Hisakazu Minakata PUC-Rio

PUC-Rio, where? June 13, Maracana

June 13, All the angles are measured !lepton CP phase  left  =U  i i solar+KamLAND SK-atm+MINOS+T2K T2K-MINOS-DC-DB-RENO

June 13,  12

 12 has been measured by solar and KamLAND experiments June 13, KamLAND Mar. 2013

 12 sin 2  12 = / Error of sin 2  12 = 4.3% Error of  m 2 21 = 2.4% June 13, KamLAND Mar.2013

June 13, How to improve  12 ?

SADO idea/proposal (July 2004) “SADO” = Several tens of km Antineutrino DetectOr Basic idea: 1 st oscillation minima of P ee is the right place for precision measurement of  12 June 13, HM-Nunokawa-Teves- Zukanovich Funchal, ArXiv PRD(2005)

Optimal distance estimated as km June 13, Without geo- nu 40km would be fine

SADO-vs KamLAND sensitivity June 13, SADO 3  sensitivity ~ KamLAND 1  sensitivity

June 13, Solar+KamLAND and SADO are good competitors Tuned reactor may have better sensitivity with long-run because tuning L is powerful 2% (1  ) in sin 2  12 reachable with systematic error of 4% Bahcall-Pena-Garay Slide at World Physics June 22-25, 2006

Quark-Lepton Complementarity June 13, Bi-maximal mixing from neutrinos Predicted value of  13 in this model agrees well with experiments !  Large  13 natural in QLC HM-A.Smirnov PRD 2004 QLC is based on observation:  12 +  C =  /4

Impressive to see the real proposals today! June 13, Sin 2  12 error: RENO ~ 1% (K.K.Joo) Daya Bay II 0.63% claimed! (Yifang Wang), Talk both at ICRR) Daya Bay II

June 13,  13

 13 : RENO If added quadrature, sin 2 2  13 = 0.1 +/ sin 2  13 = / Error of sin 2  13 = 19% June 13,

 13 : Daya Bay If added quadrature, sin 2 2  13 = / sin 2  13 = / Error of sin 2  13 = 13% June 13,

How to improve  13 ? June 13, Memory of Lev Kurchatov Inst.

Ultimate error of  13 ? June 13, Daya Bay ultimate (syst. only) P. Coloma etal. JHEP12  (sin 2  ) / sin 2  = ( )  / 

June 13, Least accurately measured angle  23

 23 : mixing angle with the largest error of 10-20% level June 13, Concha etal. JHEP 2012

Error of  23 is large because.. Jacobian effect: Octant degeneracy + exp. uncertainty  merging of clone solution to true one June 13, HM-Sonoyama-Sugiyama PRD 2004 

June 13, How to measure  23 accurately?

June 13, Use solar term or R+A to solve  23 octant degeneracy T2K-II + phase II reactor T2KK =0 assumed sin 2 2 13 sin 2  23 sin 2 2 13 > 3 2~3 T2KK 2 (rough) T2KK has better sensitivity at sin 2 2 13 < 0.06~0.07. hep-ph/ Hiraide etal. PRD2006 Kajita etal. PRD2007

Use atmospheric neutrino to probe solar oscillation June 13, Hyper-K LOI : ArXiv Barger etal. PRL 2012

June 13, Toward measuring 

How to measure CP  superbeam appears to be the prime candidate T2KK CP sensitivity ~ T2HK CP sensitivity June 13,

Determination of  in correlation with  13 ? So far CP  measurement has been discussed in a framework of simultaneous  –  13 determination  intrinsic  -  13 degeneracy enriched with unknown mass hierarchy Right framework? NO!  Better setting: simultaneous  –  23 determination June 13, People were focused on another cosmos..

Why  23 relevant for CP? In precision era for CP the errors of  will be dominated by uncertainty of s 2 23  sin  =  cos  = June 13, For a given set of (P, P-bar) with finite error, a change in s 2 23 can be compensated by adjusting  Error formula for CP   order unity HM-Parke, ArXiv

June 13, A new method for  23 and 

Simultaneous  23 –  determination June 13, For a given set of (P, P-bar) there are 2x2=4 solutions of  23 and  What you need is to switch  13   23 everything goes through as in (  13  ) case

1 st Oscillation maximum June 13, Things are much simpler in oscillation maximum

1 st Oscillation maximum (continued) June 13, HM-Parke, ArXiv

Use e appearance channel simultaneous  –  23 determination by e and e -bar appearance channels  23 intrinsic degeneracy June 13,

Breaking  23 –  degeneracy June 13, At 1 st VOM Spectrum information must solve the degeneracy! Off 1 st VOM Hyper-K:  E= +/- 10%: LBNE:  E= +/- 20%:

2 nd vacuum oscillation maximum June 13, At 2 nd VOM,  /2  E= +/- 3%: Movement of clone solution is more prominent at 2 nd VOM

Conclusion Current status of mixing angle measurement outlined Some ideas seeking for better precision discussed Further improvement appear realistic for  12 (new projects) and  13 (continue running), but may not be for  23 at near maximal, because… Fortunately, if you measure  then you automatically get  23 ! June 13,