precision measurement of mixing angles and cp

Precision measurement of mixing angles and CP

Hisakazu MinakataPUC-Rio

RENO50@KNRC-Seoul

PUC-Rio, where?

June 13, 2013

Maracana

June 13, 2013 RENO50@KNRC-Seoul

All the angles are measured !lepton CP phase d left

na=Uai ni

solar+KamLANDSK-atm+MINOS+T2K T2K-MINOS-DC-DB-RENO


q12

RENO50@KNRC-Seoul

q12 has been measured by solar and KamLAND experiments

June 13, 2013

KamLAND Mar. 2013

RENO50@KNRC-Seoul

q12

• sin2q12 = 0.304 +/- 0.013

• Error of sin2q12 = 4.3%

• Error of Dm221 = 2.4%

June 13, 2013

KamLAND Mar.2013


How to improve

q12?

RENO50@KNRC-Seoul

SADO idea/proposal (July 2004)

• “SADO” = Several tens of km Antineutrino DetectOr

• Basic idea: 1st oscillation minima of Pee is the right place for precision measurement of q12

June 13, 2013

HM-Nunokawa-Teves-Zukanovich Funchal, ArXiv 0407326 PRD(2005)

RENO50@KNRC-Seoul

Optimal distance estimated as 50-60 km

June 13, 2013

Without geo-nu 40km would be fine

RENO50@KNRC-Seoul

SADO-vs KamLAND sensitivity

June 13, 2013

SADO 3s sensitivity ~ KamLAND 1s sensitivity


Solar+KamLAND and SADO are good competitors

• Tuned reactor may have better sensitivity with long-run because tuning L is powerful

2% (1s) in sin2q12 reachable with systematic error of 4%

Bahcall-Pena-Garay Slide at World Physics Summit

@Galapagos, June 22-25, 2006

Quark-Lepton Complementarity


Bi-maximal mixing from neutrinos

Predicted value of q13 in this model agrees well with experiments ! Large q13 natural in QLC

HM-A.Smirnov PRD 2004

QLC is based on observation: q12 + qC = p/4

Impressive to see the real proposals

today!


Sin2q12 error: RENO ~ 1% (K.K.Joo) Daya Bay II 0.63% claimed! (Yifang Wang), Talk both at ICRR)

Daya Bay II


q13

RENO50@KNRC-Seoul

q 13: RENO

• If added quadrature, sin22q13 = 0.1 +/- 0.018

• sin2q13 = 0.0257 +/- 0.0048

• Error of sin2q13 = 19%

June 13, 2013

RENO50@KNRC-Seoul

q13: Daya Bay

• If added quadrature, sin22q13 = 0.089 +/- 0.011

• sin2q13 = 0.0228 +/- 0.0029

• Error of sin2q13 = 13%

June 13, 2013

RENO50@KNRC-Seoul

How to improve q13?

• Continued running of reactor experiments• Can accelerator measurement supersade reactor q13 accuracy? If yes, when?

• What is the ultimate error of q13 ?

• If sin22q13 = 0.1 +/- 0.005 5% error for sin2q13

• Is 2-3% error achievable for sin2q13 ? • Neutrino factory?• Reactor + identical 2 detector appears to be

practically the best way June 13, 2013

Memory of Lev Mikaelyan @ Kurchatov Inst.

RENO50@KNRC-Seoul

Ultimate error of q13?

June 13, 2013Daya Bay ultimate (syst. only)

P. Coloma etal. JHEP12

D(sin2q) / sin2q = (1.6-2.0) (Dq / q)


Least accuratel

y measured angle q23

RENO50@KNRC-Seoul

q23: mixing angle with the largest error of 10-20% level

June 13, 2013Concha etal. JHEP 2012

RENO50@KNRC-Seoul

Error of q23 is large because ..

• Jacobian effect:

• Octant degeneracy + exp. uncertainty merging of clone solution to true one

June 13, 2013

HM-Sonoyama-Sugiyama PRD 2004


How to measure

q23 accurately

?

RENO50@KNRC-SeoulJune 13, 2013

Use solar term or R+A to solve q23 octant degeneracy

T2K-II + phase II reactorT2KKd=0 assumed

sin2 2q

13

sin2 q23

sin2 2q

13

> 3s2~3s

T2KK 2s(rough)

T2KK has better sensitivityat sin2 2q13 < 0.06~0.07 .

hep-ph/0601258

Hiraide etal. PRD2006

Kajita etal. PRD2007

RENO50@KNRC-Seoul

Use atmospheric neutrino to probe solar n oscillation

June 13, 2013

Hyper-K LOI : ArXiv 1109.3262

Barger etal. PRL 2012


Toward measuring

d

RENO50@KNRC-Seoul

How to measure CP

• nm superbeam appears to be the prime candidate

• T2KK CP sensitivity ~ T2HK CP sensitivity

June 13, 2013

RENO50@KNRC-Seoul

Determination of d in correlation with q13?

• So far CP d measurement has been discussed in a framework of simultaneous d – q13 determination intrinsic d - q13 degeneracy enriched with unknown mass hierarchy

• Right framework? NO! Better setting: simultaneous d – q23 determination

June 13, 2013

People were focused on another cosmos ..

RENO50@KNRC-Seoul

Why q23 relevant for CP?

• In precision era for CP the errors of d will be dominated by uncertainty of s2

23

• D sind =• D cosd =

June 13, 2013

For a given set of (P, P-bar) with finite error, a change in s2

23 can be compensated by adjusting d

Error formula for CP d h = order unity

HM-Parke, ArXiv 1303.6178


A new method for q23 and d

RENO50@KNRC-Seoul

Simultaneous q23– d determination

June 13, 2013

For a given set of (P, P-bar) there are 2x2=4 solutions of q23 and d

What you need is to switch q13 q23

everything goes through as in (q13-d) case

RENO50@KNRC-Seoul

1st Oscillation maximum

June 13, 2013

Things are much simpler in oscillation maximum

RENO50@KNRC-Seoul

1st Oscillation maximum (continued)

June 13, 2013

HM-Parke, ArXiv 1303.6178

RENO50@KNRC-Seoul

Use ne appearance channel

• simultaneous d – q23 determination by ne and ne-bar appearance channels

• q23 intrinsic degeneracyJune 13, 2013

RENO50@KNRC-Seoul

Breaking q23– d degeneracy

June 13, 2013

At 1st VOM

Spectrum information must solve the degeneracy!

Off 1st VOM

Hyper-K: D E= +/- 10%: LBNE: D E= +/- 20%:

RENO50@KNRC-Seoul

2nd vacuum oscillation maximum

June 13, 2013

At 2nd VOM, D=3p/2

D E= +/- 3%: Movement of clone solution is more prominent at 2nd VOM

RENO50@KNRC-Seoul

Conclusion

• Current status of mixing angle measurement outlined

• Some ideas seeking for better precision discussed

• Further improvement appear realistic for q12 (new projects) and q13 (continue running), but may not be for q23 at near maximal, because…

• Fortunately, if you measure d, then you automatically get q23!

June 13, 2013

precision measurement of mixing angles and cp

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