On-going & Near Future for q13

Takashi KobayashiKEK

111005ICFA seminar@CERN

Contents

• Introduction• T2K results and near future prospect• MINOS results• Global fit• Near future prospect in the world• Implication of large q13 on future • Summary

3 flavor mixing of neutrinos

3

2

1

PMNSU

e

10000

0010

0

00

001U 1212

1212

1313

1313

2323

2323MNS cssc

ces

esc

cssc

i

i

)sin(s ),cos(c ijijijij qq

3

e

Flavor eigenstates m1

m2

m3

Mass eigenstates

6 independent parameters govern oscillationq12, q23, q13, Dm12

2, Dm232, Dm13

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Atm/Acc Acc/Reactor Sol/Reactor

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Dmij=mi2-mj

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Pontecorvo-Maki-Nakagawa-Sakata Matrix (CKM matrix in lepton sector)

Present knowledge (before June, 2011)

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OR

1

2

3

Which??

e??

Big diff from KM matrix

unkown

Sol/Reactor

Atm/Acc

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Why q13 so important?e appearance and CPV

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132312sin sss CPV effect(sinq12~0.5, sinq23~0.7, sinq13<0.2)

Unknown!

CPVSol term

The size of q13 decides future direction!

Brief history and present situation In 1998, evidence of x (disappearance)

discovered SK in atm observation In 1999, as a next critical step toward CPV search,

importance of e appearance search pointed out (K.Nishikawa&Y.Totsuka)

In 2001, LoI of T2K After 10yrs of hard work worldwide for various

experiments to discover non-zero q13, now we are getting into “harvest” season

Final conclusion on q13 will come very soon (hopefully)

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Searches for non-zero q13 By using accelerator neutrino

• ： <E> ~ O(GeV) e appearance

• P(e) = sin2q23 ・ sin22q13 ・ sin2(1.27Dm231L/E) + many terms (incl. )

Appearance measurement of q13.

Statistics limited

By using reactor neutrino

• ： <E> ~ a few MeV e disappearance

• P(ee) = 1- sin22q13 ・ sin2(1.27Dm231L/E) + O(Dm2

21/Dm231)

Almost pure measurement of q13.

Small deficit signal systematics dominated

e

T2K (2009~), NOvA (2014~)

Double Chooz(2011~), RENO(2011~), Daya Bay(2012~)

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Tokai-to-Kamioka (T2K) long baseline neutrino oscillation experiment

OA3°

OA0°OA2°

OA2.5°

振動確率＠Dm2=3x10-3eV2

x

Intense off-axis (2.5deg) beam from J-PARC MR tuned at osc. max.

Reached 145kW (~0.9x1014ppt) Data taking Jan. 2010 ~ Mar.11,

2011 All data (1.43e20POT) analyzed

1.43e20pot accumulated(Jan2010~Mar2011)

T2K analysis results

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All data analysed Event selection

Signal Efficiency = 66% Background Rejection:

77% for beam νe 99% for NC

6 candidate events remain 1.5±0.3 BG expected Probability to observe >=6 evts w/ sin22q13=0:

0.7% 2.5 excess observed

One of most critical selection criterion validated by Atm- elike data &Atm- data+MC hybrid control sample

PRL 107, 041801 (2011)

T2K allowed regions

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Chooz 90%CLupper bound

@CP=0

PRL 107, 041801 (2011)

T2K&J-PARC status and plan J-PARC has not been operated since Mar. 11, 2011 Intensive recovery works are on-going We will resume J-PARC operation in Dec. 2011

First, LINAC will start operation on Dec. 12, 2011 We plan to have >2 “cycle”(~month) beam for users within JFY2011 (by the

end of Mar,2012) In FY2012 (Apr.2012-Mar.2013) J-PARC plan to operate fully (~9month)

(budget requested) LINAC energy recovery from 181MeV to 400MeV originally scheduled in

2012 was delayed to start July 2013 User’s needs to take longer beam after long shutdown by the earthquake Delay of preparation caused by earthquake

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Prospect of beam power Highest priority is to establish non-zero

q13 and precise measurement of q13 as soon as possible

T2K is still very much statistically limited (only 2% of approved POT has been taken)

Accelerator power improvement is CRITICAL (At present 145kW) Short term

Replacement of inj. Kicker before next beam Addition of RF (planned) for higher rep&ppb Higher capacity for beam loss (collimator) Tuning of present MR power supply for higher

rep rate (3.042.6 more) High power beam study

Longer term (few yrs) toward design intensity and beyond

R&D of high gradient RF core R&D of high rep rate MR power supply

(~1Hz or more) 12

T2K sensitivities and milestones

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We have : 0.07[MWx107s] = 0.143e21 potWe aim to have By Summer 2013: ~0.5 [MWx107s] ~ 1e21pot

Conclude non-zero q13

>5sigma for present T2K central value Within a few yrs : ~ 1 [MWx107s] ~ 2e21pot

> 3sigma for sin22q13 > 0.04 Approved goal : 3.75 [MWx107s] ~ 8e21pot

> 3sigma for sin22q13 >~ 0.02

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MINOS (1st gen. exp.) FNAL 120GeV Main

Injector Soudan mine (735km)

Horn-focused wide band beam

(magnetized)Iron-scintillator sampling calorimeter 5,400tons @ far, 980tons @

near Taking data >6yrs 8.2e20pot data w/ neutrino

run is used for ne appearance search

Far detector

MINOS latest results

A global fitting

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G.L.Fogli, et.al, arXiv:1106.6028v1 [hep-ph]

Exclude q13=0 at more than 3 level Best fit : sin2q13=0.021 sin22q13 = 0.084 Most urgent & important task:

EXPERIMENTALLY DEFINITELY conclude

Near future prospects in the world 1st gen LBL experiment

OPERA Expected (6.6E19POT)

Beam e: 48.5 NC : 5.2 Signal : 5.2

(sin22q13=0.1) (No kinematical cut)

Results expected in 2012 q13 optimized

experiments Reactor experiments NOvA

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RENO experiment

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FDND

Co

16.1GW reactor & 2x16ton detectors (1.4km)

Started data taking with both near & far detectors from Aug. 1, 2011.

First results on sin2(2q13) ~0.5 are expected to be available within a half year.

sin2(2q13) > 0.02 at 90% within ~3yrs

T2K center

Fogli Global fit center

Double Chooz

8.2GW reactor & 2x8ton detector (1.05km) Far detector completed, started data taking since

Apr. 13, 2011, >120dys w/ 75% phys data live Data taking w/ near det expected from early 2013 Sin22q13 sensitivity (90%CL) ~0.08 in half yr, 0.03

ultimately

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T2K center

Daya Bay experiment 6x2.95=17.4GW & 4x20t far/4x20t near det’s

(1.6~2km) 4/8 det’s filled, 2det’s taking data Data taking with full det’s from Summer 2012 sin22q13 <0.03(0.02) at 3 in 1(3) yrs

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NOvA

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FNAL NuMI off-axis beam Power upgrade 320kW700kW

Recycler: anti-proton proton Rep cycle 2.2s 1.33s

New 14kton liquid scintillator fine grained detector @810km

Far detector will complete and start full operation in 2014

NOvA expected sensitivities

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T2K region

Can measure large q13 (~T2K center) very soon

For smaller q13 good competition

Have some sensitivity on mass hierarchy

Fogli

T2K

Fogli

T2K

Implication of large q13 on Future If sin22q13> ~0.01

Make conventional Multi-MW super beam long baseline experiments possible to explore CPV in lepton sector

Although big step needed IF not

Need “ideal” beam such as Neutrino Factory or beta beam to probe CPV

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T2K region

Implication of large q13 on Future CPV asymmetry get smaller for

larger q13 Severer requirement on systematic

error Matter effect becomes comparable

even at @295km Need energy spectrum

information to disentangle CPV and Matter effect

~20% CPV effect at sin22q13=0.1 w/ sinCP=1 (max. vio.) at 1st peak To detect CPV >3 for sin>0.2

(Asym=4%) O(10k) events necessary

Much higher statistics is necessary >MW proton & huge detector mandatory 24

T2K 90% region

1st peak @ 295km (0.6GeV)

Pure CPV effect

Matter effect

)()()()(

ee

ee

PPPP

A

Next talk

Summary Quest for non-zero q13 is turning around final corner T2K detected first indication of e appearance at 2.5

significance 0.03(0.04)<sin22q13<0.28(0.34) (inv hier)

MINOS presented consistent results New reactor experiments are getting online NOvA will come in 2014 Discovery of finite q13 will come very soon (hopefully)! Large q13 makes possible to explore CPV with upgraded

>MW beam and Huge high sensitivity detector

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