Recent results on neutrino oscillations and CP violation measurement in Neutrinos

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1 Recent results on neutrino oscillations and CP violation measurement in Neutrinos M.Nakahata Kamioka observatory, ICRR, IPMU, Univ. of Tokyo CP Violation in Elementary Particles and Composite ystems, Feb.19, 0, Mahabaleshwar (India)

2 Contents What are neutrino oscillations Results and topics from recent measurements q 1 and Dm 1 measurements q 3 and Dm 3 measurements q measurements Unknown properties of neutrinos Neutrino CP measurement How to measure CP phase Detector for the CP phase measurement ensitivity

3 Weak eigenstates n e n m n t Neutrino oscillations ( ) = n ( ( 1 ) Mass eigenstates U e1 U m1 U t1 U e U m U t U e3 U m3 U t3 ) n n 3 flavor case ( n a ) = ( cosq n b Oscillation probability sinq - sinq cosq ) n 1 ( ) P(n a n b ) = sin q sin (1.7Dm L/E) Dm = m - m 1 (ev ): mass square difference L (km): Neutrino travel length E (GeV): neutrino energy n

4 Pontecorvo-Maki-Nakagawa-akata (PMN) matrix U= c3 +s3 +c 0 +se -id +c1 +s s1 +c s3 +c3 -se -id 0 +c c1c s1c se -id = -s1c3-c1ss3e -id c1c3-s1ss3e -id cs3 s1s3-c1sc3e -id -c1s3-s1sc3e -id cc3 Dmij = mi -mj ;Dm 1, Dm 3, Dm 31 sij=sinqij cij=cosqij d : Dirac P phase

5 Experiments for the oscillation parameters c1c s1c se -id U= -s1c3-c1ss3e -id c1c3-s1ss3e -id cs3 s1s3-c1sc3e -id -c1s3-s1sc3e -id cc3 Primarily sensitive to olar n, long BL reactor n Atm. n, long BL accelerator n hort BL reactor n Dm1 sij=sinqij cij=cosqij Dm3 q1 q3 q d Future long BL accelerator n BL=baseline (sign) (=, > or < 45 )

6 Ga AGE and GALLEX/GNO 7 Be Borexino Measured solar neutrino fluxes oscillated expectation oscillated expectation 64.6 NU 66.1+/-3.1 NU 44 /day/100t 46±. /day/100t Prediction w/o osc. deficit 37 Cl Homestake Kamiokande H O uper-k oscillated expectation oscillated expectation.87 NU.56 +/-0.3 NU.3x10 6 /cm /s (.80±0.38)x10 6 /cm /s (.37±0.04)x10 6 /cm solar best fit parameter Dm 1 =4.9x 10-5 ev sin q 1 =0.314 (with sin q =0.1) D O NO CC NO E NO NC Oscillated expectation 1.63x10 6 /cm /s (1.70±0.06)x10 6 /cm /s.3x10 6 /cm /s (.14±0.15)x10 6 /cm /s Results 5.3x10 6 /cm /s (5.5±0.0)x10 6 /cm /s

Day/night asymmetry (%) Measurement of Matter effect (uper-k)

effect. day A DN = Day flux Night flux 0.

0 % K-II -4.3±3.8±1.0 % night K-III -4.3±.7±0.7 % sin θ 1 =0.

7 Day/night asymmetry (%) Measurement of Matter effect (uper-k) During night, n e probability increases due to the earth matter effect. day A DN = Day flux Night flux 0.5 (Day flux + Night flux) A DN (±stat.±sys.) K-I -.0±1.7±1.0 % K-II -4.3±3.8±1.0 % night K-III -4.3±.7±0.7 % sin θ 1 =0.314 K-IV -.8±1.9±0.7 % K combined -.8±1.1±0.5 % Best Fit 1σ tat. 1σ tat. + ys..3 σ away from zero. ±1σ olar ±1σ Kamland

8 KamLAND reactor neutrino data Long baseline ~ 180 km Data from Mar. 00 to Nov. 009 Energy spectrum shows clear deficit of reactor neutrinos. The plot as a function of L/E n shows clear oscillatory pattern. Phys.Rev. D83 (011) 0500

9 Filled area: 3σ q 1 - Dm 1 :solar global vs. KamLAND KamLAND 5σ 4σ olar global olar global: Dm = ( ) [ 10-5 ev ] sin q 1 = KamLAND Dm 1 = ( ) [ 10-5 ev ] sin q 1 = olar + KamLAND Dm 1 = ( ) [ 10-5 ev ] sin q 1 = 0.307±0.014 with sin q = 0.05 All with sin q = 0.1 olar+kamland

10 Atmospheric and long BL accelerator n KK: MINO: 005 ~ TK: 010 ~ uper-k

11 q 3 Dm 3 : K atm. and accelerators K atm. 3n TK MINO K atm. L/E K atm. n Full TK (expected) 11 Future: TK will reach accuracy of d(sin q 3 )=0.01 and d(dm 3)=0.0001eV.

12 3.8 σ level excess. Recent observation at uper-k atmospheric n t appearance CC n t events n t t hadrons Zenith angle distribution after seleting CC n t like events n t hadrons The observed excess is consistent with n t appearance N t N exp =1.4 ± 0.35(stat.) (syst.)

13 Baseline: 73km, <En> = 17 GeV CERN n t events at OPERA Detect decay of t by emulsion chamber Emulsion chamber OPERA detector M. Nakamura (Neutrino 01)

14 Methods of q measurements hort baseline reactor: n e disappearance P( n e n e) 1 sin (q )sin 1.7Dm 31L( m) ( ) E ( MeV ) n q only Long baseline accelerator: n e appearance P( n ub-leading d -d a -a for P(n m n e ) m n ) sin 8C 8C 4 8C 8C e 1 C C 1 1 C 3 ( C C 3 al 4E ( C n a Dm (q 31 1 C 3 )sin (1 sind sin D (1 cosd q 3 )sin sin 1 )cosd 3 C 3 D 1 1.7Dm 31L( km) ( ) E ( GeV ) sin D C sin D )cosd n sin D matter sin D 31 cosd )sin n e appearance: depends on d and mass hierarchy Leading term sin D D ij ij D 1 1 sinq, C a Dm ij ij G L F CPC CPV solar E. n ij e n cosq E n ij

15 TK(Tokai-to-Kamioka) experiment Off-axis beam.5deg. off-axis in order to make narrow band beam with higher intensity p p + Decay volume Near detectors off-axis 30GeV Target protons m + & Horns Muon monitor on-axis uper-k from J-PARC MR 0 10m 80m 95km n m.5 o

TK result (Run 1++3) Data of 3.01x10 0 POT (protons on target) [it is only 5% of designed POT of TK.] 11 electron neutrinos observed. Expected number of background 3. ± 0.43 (syst.

16 TK result (Run 1++3) Data of 3.01x10 0 POT (protons on target) [it is only 5% of designed POT of TK.] 11 electron neutrinos observed. Expected number of background 3. ± 0.43 (syst.) for sin (q )=0 Reconstructed n energy (Data from June) n e appearance Allow region on sin θ and δ CP Normal hierarchy q =0 is excluded with 3.s level. Inverted hierarchy < sin θ < Best fit : sin θ =0.11 (for Δm 3=.4 x 10-3 ev, δcp=0)

17 Double Chooz Reactor q experiments RENO Near Detector Far Detector Daya Bay

18 Results of reactor q experiments Double Chooz (Jun. 01) Daya Bay (Jun. 01) Reno (April 01) sin θ = 0.109±0.030±0.05 (.9s level) sin θ = 0.089±0.010±0.005 (8s level) sin θ = 0.1±0.0±0.019 (4.9s level) PRD 86, (01) arxiv: [hep-ex] PRL108 (01) 19180

19 ummary of q measurements ±1s range Δm >0, δ=0 Δm <0, δ=0 Δm >0, δ=0 Δm <0, δ=0 sin θ All results are consistent and sin θ =~0.1.

20 Unknown properties of Neutrinos What is the value of CP phase d? (q 3 45 ) = 0?, >0?, or <0? Which mass hierarchy? Absolute value of mass? Majorana or Dirac particle? LND/MiniBooNE, Ga and reactor anomalies? Normal hierarchy? Inverted hierarchy? Degenerate? m 3 m m 1 Dm 1 =~7.4x10-5 ev Dm 3 =~.4x10-3 ev n e n m n t Dm 3 =~ ー.4x10-3 ev m m 1 Dm 1 =~7.4x10-5 ev m 3

21 Unknown properties of Neutrinos What is the value of CP phase d? (q 3 45 ) = 0?, >0?, or <0? Which mass hierarchy? Absolute value of mass? Majorana or Dirac mass? LND/MiniBooNE, Ga and reactor anomalies? Normal hierarchy? Inverted hierarchy? Degenerate? m 3 m m 1 Dm 1 =~7.4x10-5 ev Dm 3 =~.4x10-3 ev n e n m n t Dm 3 =~ ー.4x10-3 ev m m 1 Dm 1 =~7.4x10-5 ev m 3

How to measure CP phase d Long baseline accelerator: n e appearance P( n ub-leading m for P(n m n e ) n ) sin 8C 8C 4 8C 8C e 1 C C 1 1 C 3 ( C 3 3 1 3 1 C 3 al 4E (q ( C n a Dm 31 1 C )sin 3 3 1 3

22 How to measure CP phase d Long baseline accelerator: n e appearance P( n ub-leading m for P(n m n e ) n ) sin 8C 8C 4 8C 8C e 1 C C 1 1 C 3 ( C C 3 al 4E (q ( C n a Dm 31 1 C )sin (1 sind sin D (1 cosd q d -d and a -a 3 sin )sin 1 )cosd 3 C 1.7Dm 31L( km) ( ) E ( GeV ) 3 D sin D C sin D n )cosd sin D sin D 31 cosd )sin D Leading term sin D ij ij D 1 1 sinq, C a Dm ij ij G L F CPC CPV solar matter E. n ij e n cosq E n ij Compare P(n m n e ) and P(n m n e ) for CP phase measurement

Effect of CP violating term in P(n m n e )

8C 8C 4 8C 8C 1 C C 1 1 C 3 ( C 3 3 1 3 1 C

sin D (1 Leading CP violating (flips sign

C 3 D 1 31 3 3 sin D C sin D 31 1 31 sin D 3

G L F E. n ij e D n 1 1 cosq E n ij 95km ~0.

23 Effect of CP violating term in P(n m n e ) P(n m n e ) = CPC CPV olar Matter CPV term 8C 8C 4 8C 8C 1 C C 1 1 C 3 ( C C 3 al 4E ( C n a Dm 31 1 C (1 sind sin D (1 Leading CP violating (flips sign for ν) cosd )cosd sin D sin D )sin 1 )cosd 3 C 3 D sin D C sin D sin D cosd )sin D a ij ij sinq, C Dm ij ij G L F E. n ij e D n 1 1 cosq E n ij 95km ~0.03 ~11.8 (6.4 from 1/sinθ) (sin θ=0.1,δ=π/4) 3 7% Eν (GeV)

24 nm ne probability (L=95km) Normal hierarchy Neutrino case Anti-neutrino case Comparison between P(n m n e ) and P(n m n e ) As large as ~5% from nominal It is sensitive also to exotic (non-pmn) CP violation cases.

25 We need a larger volume detector for the CP phase measurement.

26 Hyper-Kamiokande Detectors Total Volume 0.99 Megaton Inner Volume 0.74 Mton Fiducial Volume 0.56 Mton (0.056 Mton 10 compartments) Outer Volume 0. Megaton Photo-sensors 99,000 0 Φ PMTs for Inner Det. (0% photo-coverage) 5,000 8 Φ PMTs for Outer Det. 5 of uper-k

27 Neutrino beam from J-PARC Hyper-K ~0.6GeV νμ 95km baseline 7

28 ν/50mev/cm /10 1 POT The n beam Expected neutrino flux at Hyper-K (unoscillated) νμ ν mode νμ ν mode νμ νe νe νμ νe νe Eν (GeV) Eν (GeV).5 o off-axis beam from J-APRC Peaked at oscillation maximum uppress BG from high energy component.

29 ignals and backgrounds ignals ingle electron event by CC interaction of n e oscillated from n m Mainly CCQE : n e + n e - + p Protons mostly have momenta below Cherenkov threshold Backgrounds (1) intrinsic n e in the beam (from m, K decays) () NC single p 0 events overlap of g rings asymmetric decay (one of the g has very low energy)

30 Expected ne candidate events.5mw 10 7 s = 0.75MW 3yrs (1.5MW 1.5yrs) 1year=10 7 s sin θ=0.1,d=0, normal MH 5.5MW 10 7 s = 0.75MW 7yrs (1.5MW 3.5yrs) ignal (nm ne CC) Wrong sign appearance n m/nm CC beam ne/ne contamination NC n (.5MW 10 7 s) 3, n (5.5MW 10 7 s) 1, signal events expected for each of n and n

Numbers and shape for CP measurement Expected ne CC candidates sin θ=0.1 0.

31 Numbers and shape for CP measurement Expected ne CC candidates sin θ= MW 3yrs δ=0 δ=1/π δ=π δ=3/π 0.75MW 7yrs δ=0 δ=1/π δ=π δ=3/π stat. error only stat. error only δ=1/π δ=π δ=3/π δ=1/π δ=π δ=3/π

32 Expected Contours 7.5MW years Normal mass hierarchy (known) 5% systematics on signal, nm BG, ne BG, n/n True points Reactor q exps.(1σ) - Good sensitivity for CP d measurement

33 σ 5% all syst CPV Discovery ensitivity % all syst (w/ Mass Hierarchy known) 7.5MWyear sin θ=0.1 normal MH 74% region of δ covered at 3σ w/ 5% sys. error 10% all syst High ensitivity to CPV w/ <~5% sys. error 33 true δ (π)

d resolution Normal mass hierarchy (known) sin θ=0.1 7.5 MW yrs (0.

34 d resolution Normal mass hierarchy (known) sin θ= MW yrs (0.75MW x 10 years) d precision < 0 (d=90 ) < 10 (d= 0 ) modest dependence on q

n e appearance in atmospheric n uclphysb669,55(003)

appearance (and nm distortion) is expected due to MW

normal mass hierarchy - in anti- n in inverted mass

36 n e appearance in atmospheric n uclphysb669,55(003) uclphysb680,479(004) downward horizontal upward ne appearance (and nm distortion) is expected due to MW effect in the Earth s matter - happens in n in the case of normal mass hierarchy - in anti- n in inverted mass hierarchy Large θ value gives us a good chance to discuss mass hierarchy and CP phase.

37 mass hierarchy: NH vs IH sin θ3 = 0.4 vs 0.6 Through matter effect (MW), we study Mass hierarchy Asymmetry between neutrinos and antineutrinos. Octant of θ3 Appearance (and nm nm disappearance) interplay dcp Magnitude of the interference

38 CP d [p] ensitivity for CP d and sin q Atmospheric neutrinos of Hyper-K 10 years sin q =0.1 1s CL s CL 3s CL Give supplemental information to the CP study conducted by the J-PARC beam

39 Combination of Beam and Atmospheric Neutrinos Allowed d cp range Beam Map Atm. n Map Atm. n + Beam Add 3s 3s Hierarchy is unknown, but NH is true True d cp = 0.0 True sin q = 0.10 Maximal mixing, sin q 3 = 1.0 Degenerate solution exists at 3s in the beam only case - just add the c maps By adding atmospheric data, single solution is obtained.

Multi-purpose detector, Hyper-K Explore full

Discovery of leptonic CP violation (Dirac d) n mass

determination (q 3 <p/4 or >p/4) Extend nucleon

years Neutrinos from astrophysical objects 00 n s /

(Andromeda) ~800 n s / 10 years (>10MeV) N relic n

40 Multi-purpose detector, Hyper-K Explore full picture of neutrino oscillation parameters. Discovery of leptonic CP violation (Dirac d) n mass hierarchy determination(dm 3 >0 or <0) q 3 octant determination (q 3 <p/4 or >p/4) Extend nucleon decay search sensitivity t proton =10 34 ~10 35 years Neutrinos from astrophysical objects 00 n s / day from un possible time variation, day/night matter effect. 50,000 (50) n s from (Andromeda) ~800 n s / 10 years (>10MeV) N relic n WIMP n, solar flare n, etc upernova un Proton Decays accelerator Letter of Intent, Hyper-K WG, arxiv: [hep-ex]

41 chedule assuming budget being approved from JPY016 JFY Construction start Tunnels Cavity excavation Concrete, liner PMT support, PMT installation Photo-sensor R&D Prep. for glass valve, PMT production PMT production Water filling Operation

42 LBNE project in the U Baseline 00 km 10kt Liquid Ar detector on surface (phase 1)

43 ensitivity of LBNE R. voboda (Neutrino 01)

44 LBNO project in Europe Baseline 300 km 0kton liquid Ar detector at 1400m underground.

45 ensitivity of LBNO ensitivity to Mass hierarchy ensitivity to CP violation 3s 5s F. Lodovico (NNN01, Oct.01)

46 ummary q 1, q 3, q, Dm 1, and Dm 3 were measured. Remaining unknown parameters are CP phase d and mass hierarchy. Recently, q was measured to be sin (q )=~0.1. This large q enabled us to measure CP phase d using long baseline accelerator neutrinos in future. The proposed Hyper-Kamiokande detector has a high sensitivity for the CP phase measurement. Hyper-K is a multiple purpose detector which investigate (discover) also nucleon decays and astrophysical neutrinos.

Recent results from Super-Kamiokande

Recent results from Super-Kamiokande ~ atmospheric neutrino ~ Yoshinari Hayato ( Kamioka, ICRR, U-Tokyo ) for the Super-Kamiokande collaboration 1 41.4m Super-Kamiokande detector 50000 tons Ring imaging