(Present long baseline neutrino experiments and) Future Projects to measure q13 and the CP violation phase

1
(Present long baseline neutrino experiments
and)Future Projects to measure q13 and the CP
violation phase
Aug. 9, 2004 _at_Hanoi

• Takashi Kobayashi
• IPNS, KEK

• Contents
• Introduction
• Present LBL experiments
• Future accelerator based projects
• Reactor experiments
• Summary

2
Introduction

• Evidences of n oscillation
• Atm n (SK,1998) solar n (SKSNO,2001)
• Finite masses!! Large mixings!!!!!
• First evidence beyond SM
• Definite confirmation w/ diff systematics
• Present (1st generation) long baseline (LBL)
  experiments (for atm n)
• Players K2K (1999), MINOS (2005),
  ICARUS/OPERA(2006)
• Next steps
• Understand whole structure of n mass/mixing
• How similar/different from quark sector?
• Standard mixing w/ 3x3 matrix?
• Mass hierarchy?
• CP violation?
• Would lead physics beyond SM
• Next generation LBL experiments and reactor exp.
• w/ High statistics and small systematics
• New era of precision Neutrino Flavor Physics
• Cf. Have been done last 40yrs for quark sector

3
The K2K (KEK-to-Kamioka) Experiment

• The first only running LBL n osc. Experiment
  (1999)
• nm beam (99) with ltEgt 1.3GeV w/ KEK 12GeV-PS
• Confirmation of atm n results
• nm disappearance and ne appearance

• Signature (nm?else)
• Reduction of of events
• Spectrum distortion

4
Latest Results on nm disapp.(June 2004)
8.9x1019 POT (1999Jun2004Feb) (1020POT proposed)
2.9s
Enrec spec for 1ring m events
Dm21.73.5x10-3 eV2 _at_sin22q1 (_at_90CL)
2.5s

• Best fit in phys. (all) region
• sin22q 1.00 (1.53)
• Dm2 eV2 2.73?10-3 (2.12)
• Confirmed n osc at 3.9s level

5
Comparison w/ other results
nm disappearance
ne appearance
PRL93(2004)051801
K2K(90CL)
(same as prev page)
Dm2 (eV2)
SK atm.n allowed (90CL)
CHOOZ(90CL)
ne disapp
sin22qme0.5sin22q13
Consistent w/ SK atm n result
6
MINOS

• wide band nm beam w/ FNAL 120GeV Main Injector
  (0.4MW)
• (magnetized)Iron-scintillator sampling
  calorimeter
• 5,400tons _at_ far, 980tons _at_ near
• nm CC int./MINOS/yr 2,500 (LE beam)
• High precision nm disappearance
• Far detector fully operational since 2003
• Beam line almost completing
• Start from 2005

First Horn being Installed
Far detector
7
CERN Neutrino to Gran Sasso (CNGS)

• Wide band nm beam w/ CERN 400GeV SPS ltEngt17GeV
• Two experiments
• OPERA 1.7kt Emulsion cloud chamber
• ICARUS 3kt Liq. Ar TPC
• 5500nm event/kt/yr
• nt appearance
• Under construction
• First beam to GS May 2006

732km
8
Expected sensitivities
nm disappearance
nt appearance
Expected signal
Sig BG
OPERA 17.2 1.1
ICARUS 11.9 0.7
MINOS
MINOS 5yrs 90 and 99 CL
Dm22.5x10-3eV2 Full mix. 5yrs of running ICARUS
1.5kt fid mass
For Dm2 0.0025 eV2, sin2 2q 1.0
d(Dm2)2x10-4eV2 d(sin22q)5 read from above plot
9
3 flavor mixing
If neutrino have finite mass, weak and mass
eigenstates can differ
mi 3 masses, Dmij 2 differences
Weak
Mass eigenstates
Maki-Nakagawa-Sakata Matrix
sijsinqij, cijcosqij
3 mixing angles and 1 CPV phase
Unknown 2 parameters
sin22q120.8 (Solar LBL reactor)
sin22q231 (Atm n)
Reactor
LBL acc. experiments
10
Whats next?
0??Ue32sinq132
0??Ue32sinq132

• Only unknown mixing q13
• Only upper bound from CHOOZ reactor exp
• At the same Dm2 as nm disapp. ?Support 3gen. mix.
  framework
• Open possibility to search for CPV (qany0 ? No
  CPV)
• Mass hierarchy (sign of Dm2)
• CPV
• Approaches
• LBL experiment Multi purpose (q13,
  sign(Dm2),CPV, q23,Dm232)
• Reactor-based ne disappearance single purpose
  (q13), complementary

11
nm?ne appearance in LBL exp
Main
CP-odd
Solar
Matter
Matter eff.
Size of q13 critical !
12
T2K experiment (approved start in 2009)
Long baseline neutrino oscillation experiment
from Tokai to Kamioka.
1GeV nm beam (?100 of K2K)
Super-K 50 kton Water Cherenkov
J-PARC 0.75MW 50GeV PS
Kamioka
Tokai
Phase2 4 MW ?
Phase2 Mton Hyper-K?

• Physics motivations
• Discovery of nm?ne appearance
• Precise meas. of disappearance nm?nx
• Discovery of CP violation (Phase2)

13
Japan Proton Accelerator Research Complex (J-PARC)
Materials and Life Science Experimental Facility
Construction 20012008
Nuclear and Particle Experimental Facility
Nuclear Transmutation
Neutrino to Kamiokande
3 GeV Synchrotron (25 Hz, 1MW)
50 GeV Synchrotron (0.75 MW)
Linac (350m)
14
J-PARC In JAERI Tokai-site
JAERIJapan Atomic Energy Research Institute
60km
February, 2004
15
J-PARC Neutrino facility
Approved in Dec. 2003 for 5 years
construction (20042008JFY)
Primary Proton beam line
Extraction point
50GeV ring
Components

• Primary proton beam line
• Target/Horn system
• Decay volume (130m)
• Beam dump
• Muon monitor
• Near neutrino detector (280m)
• Second near neutrino detector (2km) not
  approved yet

Target/Horns
Target station
Decay volume
beam dump
Muon monitor
Near neutrino detector
SK direction
16
Ground breaking of n facility _at_ J-PARC

• Decay volume part
• July, 2004

17
Off Axis Beam
On-axis
(ref. BNL-E889 Proposal)

• Quasi Monochromatic Beam
• x 23 intense than NBB
• First real application

Tuned at oscillation maximum
Statistics at SK (OAB 2 deg,1 yr,22.5 kt)
4500 nm tot 3000 nm CC ne 0.2 at nm peak
OAB2.0deg OAB2.5deg OAB3.0deg
18
T2K sensitivity on ne appearance
Off axis 2 deg, 5 years
at
d0, q23p/4
10 sys. err
CHOOZ excluded
Dm2
x20
Off axis 2 deg, 5 years
Sin22q13gt0.006
sin22q13
sin22q13 Background in Super-K (as of Oct 25, 2001) Background in Super-K (as of Oct 25, 2001) Background in Super-K (as of Oct 25, 2001) Background in Super-K (as of Oct 25, 2001) Background in Super-K (as of Oct 25, 2001) Signal Signal BG
sin22q13 nm ne nm ne total Signal Signal BG
0.1 12.0 10.7 1.7 0.5 24.9 114.6 139.5
0.01 12.0 10.7 1.7 0.5 24.9 11.5 36.4
19
Sensitivity for CPV in T2K-II
CHOOZ excluded sin22q13lt0.12_at_Dm3123x10-3eV2
Dm2126.9x10-5eV2 Dm3222.8x10-3eV2 q120.594 q23
p/4
stat5syst.
stat2syst.
(signalBG) stat only
stat10syst.
no BG signal stat only
T2K 3s discovery
T2K-I 90
3s CP sensitivity dgt20o for sin22q13gt0.01
with 2 syst.
20
NOnA

• Use Existing NuMI beamline
• New 50kt fine grained detector _at_800km and _at_ 12km
  off axis
• Liq scint. tracker particle board absorber
  (1/3X0)
• (Alternativefull active liq.sci.)
• Possible future upgrade of MI (0.4MW?2MW)Proton
  driver
• Proposed. (2008?)

Assuming Dm22.5x10-3eV2
Messier, n2004
21
NOnA Physics Reach
ne appearance
Mass hierarchy
50kton baseline detector
50kton baseline detector
Feldman, Aspen PAC 2004
22
Europe SPL?Frejus

• 4MW 2.2GeV Superconducting Proton Linac (SPL) _at_
  CERN
• Low energy wide band (En0.3GeV)
• L130km
• Water Cherenkov 40? 400kt (UNO)
• 18,000 nm CC/year/400kt
• q13, CPV
• Small matter effect
• SPL in RD, UNO in conceptual design

23
BNL-Homestake
(Ref Diwan et al., PRD68, 012002, 2003)

• 28GeV AGS upgrade to 1MW (2MW) cf current 0.1MW
• Wide band beam (0.56GeV)
• L2,540km
• Mton detector
• 13,000 nm CC/year/500kt
• Cover higher osc. maxima
• Goals
• ne appearance
• Sign of Dm23
• CPV
• q12, Dm12
• Possible w/ only n run at certain parameter
  region
• LOI written.

24
Brookhaven to Homestake Physics Reach
Even with only n data, CP violation and mass
hierarchy are visible in some regions of
parameter space.
Normal hierarchy
Reversed hierarchy
Diwan, 3/2004 APS study meeting
25
Reactor ne disappearance

• ne from nuclear reactor ltEgt3MeV
• 1-P(?e? ?e) sin2(2?13)sin2(?m231L/4E)
  O(?m221/?m231) pure q13
• Small systematic error (lt1) required
• Identical near det _at_ O(100)m far det _at_a few km

G. Mention (APC)
ne signature
26
Complementarity of Reactor-Accelerator Meas.
Reactor Measurement Pure sin22q13 measurement
Reactor-Accelerator combination gt a lot of
physics potential
Answer to q23 degeneracy
J-PARC Measurement
If accuracy is good enough gt sindl
Reactor Measurement
27
Reactor experiment proposals
Penly Chooz Cruas
Braidwood
Daya bay
Krasnoyarsk
Kashiwasaki
Diablo Canyon
Approved in france
Taiwan
90CL Sensitivity sin2q13 q13(deg)
0.020.03
2008
Angra
28
Double-CHOOZ

• Twin reactor cores
• P2x4.2 GWth
• Two 10 tons detectors
• 80 dodecane 20 PXE 0.1 Gd
• Near 100-200 m 60-80 mwe
• Far 1.05 km - 300 mwe
• 3 years Sensitivity
• 0.6 systematics
• No signal sin2(2?13) lt 0.02-03 (90 C.L.)
• Signal sin2(2?13) gt 0.04-05 (3s)
• Prospect (approved funded in France)
• 2007 far detector running
• 2008 near detector running
• Cost 7Meuros civil constr.

Near detector site (to be built)
Near
Far
Existing Far detector site
29
Summary

• First 1st generation experiment K2K
• Confirmed n oscillation observed in atm n at SK
  _at_3.9s
• Waiting precise meas. from MINOS(2005), nt app.
  from CNGS(2006)
• Next important issues
• Discovery and measurement of only unknown mixing
  q13
• Mass hierarchy
• CP violation
• Next generation LBL experiments covers most
• T2K using J-PARC and SK started construction.
  Start exp. In 2009
• q13 sensitivity 0.006 (90CL), 0.018 (3s)
• d20deg in phase 2
• NOnA proposal w/ similar potential to T2K
• Pure q13 measurements by reactor experiments
• complementary to disentangle parameter relations
• q13 sensitivity 0.010.03 (90)
• Systematic error (lt1) is key issue
• Double-CHOOZ is partially approved
• Neutrino field will continue to be very exciting
  for coming decades

30
Attempt to compare Double-Chooz with T2K (3s
discovery potential)
Double-CHOOZ starts with two detectors in January
2008 T2K starts at FULL intensity in January 2010
Assumption
From Huber, Lindner, Schwetz (hep/0405032)
31
Expected sensitivites
nm disappearance
ne appearance
MINOS
(5 years, 3kt)
MINOS 5yrs 90 and 99 CL
90 CL Exclusion Limits
For Dm2 0.0025 eV2, sin2 2q 1.0
d(Dm2)2x10-4eV2 d(sin22q)5 read from above plot
32
Double-CHOOZ prospect for ?13
Discovery potential sin2(2?13)gt0.04 (3s)
Far detector
?m22.4 10-3 eV2
c)
a)
Sensitivity sin2(2?13)lt0.03 (90 C.L.)
7 m
b)
d)
10 tons, 3 years
P. Huber et. al. hep/0403068
?m22.0 10-3 eV2
a) ? target 0.1 Gd doped scintillator
b) ?-catcher undoped scintillator
c) buffer non scintillating oil
d) Muon Veto scintillating oil
Th. Lasserre (Saclay)
33
Sensitivity on ne appearance
K2K excluded (2003)
Excluded by CHOOZ
Assume design intensity From the beginning
MINOS
ICARUS 5yr?
90 Sensitivity on sin22q13
Typical limit of proposed reactor n exps.
0.006 in 5 years
34
sin2(2?13) at LBL reactors
?m22.0 10-3 eV2
5 years
3 years
T2K
5 years
Nova
Th. Lasserre
35
Reconstruction of Super-K II

• Reconstructed in October 2002
• 47 of the PMTs (5200)
• Full OD 8 inch PMTs (1885)
• PMTs in plastic shells to prevent future chain
  implosions

36
Full reconstruction schedule(approved)
2003
2004
2005
2006
10
6
4
Today
SK-II

• Reconstruction
• Nov,2005 to March, 2006
• Water filling April and May in 2006
• Start taking data from June 2006

37
Sensitivity for Mixing Angle
sin22q130.018 (3s)
sin22q130.006 (90)
0.5xsin22q13
Background systematic error required to be less
than 10
38
Sensitivities
Search for ne appearance
nm disappearance
J-PARC
NOnA
excluded by reactor
x20
J-PARC
True Dm232 (eV2)
d(sin22q)0.01 in 5 years d(Dm2) lt110-4 in 5
years
J-PARC1 sin22q13gt0.006 NOnA sin22q13gt0.005
J-PARC w/ beam MC sim, full SK det. sim.
39
T2K collaboration

• Formed in May 2003
• 12 countries, 53 institutions
• 150 collaborators
• Spokesperson K.Nishikawa

CanadaTRIUMF, U. Alberta, York U., U. Toronto,U.
Victoria, U. Regina ChinaIHEP(Inst. Of High
Energy Phys.) FranceCEA Saclay ItalyU. Roma,
U. Bari, U. Napoli, U. Padova JapanICRR, U.
Tokyo, KEK, Tohoku U., Hiroshima U., Kyoto U.,
Kobe U., Osaka City U., U. Tokyo, Miyagi U. of
Education KoreaSeoul National U., Chonnam
National U., Dongshin U., Kangwon U., Kyungpook
National U., KyungSang National U.,SungKyunKwan
U., Yonsei U. PolandWarsaw U. RussiaINR Spain
U. Barcelona, U. Valencia SwitzerlandU.
Geneva UKRAL, Imperial College London, Queen
Mary Westfield College London, U.
Liverpool USAUCI, SUNY-SB, U. Rochester, U.
Pennsylvania, Boston U., CSU, Duke, Dominguez
Hills, BNL, UCB/LBL, U. Hawaii, ANL, MIT, LSU,
LANL, U. Washington
2
40
Detectors for CNGS
T300 data
ECC

• OPERA
• t identification by decay topology (kink)
• ECC (Emulsion Cloud Chamber)
• Proven by DONUT experiment
• 1.7kton of ECC
• 206,336 bricks
• Spectrometer (electronic tracker 1.6T dipole)

• ICARUS
• t identification by kinematic var. dist.
• 3kton Liq Ar TPC
• Constructed proved performances of 300ton
  module at Pavia
• Installation of T600 module to Gran Sasso
  recommended
• Construction of 3kton by the CNGS beam (2006)

41
Long baseline osc. experiments

• 1st phase experiments (Now)
• Confirmation of atm. n results
• K2K(1999)/MINOS(2005)/ICARUS/OPERA(2006)
• 2nd phase experiments (Now10yrs)
• Discovery of ne appearance
• Designed Optimized aft. SK atm n
• MW beam w/ 50kton detector
• T2K-I (approved. 2009)/NOnA (2009?) / (C2GT)
• 3rd phase experiments(1020yrs?)
• CP violation and mass hierarchy thru nm?ne app.
• Typically Multi-MW beam Mton detector
• 2nd phase is critical step to go

Classification by G.Feldman _at_SB WS_at_BNL
42
Expected of nt evts in 5yrs

• full mixing

OPERA

Dm2 (x 10-3eV2) signal 1.8 signal 2.5 signal 4.0 Back
Final Design 9.0 17.2 43.8 1.06
With possible improvements 10.3 19.8 50.4 0.67
40 from charm Changeable Sheet (15
eff.), dE/dx (charm reduction by 40)
ICARUS (T3000)
1.5 kton fiducial
43
T2K-II

• (0.75MW?)4MW 50GeV PS _at_ J-PARC
• OA 23deg
• Enpeak0.50.8GeV
• L295km
• Hyper Kamiokande
• 360k nm CC/yr
• q13, CPV
• Small matter effect

OAB2.0deg OAB2.5deg OAB3.0deg
44
Far Detector Hyper-Kamiokande
2 detectors48m 50m 250m, Total mass 1 Mton

45
CPV vs matter effect
nm?ne osc. probability w/ CPV/matter
295km
730km
_at_sin22q130.01
Smaller distance/lower energy ? small matter
effect Pure CPV Less sensitivity on sign of
Dm2 Combination of diff. EL help to solve.
46
n / n CC interaction spectrum for CPV meas.
nm
cross section difference
NCC(/100MeV/22.5kt/year)
nm
Wrong sign BG (x10 nm case)
47
Cross section difference
5
CCqe ratio diff 15 _at_ energy window
Quick rise in low energy side ? need detailed
info. ? cross section measurement? (nfact?)
48
ne(bar) disappearance (q12, Dm122)

• Combined results of
• Solar neutrino observations (SK, SNO, )
• Reactor anti-n observation (KamLAND)
• Large mixing!

J.N. Bahcall et al., J. High Energy Phys. (2003)