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Establish 3 flavor framework (or find something new) Discovery ... Give hint on Matter/Anti-matter asymmetry in the universe. What's super muon-neutrino beam? ... – PowerPoint PPT presentation

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Title: Super%20muon-neutrino%20beam


1
Super muon-neutrino beam
nFact02 July 1, 2002 Imperial College London
  • Takashi Kobayashi
  • IPNS, KEK
  • Contents
  • Introduction
  • Super-beam long baseline experiments
  • Physics sensitivity
  • Summary

2
Next goals of LBL experiments
  • Establish 3 flavor framework (or find something
    new)
  • Discovery of ne appearance (q13gt0?)
  • At the same Dm2 as nm disapp. ?Firm evidence of
    3gen. mix.
  • Open possibility to search for CPV
  • Confirmation of nm?nt
  • Appearance
  • NC measurement
  • Precision measurements of ocs. params.
  • Dm23,q23/Dm13,q13
  • Test exotic models (decay, extra dimensions,.)
  • Sign of Dm2
  • Search for CPV in lepton sector
  • Give hint on Matter/Anti-matter asymmetry in the
    universe

3
Whats super muon-neutrino beam?
Conventional neutrino beam production
with MW-class proton beam
For high precision LBL experiments
4
Super beam LBL experiments 2nd generation
LBL experiments w/ high intensity conventional
beam
  • High statistics
  • Beam intensity ?100kW ? ?MW (super beam)
  • AND/OR detector mass 10kt ? 1001,000kt
  • Designed and optimized after the knowledge of
    Super-Kamiokande/K2K results
  • Primary goal ne app. ? CPV, sign of Dm2
  • Japan JHF(off-axis)?SK/HK
  • FNAL Off-axis NuMI, Proton driver upgrade,
  • BNL Super AGS(off-axis)??
  • CERN SPL?Furejus, Off-axis CNGS

5
Next critical pathnm?ne appearance
Backgroud
Signal
  • Beam intrinsic ne contamination
  • Identical signature w/ signal
  • Different energy distribution
  • NC p0 production
  • NC multi pion production

nm
ne
Single EM shower
6
Key for ne appearance experiment
  • High statistics
  • Small background contamination (beam)
  • intrinsic ne ? short decay pipe,
  • off-axis, ? less high energy tail ? less
    inelastic
  • Background rejection (beamdetector)
  • event topology (e?p0)
  • narrow spectrum beam w/ neutrino energy
    reconstruction
  • ? additional kinematical constraint
  • Small systematic error on background estimation
  • near/far spectrum difference
  • cross section
  • detector response

7
High intensity narrow band beam-- Off-axis (OA)
beam --
(ref. BNL-E889 Proposal)
nm flux
Decay Kinematics
1
2
5
1/gpq
  • Increase statistics _at_ osc. max.
  • Decrease background from HE tail

8
Charged current cross sections
  • Inelastic
  • NCp0
  • multi p
  • .

CCqe dominate ?1GeV Inelastic dominate ?1GeV
Backgroud
CCqe (nmn?mp)
9
Background rejection
Typical OA spectrum
  • Event topology
  • p0 for example,
  • additional EM activity?
  • vertex displacement (g flight)
  • angular distribution
  • intrinsic beam ne no way
  • En distribution
  • Signal peaked at osc. max.
  • Fake ne event by p0beam ne broad

OA2deg_at_JHF
nm
ne
10
En reconstruction
  • ?1GeV
  • 2-body kinematics
  • of dominant CCqe
  • Water Ch. works well
  • ?1GeV
  • Inelastics (nuclear resonances) dominate
  • (Fine grain) sampling calorimeter. Resolution?
  • Full reconstruction of secondary particles?

11
En reconstruction ?1GeV region
?
CC quasi elastic reaction
p
CCqe
Inelastic (BG)
SK Full Det. Sim.
s80MeV(10) limited by Femi motion
Small BG
12
Syst. error far/near spectrum diff.
K2K case (MC)
FD(300m) (xLSK2/LFD2)
SK
Large(x2) effect around peak!!
Important not only for nm disappearance, but also
for sig/BG estimation for ne search
13
(super-beam) LBL experiments
Ep (GeV) Power (MW) Beam ltEngt (GeV) L (km) Mdet (kt) nmCC (/yr) ne _at_peak
K2K 12 0.005 WB 1.3 250 22.5 50 1
MINOS(LE) 120 0.41 WB 3.5 730 5.4 2,500 1.2
CNGS 400 0.3 WB 18 732 2 5,000 0.8
JHF-SK 50 0.75 OA 0.7 295 22.5 3,000 0.2
JHF-HK 50 4 OA 0.7 295 1,000 600,000 0.2
OA-NuMI 120 0.3 OA 2 730? 20kt? 1,000? 0.5
OA-NuMI2 120 1.2 OA 2 730? 20kt? 4,000? 0.5
AGS??? 28 1.3 WB/OA 1 2,500? 1,000? 1,000?
SPL-Furejus 2.2 4 WB 0.26 130 40(400) 650(0) 0.4
OA-CNGS 400 0.3 OA 0.8 1200 1,000? 400 0.2
  • The plans are in very different phases. Most are
    in optimization phase.
  • JHF-SK most advanced
  • budget request submitted
  • EXISITING real detector

14
JHF-Kamioka Neutrino Project
(hep-ex/0106019)
Plan to start in 2007
1GeV n beam
Kamioka
JAERI (Tokaimura)
Super-K 22.5 kt
Hyper-K 1000 kt
0.77MW 50 GeV PS
4MW 50 GeV PS
( conventional n beam)
Phase-I (0.77MW Super-Kamiokande) Phase-II
(4MWHyper-K) Phase-I ? 200
15
Principle of JHF-Kamioka project
  • Intense Narrow Band Beam by off-axis.
  • Beam energy is at the oscillation maximum.
  • High sensitivity, less background
  • 1 GeV n beam for Quasi-elastic interaction.

m events
En(reconstruct)
s80MeV
En(reconstruct) En (True) (MeV)
En (True)
16
JHF Facility
Super Conducting magnet for n beam line
JAERI_at_Tokai-mura (60km N.E. of KEK)
(0.77MW)
Construction 20012006 (approved)
Near n detectors _at_280m and _at_2km
Budget Request of the n beam line submitted
1021POT(130day) 1 year
17
Expected spectrum
ne contamination
0.21
m-decay
K-decay
Very small ne/nm _at_ nm peak
4500 tot int/22.5kt/yr 3000 CC int/22.5kt/yr
18
Detectors at near site
  • Muon monitors _at_ 140m
  • Behind the beam dump
  • Fast (spill-by-spill) monitoring of beam
    direction/intensity
  • First Front detector Neutrino monitor _at_280m
  • Intensity/direction
  • Neutrino interactions
  • Second Front Detector _at_ 2km
  • Almost same En spectrum as for SK
  • Absolute neutrino spectrum
  • Precise estimation of background
  • Investigating possible sites

Neutrino spectra at diff. dist
1.5km
295km
280m
0.28km
19
Far Detectors
1st Phase (2007, 5yrs) Super-Kamiokande(22.5kt)
2nd Phase (201x?) Hyper-Kamiokande(1Mt)
41.4m
40m
48m 50m 500m, Total mass 1 Mton
20
USA FNAL and BNL plan
  • BNL Super AGS (1.3MW, LOI submitted)
  • FNAL Super NUMI (1.6 MW) or the new proton
    driver.

(hep-ex/0205040,0204037,hep-ph/0204208)
Soudan
Off-axis beams 2 detectors
Homestake
WIPP
100km
FNAL
BNL
21
OA-NuMI
A. Para, M. Szleper, hep-ex/0110032
Osc. max. _at_ 730km 1.8GeV (Dm23x10-3eV2)
  • Features
  • Nuclear resonance region
  • ? Inelastic background
  • ? Energy reconstruction?
  • Too large angle? Kaon peak
  • Beam goes 3.5deg downward
  • ? hard to place 2nd near det. ? Far/near
    ratio?
  • Para/Szlepers prescription
  • using Matrix (hep-ex/0110001)

K decay
0.78deg
22
Europe SPL?Furejus
CERN
Geneve
  • SPL _at_ CERN
  • 2.2GeV, 50Hz, 2.3x1014p/pulse
  • 4MW
  • Now under RD phase

130km
40kt ?400kt
Italy
23
Detectors
Liquid Ar TPC (100kton)
UNO (400kton Water Cherenkov)
24
Physics Sensitivity
25
ne appearance in JHF-Kamioka (phase 1)
Backgrounds
9.3 events
1.8 events
11.1 events
Signal
123.2 events _at_ sin22q130.1, Dm2310-3eV2
(5 years running)
26
ne appearance (continue)
sin22qme0.05 (sin22qme ? 0.5sin22q13)
Dm2
CHOOZ
20 improvement
310-3
sin22qme 1/2?sin22q13
sin22q13lt0.006 (90 C.L.)
27
nm disappearance
1ring FC m-like
dsin22q
Oscillation with Dm2310-3 sin22q1.0
d(sin22q)
OAB-2degree
Non-QE
0.01
3?10-3
True Dm2
Reconstructed En (MeV)
dsin22q23 0.01 dDm232 lt 110-4eV2
28
Sensitivity(3s) to CPV(2nd phase)
Chooz excluded
_at_Dm313x10-3eV2
dgt14deg
dgt27deg
Preliminary
JHF1 3s discovery
29
US Super n beam
  • They are studying the physics potential of
    several options, which are competitive to
    JHF-Kamioka project.

NUMI-offaxis
0.003
Ue32 1/4?sin22q13
30
Possibility to discriminate sign of Dm2 (Matter
effect)
hep-ex/0206025
  • Small matter effect in JHF-SK (1GeV-295km)
  • Other longer baseline projects could play
    complementary role

OA-NuMI MC study
Dm232true
Running time nmnm13 (cross sec. diff)
3s
For example, 5yrs of OA-NuMIx20kt(w/ proton
driver)
31
Summary
  • Exciting topics in 2nd generation LBL
    experiments.
  • ne appearance
  • CPV, sign of Dm2,
  • Several super-beam experiments are under
    consideration
  • US, Europe and Japan
  • They are in very different stages.
  • Earliest beam is expected in 2007 at JHF-Kamioka
    project
  • Accelerator construction started in 2001.
  • Budget request for n facility submitted this year.

32
Summary (II)
  • Physics sensitivity of JHF-Kamioka project
  • sin2q130.006 (90CL)
  • d(Dm2)?3, d(sin2q23)1
  • can discover CPV if d?20o (in 2nd phase)
  • Experiments are complementary each other
  • JHF-Kamioka hard to see matter effect
  • ? Longer baseline/higher energy experiments
  • nFact will come after the (at least) 1st round of
    super-beam experiments (1020yrs)
  • If sin2q13?0.01, JHF-SK may not see, but JHF-HK
    may.
  • But sensitivity to CPV in JHF-HK reduces
  • ? CPV in nFact?

33
Future Prospect
2002 JHFn budget requestapproval 2003 start
construction 2005 K2K final results
2007
JHF1
Hint?
201x
3s discovery
JHF2 Search q13 lt10-3 Proton decay
JHF2 CPV precision meas. q13 Proton decay
20xx
Future SuperBeam, VLBL, n-fact for very small
q13, CPV, sign of Dm2
34
(Super) Neutrino Beams
ltEngt (GeV) L (km) CC n/kt/yr L/Losci. f(ne) _at_peak
K2K 1.3 250 2 0.47 1
NuMi (High E) 15 730 3100 0.12 0.6
NuMi (Low E) 3.5 730 469 0.51 1.2
CNGS 17.7 732 2448 0.10 0.8
JHF-I 0.7 295 133 1.02 0.2
Numi off-axis 2.0 730 80 0.89 0.5
JHF-II 0.7 295 691 1.02 0.2
SPL 0.26 130 16.3 1.21 0.4
35
FNAL, BNL to Soudan
1? off-axis
Events/0.1GeV/5years/100kTon
Events/0.1GeV/5years/10kTon
x
  • Water Cherenkov like Super-K

36
3. Experiments with the super neutrino beam
37
Contents
  • Introduction
  • Physics goals of next generation long baseline
    experiments
  • Super-beam experiments
  • Physics potential of super-beam experiments
  • Comparison with nFact
  • Open questions
  • Summary

38
Far/near spectrum ratio
0.5km
Decay pipe len. LDV80m
0.28km
want near det. _at_ ?10xLDV
1.0km
1.5km
2.0km
0 1 3 5 (GeV)
39
Sensitivity for Mixing Angle
sin22qme sensitivity
JHF2-HK 1yr
40
nm ?nt confirmation w/ NC interaction
  • NC p0 interaction (n N ? n N p0)
  • nm? ne CC NC(0.5CC) 0 (sin22qme0)
  • nm CC NC(0.5CC) 0 (maximum
    oscillation) nt
    NC
  • p0 is sensitive to nt flux. Limit on ns
    (df(ns)0.1)

nm? nt
CC
nt
t
p0 e-like
D39044
nt
NC
nt
nm? ns
p0
3.5?10-3
Dm232
41
(High Intensity) Proton Accelerators
Power (MW) Energy (GeV) Intensity (1012 ppp) Rep. rate (Hz)
KEK-PS 0.005 12 6 0.45
AGS 0.14 24 60 0.6
FNAL-MI 0.41 120 40 0.53
SPS 0.3 400 35 0.16
JHF-I 0.77 50 330 0.29
Super-AGS 1.3 28 120 2.5
FNAL-proton driver-I 1.2 16 30 15
SPL 4 2.2 230 50
JHF-II 4 50
Not the construcion stage yet, but RD stage.
42
Some ideas for OA-NuMI detector(under
consideration)
SOMINOS(FeSci) SzleperVelasco
Plastic pellets RPC (A.Para)
20m
20m
5kt, 12m dia., 875planes
1m
70ton/plane
43
Super Proton Linac (SPL) _at_ CERN
Reuse some parts from LEP
Under RD phase
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