Transcript Document 7180471

Neutrino Factory
(and the International Scoping Study (ISS))
mother link http://muonstoragerings.cern.ch (see NUFACT05)
and http://www.hep.ph.ic.ac.uk/iss/
‘ECFA/CERN studies of a European Neutrino Factory Complex' CERN 2004-002
and
Physics with a MMW proton driver (MMW workshop) CERN-SPSC-2004-024
POFPA 18 october Alain Blondel
ECFA/04/230
Kayser -- EPS05
Accelerator neutrinos are CENTRAL to the future program.
POFPA 18 october Alain Blondel
POFPA 18 october Alain Blondel
1. An ambitious neutrino programme is a distinct possibility,
but it must be well prepared to have a good proposal in time for the big decision
period in 2010 (Funding window: 2011-2020)
2. Two avenues have been identified as promising
a) SuperBeam + Beta-Beam + Megaton detector (SB+BB+MD)
b) Neutrino Factory (NuFact) + magnetic detector
The physics abilities of the neutrino factory are (much) superior
in particular for flux normalisation
but….. « what is the realistic time scale? »
3. (Hardware) cost estimate of a neutrino factory ~1B€ + detectors.
This needs to be verifed and ascertained on a localized scenario (CERN, RAL…)
and accounting.
The cost of a (BB+SB+MD) is not very different
Cost/physics performance/feasibility comparison needed
POFPA 18 october Alain Blondel
-- Neutrino Factory -CERN layout
1016p/
s
1.2 1014 m/s =1.2 1021 m/yr
0.9 1021 m/yr
3 1020 ne/yr
3 1020 nm/yr
m+  e+ ne
_
nm
oscillates ne 
nm
interacts giving mWRONG SIGN MUON
POFPA 18 october Alain Blondel
interacts
giving m+
Neutrino fluxes m+ -> e+ ne nm
nm/n e ratio reversed by switching m+/ mne nm spectra are different
No high energy tail.
Very well known flux (aim is 10-3)
- absolute flux measured from muon current
or by nm e- -> m- ne in near expt.
-- in race track or triangle ring,
muon polarization precesses and averages out
(-> calib of energy, energy spread)
-- E&sE calibration from muon spin precession
-- angular divergence: small effect if q < 0.2/g,
can be monitored
similar comments can be made for beta-beam,
but not for superbeam.
m polarization controls ne flux:
m+ -X> ne
in forward direction
POFPA 18 october Alain Blondel
Cervera et al
Detector
studies so far:
Iron calorimeter
Magnetized
Charge discrimination
B=1T
Fiducial mass = 40 kT
cut at 5 GeV muon.
old scheme!
Bueno et al
Also: L Arg detector: magnetized ICARUS
Wrong sign muons, electrons, taus and NC evts
*->
Baseline
732 Km
3500 Km
Events for 1 year 2 1020 muon decays
nm signal (sin2 q13=0.01)
nm CC
ne CC
3.5 x 107 5.9 x 107
1.2 x 106 2.4 x 106
1.1 x 105
1.0 x 105
CF ne signal
at J-PARC
=40
POFPA 18 october Alain Blondel
Studies and plots made so far have been based on this study by Anselmo Cervera,
which is optimized for the sensitivity to very low q13. Clearly cuts should be relaxed
for large values of q13.
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systematics……………………………………degeneracies
. correlations
approval date:
~NOvA +PD
(g=100, 130km)
b-beam + SPL3.5 SB+Mton
Lindner et al
newer plot should come out of scoping study – « correlations » are sensitive to
assuptions on the solar and atmospheric parameters– what will they be?
POFPA 18 october Alain Blondel
Three family oscillations look at nm ne oscillation
Mezzetto
L= p/2.54 E/dm2
l = p/2.54 E/Dm2
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CP violation
P(nenm) - P(nenm)
P(nenm) + P(nenm)
= ACP a
sind sin (Dm212 L/4E) sin q12
sinq13 + solar term…
… need large values of sin q12, Dm212 (LMA) but *not* large sin2q13
… need APPEARANCE … P(nene) is time reversal symmetric (reactor ns do not work)
… can be large (30%) for suppressed channel (one small angle vs two large)
at wavelength at which ‘solar’ = ‘atmospheric’ and for nenm , nt
… asymmetry is opposite for nenm and nent
P(nenm) = ¦A¦2+¦S¦2 + 2 A S sin d
P(nenm) = ¦A¦2+¦S¦2 - 2 A S sin d
POFPA 18 october Alain Blondel
T asymmetry for sin d = 1
!
asymmetry is
a few %
and requires
excellent
flux normalization
(neutrino fact., beta beam
or
off axis beam with
Maximum
Asymmetry
not-too-near
near detector)
NOTEs:
1. sensitivity is more or less
independent of q13 down to
max. asymmetry point
2. This is at first maximum!
Sensitivity at low values
of q13 is better for short
baselines, sensitivity at
large values of q13 is
better for longer baselines
(2d max or 3d max.)
error
arbitrary scale
0.10
0.30
10
30
3.sign of asymmetry changes
with max. number.
POFPA 18 october Alain Blondel
6%
90
Towards a comparison of performances on equal footing
CP violation example
P(nenm) - P(nenm)
P(nenm) + P(nenm)
= ACP a
sind sin (Dm212 L/4E) sin q12
sinq13 + solar term…
ne diff. cross-section*flux
to know nm and nm diff. cross-section and detection
Near detector should give
BUT:need
efficiency
with small (relative) systematic errors.
interchange role of
ne
and
nm for superbeam
in case of beta-beam one will need a superbeam at the same energy. Will it be
possible to measure the required cross sections with the required accuracy
at low energies with a WBB?
What is the role of the difference in mass between electron and muons?
how well can we predict it?
In case of sub-GeV superbeam alone how can one deal with this?
POFPA 18 october Alain Blondel
Zeller
ds/dn O(e,e), n=Ee-Ee’=Enegy transfer (GeV)
Ee=700-1200 MeV
These are
for electron
beam.
errors are ~5-10%
but what happens
when a muon mass
is involved?
Blue: Fermi-gas
Green: SP
Red: SP+FSI
QE
D
POFPA 18 october Alain Blondel
A discussion is necessary to establish reasonable systematic errors
in measuring the CP or T asymmetry
this discussion should include the following questions:
1.
what kind of near detector will be needed?
2. how does one measure the cross-section*efficiency of the appearance
channel in a beam with only one flavor? (superbeam or beta-beam alone)
my guess: these issues will be quite serious at low energies (E ~ few mm )
and gradually become easier at high Energies.
Neutrino factory provides all channels in the same beam line/detector
POFPA 18 october Alain Blondel
CP asymmetries and matter effect
compare nenm to nenm probabilities
m is prop. to matter density, positive for neutrinos, negative for antineutrinos
A=
+
_
m / ne - m / ne
-
+
_
m / ne + m / ne
-
HUGE effect for distance around 6000 km!!
Resonance around 12
GeV when
Dm223 cos2q13  m = 0
POFPA 18 october Alain Blondel
CP violation (ctd)
Matter effect must be subtracted. One believes this can be done with uncertainty
of order 2%. This is potential systematic error for large values of sin22q13!
However the energy shape of matter effect and CP violation are different
It is important to subtract in bins of measured energy.
knowledge of spectrum is essential here!
low threshold is crucial since matter effect is reduced at low E
while CP asymmetry changes sign from 1st (6 GeV@300km) to 2d max (2 GeV@3000km)
De Rujula, Gavela, Hernandez
5-10 GeV
10-20 GeV
20-30 GeV
30-40 GeV
40-50 GeV
40 kton L M D
50 GeV nufact
5 yrs 1021m /yr
In fact, 20-30 GeV
Is enough!
Best distance is
2500-3500 km
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NB: This works just as well
INO ~7000 km (Magic distance)
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4MW, 1 Mton
upgrade of T2K
By 2010 we must
know how much these
facilities cost and how
long they would take
to build.
assume
2% flux error in T2K
vs.
5% matter eff. error
on nufact
and 5 GeV muon thres.
NUFACT with
thick magnetized
Iron detector
in two locations
7000km
and 3000 km
POFPA 18 october Alain Blondel
right-sign muons
wrong-sign muons
electrons/positrons
positive t-leptons
negative t -leptons
no leptons
X2 (m+ stored and m- stored)
Simulated distributions for a 10kt LAr detector
at L = 7400 km from a 30 GeV nu-factory with
1021 m+ decays.
Bueno, Campanelli, Rubbia; hep-ph/00050007
a)
b)
c)
d)
e)
f)
20
Events
Oscillation parameters can be
extracted using
energy distributions
Note: ne  nt is specially important
(Ambiguity resolution & Unitarity
test): Gomez-Cadenas et al.
EVIS (GeV)
channel at neutrino factory
High energy neutrinos at NuFact allow observation of
A. Donini et al
nent
(wrong sign muons with missing energy and P). UNIQUE
Liquid Argon or OPERA-like detector at 732 or 3000 km (better)
Since the sind dependence has opposite sign with the wrong sign muons, this solves ambiguities
that will invariably appear if only wrong sign muons are used.
d
q13
ambiguities with
only wrong sign muons (3500 km)
associating taus to muons
equal event number curves
(no efficencies, but only OPERA mass)
muon vs taus
studies on-going
POFPA 18 october Alain Blondel
e.g. Rigolin, Donini, Meloni
POFPA 18 october Alain Blondel
Wrong sign muons
alone
Wrong sign muons
and taus
Wrong sign muons
and taus
+ previous exp.
POFPA 18 october Alain Blondel
red vs blue = different baselines
red vs blue = muons and taus
dashed vs line = different energy bin
(most powerful is
around matter resonance @ ~12 GeV)
POFPA 18 october Alain Blondel
Conclusion:
Neutrino Factory has many handles on the problem
(muon sign + Gold + Silver + different baselines + binning in energy)
thanks to high energy!
"It could in principle solve many of the clones for q13 down to 10
The most difficult one is the octant clone which will require
a dedicated analysis" (Rigolin)
POFPA 18 october Alain Blondel
TARGET DATE: 2010
2010 will be a time
of major decisions
in particle physics
LHC will be completed
first results will appear
ILC 
first results from
MINOS, OPERA
double-CHOOZ
might be available.
T2K will be starting
and very rapidly
dominating!
It will be time for the
next step
in neutrino physics!
Barry Barish, CERN SPC sept05
POFPA 18 october Alain Blondel
evolution of sin22q13 sensitivity
Mezzetto
observation and study of CP violation requires
-- all accelerator neutrinos n
n
n
n
e
m
e
m
-- high precision in
neutrino vs antineutrino normalization
-- redundancy.
probably out of reach of these experiments
 need to go further
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4MW, 1 Mton
upgrade of T2K
By 2010 we must
know how much these
facilities cost and how
long they would take
to build.
assume
2% flux error in T2K
vs.
5% matter eff. error
on nufact
and 5 GeV muon thres.
2010
NUFACT with
thick magnetized
Iron detector
in two locations
7000km
and 3000 km
POFPA 18 october Alain Blondel
Design study
Design study will take place in two phases
1. Scoping study:
understand what are the most important parameters
of the facility to be studied, what are the critical tests to be performed,
and how to organize it. Assemble the team.
2. Design study:
proceed to the design study and associated R&D experiments,
with the aim to deliver a CDR that a laboratory can chose as its next project.
For design study we intend to request EU funding – probable date spring 2007
It will be WORLD WIDE:
1. It is likely that there will be no more than one Megaton detector and/or
one Neutrino Factory in the world so we better agree on what we want.
2. Expertise on Neutrino Factory is limited world-wide (mostly in US)
3. Resources e.g. at CERN are also very limited
4. International community meets regularly at NUFACT meetings and is engaged
in common projects (R&D experiments)
Muon cooling exp. MICE at RAL, Target Experiment nTOF11 at CERN
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Collaborators
------
of the
scoping study:
ECFA/BENE working groups (incl. CERN) (funded by CARE)
Japanese Neutrino Factory Collaboration
US Neutrino Factory and Muon collider Collaboration
UK Neutrino Factory Collaboration (also part of BENE)
others (e.g. India INO collaboration, Canada, China, Corea ...)
~400-500 persons
objectives:
 Evaluate the physics case for a second-generation super-beam, a beta-beam facility and
the Neutrino Factory and to present a critical comparison of their performance;
 Evaluate the various options for the accelerator complex with a view to defining a baseline
set of parameters for the sub-systems that can be taken forward in a subsequent
conceptual-design phase;
 Evaluate the options for the neutrino detection systems with a view to defining a baseline
set of detection systems to be taken forward in a subsequent conceptual-design phase.
POFPA 18 october Alain Blondel
Physics
Yorikiyo Nagashima
compare performance of various options
on equal footing of
parameters and conventions
and agreed standards of
resolutions, simulation etc.
identify tools needed to do so
(e.g. Globes upgraded)
propose « best values » of
baselines, beam energies etc..
Detectors (NEW!)
Alain Blondel
1. Water Cherenkov (1000kton)
2. Magnetic sampling detector (100kton)
3. Liquid Argon TPC (100 kton)
magnetized Liquid Argon TPC (15kton)
4. Hybrid Emulsion (4 kton)
5. Near detectors (and instrumentation)
( SB,BB or NF )
coordination
Peter Dornan
+
‘wise men’
Ken Peach
Vittorio Palladino(BENE)
Steve Geer
Yoshitaka Kuno
Michael Zisman
-----
Accelerator:
proton driver (energy, time structure and consequences)
target and capture (chose target and capture system)
phase rotation and cooling
acceleration and storage
evaluate economic interplays and risks
include a measure of costing and safety assessment
POFPA 18 october Alain Blondel
Time scales:
NUFACT05
26 June 2005 launch of scoping study
CERN 22-24 September 2005 first meeting
KEK 23-25 January 2006,
RAL 27-29 April 2006 (BENE) (2-6 may meeting on the future of CERN in DESY-Zeuthen)
UC Irvine 21-23 August 2006 (just before NUFACT06)
NUFACT06 (summer 2006) discussion of results of scoping study
September 2006 ISS report
2007 full design study proposal submission to EU as design study.
2010 conclusions of Design Study & CDR
NB: This matches well the time scales set up at CERN – participation of CERN
is highly desirable to ensure that the choices remain CERN-compatible. This effort
is similar to and synergetic with the PAF and POFPA working groups at CERN.
NNBB we will try to have an available report at each ISS meeting.
POFPA 18 october Alain Blondel
Progress
The performance plots shown earlier mostly based on 2000-2002 ECFA study.
Much progress has been gathered since then.
1. accelerator performance:
study II-a (2004): use of RF phase rotation leads to capture of both mu+ and muglobal improvement by factor 4.8 (also reduction of cost to ~1G€ from 1.6)
 at 4MW on target, collect 9.6 1020 muon decays of one sign at a time in a 107 s year
in a racetrack geometry
in triangle geometry each straight gets 2/3 of this number.
2. detector performance:
. proposal (Nelson) of a 90 kton (was 40kton) detector with 4 times better granularity.
Expect threshold for muons to ~1.5 GeV for similar sign resolution. Cost estimate.
Electron ID? Tau detection?
. operation of (10 liters) Larg prototype in 0.5 T mag. Field.
. tau detectors should be feasible with ~4 times
mass
(4Blondel
kton)
POFPAOPERA
18 october
Alain
PROGRESS
3.Accelerator R&D
A. Target experiment nTOF11 MERIT is approved at CERN
(Data taking 2007)
B. MICE experiment approved at RAL
C. PRISM experiment (low energy muon FFAG) is approved at Osaka
D. 2004 study re-evaluated cost of NUFACT
POFPA 18 october Alain Blondel
Some Highlights of the first Scoping Study meeting
CERN 22-24 september 2005
see transparencies at:
http://dpnc.unige.ch/users/blondel/ISSatCERN.htm
register at http://www.hep.ph.ic.ac.uk/iss/
1. first presentation of the preliminary study for the Fréjus
underground laboratory
2. presentation of « feasible » 90 kton fine-grained magnetized iron
calorimeter for ~200M€ (same cost basis as NOvA)
3.
first observation of tracks in the magnetized liquid argon prototype
4. presentation of upgraded performance estimate for the neutrino factory
1021 muon decays per year per direction!
and status of beta-beam study.
5. planning of implementation of all sorts of detectors in a
common oscillation program GLOBES
6. performance vs primary proton energy
POFPA 18 october Alain Blondel
Megaton
Water Cherenkov
(J.-E. Campagne)
+ HV, electronics, etc..!
the largest single cavern is 4XSK.
need to add cost of electronics,
cavern and water treatment
 ~1G€
do we need so many tubes?
 R&D for photodetectors!!!
Japan-France collaboration
collaboration with industry
(Photonis)
POFPA 18 october Alain Blondel
POFPA 18 october Alain Blondel
Jeff Nelson
Detector concept: End view
Leslie Camillieri
Return yoke
alternatively could simply add a large
magnet to a NOvA-like design! (cost?)
Coil
“Nova-Like” Detector
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Coil
10 liters prototype liquid argon TPC
has been tested in 0.5 T at ETHZ
A. Rubbia
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$$$$$
… COST …
$$$$$
USA, Europe, Japan have each their scheme for Nu-Fact.
Only one has been costed, US 'study II' and estimated (2001) ~2B$.
The aim of the R&D is also to understand if one could reduce cost in half.
+ detector: MINOS * 10 = about 300 M€ or M$
Neutrino Factory CAN be done…..but it is too expensive as is.
Aim of R&D: ascertain challenges can be met + cut cost in half.
POFPA 18 october Alain Blondel
$$$$$
… COST …
$$$$$
41
Why we are optimistic:
In the previous design
~ ¾ of the cost came from
these 3 equally expensive
sub-systems.
New design has similar
performance to Study 2
performance and keeps
both m+ and m- !
(RF phase rotation)
NUFACT 2004: cost can be reduced by at least 1/3
= proton driver + 1 B €
==>the Neutrino Factory is not so far in the future after all…
S. Geer: We are working towards a “World Design Study” with an
emphasis on cost reduction.
protons on heavy target
(good for pi-)
Total Yield of p+ and p−
100GeV
120GeV
40GeV
50GeV
30GeV
20GeV
15GeV
5GeV
6GeV
75GeV
3GeV
0.1000
2GeV
Pions/(Proton*GeV)
0.1200
4GeV
0.1400
8GeV
10GeV
0.1600
Normalised
to unit
beam power
(-30%)
GEANT 4 Pi+
GEANT 4 PiMARS15 Pi+
MARS15 Pi-
0.0800
0.0600
Yields (on a tantalum rod) using
MARS15 and GEANT4.
0.0400
Better to include the acceptance of the
next part of the front end 
0.0200
0.0000
1
10
100
1000
Proton Energy (GeV)
POFPA 18 october Alain Blondel
100GeV
120GeV
30GeV
40GeV
50GeV
75GeV
0.005
3GeV
0.006
4GeV
0.007
20GeV
0.008
8GeV
10GeV
Somewhat
odd
behaviour
for
π+ < 3GeV
2.2GeV
Pions per Proton.GeV (est. Phase Rotator)
0.009
5GeV
6GeV
Phase Rotator
Transmission
(MARS15)
15GeV
The discontinuity between 3-5 GeV is suspicious
as it corresponds to change of model in MARS
(there is no real physics reason)
HARP data will be available end 2005-early 2006 at
3 GeV/c(2.2 GeV),
5 GeV/c (4.15 GeV),
8 GeV/c (7.1 GeV)
pi+/(p.GeV)
pi-/(p.GeV)
pi+/(p.GeV)
0.004
pi-/(p.GeV)
0.003
Doubled lines
give some idea of
stat. errors
Optimum moves down because higher
energies produce pions with momenta
too high for capture
0.002
0.001
0
1
10
100
1000
Proton Energy (GeV)
optimum 5-10 GeV. Within 30% of optimum: 4-40 GeV
POFPA 18 october Alain Blondel
Conclusions
1. The Neutrino Factory remains the most powerful tool imagined so far
to study neutrino oscillations
n n
Unique: High energy nenm and
e
t transitions
at large q13 has the precision
at small q13 has the sensitivity
Much progress can be envisaged in performance wrt early studies.
2. The complex offers many other possibilities (muons!)
3. It is a step towards muon colliders
4. There are good hopes to reduce the cost significantly thus making it
an excellent option for CERN in the years 2011-2020
5. Regional and International R&D on components and R&D experiments
are being performed by an enthusiastic and motivated community
International scoping study underway.
6. Opportunities exist in Europe and CERN:
HI proton driver, (CERN), Target experiment @ CERN, Collector @CERN
MICE @ RAL
POFPA 18 october Alain Blondel
Conclusions:
7. need to understand the best synergy between a neutrino programme
and the LHC lumi upgrade.
8. I would consider that re-instating a neutrino factory development team at CERN
to be a high priority for the 2006-2010 period!
9. there is quite a variety of detectors and experimental (near and far)
areas to design, which are well fit to CERN’s Experimental teams compentence.
POFPA 18 october Alain Blondel
Superbeam+Betabeam option
1.
What is the importance of the superbeam in this scheme?
T violation?
increased sensitivity?
have a (known) source of muon neutrinos for reference?
2. At which neutrino energy can one begin to use the event energy distribution?
Fermi motion and resolution issues.
What is the impact of muon Cherenkov threshold?
3. What is the best distance from the source? What is the effect of changing the
beta-beam and superbeam energy? (event rates, backgrounds, ability to use dN/dEn )
Should energy remain adjustable after the distance choice?
4, what is the relationship between beta-beam energy vs intensity?
5. What is really the cost of the detector?
what PM coverage is needed as function of energy and distance.
NB superbeam requires 4 MW proton driver,
beta-beam claim to be able to live with 200 kW!
POFPA 18 october Alain Blondel
Questions for Neutrino Factory experiments:
1.
Do we REALLY NEED TWO far locations at two different distances?
2.
3000 km  1st osc. max at 6 GeV and 2d max at 2 GeV.
Muon momentum cut at 4 GeV cuts 2d max info. Can this be improved?
3.
Can we eliminate all degenracies by combination of energy distribution and
analysis of different channels (tau, muon, electron, both signs, NC…)
4.
what are the systematics on flux control? (CERN YR claims 10-3)
5. optimal muon ENERGY? Cost of study II was
1500M$
+ 400M$*E/20
POFPA
18 october
Alain Blondel