neutrino factory (and the international scoping study (iss))

POFPA 18 october Alain Blondel

Neutrino Factory

(and the International Scoping Study (ISS))

mother link http://muonstoragerings.cern.ch (see NUFACT05)

‘ECFA/CERN studies of a European Neutrino Factory Complex' CERN 2004-002 ECFA/04/230and Physics with a MMW proton driver (MMW workshop) CERN-SPSC-2004-024

and http://www.hep.ph.ic.ac.uk/iss/


Kayser -- EPS05

Accelerator neutrinos are CENTRAL to the future program.


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 normalisationbut….. « 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


-- Neutrino Factory --CERN layout

e+ e

_

interacts

giving oscillates einteracts givingWRONG SIGN MUON

1016p/s

1.2 1014 s =1.2 1021 yr

3 1020 eyr

3 1020 yr

0.9 1021 yr


Neutrino fluxes + -> e+ e

/ e ratio reversed by switching

e spectra are different No high energy tail.

Very well known flux (aim is 10-3)

- absolute flux measured from muon current or by e -> e in near expt.

-- in race track or triangle ring, muon polarization precesses and averages out (-> calib of energy, energy spread)

-- E& calibration from muon spin precession

-- angular divergence: small effect if < 0.2/can be monitored

similar comments can be made for beta-beam, but not for superbeam.

polarization controls e flux:

+ -X> e in forward direction


Detector

studies so far:Iron calorimeterMagnetized

Charge discriminationB = 1 T

Fiducial mass = 40 kTcut at 5 GeV muon.

Baseline

3500 Km

732 Km 3.5 x 107

1.2 x 106

5.9 x 107

2.4 x 106

1.1 x 105

1.0 x 105

CC e CC signal (sin2 13=0.01)

Events for 1 year 2 1020 muon decays

Also: L Arg detector: magnetized ICARUS Wrong sign muons, electrons, taus and NC evts *->

CF e signalat J-PARC=40

Cervera et al

Bueno et al

old scheme!


Studies and plots made so far have been based on this study by Anselmo Cervera, which is optimized for the sensitivity to very low 13. Clearly cuts should be relaxedfor large values of 13.


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?

……………………………………degeneraciescorrelationssystematics

.

beam + SPL3.5 SB+Mton

approval date:

~NOvA +PD

km


Mezzetto

L= /2.54 E/m

l = /2.54 E/m

Three family oscillations look at e oscillation


P(e) = ¦A¦2+¦S¦2 + 2 A S sin

P(e) = ¦A¦2+¦S¦2 - 2 A S sin

= ACP sinsolar term…

sinsin (m212 L/4E) sin

… need large values of sin m212 (LMA) but *not* large sin2

… need APPEARANCE … P(ee) is time reversal symmetric (reactor s do not work)

… can be large (30%) for suppressed channel (one small angle vs two large)

at wavelength at which ‘solar’ = ‘atmospheric’ and for e , … asymmetry is opposite for e and e

P(e) - P(e)

P(e) + P(e)

CP violation


T asymmetry for sin = 1

0.10 0.30 10 30 90

!asymmetry is

a few % and requires

excellent flux normalization

(neutrino fact., beta beam or

off axis beam withnot-too-near

near detector)

NOTEs:1. sensitivity is more or lessindependent of 13 down to

max. asymmetry point

2. This is at first maximum!Sensitivity at low valuesof 13 is better for shortbaselines, sensitivity atlarge values of 13 isbetter for longer baselines(2d max or 3d max.)

3.sign of asymmetry changes with max. number.

errorarbitrary scale

Maximum Asymmetry

6%


Towards a comparison of performances on equal footing

CP violation example

= ACP sinsolar term…

sinsin (m212 L/4E) sin P(e) - P(e)

P(e) + P(e)

Near detector should give e diff. cross-section*flux

BUT:need to know and diff. cross-section and detection efficiency

with small (relative) systematic errors.

interchange role of e and for superbeam

in case of beta-beam one will need a superbeam at the same energy. Will it bepossible 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?


d/de,e’EeEe’Enegy transfer (GeV)Ee=700-1200 MeV

Blue: Fermi-gasGreen: SPRed: SP+FSI

QE

Zeller

These are for electronbeam. errors are ~5-10% but what happenswhen a muon mass is involved?


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 m )and gradually become easier at high Energies.

Neutrino factory provides all channels in the same beam line/detector


CP asymmetries and matter effectcompare e to e probabilities

e

_

e-

e

_

e-

//

// A

is prop. to matter density, positive for neutrinos, negative for antineutrinos

HUGE effect for distance around 6000 km!!

Resonance around 12 GeV when

m223 cos213 =

0


CP violation (ctd) Matter effect must be subtracted. One believes this can be done with uncertaintyof order 2%. This is potential systematic error for large values of sin2213! However the energy shape of matter effect and CP violation are differentIt 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)

5-10 GeV

10-20 GeV20-30 GeV

30-40 GeV40-50 GeV

40 kton L M D 50 GeV nufact5 yrs 1021/yr

In fact, 20-30 GeV Is enough!

Best distance is 2500-3500 km

De Rujula, Gavela, Hernandez


NB: This works just as well

INO ~7000 km (Magic distance)


By 2010 we must know how much these facilities cost and how long they would take to build.

4MW, 1 Mton upgrade of T2K

NUFACT withthick magnetized Iron detector in two locations 7000kmand 3000 km

assume 2% flux error in T2Kvs. 5% matter eff. error on nufactand 5 GeV muon thres.

20Oscillation parameters can be extracted using energy distributions

a) right-sign muonsb) wrong-sign muonsc) electrons/positronsd) positive -leptonse) negative -leptonsf) no leptons

X2 (+ stored and - stored) Eve

nts

Bueno, C

am

pan

elli, R

ubb

ia; h

ep-p

h/0

00500

07

Simulated distributions for a 10kt LAr detectorat L = 7400 km from a 30 GeV nu-factory with

1021 + decays.

EVIS (GeV)

Note: e is specially important(Ambiguity resolution & Unitarity test): Gomez-Cadenas et al.


channel at neutrino factory

High energy neutrinos at NuFact allow observation of e(wrong sign muons with missing energy and P). UNIQUE

Liquid Argon or OPERA-like detector at 732 or 3000 km (better)

Since the sin dependence has opposite sign with the wrong sign muons, this solves ambiguitiesthat will invariably appear if only wrong sign muons are used.

ambiguities with only wrong sign muons (3500 km)

equal event number curvesmuon vs taus

associating taus to muons (no efficencies, but only OPERA mass)

studies on-going

A. Donini et al


e.g. Rigolin, Donini, Meloni


Wrong sign muons alone

Wrong sign muons and taus

Wrong sign muons and taus + previous exp.


red vs blue = different baselines

dashed vs line = different energy bin (most powerful is around matter resonance @ ~12 GeV)

red vs blue = muons and taus


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 down to 10

The most difficult one is the octant clone which will require a dedicated analysis" (Rigolin)


2010 will be a time of major decisions in particle physics

LHC will be completed first results will appear

ILC first results fromMINOS, OPERAdouble-CHOOZmight be available.

T2K will be startingand very rapidly dominating!

It will be time for the next step in neutrino physics!

TARGET DATE: 2010

Barry Barish, CERN SPC sept05


evolution of sin2213 sensitivity

observation and study of CP violation requires -- all accelerator neutrinos -- high precision in neutrino vs antineutrino normalization-- redundancy.

probably out of reach of these experiments need to go further

ee

Mezzetto


By 2010 we must know how much these facilities cost and how long they would take to build.

4MW, 1 Mton upgrade of T2K

NUFACT withthick magnetized Iron detector in two locations 7000kmand 3000 km

2010

assume 2% flux error in T2Kvs. 5% matter eff. error on nufactand 5 GeV muon thres.


Design studyDesign 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 engagedin common projects (R&D experiments)Muon cooling exp. MICE at RAL, Target Experiment nTOF11 at CERN


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 ...)

objectives: Evaluate the physics case for a second-generation super-beam, a beta-beam facility andthe 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 baselineset of parameters for the sub-systems that can be taken forward in a subsequentconceptual-design phase;

Evaluate the options for the neutrino detection systems with a view to defining a baselineset of detection systems to be taken forward in a subsequent conceptual-design phase.

~400-500 persons


Detectors (NEW!)

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 )

Physics

compare performance of various options on equal footing of parameters and conventionsand agreed standards of resolutions, simulation etc.

identify tools needed to do so (e.g. Globes upgraded)

propose « best values » of baselines, beam energies etc..

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 risksinclude a measure of costing and safety assessment

Yorikiyo Nagashima

Alain Blondel

Michael Zisman coordinationPeter Dornan+ ‘wise men’Ken PeachVittorio Palladino(BENE)Steve GeerYoshitaka Kuno


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.


ProgressThe 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 mu-global 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 OPERA mass (4 kton)


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


Some Highlights of the first Scoping Study meetingCERN 22-24 september 2005

see transparencies at:

http://dpnc.unige.ch/users/blondel/ISSatCERN.htmregister at http://www.hep.ph.ic.ac.uk/iss/

1. first presentation of the preliminary study for the Fréjusunderground laboratory

2. presentation of « feasible » 90 kton fine-grained magnetized ironcalorimeter 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 factory1021 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

http://dpnc.unige.ch/users/blondel/ISSatCERN.htm

http://www.hep.ph.ic.ac.uk/iss/








need to add cost of electronics, cavern and water treatment ~1G€

do we need so many tubes?

R&D for photodetectors!!!

Japan-France collaborationcollaboration with industry(Photonis)

Megaton Water Cherenkov(J.-E. Campagne)

+ HV, electronics, etc..!

the largest single cavern is 4XSK.


A Strawman Concept for a NufactI ron Tracker Detector

15m diameter polygon 4 piece laminate Can be thin if planes

interconnected e.g. down to 1cm

I dea from 1st NOVA Proposal 60kA- turn central coil

0.5m x 0.5m Average field of 1.5T Extrapolation of MINOS

Triangular liquid scintillator cells Structure based on NOvA using

MINERvA- like shapes 4cm x 6cm cells (starting point) 3mm thick PVC walls Looped WLS fibers & APDs

A sample would look like 1 cm Fe 0.7 cm PVC 3.3 cm LS 2/3rds Fe; ρ ? 2 Based on 175M$ for 90kt

Detector concept: End view

“Nova-Like” Detector Coil

Coil

Return yoke

Leslie Camillieri

alternatively could simply add a large magnet to a NOvA-like design! (cost?)

Jeff Nelson


10 liters prototype liquid argon TPChas been tested in 0.5 T at ETHZ

A. Rubbia


$$$$$ … COST … $$$$$$$$$$ … COST … $$$$$

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.

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.

+ detector: MINOS * 10 = about 300 M€ or M$

41

Why we are optimistic:

We are working towards a “World Design Study” with an emphasis on cost reduction.

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 + and - ! (RF phase rotation)

S. Geer:

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…

$$$$$ … COST … $$$$$$$$$$ … COST … $$$$$


8G

eV

10

Ge

V

15

Ge

V

20

Ge

V

4G

eV

3G

eV

2G

eV

5G

eV

6G

eV 3

0G

eV

40

Ge

V

50

Ge

V

75

Ge

V

10

0G

eV

12

0G

eV

0.0000

0.0200

0.0400

0.0600

0.0800

0.1000

0.1200

0.1400

0.1600

1 10 100 1000

Proton Energy (GeV)

Pio

ns/

(Pro

ton

*GeV

)

GEANT 4 Pi+

GEANT 4 Pi-

MARS15 Pi+

MARS15 Pi-

Total Yield of + and −

Normalisedto unit

beam power

Yields (on a tantalum rod) using MARS15 and GEANT4.

Better to include the acceptance of the next part of the front end

protons on heavy target(good for pi-)

(-30%)


12

0G

eV

10

0G

eV

75

Ge

V50

Ge

V

40

Ge

V30

Ge

V

20

Ge

V

15

Ge

V10

Ge

V

4G

eV

2.2

Ge

V

3G

eV

5G

eV

6G

eV

8G

eV

0

0.001

0.002

0.003

0.004

0.005

0.006

0.007

0.008

0.009

1 10 100 1000

Proton Energy (GeV)

Pio

ns

per

Pro

ton

.GeV

(es

t. P

has

e R

ota

tor)

pi+/(p.GeV)

pi-/(p.GeV)

pi+/(p.GeV)

pi-/(p.GeV)

Phase Rotator Transmission

(MARS15)

Optimum moves down because higher energies produce pions with momenta too high for capture

Doubled lines give some idea of stat. errors

Somewhat odd

behaviour for

π+ < 3GeV

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)

optimum 5-10 GeV. Within 30% of optimum: 4-40 GeV


Conclusions 1. The Neutrino Factory remains the most powerful tool imagined so far to study neutrino oscillations

Unique: High energy e and etransitions

at large has the precisionat small has the sensitivityMuch 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


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 CERNto 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.

Conclusions:


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/dE )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!


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.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

SPSC 2004 Villars Alain Blondel, 24/09/04

Where do you prefer to take shifts?

SPSC 2004 Villars Alain Blondel, 24/09/04

-- Neutrino Factory --CERN layout

e+ e _

interacts

giving oscillates e interacts giving WRONG SIGN MUON

1016p/s

1.2 1014 s =1.2 1021 yr

3 1020 eyr3 1020 yr

0.9 1021 yr

neutrino factory (and the international scoping study (iss))

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