Towards a world-wide Neutrino Facility step I: the International Scoping Study (ISS)

GDR-Lyon 20 sept2005 Alain Blondel

Towards a world-wide Neutrino Facility

step I: the International Scoping Study (ISS)

mother link http://muonstoragerings.cern.ch

‘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

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


Kayser -- EPS05

Accelerator neutrinos are CENTRAL to the future program.


evolution of sin2213

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



2010 will be a time of major decisions in particle physics

LHC will be completed first results will appear

ILC first results fromCNGS, T2Kdouble-CHOOZother reactor expts.might be available.

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

TARGET DATE: 2010

Barry Barish, CERN SPC sept05


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 (40kton)

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, though perhaps lower, but

more uncertain.

Cost/physics performance/feasibility comparison needed


400 MeV Neutrinos

small contamination from e (no K at 3 GeV!)

A large underground water Cherenkov (400 kton) UNO/HyperKor/and a large L.Arg detector. also : proton decay search, supernovae events solar and atmospheric neutrinos. Performance similar to J-PARC IIThere is a window of opportunity for digging the cavern starting in 2009 (safety tunnel in Frejus)

CERN-SPL-based Neutrino SUPERBEAM

Fréjus underground lab.

target!


CERN: -beam baseline scenario

PS

Decay

RingISOL target & Ion source

SPL

Cyclotrons, linac or FFAG

Decay ring

B = 5 T

Lss = 2500 m

SPSECR

Rapid cycling synchrotron

Nuclear Physics

,

Same detectors as Superbeam !

target!

Stacking!

neutrinos of Emax=~600MeV

eFNe e189

1810

eLiHe e63

62


Beta-beam at FNAL?

WinterCERN FNAL

max = maxproton/3

for 6He

fault of this one has to buy a new TeV acccelerator.

High gamma beta-beam increases sensitivity considerably

(Hernandez, Gomez-Cadenas)


Combination of beta beam with super beam

combines CP and T violation tests

e (+) (T) e (+)

(CP)

e (-) (T) e (-)


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!


EC: A monochromatic neutrino beam

Decay T1/2 BR EC/ ECI B(GT) EGR GR QEC E E

148Dy 148Tb* 3.1 m 1 0.96 0.96 0.46 620 2682 2062

150Dy 150Tb* 7.2 m 0.64 1 1 0.32 397 1794 1397

152Tm2- 152ET* 8.0 s 1 0.45 0.50 0.48 4300 520 8700 4400 520

150Ho2- 150Dy* 72 s 1 0.77 0.56 0.25 4400 400 7400 3000 400

Electron Capture: N+e- N’+e Burget et alintensity? potential?


-- Neutrino Factory -- CERN layout --

e+ e

_

interacts

giving

oscillates e

interacts giving

WRONG SIGN MUONWRONG SIGN MUON

Golden Channel

1016p/s

1.2 1014 s =1.2 1021 yr

3 1020 eyr

3 1020 yr

0.9 1021 yr

target!cooling!

acceleration!

also (unique!) eSilver channel


Neutrino fluxes + -> e+ e

/ e ratio reversed by switching

e spectra are different No high energy tail.

Very well known flux (10-3)

-- E& calibration from muon spin precession

-- angular divergence: small effect if < 0.2/

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

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

Similar comments apply to beta beam, except spin 0 Energy and energy spread have to be obtained from the properties of the storage ring (Trajectories, RF volts and frequency, etc…)

polarization controls e flux:

+ -X> e in forward direction

is that all true?


INO ~7000 km (Magic distance)


Lindner et al

newer plot should come out of NUFACT05 and scoping study

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

.

beam + SPL3.5 SB+Mton

approval date:

~NOvA +PD


What happens to this at high if -- two baselines are considered and -- a threshold of 1.5 GeV for wrong sign muons is imposed on the 3000 km det -- and there is a 4kton tau detector at the 3000 km station?


Degeneracies

Stephano Rigolin:

P. Huber’s plots assume: 4 GeV threshold, only golden channel. Experimenters need to provide characteristics of tau detectors and think about efficiency for wrong sign muons at low energies.


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


This ‘conceptual detector’ was used for the sensitivity studies, with cut-off at muon energy of 4 GeV

30 m

13.1 m

14.5 m B BMonolith



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

A. Rubbia


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?


The Beta-beam accelerator study is funded within EURISOL DESIGN STUDY and this is making impressive progress. (it is still a very new concept however)

The MICE experiment is now approved at RAL (+recognized as CERN RE11)and scheduled to run in 2007

The target experiment nTOF11 is now approved at CERN, scheduled to run in 2007

There is a proposal for an electron-model FFAG experiment

The Neutrino Factory and Superbeam design study (with RAL as home institute) was prepared for a EU DS call in 2004 (sub march 2005) which never took place.It turned out to be too far-fetched to substitute an I3 proposal to this. In the process the need to include detector R&D was identified.

Meanwhile…

Optimization of the neutrino factory in the US has led to cost reduction by 40%

There is a funded UK neutrino factory collaboration


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.

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.


Detectors (NEW!)

Water Cherenkov (1000kton)Magnetized Iron Calorimeter (50kton)Low Z scintillator (100 kton)Liquid Argon TPC (100 kton) magnet?Hybrid Emulsion (4 kton)

Near detectors (and instrumentation)

( SB,BB 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 will be broadcast, (do register!) (CERN first page) KEK 23-25 January 2006, RAL 27-29 April 2006 (BENE)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

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.

Documents

Towards a world-wide Neutrino Facility step I: the International Scoping Study (ISS)