Alain Blondel

Three family oscillations

Low energy Super-beam: JHF

CERN-SPL … and beta-beam

Neutrino Factory

Neutrino Factory R&D and new developments: EMCOG, MICE, ring cooler

BENE and design studies

Conclusions

Future neutrino experimentsThe road-map…

and a few itineraries

Alain Blondel

1. We know that there are three families of active, light neutrinos (LEP)2. Solar neutrino oscillations are established (Homestake+Gallium+Kam+SK+SNO+KamLAND)3. Atmospheric neutrino () oscillations are established (IMB+Kam+SK+Macro+Sudan)

4. At that frequency, electron neutrino oscillations are small (CHOOZ) This allows a consistent picture with 3-family oscillations ~300 m12

2~7 10-5eV2 ~450 m23 2~ 2.5 10-3eV2 ~ 100 with several unknown parameters mass hierarchy

Where are we?

*)to set the scale: CP violation in quarks was discovered in 1964 and there is still an important program (K0pi0, B-factories, Neutron EDM, BTeV, LHCb..) to go on for 10 years…i.e. a total of ~50 yrs. and we have not discovered leptonic CP yet!

5. There is indication of possible higher frequency oscillation (LSND) to be confirmed (miniBooNe) This is not consistent with three families of neutrinos oscillating, and is not supported (nor is it completely contradicted) by other experiments. (Case of an unlikely scenario which hangs on only one not-so-convincing experimental result) If confirmed, this would be even more exciting See Barger et al PRD 63 033002

Where do we go? leptonic CP & T violations=> an exciting experimental program for at least 25 years *)

Alain Blondel

The neutrino mixing matrix: 3 angles and a phase

Unknown or poorly known even after approved program:13 , phase , sign of m13

OR?

m223= 3 10-3eV2

m212= 3 10-5 - 1.5 10-4 eV2

23(atmospheric) = 450 , 12(solar) = 300 , 13(Chooz) < 130

2

m212= 3 10-5 - 1.5 10-4 eV2

m223= 3 10-3eV2

Alain Blondel

Consequences of 3 Family oscillation:

I There will be ↔ e and ↔ e oscillation at L atm

P (↔ e )max =~ ½ sin 22 13 +… (small)

II There will be CP or T violation

CP: P (↔ e) ≠ P (↔ e

T : P (↔ e) ≠ P (e ↔

III we do not know if the neutrino which contains more e is the lightest one (natural?)

or not.

Oscillation maximum 1.27 m2 L / E =/2

Atmospheric m 2= 2.5 10-3 eV 2 L = 500 km @ 1 GeVSolar m2 = 7 10-5 eV2 L = 18000km @ 1 GeV

Alain Blondel

= 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 (reactors or sun are out)

… 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)

P(e) = ¦A¦2+¦S¦2 + 2 A S sin

P(e) = ¦A¦2+¦S¦2 - 2 A S sin

Alain Blondel

LEPTONIC T , CP VIOLATION

The baryon asymmetry in the Universe… requires CP or T violation.

That of the quarks is not enough!

Boris Kayser

This leptonic asymmetry would in turn generate baryon asymmetry. (energies typical of the particles that would be exchanged in Baryon decay 1015 GeV or so)

NB this is CP asymmetry for the Heavy Majorana Neutrinos 1. we don’t know if neutrinos are Majorana particles 2. The CP phases that enter are those of the heavy neutrinos, not the light ones.

Nevertheless: leptonic CP violation may be the reason why we exist… lets look for it!

Alain Blondel

Road Map

Experiments to find : 1. search for e in conventional beam (ICARUS, MINOS) limitations: NC background, intrinsic e component in beam 2. Off-axis beam (JHF-SK, off axis NUMI, off axis CNGS) or 3. Low Energy Superbeam

Precision experiments to find CP violation -- or to search further if is too small

1. Neutrino factory with muon storage ring

2. beta-beam 6He++ Li+++ e e

fraction thereof will exist .

e+ eand e- e

eFNe e189

1810

Alain Blondel

Where will this get us…

comparison of reach in the oscillationsright to left:present limit from the CHOOZ experiment, expected sensitivity from the MINOS experiment, 0.75 MW JHF to super Kamiokande with an off-axis narrow-band beam, Superbeam: 4 MW CERN-SPL to a 400 kton water Cerenkov in Fréjus from a Neutrino Factory with 40 kton large magnetic detector. INCLUDING SYSTEMATICS

sin213

0.10 10 2.50 50 130

Mezzetto

Alain Blondel

JHF Super-Kamiokande

295 km baseline J-PARC approved neutrino beam under discussion

but set as first priority by international committee

Proposal to be submitted early 2004

Super-Kamiokande: 22.5 kton fiducial Excellent e/ ID -- 10-3

Additional 0/e ID -- 10-2

(for E~ 500 MeV- 1 GeV)

Matter effects small need near detector! European collaboration

forming (mailing list: UK(5)-Italy(5)-Saclay-Gva-ETHZ- Spain(2))

This experiment is at the right ratio of Energy to distance Lmax = 300 km at 0.6 GeV

Alain Blondel

Detector Phase I: the Super Kamiokande Detector

Alain Blondel

/e Background Rejection

e/ separation directly related to granularity of coverage. Limit is around 10-3 (mu decay in flight) SKII coverage OKOK, less maybe possible

Alain Blondel

p

140 m0 m 280 m 2 km 295 km

Problem with water Cerenkov: not very sensitive to details of interactions. Either 280 m or 2 km would be good locations for a very fine grained neutrino detectorPlanned: a scintillating fiber/water calorimeter.

Liquid argon TPC would be a very good (better) candidate!

Event numbers: near/SK = m(near[tons]) / 22500 . (300/2)2 = m(near[tons])

=> Need 10-50 tons fiducial or so

The J-PARC-Beamline

1.5km

295km

Neutrino spectra at diff. dist

280m

Alain Blondel

Under discussion:

Possible Swiss contributions to JPARC-

a) Beam design and control: studies of high power horn in GVA – in collab. with CERN and LAL Orsayexpertise in hadronic production

b) A liquid Argon near detector? Generated interest in JHF-Europe! ETHZ leads the show.

What would be the envelope?

Alain Blondel

Schematic drawing of Hyper-Kamiokande

1 Mton (fiducial) volume: Total Length 400m (8 Compartments)

Super-K

40

m

Other major goal: improve proton decay reachSupernovae until Andromedes, etc…

Alain Blondel

Motivations to go beyond this…

1. Intrinsic limits of conventional neutrino beams (intensity, purity, only , low energy )

2. Go back to Europe and try to establish a possible CERN-based program on the long run

Superconducting Proton Linac SPL Superbeam Neutrino factoryThe ultimate tool for neutrino oscillations

Beta beam Very large underground labWater Cerenkov, L.Arg

The common source: SPL

EURISOLHigh intensity Low energy muon beams

SPL physics workshhop: June 2004 CERN SPC Cogne meeting sept.2004

Alain Blondel

-- 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

Alain Blondel

300 MeV Neutrinos

small contamination from e (no K at 2 GeV!)

A large underground water Cerenkov (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 stating in 2008 (safety tunnel in Frejus)

Possible step 0: Neutrino SUPERBEAM

Fréjus underground lab.

Alain Blondel

Europe: SPLFrejusG

enev

e

Italy

130km

40kt400kt

CERN

SPL @ CERN2.2GeV, 50Hz, 2.3x1014p/pulse 4MWNow under R&D phase

Alain Blondel

Neutrino Factory studies and R&D

USA, Europe, Japan have each their scheme. Only one has been costed, US study II:

Neutrino Factory CAN be done…..but it is too expensive as is. Aim: ascertain challenges can be met + cut cost in half.

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

Alain Blondel

EMCOG (European Muon Concertation and Oversight Group) FIRST SET OF BASIC GOALS

The long-term goal is to have a Conceptual Design Report for a European Neutrino Factory Complex by the time of JHF & LHC start-up, so that, by that date, this would be a valid option for the future of CERN. An earlier construction for the proton driver (SPL + accumulator & compressor rings) is conceivable and, of course, highly desirable. The SPL and targetry and horn R&D have therefore to be given the highest priority.

Cooling is on the critical path for the neutrino factory itself; there is a consensus that a cooling experiment is a necessity.

The emphasis should be the definition of practical experimental projects with a duration of 2-5 years. Such projects can be seen in the following four areas:

Alain Blondel

1. High intensity proton driver. Activities on the front end are ongoing in many laboratories in Europe, in particular at CERN, CEA, IN2P3, INFN and GSI. Progressive installation of a high intensity injector and of a linear accelerator up to 120 MeV at CERN (R. Garoby et al) would have immediate rewards in the increase of intensity for the CERN fixed target program and for LHC operation. This (HIPPI) has received funding from EU!

2. Target studies problem at 4 MW!!. This experimental program is underway with liquid metal jet studies. Goal: explore synergies

among the following parties involved: CERN, Lausanne, Megapie at PSI, EURISOL, etc…Experiment at CERN under consideration by the collaboration.

3. Horn studies. Problem at 50 Hz and 4 MW A first horn prototype has been built and pulsed at low intensity. Mechanical properties measured

(S. Gilardoni’s thesis, GVA) 5 year program to reach high intensity, high rep rate pulsing, and study the radiation resistance of

horns. Optimisation of horn shape. IN2P3 Orsay has become leading house for this. Collaborations to be sought with Saclay, PSI (for material research and fatigue under high stress in radiation environment)

4. Muon Ionization Cooling Never done! A collaboration towards and International cooling experiment MICE has been established with the

muon collaboration in United States and Japanese groups. There is a large interest from European groups in this experiment. Following the submission of a letter of Intent to PSI and RAL, the collaboration has prepared a full proposal at RAL. Proposal has been strongly encouraged and large UK funding secured (10M£). PSI offers a solenoid for the muon beam line CERN, which as already made large initial contributions in the concept of the experiment, has earmarked some very precious hardware that could be recuperated.

Alain Blondel

MUON Yield without and with Cooling

What muon cooling buys

exact gain depends on relative amont of phase rotation (monochromatization vs cooling trade off)

cooling of minimum ionizing muons has never been realized in practiceinvolves RF cavities, Liquid Hydrogen absorbers, all in magnetic fielddesigns similar in EU and US Nufact concepts

Alain Blondel

principle:

this will surely work..!

reality (simplified)

….maybe…

IONIZATION COOLING

Difficulty: Wide aperture -> expensive. Affordable prototype of cooling section only cools beam by 10%, while standard emittance measurements barely achieve this precision.

Solution: measure the beam particle-by-particle

DARK current & RF NOISE!!?

A delicate balance between energy loss and multiple scattering, & a technological challenge

Alain Blondel

MICE

An International Muon Ionization Cooling Experiment

Alain Blondel

Incoming muon beam

Diffusers 1&2

Beam PIDTOF 0

CherenkovTOF 1

Trackers 1 & 2 measurement of emittance in and out

Liquid Hydrogen absorbers 1,2,3

Downstreamparticle ID:

TOF 2 Cherenkov

Calorimeter

RF cavities 1 RF cavities 2

Spectrometer solenoid 1

Matching coils 1&2

Focus coils 1 Spectrometer solenoid 2

Coupling Coils 1&2

Focus coils 2 Focus coils 3Matching coils 1&2

10% cooling of 200 MeV/c muons requires ~ 20 MV of RF single particle measurements =>

measurement precision can be as good as out/ in ) = 10-3

never done before either….

Alain Blondel

We propose a Swiss contribution to the International Muon Ionization Cooling Experiment MICE

-- part of international concerted effort-- the Swiss collaborators play an essential role in the design of the experiment and in its leadership.-- well matched to the competence of experimental particle physicists-- will lead to first experimental observation of ionization cooling. -- + detailed study of various absorbers, optics, and limits of accelerating gradient.

=> PSI will provide a muon beam solenoid.

=> Spectrometer (tracker and contribution to spectrometer solenoid) 720 kCHF

=> Collaborate with CERN to provide RF power source, based on equipment available at CERN (well justified geographically, maintains ties with CERN without asking CERN the impossible) Cant FORCE funds be allocated for this? Est 760 kCHF

Submitted as SNF request with funding profile for 5 years. As a starting point for discussion. Total (including common funds, maintenance, travel and 2 PhD + 2 MA) 3.2 MCHF

Alain Blondel

250 microns pads connected in 3 sets of strips

MICE tracker option:TPC with GEM readout.

1st Prototype being builtwill take data by end october.

Alain Blondel

Alain Blondel

Design studies

FP6 foresees funding for design studies of new infrastructures. Encouraged by EU in reference with the (approved) CARE.

In preparation is the proposal for a European based Design study of a

neutrino factory and superbeam

RAL as leading house. (Peach/Edgecock)

Proton driver CERN in coll. With RAL, etc.,Target many interested. Still searching a leading house. (PSI not interested?) TTA at CERN under consideration. (pulsed beam important)Horn and collectors LAL orsayCooling; MICEAcceleration, FFAG Saclay, GrenobleStorage ring and instrumentation NN.

Europe alone does not have critical mass for all this. => world collaboration with USA and Japan was launched at NUFACT03 in June 2003.

Alain Blondel

Conclusions

Neutrino Physics is alive an attractive. We have an exciting program for many years. discovery and studies of leptonic CP violationThis addresses very fundamental questions (GUTS, matter asymmetry, masses) from a completely different viewpoint than the energy frontier.

1. We should not miss the opportunity to make a coherent contribution to JPARC-

2. We must however make sure that there is a competitive long term program in Europe (and at CERN preferably)

SPL is a good start and we must support it very strongly.

Without target, horns etc… it would be however useless.And it makes full sense for particle physics as a driver for a neutrino factory

Support neutrino factory R&D: MICE and collaborations with e.g. target experiment, etc…

Alain Blondel

RESERVE

Alain Blondel

RoadmapYou are here

You w

ant t

o go

ther

e

Where do we stand?

Where do we go?

Which way do we chose?

Cheapest?

Shortest?

Fastest?

Taking into account politics?

Alain Blondel

Designing a superbeam experiment

The process to be detected for superbeam experiments is appearance of e

e + N -> e - X event with an electron in the final state.

backgrounds: 1. e contamination in the beam from e+ ee+ e

Le+ e

2.production in Neutral Current events.

solutions: 1. detector must separate electrons from muons 2. beam must be as pure and as monochromatic as possible or: 2’. avoid K production by using low energy proton source 3. stay at low energy (~< 0.6 GeV)to avoid production

flux (E2 /L2) X cross-section (E) goes like E3 /L2 on first oscillation: oscillation goes like (L/E)2 =>oscillated signal goes like Ebackground goes as E3 /L2 => go far to avoid background ( => around 1st maximum)on subsequent oscillations: flux and signal decrease, signal/noise does not improve, to be avoided unless it provides complementary information– to be demonstrated

Alain Blondel

Charged current cross sections

CCqe (+n+p)

InelasticNC0

multi ….

CCqe dominate 1GeV≲Inelastic dominate 1GeV≳

Background

data are old, sparce and sometimes ambiguous.

Alain Blondel

(Super) Neutrino Beams

<E>(GeV)

L(km)

#CC/kt/yr

L/Losci.* f(e) @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 0.09 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%

Alain Blondel

T asymmetry for sin = 1

0.10 0.30 10 30 90

JHFI-SK

!asymmetry is

a few % and requires

excellent flux normalization

(neutrino fact.or

off axis beam withnot-too-near

near detector)

!

JHFII-HK

neutrino factory

Alain Blondel

Detectors at near site Muon monitors @ ~140m

Behind the beam dump Fast (spill-by-spill) monitoring of beam

direction/intensity

First Front detector “Neutrino monitor” @280m Intensity/direction Neutrino interactions

Second Front Detector @ ~2km Almost same E spectrum as for SK

Absolute neutrino spectrum Precise estimation of background Investigating possible sites

1.5km

295km

Neutrino spectra at diff. dist

280m

Alain Blondel

Syst. error: far/near spectrum diff.Typical OA beam(80mDV)

280m

295km

K2K case (MC)

FD(300m)(xLSK

2/LFD2)

SK

Important not only for disappearance,but also for sig/BG estimation for e search

Large(~x2) effectaround peak!!