Alain Blondel CHIPP Neutrino meeting NEUCHATEL 21-22 June 2004.

Alain Blondel CHIPP Neutrino meeting NEUCHATEL 21-22 June 2004


Aims of the meeting

At least four universities in Switzerland do research in Neutrino Physics. It is felt that the subject is very important (one of the three pillars of particle physics in the forseable future), but that we would benefit from sharing our views on this future.

Even before the birth of CHIPP it had been envisaged to assemble the Swiss neutrino community to share our activities, discuss physics and define our longer time goals in common. The advent of CHIPP has given this project a natural framework.


participants: about 40 mostly from institutes engaged in neutrinos (Be, Ge, Ne, ETHZ) + a good participation from other groups (EPFL, PSI, UZ…)

directed at

- revue of present activities (HARP/K2K, OPERA, ETHZ)- mid-term future (T2K)- neutrinoless double beta decay- longer term future (Future CERN neutrino programme, R&D on detectors (Larg TPC) and acelerators (MICE) )


Summary -- ongoing activities

HARP/K2K HARP data taking was concluded in 2002, the experiment took a large amount of data pertinent to the particle production from various beams and targets for future neutrino facilities (in particular the K2K and MiniBoone targets, also superbeam and neutrino factory). The first results of HARP and of K2KII were made public this year. The Geneva group is member of HARP and K2KII. This activity is expected to phase out after data taking in K2K is finished in 2005.

OPERA is an experiment in preparation to take data in the CNGS beam in 2006 for at least five years. The target lead emulsion sandwich is designed to identify tau appearance events with low background. (a total of 10-20 events is expected after 5 years run). OPERA also claims be sensitive to the <-> e appearance down to an angle of about 70. Neuchâtel and Bern are involved in OPERA, and all forces will be absorbed on the preparation of the experiment until the start in 2006.


ICARUS is a large liquid argon TPC. The technique has been the object of extensive R&D for many years, and results from the operation of a 600 ton prototype since 2001 were shown (Michel parameter from muon decays) . It offers the capability of tracking, as well as scintillation and Cherenkov light detection. Free drift of electrons with absorption length of up to 3 m have been observed. The group at ETHZ is committed to ICARUS, which will install the 600 ton prototype as fast as permitted (hopefully data at CNGS end 2005), and then further modules of 1.2 tons in LNGS as permitted. ICARUS should be quite powerful to search the <-> e appearance down to an angle of about 30.


Probability of claiming a 4 discovery in 5 years

SK 90% CL

Opera, no beam upgrade but half background

Opera with beam*2

Opera withbeam*3

Opera with beam*4

Opera no beam upgrade

Opera with f oreseen beamupgrade

(1.5)

1.9 10-33 10-3

PionPionyieldyield

To be decoupled from absorption and reinteractioneffects we have used a thin target

datadatapp--e/e/misidentification misidentification background background

K2K replica targetK2K replica target

5% 5% Al targetAl target

200% Al target

<-- First results from HARP

<-- OPERA confident to demonstrate tau appearance in 5 years

ICARUS operated 600ton proto with electron abs. length of 3m…


Summary: T2K

There was a clear consensus that the T2K experiment appears to be the most promising experiment along the line of research started with CNGS, and there is strong support for a qualified and visible participation of the Swiss groups in the experiment.

At present, T2K Europe has proposed to equip the 280 m pit with the large magnet inherited from NOMAD/UA1, so that the near detector be a full-fledge spectrometer to analyse all particles produced at these energies by neutrinos on a water target; University of Geneva, in particular, considers participating in the construction of the tracker. A second near-detector station at 2km from the neutrino target is likely to be realized in the second phase of the experiment. It would have a flux much more similar to the flux at the far detector than the 280 m station. There, the merits of a liquid argon TPC detector as proposed by ETHZ for near stations in LBL neutrino beams will be manifest. Such a detector would represent a natural and very powerful solution allowing precise topological measurement of final states with pions and photons.

Future investigations along both lines will be conducted in order to define a coherent and organized participation of Switzerland to the T2K project.


Status of T2K

Tokai to Kamioka Neutrino Project at J-PARCJune 21, 2004

Koichiro Nishikawa

Kyoto University

beam of ?1GeVKamioka

J-PARC(Tokai-village)

?? xx disappearance

?? ee appearance

NC measurement

0.75 MW 50 (40) GeV PS

Super-K: 50 ktonWater Cherenkov

~Mt “Hyper Kamiokande”

4MW 50GeV PS

CP violationproton decay

Approved exp (x102 of K2K)

Future Extension

“T2K” (Tokai-to-Kamioka) neutrino experiment

LOI: hep-ex/0106019

Collaboration• Formed in May 2003• 12 countries, 52 institutions• 148 collaborators (w/o students)


• Muonmonitors @ ~140m– spill-by-spill monitoring of beam direction/intensity

• First Front detector @280m– 0 degree definition– High stat. neutrino inter. studies

• (Second Front Detector @ ~2km for future addition)

• Far detector @ 295km– Super-Kamiokande(50kt)

1.5km

295km

0.28km

Neutrino spectra at diff. dist

dominant syst. in K2K

p

140 m0 m 280 m 2 km 295 km


The present detector concept

empty targets

water targets

suggested detectors:

loverre, sanchez, radicioni


Summary -- double beta decay

The issue of whether neutrinos are Dirac type or Majorana-type particles is one of the most fundamental ones. If successful, a neutrino-less double beta decay experiment could answer this question and determine the absolute scale of neutrino masses. A more detailed answer would require knowledge of the mass hierarchy of neutrinos which can be established with more powerful neutrino oscillation experiments. The group in Neuchâtel participates in the development of Xenon gas TPCs with the aim of progressively enlarging the sensitive mass to ten tons, at which point a sensitivity to an average mass of 30 meV could be achieved, which would be enough to be sensitive to inverted hierarchy scenarios. The uncertainties in nuclear matrix elements are recognized to be an issue (at the level of a factor 2) and necessitate use of several different nuclei.


Full detector viewWith Pb shielding

Assuming

1) that the Xe chamber + Ba tagging gives 0 background from radioactivity...2) that the energy resolution is (E)/E=2 % (2!)

Conclusion:

With a coordinated effort, the meV region is within reach!

Mass Enrichment Eff. Time Background

(kg) (%) (%) (yr) (events) (yr) QRPA SM1000 90 70 5 0.3 0.05 0.0810000 90 70 10 5.5 0.02 0.03

T1/2

0 <m> (eV) <m

> (eV)

2*1027

1.3*1028


Summary -- future

In conclusion, the Swiss neutrino community is strongly interested in a possible future high intensity neutrino physics programme at CERN, is engaged in the R&D leading to it and supports this R&D within international collaborations.


Michel Spiro Particle Physics at the Megawatt proton source. CERN 27 May 2004

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 starting in 2008 (safety tunnel in Frejus or TGV test gallery)

CERN-SPL-based Neutrino SUPERBEAM

Fréjus underground lab.


-- 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


CERN: -beam baseline scenario

PS

Decay

RingISOL target & Ion source

SPL

Cyclotrons, linac or FFAG

Decay ring

Brho = 1500 Tm

B = 5 T

Lss = 2500 m

SPS

ECR

Rapid cycling synchrotron

MeV 8 6.1 Av erag e

MeV 9 3 7.1 Av erag e

1 89

1 81 0

63

62

cm s

cm s

E

eF eNe

E

eL iHe

Nuclear Physics

,

,

SPL is the possible basis of 2) Low E. Superbeam

3) Beta-beam 4) Neutrino Factory

1) SPS & CNGS intensity X 2


Linac4approval

SPLapproval

LHCupgrade

RF test place ready

3 MeV test place ready

Possible planning

CDR 2

if the SPL is firmly supported…

Garoby


An « 0ptimal » schedule for a Megaton Physics Project in Europe

Safety Tunnel

Large Cavity

R&D PMT’s, etc.

PMT’s production

2003 2004 2007 2008 2012 2015 2020

Detector installation

Start Megaton Physics

SPL + Super-beam realization

Procedure :

Beta-beam realization

excavation

excavation

R&D PMT’s, etc

PMT’s production

Detector inst.

Start Megaton Physics ………………...………………….

SPL+Super-beam realization

Beta-beam realization

EoI

Year

?

?

studyPre-study

LoI Prop Approv.

Mosca


Neutrino detectors



Components of the Project

-> a very large Laboratory to allow the installation of a Megaton-scale Cerenkov Detector ( 106 m3) and/or a Liquid-Argon Detector

Present Tunnel

FutureSafety Tunnel

Present Laboratory

Future Laboratorywith Water Cerenkov Detectors

CERN

The 'Baseline' European Project:in the Franco-Italiantunnel Fréjus

Main advantages:1) Large depth(>4800 mwe)2) Beam at the right distance3) Easy access, central european position4) Support from local autorities, governments

MoU CEA/IN2P3/INFN

For low energy neutrinos the proven technology is Water Cherenkov. (up to energies of ~800 MeV, above this pion production confuses the topologies )==> adequate for superbeam and betabeam

possible for higher energy beta beam?certainly not adequate for neutrino factory.

There exist an international 'collaboration' (UNO) --> Meeting in Paris 19/06/04 for R&D and further physics studies

Alain Blondel CHIPP Neutrino meeting NEUCHATEL 21-22 June 2004 Michel Spiro Particle Physics at the Megawatt proton source. CERN 27 May 2004

Chang Kee Jung

Alain Blondel CHIPP Neutrino meeting NEUCHATEL 21-22 June 2004 Michel Spiro Particle Physics at the Megawatt proton source. CERN 27 May 2004

Liquid Argon TPCAdequate for Super beam beta beam AND neutrino factory Network proposed for R&DBut is it always better?Ereditato Rubbia


Introduction: physics

Mezzetto


Outlook:

2006

2007

2008


Summary -- future

In conclusion, the Swiss neutrino community is strongly interested in a possible future high intensity neutrino physics programme at CERN, is engaged in the R&D leading to it and supports this R&D within international collaborations.

Alain Blondel CHIPP Neutrino meeting NEUCHATEL 21-22 June 2004.

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Transcript of Alain Blondel CHIPP Neutrino meeting NEUCHATEL 21-22 June 2004.