Experimental Neutrino Physics in Belgium

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Experimental Neutrino Physicsin Belgium

• Pierre Vilain (ULB)

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BEBC,15-foot gt1976
A long tradition
Gargamelle 1973
CHARM-II 1986
Hybrid emulsion 1978
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In this talk
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CHORUS (WA95) ?? -?? oscillation search
at large ?m2 and

very small mixing
Tenure P. Vilain, G. Wilquet Ph.D. P.
Annis, R. El Aidi, M. Gruwé, C. Mommaert,
M. Vander Donckt, B. Van de Vyver
Tenure T. Delbar, D. Favart, G. Grégoire Ph.D.
G. Brooijmans, J. Hérin, S. Kalinin, V.
Lemaître, L. Michel
Belgium (Brussels, Louvain-la-Neuve), CERN,
Germany (Berlin, Münster), Israel (Haifa), Italy
(Bari, Cagliari, Ferrara, Naples, Rome,
Salerno), Japan (Toho, Kinki, Aichi, Kobe,
Nagoya, Osaka, Utsunomiya), Korea
(Gyeongsang), The Netherlands (Amsterdam),
Russia (Moscow), Turkey (Adana,Ankara,Istanbul)
25 institutions 120 physicists
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Detector
Air-core magnet
?p/p 0.035 p (GeV/c) ? 0.22
Active target
18 diamond-shaped fiber trackers (DT)

• -nuclear emulsion target (770kg)
• -scintillating fiber tracker

?
muon spectrometer
27 GeV
Calorimeter
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The Diamond Trackers (built in Belgium)
- 300 000 fibers (of 500 ?m) - 18 optoelectronic
chains, each with 4 Image Intensifiers - ? ?
180 ?m
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Target region
Tracks reconstructed in

• Fiber target trackers
• angle resolution 2 mrad
• position resolution 150 mm

Extrapolated to

• Interface emulsion sheets
• Changeable Sheets (CS)
• Special Sheets (SS)

Scanned back into
n

• Emulsion target
• 4 stacks each made of 36 plates
• Total mass 770 kg

- 2 106 triggers recorded - 200 K located
vertices (in 2003)
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Results (published in 2001)
?? search - no muon at primary vertex - kink
on a negatively
charged track - pT and angular cuts
After selection 0 event found 1.1
background event expected
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PHASE II Netscan technique
scanning speed
All tracks (qlt400mrad) in the scanning volume
(1.5X1.5X6.3mm3) are recorded at 11 min./event.
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Before end 2003

• 200,000 events fully analysed ?
• - improve mixing angle limit by a factor 3
• - charm physics
• So far, from a sub-sample of data
• Diffractive Ds prod. (Phys. Lett. B, 435 (1998)
  458)
• ? (D0) / ? (CC) (Phy.Lett B, 527, (2002), 173)
• CC associated charm production (Phys.Lett.B, 539,
  (2002), 188)
• B m (Phys. Lett B, 548, (2002), 48)
• ? (L c) / ? (CC) (Phys.Lett.B, 555,(2003),156)

• In preparation
• Associated charm production in CC and NC
• D D0 p
• D0 neutrals
• Anti-neutrino charm production
• QE L c production, etc...

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RD on capillary detectors filled with liquid
scintillator
Since 1993 (RD46) various targets in front of
CHORUS 1998-2002 EC TMR network Micro-track
Imaging (8 groups ULB 86
K? ? 25 man-months)
Electron Bombarded CCD tube
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Ph. D. Theses
Main contribution in
- 1994 ULB M. Gruwé Optoelectronic
chains - 1995 UCL L. Michel Liquid
organic scintillators - 1995 VUB C. Mommaert
Fiber tracker readout, DAQ - 1998 UCL G.
Brooijmans Reconstruction in TT - 1999 ULB
M. Vander Donckt Reconstruction in DT - 2001 ULB
P. Annis Reconstruction in DT -
2002 VUB B. Van de Vyver Charm study in
emulsion - 2003 UCL S. Kalinin
Charm study in emulsion
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• HARP (PS214)
• designed to measure with few accuracy cross
  sections for hadron production of protons (3 to
  15 GeV/c) on various elements

Not really a neutrino experiment but will provide
important inputs for

• the design of a nu-factory
• the mastering of existing nu-beams
• the interpretation of atmospheric nu-oscillation
  experiments

HARP was designed, built and assembled in 17
months!
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COLLABORATION
120 physicists

• 24 institutions from
• Belgium (UCL)
• Bulgaria (2)
• France (1)
• Germany (1)
• Italy (9)
• Russia (4)
• Spain (1)
• Switzerland (1 Cern)
• UK (3)

Tenure G. Grégoire Postdoc J. S. Graulich 2
technicians BUDGET 140 K?
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Schematic layout
HARP consists of a barrel spectrometer (TPC) and
of a forward spectrometer (NDC) to cover the full
solid angle, complemented by particle-id
detectors
Ckov ToF e-id
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Particle ID
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Cherenkov
-Conception -Construction -Operation by UCL (2
phys. 2 tech.)
cylindrical mirror, 8 m2 curvature radius 2.4 m
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Data Acquisition ended in october 2002
The scientific program was fully covered - 10
beam momenta (from -15 to 15 GeV/c) - many
different targets -
thick and thin (Be, C, Al, Cu, Sn, Ta, Pb)
- cryogenic (N2 , O2 , D2 ,
H2 ) - special ( for
K2K, MiniBoone) -
empty - 2 106 recorded triggers for each
setting
ANALYSIS IN PROGRESS.
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CNGS 1 ?? Appearance
From 2006
ECC
Cover the atm. SK region
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Tenure P. Vilain, G.Wilquet 1 engineer G.
Van Beek No PhD student or postdoc yet
Belgium IIHE(ULB) Brussels
China IHEP Beijing, Shandong
Croatia Zagreb
Collaboration
?
France LAPP Annecy, IPNL Lyon, LAL Orsay, IRES
Strasbourg
Germany Berlin, Hagen, Hamburg, Münster, Rostock
35 groups 160 physicists
Israel Technion Haifa
Italy Bari, Bologna, LNF Frascati, LAquila,
LNGS, Naples, Padova, Rome, Salerno
Japan Aichi, Toho, Kobe, Nagoya, Utsunomiya
Russia INR Moscow, ITEP Moscow, JINR Dubna,
Obninsk
Switzerland Bern, Neuchâtel
Turkey METU Ankara
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A hybrid experiment
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Scintillator strip Target Trackers (TT)
- 64 Scint. Strips WLS fiber - 2 Multi-anode PMT
Bern, ULB Brussels,JINR Dubna,Israel, LAL Orsay,
Lyon,Neuchâtel, Strasbourg, Zagreb
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TT construction
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Wall 0 (still 62 to build...)
COST (M?) OPERA 57.9 TT
4.1 of which ULB 0.61
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CONCLUSION
Very active field for the next years
BUT...
we must attract young people to - contribute to
the data analysis - work on future projects
(muon collider ?)
and to give another Neutrino talk at your next
visit !