Transcript SPS-C meeting June 25th, 2013 STATUS AND PLANS OF ICARUS-NESSIE (part 1 : status) Daniele Gibin Università di Padova and INFN, Padova.

SPS-C meeting June 25th, 2013
STATUS AND PLANS OF ICARUS-NESSIE
(part 1 : status)
Daniele Gibin
Università di Padova and INFN, Padova
The ICARUS Collaboration
M. Antonelloa, B. Baibussinovb, P. Benettic, F. Boffellic,E. Calligarichc, N. Cancia,
S. Centrob, A. Cesanaf, K. Cieslikg, D. B. Clineh, A.G. Coccod, A. Dabrowskag, D. Dequalb,
A. Dermenevi, R. Dolfinic, C. Farneseb, A. Favab, A. Ferrarij, G. Fiorillod, D. Gibinb,
S. Gninenkoi, A. Guglielmib, M. Haranczykg, J. Holeczekl, A. Ivashkini, J. Kisiell,
I. Kochanekl, J. Lagodam, S. Manial, G. Mannocchin, A. Menegollic, G. Mengb,
C. Montanaric, S. Otwinowskih, A. Piazzolic, P. Picchin, F. Pietropaolob, P. Plonskio,
A. Rappoldic, G.L. Rasellic, M. Rossellac, C. Rubbiaa,j, P. Salaf, E. Scantamburloe,
A. Scaramellif, E. Segretoa, F. Sergiampietrip, D. Stefana, J. Stepaniakm,R. Sulejm,a,
M. Szarskag, M. Terranif, F. Varaninib, S. Venturab, C. Vignolia, H. Wangh, X. Yangh,
A. Zalewskag, A. Zanic, K. Zarembao.
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Laboratori Nazionali del Gran Sasso dell'INFN, Assergi (AQ), Italy
Dipartimento di Fisica e INFN, Università di Padova, Via Marzolo 8, I-35131 Padova, Italy
Dipartimento di Fisica Nucleare e Teorica e INFN, Università di Pavia, Via Bassi 6, I-27100 Pavia, Italy
Dipartimento di Scienze Fisiche, INFN e Università Federico II, Napoli, Italy
Dipartimento di Fisica, Università di L'Aquila, via Vetoio Località Coppito, I-67100 L'Aquila, Italy
INFN, Sezione di Milano e Politecnico, Via Celoria 16, I-20133 Milano, Italy
Henryk Niewodniczanski Institute of Nuclear Physics, Polish Academy of Science, Krakow, Poland
Department of Physics and Astronomy, University of California, Los Angeles, USA
INR RAS, prospekt 60-letiya Oktyabrya 7a, Moscow 117312, Russia
CERN, CH-1211 Geneve 23, Switzerland
Institute of Theoretical Physics, Wroclaw University, Wroclaw, Poland
Institute of Physics, University of Silesia, 4 Uniwersytecka st., 40-007 Katowice, Poland
National Centre for Nuclear Research, A. Soltana 7, 05-400 Otwock/Swierk, Poland
Laboratori Nazionali di Frascati (INFN), Via Fermi 40, I-00044 Frascati, Italy
Institute of Radioelectronics, Warsaw University of Technology, Nowowiejska, 00665 Warsaw, Poland
INFN, Sezione di Pisa. Largo B. Pontecorvo, 3, I-56127 Pisa, Italy
The ICARUS detector at LNGS Laboratory
● ICARUS is the first large mass LAr-TPC (760 tons) in operation since
May 2010 installed underground in Hall B of LNGS Laboratory.
● Exposed to CNGS n beam, taking data also with Cosmic rays to study
the detector capability for atmospheric n and proton decay search.
● Different detector operating conditions
have been tested in the last months:
 Larger drift electric field (1 kV/cm);
 New pump for LAr purification.
● ICARUS decommissioning will start on
June 27th (up to 2nd half 2014):
 Emptying cryostats – LAr recovery;
 TPC chambers, cryogenic plant,
read-out electronics, chimneys,...
and ancillary systems will be recovered.
● The analysis of the large amount of physics data becoming
progressively the main activity of the collaboration
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ICARUS CNGS RUN (Oct 2010 – Dec 2012)
 Exposed to CNGS n beam since
2010 October 1st up to 2012
December 3rd
 Total collected event statistics:
8.6 1019 pot with a remarkable
detector live-time > 93 %
 First published physics results :
2012
2011
2010
 Superluminal n searches:
1. Cherenkov-like e+e– emission: PL B711 (2012) 270
2. n tof measurement PL B713 (2012), 17
3. n tof precision measurement: JHEP 11 (2012) 049

 nm→ne”LSND/MiniBooNE” anomaly Eur. Phys. J. C 73 (2013).
present activities focused on: ne, nm full reconstruction,
analysis tool optimization, last developments on detector tuning,
technical papers.
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On going activities: a search for LSND effects
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CNGS facility delivers an almost pure nm beam peaked in 10-30 GeV
energy range (beam associated ne ~1%):
the signature of nm-ne signal is observed visually.
Differences w.r.t. the LSND experiment:
L/En ≈ 1 m/MeV at LSND, but L/En ≈ 36.5 m/MeV at CNGS
LSND-like short distance oscillation signal averages to:
sin2(1.27Dm2new L /E) ≈ ½ and <P> nm→ne ≈ ½ sin2(2qnew)
When compared to other long baseline results (MINOS,T2K)
ICARUS operates in a L/En region in which contributions from
standard neutrino oscillations are not yet too relevant.
The unique detection capabilities of LAr-TPC technique allows
to identify individual ne events with high efficiency.
 New
analysis presented here refers to 1995 n interactions
(6.0 1019 pot statistics).
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Selection of ne events
 Primary vertex: > 5 cm from TPC walls (50 cm
from downstream) for shower identification
 Energy cut: < 30 GeV (beam ne extends to
higher En), only 15% signal events rejected
 nm CC events identified by L > 250 cm primary
track without hadronic interactions
ne MC event
The “Electron signature” requires:
 A charged track from primary vertex, m.i.p. on 8 wires, subsequently
building up into a shower; very dense sampling: every 0.02 X0 !!!
 Clearly separated (150 mrad) from other ionizing tracks near the
vertex in at least one of 2 transverse views.

 Electron efficiency studied with a sophisticated Montecarlo reproducing
in every detail the actual signals from wire planes: h = 0.74 ± 0.05
(h’ = 0.65 ± 0.06 for intrinsic ne beam due to its harder spectrum).
The expected number of e- events from intrinsic νe beam,
q13~90 and nm-nt oscillations is then 6.4±0.8.
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e/g separation and p0 reconstruction in ICARUS
Ek = 102 ± 10 MeV
θ
• MC: single electrons (Compton)
• MC: e+ e– pairs (g conversions)
• data: EM cascades (from p0 decays)
p0 reconstruction:
pπo = 912 ± 26 MeV/c
mπo = 127 ± 19 MeV/c²
θ = 28.0 ± 2.5º
Ek = 685 ± 25 MeV
Collection
Mgg:
133.8±4.4(stat)±4(syst) MeV/c2
1 m.i.p.
2 m.i.p.
2 m.i.p.
1 m.i.p.
MC
Unique feature of LAr to distinguish e from g and reconstruct p0
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4 ne events observed in 1995 n interactions
1
Event reconstruction
(1) Etot = 11.5 ± 1.8 GeV,
pt = 1.8 ± 0.4 GeV/c
(2) Etotvis = 17 GeV,
pt = 1.3 ±0.18 GeV/c
(3) Etot = 27 ± 2.0 GeV,
pt = 3.5 ± 0.8 GeV/c
(4) Etot = 14 ± 1 GeV,
pt = 1.5 ±0.1 GeV/c
In all events: single electron
shower clearly opposite to
hadronic component in the
transverse plane
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ICARUS results on the LSND-like anomaly
 The first ICARUS result (Eur. Phys. J. C 73 (2013)
based on 1091 n
interactions (3.3 1019 pot ) strongly limits the window of possible
parameters for LSND anomaly indicating a narrow region around
(Dm2–sin22q)=(0.5 eV2-0.005) where all experiments are compatible.
 New updated analysis includes an additional event sample of 2.7 1019 pot
(statistics x 2)  in total 6.0 x 1019 pot and 1995 n events
 The limits on number
of events due to
LSND anomaly:
3.68 (90% CL)
8.34 (99% CL)
the corresponding
limits on oscillation
probability are:
Pνμ→νe ≤ 3.4 10-3 (90% CL)
Pνμ→νe ≤ 7.6 10-2 (99% CL)
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New exclusion
area from ICARUS
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CNGS muon neutrino beam: search for disappearance
• Poor information available for nm disappearance, although they may
eventually present the same effect as Reactor and Gallium anomalies.
Could represent a significant contribution to the question.
• On-going studies to estimate all sources of systematic uncertainties
 Beam calculation systematics (p. production, focusing and transport)
Comparison of FLUKA predictions with
NA49 data for primary p± (on C) and K±
production (on free proton).
pC -> p±
p+
ppp -> K±
K+
K-
~5% extimated uncertainty on particle
production mostly based on NA49 angle
integrated data (3.8% exp. systematics),
assuming the XF scaling between reality
and MC is the same within few %.
Further comparisons foreseen.
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Beam and detector systematics on nm disappearance
First muon pit
Results at Muon pits: data vs MC
Effect of Earth B field (in 1 km
decay tunnel) included in MC.
 Data
MC
Experimental uncertainties:
muon detector calibration
(work ongoing), density of rock
in between the two pits (67 m).
● Spill by spill corrections for (small) horn/reflector instabilities
● ICARUS trigger system efficiency
● Selection efficiency & possible contamination from interactions in the
materials around the active LAr: data and MC scanning ongoing
● Detector response uniformity/stability for interaction vertices.
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Muon momentum via multiple scattering measurement
 Two complementary methods for muon momentum reconstruction with
M.S. have been developed: “classical” and based on Kalman Filter
 Accurate, automatic track cleaning from d rays and crossing tracks
applied in both cases
is
 The study of
a stopping m sample in 1÷4 GeV energy range - the one of
interest for future experiments – allows the experimental cross-check
of methods by comparing calorimetric and M.S. determinations of Pm
 Calorimetric measurement includes reconstruction of bremsstrahlung
gs, quenching correction, and recovery of few faulty or noisy wires.
Estimated precision and resolution on MC events at ~ 1% level.
 An additional cross-check is derived from the energy/range
relationship of muons.
Key tool to measure escaping m’s momentum: essential for νμ CC
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Comparison MS - calorimetry
Calibration from CNGS muons
Classical method:
based on the RMS of
deflection angles between
consecutive track segments
CNGS
stopping
muons
s(PMS/PCal) = 0.18
Kalman filter method:
fit of the track vs initial
momentum guess
CNGS
stopping muons
s(PMS/PCal) = 0.09
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Further extension to much more
complex/higher energy CNGS n:
ongoing evaluation/correction for
possible detector effects (electric
field in-homogeneity, hardware
effects… ). Preliminary results are
encouraging.
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3D reconstruction (example of stopping µ)
NEW: Simultaneous 3D
polygonal fit 2D hit-to-hit
associations no longer needed
Adv.High Energy Phys. 2013 (2013)
260820
Collection view
T300 real event
Induction 2 view
Induction 1 view
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Automation of reconstruction
 CNGS n event primary vertex: automatic reconstruction
Validation with visually identified CNGS vertices
algorithm efficiency ~ 97%
 automatic event segmentation algorithm
Track identification
Shower identification
Ready in 2D, to be extended in 3D
FIRST STAGE, output from segmentation: clusters and vertices
Candidates for shower: high density of vertices
Just single hits-> neutron, noise
SECOND STAGE, Track clusters, after merging clusters from the segmentation stage:
Selected example in green
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are excluded during the clusters merging .
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Performance of the ICARUS T600 Trigger
● Main trigger source: scintillation
light signals from PMT system
integrated with low noise (RC=10 ms)
preamps to efficiently exploit the
6ns fast and 1.6 ms slow components
● CNGS neutrino trigger:
PMT-Sum signal (thr. ~100 phe) for each chamber
in coincidence with CNGS “Early Warning” beam gate (60 ms)
~80 triggers/day (few tens events expected).
● Cosmic Rays trigger:
PMT-Sum signal coincidence of two adjacent chambers
(50% central cathode transparency)
~130 events/h (~160 expected)
Preliminary analysis done, needing a more detailed study of the
collected data and comparison with MC simulation.
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Additional trigger on local charge deposition
● Dedicated algorithm implemented on FPGA on SuperDAEDALUS chip:
on-line hit-finding of ionization charge signal from single TPC wires
Collection view
1.5m drift
1.5m drift
Collection view
Events under threshold for PMT’s
Short muons traks
~2 MeV isolated electron
CR events
Used to improve the
cosmic ray/CNGS
trigger efficiency in
0.1 – 1 GeV range
An efficient data
reduction system
0-skipping
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East Cryostat New pumps
●LAr continuously filtered!
●LAr recirculation upgrade: new more efficient
max drift
West Cryostat
60 ppt O2 equiv.
LAr purification (<60 parts per trillion O2 equivalent)
non-immersed motor pump installed in East-cryo
●tele > 5ms
(~60 ppt [O2]eq), maximum charge
attenuation at 1.5 m: 17%.
●A paper in preparation on successful
commissioning and three year underground
operation of the cryogenic plant.
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Summary
On longer time scale further activities must
be vigorously continued within the year 2013
and even somehow beyond to complete the
analysis of all collected data, with some more
finalized papers:
Completion of the analysis of the full 8.6
1019 pot collected sample;
A more complete study of the actual
nature of the CNGS events
Cosmic rays and other data analysis.
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Thank you !
LNGS_May2011
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