Maria%20Gabriella%20Catanesi

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Production StudiesHARP results NA61 prospects

• Maria Gabriella Catanesi
• INFN Bari Italy

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Outline

• Present measurements Harp results
• K2K MiniBoone fluxes
• Super Beams Neutrino Factory Design
• Atmospheric fluxes ( lt 15 GeV)
• Hadron Production Models
• Coming soon
• Na61 Atmospheric (lt 200 GeV) T2K neutrino
  Flux

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Harp

• Inaugurates a new era in Hadron Production for
  Neutrino Physics
• Based on a design born for Heavy Ions physics
  studies
• Full acceptance with P.Id.
• High event rate capability (3KHz on TPC)
• Built on purpose
• Collaboration includes members of Neutrino
  Oscillation Cosmic rays experiments
• (124 Physicists from 20 institutions)
• And makes measurements on specific targets of
  existing neutrino beams.

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Existing measurements at the end of the millenium
Boxes show importance of phase space region for
contained atmospheric neutrino events.
Barton et. al.
Overall quoted errors Absolute rates
15 Ratios 5 These figures are typical of
this kind of detector setup
Abbott et. al.
Measurements. 1-2 pT points 3-5 pT
points gt5 pT points
Eichten et. al.
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HARP Data taking summary
HARP took data at the CERN PS T9 beamline in
2001-2002 Total 420 M events, 300 settings
SOLID
CRYOGENIC
n EXP
K2K Al MiniBoone Be LSND H2O
5 50 100 Replica 5 50 100 Replica 10 100
12.9 GeV/c 8.9 GeV/c 1.5 GeV/c
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• Forward Spectrometer
• 30 mrad lt ? lt 210 mrad.
• 750 MeV/c lt p lt 6.5 GeV/c
• K2K,MiniBoone, Cosmic rays

Detector layout
Forward spectrometer
Large Angle spectrometer

• Large Angle Spectrometer
• 0.35 rad lt ? lt 2.15 rad
• 100 MeV/c lt p lt 700 MeV/c
• Super Beams - Nufactories

More details in the NIM paper The Harp Detector
_at_ the CERN PS
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FORWARD ANALYSIS
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FW Momentum Resolution
ELASTICS
TOF
BEAM
open data filled MC
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FW PID principle
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Relevance of HARP for K2K neutrino beam
One of the largest K2K systematic errors comes
from the uncertainty of the far/near ratio
pions producing neutrinos in the oscillation peak
measured by HARP
oscillation peak
K2K far/near ratio
En (GeV)
K2K interest
Beam MC confirmed by Pion Monitor
Beam MC
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Far/Near Ratio in K2K
Predicted Flux Shape
Predicted Far/Near Ratio
Near Detector
Far Detector

• HARP gives factor 2 error reduction across all
  energies

Nucl.Phys.B7321-45,2006 hep-ex/0510039
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MiniBoone Harp Be 8.9 GeV 5 ?
p
Harp Forward Spectrometer Acceptance
(But also SCIBOONE)
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HARP Be 8.9 GeV/c data Sanford-Wang
parametrization
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• More HARP data for accurate flux predictions
  coming

main source of ?e flux for MiniBooNE
K production data thick targets p -
production data
Direct measurement with rescattering and
absorption
Anti-neutrino flux measurement
p
K
p
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?- data needed for MiniBooNE antineutrino flux
Paper in preparation
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Large Angle Analysis
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LA Spectrometer performance
p-p PID with dE/dx
momentum calibration cosmic rays elastic
scattering
momentum resolution
PID dE/dx used for analysis TOF used to
determine efficiency
p-e PID with dE/dx
elastic scattering absolute calibration of
efficiency momentum angle (two spectrometers!)
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The elastic scattering benchmark
momentum scale
1/p (predicted-measured)/(1/p)
Comparison of predicted vs measured track
allows LA tracking benchmark
missing mass peak from large angle proton
track (position of peak verifies momentum scale
-- 15 shift is completely excluded)
efficiency
Momentum scale Sys. Error lt 3
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Stability from LH2 target to other targets
consider average momentum of protons with dE/dx
?7-8 MIPs
H2 setting
H2
Al 13 12 8 5 3
Carbon 12 8 5 3
Tin 12 8 5 3
?2
Copper 12 8 5 3
Lead 12 8 5 3
Be 12 9 8 5 3
Ta 12 8 5 3
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Neutrinofactorystudy

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Ta Target Data

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yield/Ekin
ds/dq cross-sections can be fed into neutrino
factory studiesto find optimum design The
optimal energy is between 5 and 8 GeV/c
published on EPJC
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Neutrino factorystudy (cont)
its also possible to enlarge the phase space (if
we accept larger errors)
On going analysis
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p-p ratios for light and heavy nuclei
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Pion yields
comparison of p and p- and yields for p-A for
Be, C, Cu, Sn, Ta and Pb
forward production only 0.35 lt q lt 0.95 rad
p
p-
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Pion yields
A-dependence of p and p- and yields for p-A for
Be, C, Cu, Sn, Ta and Pb (3, 5, 8, 12 GeV/c)
forward production only 0.35 lt q lt 1.55 rad
p
p-
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proton beams on long targets

• Data analysed on tantalum and carbon targets
  (lead later)
• Especially useful for the neutrino factory target
• Interesting to tune models for re-interactions
  (and shower calculations in calorimeters etc.)
• As for the thin targets, corrections for the
  absorption and re-interaction of the produced
  particles are made
• NO correction is made for the absorption and
  re-interaction of the beam proton (this is what
  we want to measure)
• Data are not directly applicable our targets are
  30mm in diameter more re-interactions of the
  scattered proton

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100 vs 5 TARGET
FW and BW p-C p
100 l target
5 l target
PRELIMINARY
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100 / 5 TARGET
bin-by-bin ratio 5 GeV/c beam p-C p/-
Large corrections !
If no effect from absorption of p expect ratio
1 If all interacting p are lost expect ratio
0.65
p-
p
PRELIMINARY
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100 / 5 TARGET
bin-by-bin ratio 12 GeV/c beam p-C p/-
If no effect from absorption of p expect ratio
1 If all interacting p are lost expect ratio
0.65
p
p-
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100 / 5 TARGET
bin-by-bin ratio 5 GeV/c beam p-Ta p/-
If no effect from absorption of p expect ratio
1 If all interacting p are lost expect ratio
0.65
p
p-
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100 / 5 TARGET
bin-by-bin ratio 12 GeV/c beam p-Ta p/-
If no effect from absorption of p expect ratio
1 If all interacting p are lost expect ratio
0.65
p-
p
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HARP publications
Forward analysis Measurement of the production
cross-section of positive pions in p-Al
collisions at 12.9 GeV/c (K2K target
measurement) M.G. Catanesi et al, hep-ex/0510039,
Nucl. Phys. B732 1-45 (2006) Measurement of the
production cross-section of positive pions in the
collision of 8.9 GeV/c protons on beryllium
(MiniBooNE target measurement) M.G. Catanesi et
al, Eur.Phys.J.C5229-53,2007. Measurement of
the production cross-section of pi in p-C and
pi- C Interactions at 12 GeV/c M.G.Catanesi et al
Astroparticle Physics - volume/issue 29/4 pp.
257-281 Forward production of pi/pi- in p-O2
and pN2 interactions at 12 GeV/C M.G.Catanesi et
al Astroparticle Physics - volume/issue 30/4
pp. 120-150 Forward production of charged pions
in the HARP experiment with incident pi/pi- on
nuclear targets M.G.Catanesi et al Accepted by
Nuclear physics A In preparation Full
characterization of the MiniBoone/SciBoone 
neutrino beam(pi-, kaon, protons, thick and
replica target)Forward production of charged
pions with incident protonson different nuclear
targetsForward production of charged pions with
incident protons and pionson different nuclear
thick targets
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HARP publications
Large Angle analysis (Neutrino Factory
measurements) Measurement of the production of
charged pions by protons on a tantalum
target M.G. Catanesi et al, Eur. Phys. J. C51
(2007) 787 Large-angle production of charged
pions by 3 GeV/c12 GeV/c protons on carbon
copper and tin targets M.G. Catanesi et al, Eur.
Phys. J. C53177-204,2008 Large-angle production
of charged pions by 3 GeV/c12 GeV/c protons on a
beryllium , aluminum and lead targets M.G.
Catanesi et al, Eur. Phys. J. C5437-60,2008 Larg
e-angle production of charged pions in the HARP
experiment with incident protons on nuclear
targets M.G.Catanesi et al. Phys. Rev. C 77,
055207 (2008) In preparation Large-angle
production of charged pions in the HARP
experiment with incident pions on nuclear targets
M.G. Catanesi et al. (Draft in preparation )
(beams 3 GeV/c -12.9 GeV/c , Al, Be,C, Cu,
Pb,Sn,Ta targets) Large Angle production of
charged pions with incident protons and pionson
different nuclear thick targets
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What next
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• NA61 Plans
• perform a comprehensive scan in energy and size
  of colliding nuclei to study the properties of
  the transition between hadron gas and quark gluon
  plasma
• measure hadron production in hadron-nucleus
  interactions needed for neutrino and
  astroparticle physics

NA61 approved in 2007 Technical Run end -2007 T2K
target run 2008
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HADRON PRODUCTION FOR T2Kat NA61/SHINE
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T2K experiment

• Physics goals
• Discovery of?????e appearance
• Precise meas. of disappearance?????x
• Neutral current events
• Discovery of CP violation (Phase2)

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T2K n beam

1. predict nm flux at far detector
2. estimate ne background

far-to-near flux ratio (T2K beam MC prediction)

• Near and far detectors see different solid
  angles
• far detector point like source at 2o
• near detector extended source 1o to 3o
• (wide off axis angular range)
• complicated far to near flux ratio

far peak shifted to higher energy (angular acc.)
extended source for near detector

• T2K F/N ratio should be know with a precision lt
  3 to match the physic requirements (20 without
  dedicated measurements )

NA61 is needed !
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T2K ? parent hadron phase space
p
K
angle (mrad)
angle (mrad)
momentum (GeV)
momentum (GeV)
need to cover all this kinematical region and
identify the outgoing hadrons K component
important for ne appearance signal
(background) requires large acceptance and
particle ID
Region of interest for pions ( 0.5lt P lt5 GeV/c
and 0 lt? lt 250 mrad)
Region of interest for Kaons ( 1lt P lt10 GeV/c
and 0 lt? lt 350 mrad)
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Why hadron measurements for T2K?

• phase-space of T2K ? beam
• no data at these energies 30 50 GeV,
• in particular for large production angles
• (?gt 100 mrad)
• extrapolations possible but not too reliable
• reinteractions / absorption of few GeV
• pions poorly described
• (up to factors of 2)
• prefer to base ? beam description on actual
  measurements
• rather than more or less reliable hadron
  interaction models

Without the NA61 data T2K will not reach the
required sensitivity
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-calibration of all detector components have been
performed successfully-preliminary uncorrected
spectra have been obtained, -high quality of
track reconstruction and particle identification
(similar to NA49) has been achieved, -a
preliminary result on the total inelastic pC
cross sectionat 31 GeV/c was obtained,
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Conclusions(1)

• HARP has made important contributions to hadronic
  cross-section measurements relevant to neutrino
  experiments
• Aluminium results for K2K have used for final K2K
  publication.
• Beryllium results for MiniBooNE and SciBoone are
  also finals. These measurements are already being
  used by the MiniBooNE collaboration.
• Tantalum (and other targets results) for the
  Neutrino Factory studies are available
• Carbon ,N2, O2 data for atmospheric neutrino
  fluxes are ready.
• More production cross-section measurements are
  finished and can be used to tune hadron
  production models.
• All the previous listed results have been already
  published but many new results will be coming
  soon stay tuned !

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Conclusions (2)

• The NA61 experiment was approved at CERN in June
  2007
• -the pilot run was performed during October 2007
• -calibration of all detector components have been
  performed successfully
• a preliminary result on the total inelastic pC
  cross section at 31 GeV/c was obtained, -
• the data and detailed simulations confirm that
  the phase-space needed for the T2K measurements
  is covered,-
• first physics results from the 2007 run are
  expected in 2009

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backup
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Example of future projects
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About the discrepancy between the HARP results
and those produced by the so called Dydak group
Protons on Be
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Protons on Be
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About the discrepancy between the HARP results
and those produced by the so called Dydak group
Protons on Be
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In Summary

• The Dydak group claims that the observed
  discrepancies should be interpreted as the
  consequence of a momentum bias (15) in our data

• We dont believe in this hypothesis because
• This bias is excluded by the elastic scattering
  analysis
• The discrepancy is visible only for p
• The discrepancy is visible only at low ?
• The size of the discrepancy smootly depends
  from the beam energy
• No shift is observed in the peak position

Any way the size of the effect is such that
doesnt change the optimal energy for the NF
driver
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Harp vs E910 (12 GeV/c P beam)
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Atmospheric neutrino fluxes motivations for
measurements
TOTEM 14 TEV
NA61/MIPP 40-200 GeV

• Initial reaction well above the highest energy
  accelerator available.
• Shower develops a large number of lower energy
  interactions accelerator measurements are
  helpful.
• Energy region from few GeV
• ? 200 GeV (contained)
• ? 2 TeV (through going)

HARP 2-15 GeV

• Accelerator measurements are very sparse.
• - Colliders most particles close to beam and
  dont enter the detector.
• - Fixed target The energies are much lower and
  few experiments have published.
• - No data available on O2 N2

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Results for pO2 or pN2 cryo targets

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LONG C TARGET
p-C p-
PRELIMINARY
forward 0.35 lt q lt 1.55
backward 1.55 lt q lt 2.15