Status of the MINERvA Project

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Status of the MINERvA Project
George Tzanakos University of Athens
Outline Introduction Physics Goals The NuMI
Beam Detector Technology The MINERvA
Detector Expected Results Connection to Neutrino
Oscillation Expts Current Status and
Outlook Conclusions
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What is MINERvA

• Main INjector ExpeRiment for v -A
• MINERvA is a newly approved FNAL Experiment
  designed to study neutrino-nucleus interactions
  with unprecedented detail.
• MINERvA uses a compact, fully active neutrino
  detector to make accurate measurements of v A
  cross sections in exclussive channels.
• The MINERvA detector will be placed in the NuMI
  beam line upstream of the MINOS Near Detector.

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Location
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The MINERvA Collaboration

• G. Blazey, M.A.C. Cummings, V. Rykalin
• Northern Illinois University, DeKalb, Illinois
• W.K. Brooks, A. Bruell, R. Ent, D. Gaskell,,
• W. Melnitchouk, S. Wood
• Jefferson Lab, Newport News, Virginia
• S. Boyd, D. Naples, V. Paolone
• University of Pittsburgh, Pittsburgh,
  Pennsylvania
• A. Bodek, R. Bradford, H. Budd, J. Chvojka,
• P. de Babaro, S. Manly, K. McFarland, J. Park,
  W. Sakumoto
• University of Rochester, Rochester, New York
• R. Gilman, C. Glasshausser, X. Jiang, G.
  Kumbartzki,
• K. McCormick, R. Ransome
• Rutgers University, New Brunswick, New Jersey
• A. Chakravorty

• D. Drakoulakos, P. Stamoulis, G. Tzanakos, M.
  Zois
• University of Athens, Athens, Greece
• D. Casper, J. Dunmore, C. Regis, B. Ziemer
• University of California, Irvine, California
• E. Paschos
• University of Dortmund, Dortmund, Germany
• D. Boehnlein, D. A. Harris, M. Kostin, J.G.
  Morfin,
• A. Pla-Dalmau, P. Rubinov, P. Shanahan, P.
  Spentzouris
• Fermi National Accelerator Laboratory, Batavia,
  Illinois
• M.E. Christy, W. Hinton, C.E .Keppel
• Hampton University, Hampton, Virginia
• R. Burnstein, O. Kamaev, N. Solomey
• Illinois Institute of Technology, Chicago,
  Illinois

Red HEP, Blue NP, Black Theorist
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Motivation Accurate v-oscillation NP

• For mass splitting (?m2) measurements in ?µ
  disappearance
• Understanding of relationship between observed
  energy incident neutrino energy (Evis ? E?) ?
  ultimate precision in ?m2
• Measurement of ?-initiated nuclear effects
• Improved measurement of exclusive cross sections

• For electron appearance (?µ ? ?e)
• Much improved measurements of ?- A exclusive ? ?
  accurate background predictions ? signal above
  background estimation
• Individual final states cross sections (esp. p0
  production)
• Intra-nuclear charge exchange
• Nuclear (A) dependence

• For Nuclear Physics
• New precise Jefferson Lab measurements of
  electron scattering are inspiring nuclear
  physicists to consider neutrinos
• Vector versus axial vector form factors
• Nuclear effects are they the same or different
  for neutrinos?

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Physics Goals

• Axial form factor of the nucleon
• Yet to be accurately measured over a wide Q2
  range.
• Resonance production in both NC CC neutrino
  interactions
• Statistically significant measurements with 1-5
  GeV neutrinos
• Study of duality with neutrinos
• Coherent pion production
• Statistically significant measurements of ? or
  A-dependence
• Nuclear effects
• Expect some significant differences for ?-A vs
  e/µ-A nuclear effects
• Strange Particle Production
• Important backgrounds for proton decay
• Parton distribution functions
• Measurement of high-x behavior of quarks
• Generalized parton distributions

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Low E Neutrinos Present Knowledge

• Mainly from experiments in the 70s and 80s at
  ANL, BNL, FNAL, CERN, Serpukov
• World sample statistics is poor!
• Systematics large due to flux uncertainties
• See examples
• Quasi elastic scattering
• Single pion production (CC)
• Total Cross Section
• Coherent pion production

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Present Status QE Scattering
S. Zeller - NuInt04
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Current Status CC Single Pion Production
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Current Status Total Cross Section
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Achieving the Objectives

• Need an Intense Neutrino Beam (NuMI Beam)
• Improved Systematics in Neutrino Flux (NuMI
  Target in MIPP Experiment)
• We need a detector with
• Good tracking resolution
• Good momentum resolution
• A low momentum threshold
• Timing (for strange particle ID)
• Particle ID to identify exclusive final states
• Variety of targets to study nuclear dependencies

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The NuMI Beam
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Neutrino Horns and Spectra

• 120 GeV primary Main Injector beam
• 675 meter decay pipe for p decay
• Target readily movable in beam direction
• 2-horn beam adjusts for variable energy range

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NuMI Beam Intensity

• Extremely intense beam means near detectors see
  huge event rates.
• Example NuMI low energy beam, get million
  events per ton-year in near hall
• MIPP measurements of NuMI target mean that n flux
  will be better predicted than ever before
• Perfect opportunity for precision n interaction
  studies.

Examples of Real MINOS ND Events in two spills
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MINERvA Event Yields

• Assume
• 161020 POT in 4 years (mixture of LE, ME, HE
  tunes)
• Fiducial Volumes 3 ton (CH), 0.6 ton C, 1 ton Fe
  1 ton Pb ?
• 16 M total CC events (8.8 M in CH, 7.2 M in C,Fe,
  Pb)
• Expected event yields
• Quasi-elastic 0.8 M events
• Resonance Production 1.6 M
• Transition Resonance to DIS 2.0 M
• DIS and Structure Functions 4.1 M
• Coherent Pion Production 85 K (CC) 37 K (NC)
• Strange Charm Particle Production gt230 K fully
  recod
• Generalized Parton Distributions 10 K
• Nuclear Effects C 1.4M Fe 2.9M Pb 2.9M

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Detector Technology

• 1.7 x 3.3 cm triangular Sci strips
• 1.2 mm WLS Fiber readout

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Detector Technology
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Detector Geometry

• Downstream (DS) Calorimeters
• ECAL Pb X0/3 between each sampling plane
• HCAL 1 inch steel (l0/6) between each sampling
  plane.
• Outer Detector (OD) (HCAL) frames

• Active Target Segmented scintillator detector
  5.87 tons
• 1 ton of US nuclear target (C, Fe, Pb) planes
  (absorber Scintillator)
• Side ECAL Pb X0/3 sampling

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Detector Structure
Steel Frame
Mounting ears
Lead Collar
Scintillator planes or calorimeter targets
Scintillator for calorimeters
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Example QE Event

• Quasi-elastic ??n??p

• Proton and muon tracks are clearly resolved
• Observed energy deposit is shown as size of hit
  can clearly see larger proton dE/dx
• Precise determination of vertex and measurement
  of Q2 from tracking

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Example Pi-zero
?0 Production

• two photons clearly resolved (tracked).
• can find vertex.
• some photons shower in ID, some inside ECAL (Pb
  absorber) region
• photon energy resolution is 6/sqrt(E) (average)

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Expected Results Examples

• QE Scattering Cross Sections
• Axial Form Factors
• Nuclear Effects
• Coherent Pion Production

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Quasi-Elastic Scattering
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Quasi-Elastic Scattering
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QE Scattering Axial Form Factor
Contributions of the form factors to the cross
section
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QE Scattering Axial Form Factor

• Vector form factors measured with electrons.
• GE/GM ratio varies with Q2 - a surprise from
  JLab
• Axial form factor poorly known

Miner?a (4 year run
Efficiencies and Purity included.
Dipole Form
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QE Scattering Axial Form Factor
Deviation from Dipole behavior. Plot FA/Dipole
form vs Q2
FA from the D2 experiments.
Cross Section/Dipole
Polarization/Dipole

• MINERvA can determine
• Whether FA deviates from a dipole
• Which Q2 form is correct cross-section or
  polarization

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Coherent Pion Production

• Tests understanding of the weak interaction
• The cross section can be calculated in various
  models

• Neutral pion production is a significant
  background for neutrino oscillations
• Asymmetric p0 showers can be confused with an
  electron shower

• Precision measurement of ?(E) for NC and CC
  channels
• Measurement of A-dependence
• Comparison with theoretical models

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Coherent Pion Production
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Coherent Pion Production
Plotted scoh vs. A
MINERvAs nuclear targets allow the first
measurement of the A-dependence of scoh across a
wide A range
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Nuclear Effects ?m2 Measurements
µ
n
p

• Evis ? E?
• Understand the relationship
• Evis? E?
• p absorption rescattering
• Final state rest masses
• v-nuclear corrections predicted to be different
  from those in charged lepton scattering (studied
  from Deuterium to Pb at high energies)

F2, Pb/C (MINERnA stat. errors)
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Nuclear Targets Evis vs Etot
Plotted Evis/E? versus E?
Nominal abs
3?
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MINERvA MINOS
(d?/?) versus ? (? ? ?m2)
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MINERvA NOvA

• NOvAs near detector will see different mix of
  events than the far detector

Total fractional error in the predictions as a
function of reach (NOvA)
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MINERvA T2K
T2Ks ND will see different mix of events than
the FD

• To make an accurate prediction one needs
• 1 - 4 GeV neutrino cross sections (with energy
  dependence )
• MINERvA can provide these with low energy NuMI
  configuration

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Current Status and Outlook

• April 2004 Stage I approval from FNAL PAC
• October 2004 Complete first Vertical Slice Test
  with MINER?A extrusions, WLS fiber and Front-End
  electronics
• January 2005 First Project Directors
  (Temple) Review
• Summer 2005 Second Vertical Slice Test
• December 2005 Projected Date for MINERvA
  Project Baseline Review
• October 2006 Start of Construction
• Summer 2008 MINERvA Installation and
  Commissioning in NuMI Near Hall

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Summary

• Presently Low Energy ?- Nucleus interactions are
  poorly measured. MINER?A, a recently approved
  experiment, brings together the expertise of the
  HEP and NP communities to use the NuMI beam and a
  high granularity detector to break new ground on
  precision low-energy ?-A interaction
  measurements.
• MINERvA will provide a high statistics and
  improved systematics study of important exclusive
  channels across a wider E? range than currently
  available. With excellent knowledge of the beam
  (NuMI MIPP), exclusive cross sections will be
  measured with unprecedented precision.
• MINERvA will make a systematic study of nuclear
  effects in ?-A interactions (different than
  well-studied e-A channels) using C, Fe and Pb
  targets.
• MINERvA will help improve the systematic errors
  of current and future neutrino oscillation
  experiments (MINOS, NOvA, T2K, and others).

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Acknowledgements
The MINERvA Collaboration Especially S. Boyd, H.
Budd, D. Harris, K. McFarland, J. Morfin, J.
Nelson, R. Ransome