MINERnA and Future Cross Section Measurements

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MINERnA and Future Cross Section Measurements

• H. Gallagher ( K. McFarland)
• Nu Superbeams Meeting
• January 2004, FNAL

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Outline

• Cross Sections and Neutrino Oscillation Physics
• oscillations physics capabilities will drive
  decisions
• Non-Oscillation Neutrino Physics Opportunities
• discussed in detail in neutrino factory design
  studies
• MINERnA
• an example of a dedicated detector to
  study neutrino interaction physics

Precision Measurements Dm2, sin2(2q23) q13
Precision measurements of background
components. CP violation neutrino /
anti-neutrino cross sections
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General Comments

• Non-Oscillation physics topics come essentially
  for free.
• Growing realization that high precision
  oscillation measurements will require improved
  knowledge of neutrino interaction processes in
  order to reach maximum sensitivity.
• Current models are based on very limited data
  from 70s-80s era bubble chambers.

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K2K and MA
(K. McFarland, Minerva PAC presentation)

• This is not a direct answer to your question, but
  its a relevanthistorical lesson
• K2K found unexpectedresults in Q2
  distributionof quasi-elastic events
• blue box is correlatedenergy scale error
• Initially, was incorrectlyfixed by increasing MA
• dipole parameterization ofform-factor
• Bodek-Budd-Arrington showed it was a mistake in
  sQE

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K2K and MA
K2K was able to fit this data by using different
MA (1.02 1.10) for resonance

events and altering the QE/non-QE
fraction by 0.93. Studied old BNL
bubble checking for consistency.
Wrong Ma1.1 (used by K2K) Over Ma1.02 (Ratio)
Arie Bodek claims that the real problem is that
all neutrino MCs use outdated form factors, in
particular non-zero GEn.
If One Uses Both wrong Form Factors (used in K2K
MC) ( Wrong Gen 0 Wrong Ma1.1) Over Best Form
Factors (Ratio) --gt Get right shape But wrong
normalization of 10
hep-ph/0202183(2002)

Wrong Gen /Best Form Factors (Ratio)
For E1 GeV
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K2K and MA (contd)

• Chris Walter at NUINT02 effect of difference
  between correct and fudged solution if one is in
  data and one is in MC.

this is a toy analysis of nm disappearance at
J-PARC Phase I
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Motivation 1 Oscillations
Seeing the dip in the oscillation probability
is an important goal of MINOS

• An important milestone,
• possibly more important
• psychologically than
• anything else.
• Difficult at low Dm2.

• CC energy distributions have two important
  complications at low energy
• Difference between Evis and En due to nuclear
  effects (particularly rescattering).
• Requires a subtraction of NC events that fake low
  energy CC.
• In both cases MINOS will have to rely on MC.

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Neutrino Energy Calibration
One place where model dependencies inevitably
occur is in the determination of the neutrino
energy from the visible hadronic energy.
Doesnt cancel in near/far comparisons as En is
coupled to Dm2.

• Visible energy is not the same as total energy
  for a number of reasons
• p leave only KE, some get absorbed
• p0s deposit all energy in calorimeter
• Nuclear binding energy
• Intranuclear scattering absorbs energy,
• affecting multiplicities and charge ratio
• The models related to hadronization in the
• low invariant mass region and intranuclear
• scattering at these energies have substantial
• uncertainties.

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n Energy Calibration
MINOS Dm2 2.5x10-3
Ideally, what is needed is a neutrino test
beam. What would we like to know better? Low
mass hadronization Isospin amplitudes in
resonance region Nuclear effects (final state
re-interactions) For MINOS, data from K2K and
miniBoone alone will not provide the answers..
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q13 NuMI Off-Axis

• Off-axis beams are in an energy range where a lot
  of things matter.
• Quasi-elastic, resonance production and DIS
  contribute significantly
• Coherent mechanisms important
• Nuclear effects, fermi motion, rescattering

Backgrounds depend Sensitively on the
beam/detector ne in beam NC resonant NC
coherent NC DIS High-y CC nt ? t ? e And
there is no near location which gives the same
mixture as that seen at the far detector.
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CP Violation
The ratio of n/n cross sections could be an
important systematic for neutrino searches for
CP violation. also for CPT violation searches
Nuclear effects also important ? Low Q2 reduction
in cross section
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For 40 years, non-oscillation neutrino physics
was neutrino physics!
Reines-Cowan n discovery and the BNL 2n
experiment fundamental n properties
SuperK, Soudan2, MINOS, K2K, miniBoone fundamenta
l n properties masses and MNS matrix
1950
1990
1960
1970
1980
2000

• structure functions (F2, F3)
• parton universality
• electroweak studies sin2(qw)
• strange sea studies
• QCD measurements
• cross sections

• hadronic weak currents
• observation of
• neutral currents
• cross sections

counter experiments CDHS, CHARM CCFR, NuTEV
Bubble Chambers BNL, ANL, FNAL, CERN, Serpukhov
Neutrinos as probes to understand matter and
interactions
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Non-Oscillation Physics Opportunities
Higher Energy Electroweak studies n-e
scattering sin2qw from NC/CC Structure
Functions measurements of as measurements of
R pdfs at large xBj polarized structure
functions Nuclear Effects Nuclear shadowing EMC
effects Heavy quark studies charm quark studies
lambda polarization
Lower Energy Precision measurements of form
factors Duality studies in the resonance
region Nuclear effects intranuclear
scattering Strange particle production Pentaquark
production
many others including new physics searches
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Medium Energy Physics
A high-intensity neutrino beam offers new
possibilities for the study of nucleon and
nuclear structure. e.g. NuMI has very similar
kinematic coverage to current generation of JLab
experiments. A new window on many of the
questions currently being explored in JLab
experiments.
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MINERnA (Main INjector ExpeRiment v-A)

• Oscillation Physics
• Future precision experiments
• will require accurate
• knowledge of the n-A
• cross sections.

Conventional n Physics Structure
Functions Quasi-elastic scattering Resonance /
single p Charm / strange production
Nuclear Physics Kinematic range very similar to
recent JLab runs. Study of nuclear structure
with a weak probe.
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The Collaboration

• D. Drakoulakos, P. Stamoulis, G. Tzanakos, M.
  Zois
• University of Athens, Athens, Greece
• D. Casper
• University of California, Irvine, California
• E. Paschos
• University of Dortmund, Dortmund, Germany
• D. A. Harris, M. Kostin, J.G. Morfin, P.
  Shanahan
• Fermi National Accelerator Laboratory, Batavia,
  Illinois
• M.E. Christy, W. Hinton, C.E .Keppel
• Hampton University, Hampton, Virginia
• R. Burnstein, A. Chakravorty, O. Kamaev, N.
  Solomey
• Illinois Institute of Technology, Chicago,
  Illinois
• I. Niculescu. G. .Niculescu

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,
H. Budd, J. Chvojka, P. de Babaro, S. Manly,
K. McFarland, I.C. Park, W. Sakumoto, R.
Teng University of Rochester, Rochester, New
York R. Gilman, C. Glasshausser, X. Jiang, G.
Kumbartzki, K. McCormick, R. Ransome Rutgers
University, New Brunswick, New Jersey H.
Gallagher, T. Kafka, W.A. Mann, W. Oliver Tufts
University, Medford, Massachusetts
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Event Rates

• Units of 1020
• Year total POT LE ME HE LEB MEB
  HEB
• 2006 3.0 3.0
• 4.0 3.0 0.7 0.3
• 4.0
  2.5 1.0 0.5
• 4.0 1.0 0.5 0.5 0.5
  0.5 1.0
• TOTAL 15.0 7.0 1.2 0.8 3.0
  1.5 1.5

• LE-configuration Events- (Em gt0.35 GeV) Epeak
  3.0 GeV, ltEngt 10.2 GeV, rate 80 K events/ton
  - 1020 pot
• ME-configuration Events- Epeak 6.0 GeV,
  ltEngt 8.0 GeV, rate 160 K events/ton - 1020
  pot
• HE-configuration Events- Epeak 9.0 GeV,
  ltEngt 12.0 GeV, rate 260 K events/ton - 1020
  pot

nm Event Rates per ton Process CC
NC Quasi-elastic 103 K 42 K Resonance 196 K
70 K Transition 210 K 65 K DIS 420
K 125 K Coherent 8.4 K 4.2 K TOTAL 940 K 288
K
Typical Fiducial Volume 3 tons CH, 1 ton Fe
and 1 ton Pb
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Physics Goals

• Quasi-elastic (n n --gt m- p, 300 K events off
  3 tons CH)
• Precision measurement of s(En) and ds/dQ
  important for neutrino oscillation studies.
• Precision determination of axial vector form
  factor (FA), particularly at high Q2
• Study of proton intra-nuclear scattering and
  their A-dependence (C, Fe and Pb targets)
• Resonance Production (e.g. n N ---gt n /m- D,
  600 K total, 450K 1p)
• Precision measurement of s and ds/dQ for
  individual channels
• Detailed comparison with dynamic models,
  comparison of electro- photo production, the
  resonance-DIS transition region -- duality
• Study of nuclear effects and their A-dependence
  e.g. 1 p lt-- gt 2 p lt--gt 3 p final states
• Coherent Pion Production (n A --gt n /m- A
  p, 25 K CC / 12.5 K NC)
• Precision measurement of s(E) for NC and CC
  channels
• Measurement of A-dependence
• Comparison with theoretical models

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Physics Goals

• Nuclear Effects (C, Fe and Pb targets)
• Final-state intra-nuclear interactions. Measure
  multiplicities and Evis off C, Fe and Pb.
• Measure NC/CC as a function of EH off C, Fe and
  Pb.
• Measure shadowing, anti-shadowing and EMC-effect
  as well as flavor-dependent nuclear effects and
  extract nuclear parton distributions.
• MINERnA and Oscillation Physics
• MINERnA measurements enable greater precision in
  measure of Dm, sin2q23 in MINOS
• MINERnA measurements important for q13 in MINOS
  and off-axis experiments
• MINERnA measurements as foundation for
  measurement of possible CP and CPT violations in
  the n-sector
• sT and Structure Functions (2.8 M total /1.2 M
  DIS events)
• Precision measurement of low-energy total and
  partial cross-sections
• Understand resonance-DIS transition region -
  duality studies with neutrinos
• Detailed study of high-xBj region extract pdfs
  and leading exponentials over 1.2M DIS events
  

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Physics Goals

• Strange and Charm Particle Production (gt 60 K
  fully reconstructed exclusive events) -
  
• Exclusive channel s(En) precision measurements -
  importance for nucleon decay background studies.
• Statistics sufficient to reignite theorists
  attempt for a predictive phenomenology
• Exclusive charm production channels at charm
  threshold to constrain mc
• Generalized Parton Distributions (few K events)
• Provide unique combinations of GPDs, not
  accessible in electron scattering (e.g. C-odd, or
  valence-only GPDs), to map out a precise
  3-dimensional image of the nucleon. MINERnA would
  expect a few K signature events in 4 years.
• Provide better constraints on nucleon (nuclear)
  GPDs, leading to a more definitive determination
  of the orbital angular momentum carried by quarks
  and gluons in the nucleon (nucleus)
• provide constraints on axial form factors,
  including transition nucleon --gt N form
  factors

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Coherent Pion Production MINERnA 25 K CC / 12.5
K NC events off C - 8.3 K CC/ 4.2 K NC off Fe and
Pb

• Characterized by a small energy transfer
• to the nucleus, forward going p. NC (p0
  production) significant background for nm --gt .ne
  oscillation search
• Data has not been precise enough to discriminate
  between several very different models.
• Expect roughly (30-40) detection efficiency with
  MINERnA.
• Can also study A-dependence with MINERnA

MINERnA
Sam Zeller
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How MINERnA Helps Oscillation Analyses

• Measurement of Dm2 (e.g.MINOS)
• Understanding intra-nuclear scattering effects
• Improved measurements of pion / nucleon
  absorption
• Improved measurement of pion production
  cross-sections
• These combine with absorption probability to
  produce further uncertainties in plot at right
• Measurement of q13 (e.g.MINOS/Off-axis)
• Precision measurement of coherent pion, and
  resonant pion cross-sections and angular
  distributions.
• Measurement of ne content of NuMI beams

MINOS Dm2 2.5x10-3
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Goals of MINERnA Require

• Identification and separation of exclusive final
  states
• Quasi-elastic ?mn??p, ?en?ep
• Single ?0, ? final states
• Muon and electron energy measurement
• Must observe recoil protons
• Important for ?n??p, ?n??p?0, etc.
• ?0 , ? reconstruction. Hadronic energy
• Adds a lot of mass. B-field for charge
• Nuclear targets (high A, Fe of interest for MINOS)

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Detector Overview

• Active target, surrounded by calorimeters
• upstream calorimeters are Pb, Fe targets
• Magnetized side and downstream tracker/calorimeter

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Fully-Active TargetExtruded Scintillator
Basic element 1.7x3.3cm triangular strips.1.2mm
WLS fiber readout in grove at bottom
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Performancep0 Energy and Angle Reconstruction

• p0s cleanly identified
• p0 energy resolution
• p0 angular resolution better than smearing from
  physics

Coherent, resonance events with p0
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Location in NuMI Near Hall

• MINERnA preferred initial running is without muon
  ranger, as close to MINOS as possible
• if this is not possible, we can run initially
  stand-alone elsewhere in the hall

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Summary

• A strong case to study neutrino interaction
  physics with a superbeam
• Relevance for oscillation experiments
• bread and butter n physics program has
  breadth as well as depth
• Complementarity to existing medium energy
  program
• Close communication with n factory studies (but
  oscillations are at low energy).
• Large phase space for both non-oscillation and
  oscillation topics qualitative
• arguments are easy to make, quantitative studies
  require definition of the important
• parameters
• Beams
• Detectors
• Oscillation sensitivities of future experiments
• cross section uncertainties at some point in
  future (i.e. what can we assume is
• learned from K2K, miniBoone, MINERvA?)