Neutrino Program at Rochester

1
Neutrino Program at Rochester

• Kevin McFarland
• 23 July 2003

2
Outline

• Personnel, etc.
• NuTeV
• Next generation oscillation experiments
• Neutrino cross-sections
• Phenomenology
• MINERvA

3
Timeline

• Neutrino program at Rochester is currently
  between major construction commitments
• Ramp up to future projects well suited to
  dovetail into end of Run 2

4
Personnel

• No one is currently full-time
• Group (mostly senior) currently planning future.
• this will have to change soon

Senior Physicists Students Collaborators Prof.
Arie Bodek (25) Mr. Brian Anderson Prof. Steve
Manly (DOE-nucl) Dr. Howard Budd (25) Mr. Paul
Conrow (RET) Prof. Frank Wolfs (NSF-nucl) Prof.
Kevin McFarland (25) Ms. Aimee Slaughter
(REU) Dr. Willis Sakumoto Dr. Sergey
Avvakumov Dr. Pawel deBarbaro Dr. Un-Ki
Yang (were 25 NuTeV) (were 100
CCFR/NuTeV) Senior Research Assoc. Undergraduates
Secondary Teachers
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Recent Recognition for Work

• Prof. Arie Bodek is an acknowledged expert on
  neutrino cross-section modeling
• gave recent NUINT02 summary talk
• Prof. Kevin McFarland has given 25 invited
  seminars and conference presentations on recent
  NuTeV electroweak result
• Thesis awards for our students
• Un-Ki Yang FNAL URA Thesis award 2002
  (CCFR/NuTeV)
• Geralyn Zeller 2003 APS Tanaka prize (NuTeV)(NWU
  student, de facto advised by McFarland)

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NuTeV Electroweak Analysis

• Recent three s anomaly in NuTeV sin2qW continues
  to be a puzzle of interest to community
• McFarland (EW Analysis leader), Zeller, thesis
• McFarland continues activity ininvestigating
  possible solutions
• e.g., recent collaboration withSven-Olaf Moch
  (DESY) oncalculation of NLO QCD effects(shown
  to be small, hep-ph/0306052)

MW 80.136 ? 0.084 GeV from
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NuTeV Students

• Avvakumov (Bodek)
• first precise measurement of w/o assuming
  CP/CPT
• test of LSND CPT hypothesis
• Yang (Bodek)
• CCFR cross-sections, QCDe.g., test of F2
  universality
• URA thesis award (2002)

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Status of Neutrino Oscillations

• Atmospheric (Super-K) and Solar (SNO, KAMLAND)
  neutrino oscillation signatures are well
  established

SNO
Kamiokande
Soudan-2
Super-K
MACRO
sin22?gt 0.92 ?m2(1.6
3.9)10-3eV2
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Oscillation Phenomenology

• Lepton Mixing Matrix has a very different
  structure than CKM matrix

• Big elements (B) are numerically 0.3-0.7
• ? Element, Ue3, is less than 0.2
• CHOOZ reactor experiment bounds
• Theory bet is that Ue3 is just around the
  corner

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So what about this Ue3?

• If Ue3 is non-zero, then phenomenology of
  neutrino oscillations becomes more rich
• CP violation in oscillations à la CKM matrix
• Observe matter effects in nm beam
• Sensitive to the hierarchy of neutrino masses
  instead of just mass-squared differences
• If Ue3 is near zero, this is very odd
• Will have big impact on GUT models

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The Importance of Precision P(nm?ne) at Superbeams

• Conventional superbeams and reactors will be
  our next windows into Ue3

• Studying this transition in neutrinos and
  anti-neutrinos gives us magnitude and phase
  information on Ue3 as well as sign of dm23
• Reactors only measure magnitude of Ue3

Non-trivial phase, d ? CP violation
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How can this be done with Conventional Beams?

• Appearance signal is difficult to extract
• beam backgrounds
• high energy feed-down (neutral currents)
• Off-axis beam technique
• makes it possible

• Beam becomes
• monochromatic
• Less feed-down
• Fewer electron neutrinos

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J-PARC Neutrino

• JAERI 50 GeV PS
• 0.77MW initially
• 4MW upgrade planned
• Extraction point for n beam is being built
• Off-axis beam to Super-K detector, near Seoul
• At Super-K, L/E295km/0.7GeV

• LOI favorably reviewed by J-PARC PAC
• Proposal submitted to Monkasho soon
• Actively encouraging non-Japanese collaborators
• Physics start date 2008 or 2009?

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NUMI Off-Axis

• NUMI (on-axis) experiment for nm disappearance
  will commence 2005
• 0.25-0.4 MW proton power
• Run 10 km off axis at L/E700km/2GeV? Other?
• LOI submitted to PAC
• Proposal to PAC in fall

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Cross-Sections and Modeling
Quasi-elastics nmn?m-p (x1, WMp) Resonance
Region e.g., nmn?m-pp0 (low Q2, W) Deep
Inelastic Scattering nmN?m-X (low Q2, W)

• Plausible models exist to describe some aspects
  of data in each region
• Transitions between regions?
• A dependence, final-state interactions, etc.

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Status of Cross-Sections

• Not well-known at 1-few GeV
• Knowledge of exclusive final states particularly
  poor
• Understanding of backgrounds requires
  differential cross-sections for these processes!
• A dependence?

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Where do Cross-Sections matter?

• nm?nm, dm223, q23
• Signal is suppression in 600-800 MeV bin (peak of
  beam)
• Dominated by non-QE background
• 20 uncertainty in non-QE is comparable to
  statistical error
• Non-QE background feeds down from EngtEpeak
• Quantitatively different for MINOS, NUMI-OA

Oscillation with Dm2310-3 sin22q1.0
Non-QE
No oscillation
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Where do Cross-Sections matter?

• nm?ne, q13
• Shown at right is most optimistic q13 we may
  instead be fighting against background
• NC p0 and beam ne background both in play
• NC p0 cross-section poorly known
• We can model sCC(ne)/sCC(nm). Is it right?
• Precision measurement is the endgame

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Where do Cross-Sections matter?
NUMI 0.7 OA, 3.8E20 POT

• nm?ne vs nm?ne, d
• Cross-sections very different in two modes
• Wrong sign background only relevant in
  anti-neutrino
• Crucial systematic in comparing neutrino to
  anti-neutrino
• Need sCC(n)/sCC(n) in sub- to few-GeV region

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Phenomenology I Bodek-Yang Duality

• The problem transition between DIS and resonance
  region
• High precision neutrino DIS data (e.g., CCFR
  NuTeV) is available
• Precise low Q2 charged lepton data (JLab, SLAC)
  in resonance region
• Quark-Hadron Duality?
• When you get near a resonance, it sucks you in.
• Bodek and Yang have shown that charged lepton
  resonance data can be described on average with
  a DIS-like cross-section

• Currently being implemented in standard n
  generators
• NUANCE (Super-K, IMB), NUGEN (MINOS)

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Phenomenology II Revisiting Quasi-Elastics

• Strategy
• charged lepton data (lots of it) used to
  determine vector form factors
• small amount of neutrino quasi-elastic data used
  to measure axial form-factors within dipole model
• previous neutrino analyses used too simple a
  cross-section model

cross-section ratio, before and after
Bodek-Budd-Arrington

• Bodek, Budd and Arrington (Argonne) have
  re-analyzed old neutrino data with more
  sophisticated vector form factors
• result is a large shift in the effective axial
  mass
• this has solved a major problem for K2K Q2
  distributions
• again, being implemented in standard generators

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Rochester Involvement inJ-PARC neutrino

• We have begun an involvement in the J-PARC
  neutrino project
• McFarland has served on International Board since
  2002
• McFarland is 280m (near) detector co-convenor
• Our primary interest is in construction of near
  detectors to measure flux and neutrino
  cross-sections
• plays well into our CDF/CMS/NuTeV detector
  strengths
• leading the field in cross-section modeling
  (Bodek, Budd, Yang)
• Current activities
• tests of aqueous liquid scintillator for
  cross-section on Oxygen(Conrow, Slaughter,
  McFarland, Wolfs)
• detector simulation/optimization (Anderson,
  McFarland)

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MINERvA Main INjector ExpeRiment n-A

• The J-PARC neutrino beam may not achieve
  operating intensity until 2009
• but NUMI beamline available 2005
• beamline off and on-axis allows for a broad range
  of neutrino energies accessible in existing NUMI
  tunnels

on-axis
5m off-axis
NUMI ME
NUMI LE
10m
5m off-axis
on-axis
15m
15m
10m
event rate per unit detector mass as a function
of neutrino energy
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MINERvA Detector

• Want a fully active detector to see, e.g., recoil
  protons from ?mn??p
• Segmented scintillator strips with WLS readout
  for the basis of the detector
• heavy FNAL investment in this technology
• lots of Rochester experience! (CDF plug, CMS
  HCAL)
• Cost driver may be photosensors
• evaluating MAPMTs, APDs, Image Intensifiers/CCDs

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MINERvA Detector

• Modular design
• Construct above ground piecewise
• Can add detector or target material as another
  layer

Active/passive frame around target
Active scintillator strip target
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Next Steps for MINERvA

• Two EOIs submitted to FNAL PAC in 2002
• one to sit in on-axis and one in off-axis beams
• merger is MINERvA, initially to run on-axis(C.
  Keppel, McFarland, J. Morfin scientific
  coordinators)
• Will submit a proposal to fall 2003 PAC
• physics case, detector conceptual design, cost
  estimate

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Collaborations with Nuclear Physics

• Neutrino cross-sections and oscillations are also
  of interest to the nuclear physics community
• Prof. Steve Manly (DOE nucl)
• proposals at JLab to study inclusive and
  exclusive resonance cross-sections on nuclei
• crucial input for neutrino cross-sections
• Bodek, McFarland signed on as collaborators
• collaborator on MINERvA
• Prof. Frank Wolfs (NSF nucl.)
• development of Aqueous scintillator

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Conclusions

• Current successes in analysis (NuTeV) and
  phenomenology
• as well as detector building skills at Rochester
• We want to build on these strengths to seed a new
  generation of neutrino oscillation
  andcross-section experiments
• we see a unique role for Rochester in developing,
  building and analyzing near detector data,
  ultimately to be applied to neutrino oscillations
• next step MINERvA
• Bridge between particle and nuclear physics