MINERnA: Responses to PAC Questions

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MINERnAResponses to PAC Questions

• Kevin McFarlandUniversity of RochesterFNAL
  PAC13 December 2003

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Question 1

• How much money do you expect from Nuclear
  Physics sources? How much from Fermilab? Can
  you provide a table of the labs obligations?
• Role of Universities and Nuclear Physics
• FNAL Detector Costs (in proposal)
• FNAL Installation, Outfitting Costs

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Reminder from YesterdayHow We Plan to Fund
MINERnA

• Seek to fund bulk of detector from University
  program funds and infrastructure programs
• This cannot happen without strong endorsement
  from this PAC and the lab

HEP/NP Partnership
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Nuclear Physics and MINERnA

• Four university groups and Jefferson Lab
• Rutgers and Hampton are two of the strongest
  medium energy nuclear physics university groups
• leaders at JLab in physics addressed by MINERnA
• Four FTE faculty, three FTE post-docs
• JLab manpower 1-2 FTE, use of facilities. No
• NSF MRI Hampton, Rutgers, Rochester
• 2/3 of MRI funding through NP groups!
• Rutgers (University) has pledged 150K
  matching.Rochester matching contingent on NP
  involvement. (Hampton is exempt from matching
  requirement.)

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Costs to FNAL Detector

• Simply put outside agencies claim they will not
  fun certain aspects of FNAL experiments,
  including utilities, installation
• Two detector project categories FNAL-specific
  EDIA, critical safety systems
• design of TRiP-based FE board 130K
• low voltage distribution (5kW total) 170K
• magnet coil MS 10K
• detector stand (not in proposal) no estimate

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Costs to FNAL Installation and Outfitting

• We are in the process of doing a real evaluation
  of this. That process has not concluded.
• In response to your (perfectly reasonable)
  question, we tried to force that process to a
  quick answer.
• This is extremely rough, but has some
  information.

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Question 2

• Quantitatively, in what way will MINERnA results
  essentially effect the design of, or the eventual
  analysis of data from, MINOS and an Off-Axis
  experiment, and the interpretation of current
  neutrino oscillation results?
• Historical Tale K2K and the Axial Mass
• MINOS and Final State Uncertainties
• (more on this subject in response to question 3)

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K2K and MA

• 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 (contd)

• Difference between the fudged cross-section (to
  match the observed Q2 distribution) and the true
  cross-section
• End resultK2K assignedsystematic of20 in
  theabsolute rateat far detector

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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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Why Neutrino CC Energy doesnt equal visible
energy in MINOS a) p only leave KE b) some p
get absorbedc) p0s deposit all energy in
calorimeterEvent multiplicity counts,
especially at low energy!Does not cancel in
near/farMINOS cant measure multiplicitiesTest
change a)b) energy loss by 20 of itself,
which is optimistic for the error with no
MINERVA
One Final State Effect Neutrino Test Beam
D.Michael, yesterday
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Question 3

• In what ways would a fine-grained detector
  improve an off-axis experiment?

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• Backgrounds to Off Axis
• nes in the beam
• NC events
• nm CC events
• nm CC present in ND, not in FD because of
  oscillations
• NC events from low energy nm s (upstream)
• ne from m decays (downstream)
• As a result, Near/Far Ratio is different for each
  of these three backgrounds!

• Ideally, want to know
• how many events look like background in Off-Axis
  Near Detector, and
• What is the composition of those events
• Minerna can measure all three samples on axis and
  extrapolate to predict what off axis ND should
  see, or for better precision, Minerva can go off
  axis!

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Another way to look at this How does Figure of
Merit change as you increase statistics?
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Question 4

• For proposal how well can measurements be
  carried out?

• We dont have full treatments of backgrounds in
  most cases of analyses.
• We do have excellent knowledge of resolutions and
  reconstruction efficiency (hit level MC and
  reconstruction package).
• CC/NC Coherent Analyses (most complete)
• Quasi-Elastic Sample
• Strange Exclusive Final States

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Measurement of CoherentPion Production

• What you sawyesterday

MINERnA 4-yr Run Plan 25 K CC / 12.5 K NC events
off C 8.3 K CC/ 4.2 K NC off Fe and Pb
Errors here do include backgrounds, efficiencies
for realistic cuts
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Coherent CC Pion Production Event Selection
Using the Minerva MC and the energy and tracking
resolutions obtained in the detector studies, we
have evaluated the efficiency for identifying CC
coherent events. Topological cuts 2 visible
tracks (gt8 hits on each) -- muon
(non-interacting) -- and pion (interacting)
candidates less than 500 MeV energy from
neutrals Pion interaction point gt 30 cm from
vertex Kinematic Cuts x lt 0.2 t (q pp)2 lt
0.2 GeV2 e 35 for these cuts.
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Coherent NC Pion Production

• Neutral pion identification has40 efficiency
• Background is real p0 from resonance production
• This is expected signal/background separation

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Measurement of FA(Q2)

• Errors are purely statistical and do not take
  into account two effects, which are reduced
  when including quasi-elastic kinemeatic
  constraints
• p/p ambiguity for interacting track
• Subtraction of D production with absorbed p
  from subsequent decay
• In addition is a 5 error due to beam
  uncertainties

Extraction of FA, assuming exact Dipole and
4-year data run
Ability to distinguish between alternative Q2
shapes from vector form factor studies
FA /FA (dipole)
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Strange Particle Production
Existing Strange Particle Production Gargamelle-PS
- 15 L events. FNAL - 100 events ZGS - 7
events BNL - 8 events Larger NOMAD
inclusive sample expected

• MINERvA will focus on fully reconstructed
  exclusive states
• require the V0 two track decay (L ? p p- and
  K0S ? p p-)
• Prompt K decay yields a twin-peak signature in
  time profile of the event
• Efficiency is high, 85 or better, because final
  state p is soft
• Non-strange backgrounds not studied
  comprehensively
• strategy is to reconstruct intermediate V0 mass,
  require monochromatic m
• very low backgrounds expected

MINERnA Exclusive States 100x earlier samples 3
tons and 4 years DS 0 m- K L0 10.5 K m- p0
K L0 9.5 K m- p K0 L0 6.5 K m- K- K
p 5.0 K m- K0 K p0 p 1.5 K DS 1 m-
K p 16.0 K m- K0 p 2.5 K m- p K0n 2.0
K DS 0 - Neutral Current n K L0 3.5 K n K0
L0 1.0 K n K0 L0 3.0 K
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Other Questions

• What would the effect on event rates if you only
  had low energy running? On physics?