Neutrino Factory Activities Glasgow

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Neutrino Factory Activities Glasgow
PPE-PPT meeting 29 April 2008 Paul Soler
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Neutrino mixing

• Weak eigenstates do not have to coincide with
  mass eigenstates

• Neutrino mixing matrix (Pontecorvo-Maki-Nakagawa-S
  akata, PMNS matrix)
• similar to CKM matrix of quark sector.

• where

• and

• States

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Neutrino oscillations

• Matter oscillation results for three neutrinos

(MSW effect)
Minakata Nunokawa JHEP 2001
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Neutrino oscillations

• Matter oscillation results for three neutrinos

Only one term in equation
(MSW effect)
Magic baseline
Clean determination of q13
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Degeneracies
Two expts., diff. L/E n and anti-n

• Intrinsic degeneracy

One expt., n and anti-n
One expt, only n
Golden ne-gtnm and Silver ne-gtnt channels
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Degeneracies

• Eightfold degeneracy
• The sign of the atmospheric mass difference
• The octant of the atmospheric angle

Strategies different experiments to resolve
degeneracy problem
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Unknown parameters

• Global fit to all neutrino oscillation
  experiments give q23, q12, Dm122 and Dm232
• q13, sign of Dm132 (mass hierarchy) and CP
  violation phase d not known.

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Neutrino Factory

• Baseline for a Neutrino Factory for the
  International Design Study (Jan 08)
• Muons accelerated to 25 GeV and fires neutrino
  beams to two 50 kton iron detectors at two
  different baselines (4000 km and 7500 km)

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Magnetised Iron Neutrino Detector (MIND)

• Golden channel signature wrong-sign muons in
  magnetised calorimeter

(Cervera et al. 2000)
Magnetic Iron Neutrino Detector (MIND)

• Far detector (3000-7000 km) can search for
  wrong-sign muons in appearance mode (for
  example, Large Magnetic Detector)

• Background charm production, charge
  misidentification.

QtPmsin2 q

• Eliminates background
• at 10-6

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Magnetised Iron Neutrino Detector (MIND)

• Golden paper (Cervera et al, 2000) defined
  analysis and efficiency for discovery of CP
  violation at low values of q13
• New analysis (Cervera, 2007)
• Efficiency plateau between 5 and 8 GeV
• Baseline Lm gt 150 cm
• Ensures charge mis-ID
• below 10-3

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Magnetised Iron Neutrino Detector (MIND)

• Collaboration Valencia-Glasgow improvements MIND
  
• analysis with full GEANT4 reconstruction

• Demonstrate that for En lt 10 GeV
• Backgrounds are below 10-3
• The efficiency can be increased with respect to
  fast analysis
• Compute
• Signal and backgrounds efficiency as a function
  of energy
• Energy resolution as a function of energy
• Optimise segmentation and B field based on the
  above parameters and taking into account
  feasibility and cost
• Add Quasi-Elastic (QE) and Resonance (RES)
  production to Deep Inelastic (DIS) events

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Magnetised Iron Neutrino Detector (MIND)

• Performance of IDS-NF baseline detectors (two
  MIND detectors, one at 4000 km and one at 7500
  km) at 3s (Huber, Winter, ISS 2007)
• Phenomenology of detector efficiency vs baseline
  (M-project,McLachlan)

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Totally Active Scintillating Detectors (TASD)
Improvement Totally Active Scintillating
Detector (TASD) using Nona and Minerna concepts
Ellis, Bross
Main problem magnetisation huge volume

• Momenta between 100 MeV/c to 15 GeV/c
• Magnetic field considered 0.5 T
• Reconstructed position resolution 4.5 mm

Reduction threshold second oscillation maximum
and electron identification

• TASD opens up possibility of running low energy
  neutrino factory (4 GeV)

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Hybrid detectors MINDTASD?

• Compromise between MIND and TASD concepts?
  Optimisation of geometry not done
• Iron free regions improve momentum and charge
  determination

• Combining MINDTASD and iron-free regions

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Other detector technologies

• Liquid argon TPC for ne (platinum channel) and
  nt appearance (silver channel). ICARUS-like.
  Simultaneous fit to all wrong and right sign
  distributions.

• Hybrid Emulsion-Magnetised Iron simultaneous nm
  (golden channel) and nt appearance (silver
  channel). ICARUS-like.

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Near detector
What needs to be measured

• Near detectors should be able to measure flux and
  energy of and
• Calibration and flux control (inverse muon
  decay)
• High event rate 109 CC events/year in 50 kg
  detector

• Measure charm x-section in near detector to
  control systematics of far detector (main
  background)

• Other physics neutrino cross-sections, PDF,
  electroweak measurements, ...
• Possible technology fully instrumented silicon
  target in a magnetic detector.

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Flux Measurement at Near Detector for NF

• Best possibility Inverse Muon Decay scattering
  off electrons in the near detector. Known
  cross-sections

Kharadzov, Tsenov

• Rates in 1 ton Near Detector for 1021 muons/yr

1.7x106 evts/yr
6.9x105 evts/yr
5.8x105 evts/yr
7x104 evts/yr
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Near Detector used to extract Pnenm

• Matrix method with Near Detector data (even if
  spectrum not identical in near and far detector!)
  to extract oscillation probability
• Where M1matrix relating event rate and flux of
  ne at ND
• M2matrix relating event rate and flux of nm
  at FD
• Mmatrix relating measured ND ne rate and FD
  nm rate
• MnOscmatrix relating expected ne flux from
  ND to FD
• Proof of principle works
• for Neutrino Factory near
• detector but need to extract
• syst errors of method

PS, Laing
q138o
Probability of oscillation determined by matrix
method under simplistic conditions. Need to
give more realism to detector and matter effects.
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Charm measurement for NF

• Motivation measure charm cross-section to
  validate size of charm background in wrong-sign
  muon signature
• Charm cross-section and branching fractions
  poorly known

• Semiconductor vertex detector only viable option
  in high intensity environment (emulsion too slow!)

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Other measurements Near Detector

• Near detector neutrino physics
• Cross-section measurements DIS, QES, RES
  scattering
• sin2?W - ?sin2?W 0.0001
• Parton Distribution Functions (polarised and
  unpolarised), nuclear shadowing
• ?S from xF3 - ??S0.003

• L polarization spin transfer from quarks to L

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Future Outlook and EU Funding

• EuroNu four year EU Design Study for A High
  Intensity Neutrino Oscillation Facility in
  Europe (Super-beam, Neutrino Factory, Beta-beam,
  neutrino detectors and physics performance). 1
  PDRA Glasgow
• DevDet is a new Integrating Activity proposal
  across Europe to coordinate Detector Development
  Infrastructures for Particle Physics Experiments
• It is a 37.8 M proposal to the European Union
  (EU) with a requested EU contribution of 11.0 M.
  It has 87 participants from 21 different
  countries
• It includes the luminosity-upgraded LHC (SLHC),
  future Linear Colliders (ILC/CLIC), future
  accelerator-driven neutrino facilities and
  B-physics facilities
• Scope for collaboration with PPT phenomenology
  of neutrino oscillations, optimal strategy for
  measurements, how accurate do we need to know
  mixing angles, mass differences and CP phase?,
  hints for higher symmetries from neutrino
  oscillations?, near detector physics (ie. PDFs,
  neutrino cross-sections, electroweak
  measurements)