LENSOverview

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LENSOverview R. S. Raghavan Virginia
Tech LONU-LENS Mini Workshop Oct 14, 2006
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• Neutrino beams from SUN
• Very Low Energy
• Pure Favor (?e)
• Largest Fluxes
• Longest Base Line
• Largest Intervening Mass
• Highest Magnetic Fields
• Unique Machine for Exploration of
• Neutrino Phenomenology in
• Vacuum, Matter Magnetic Fields
• STATUS
• From High Energy Nus ( 8B Atmos)
• Non-zero Neutrino Mass
• ?Neutrino Flavor Conversion
• NEXTDoor open to Explore
• New Physics Astrophysics

Solar Neutrinos-Past Future
SSM Prediction
Directly measured so far
Directly measured
The New Frontier

• New Quest Discoveries beyond Oscillations-
• New Paradigm Precision Data, solar model
  independence
• New Frontier lt 2 MeV
• ?Central Objectives of LENS

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Tagged ? capture reaction in Indium ?LENS is
the only developed CC real time detector for
solar neutrinos
signal
delay
Tag cascade

• Unique
• Specifies ? Energy
• E? Ee Q
• Complete LE nu spectrum
• Lowest Q known? 114 keV
• ?access to 95.5 pp nus
• Target isotopic abundance 96
• Powerful delayed coinc. Tag
• Can suppress bgd 1011 x signal
• Downside
• Bgd from 115In radioactivity to
• ( pp nus only)? rate 1011 x signal
• Tools
• Time Space coinc.? Granularity (106suppression)
• Energy Resolution
• In betas lt500 keV ?Tag 613 keV
• 3. Other analysis cuts

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Indium Solar Neutrino DetectionRD History
Hi
Granularity(109) --Lo precision pp (3s) Tagged
pp reaction in Indium RSR-PRL 1976 Bell Labs
(rsr, Pfeiffer, Mills) 1976-79 pp
InLS/Plastic Sandwich

Indium ß-spectrum Bell Labs-MIT
(rsr, Deutsch) 1979-84 pp
Plastic/Quartz Fiber Scint Oxford (Booth)
1978-90 pp
Indium Tunnel Diodes CEA Saclay (Cribier, Spiro)
1979-81 pp Hybrid
TPC/Plastic Penn-Coll de France-KEK-BL-TUM
1987-89 Be InLS (KEK- Suzuki,
Inoue) Borexino
1989 - Be ?-e-scattering
no tag

?Brute force reduction of bgd via

invention of new
ultrapurity chemistry New tgged pp capture
reactionsnon radioactive targets RSR-PRL
1997 LENS RD LNGS-EU-Russia-USA 1999-01
pp Yb, Gd, Se YbLS

Lo Granularity (105) Hi
Precision pp (3) (SNO result !
) RSR-hep-ph/010605 LENS RD LNGS--
2001-03 pp In InLS
LENS-Sol/CAL
2004- Nu Lum InLS (LENS-Sol)

Plastic Sandwich
(LENS-Cal)



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• Major Progress from LENS LNGS? LENS Sol
• lt Towards Hi Precision pp gt
• Hi
  Quality InLS Developed
• Background
  Analysis Insights
• New Detector
  Design Invented

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• Expected Result from LENS
• Background precisely and concurrently measured
• Well resolved low energy solar nu spectrum
• ? pp, 7Be, pep, CNO with 99 of solar nu flux
• Solar luminosity in nus
• pp spectral shape accessible for first time

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• pp Spectral Shape ?New Science Goal
• Directly Probe Temperature Profile of Energy
  Production in the Sun
• by experimentally measuring the Gamov Energy
  Shift in
• pp Fusion (not observed in laboratory so
  far)
• Experiments focused so far on fluxes, not
  (absolute) energies of solar nus ----not
  possible via electron scattering or
  radiochemistry
• ? need energy specific CC detection
  technology -?LENS
• Energies of neutrinos from Fusion reactions are
  usually taken from exothermal
• energy release (Q value i.e. difference of
  initial and final masses) e.g.
• p p ? d e ?e (420 keV max) p
  e- p ? d ?e(1442 keV)
• This does not include the kinetic (Gamov) energy
  needed to initiate pp fusion
• Gamov Energy E0 (T) is temperature dependent
• E (T) is added to the pp and pep energy spectra
  weighted by the fraction of the flux produced at
  that temperature---E is typically 5 keV
• i.e. pp?425 keV and pep?1447 keV
• Can one observe the Gamov shift by measuring pp
  and pep energies?
• If so---we can directly measure the

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aMaximum energy bShift of mean energy of signal
spectrum in the detector, in the case of pp in
the energy range lt110-340gt keV cShift of
maximum energy in sun. The ?E includes likely
systematic errors (see text)
P lab (q,Qs) q2 p W F(Z,W,Qs) (Z -1 )
Sun
Target
Fit measured spectrum to Psun leaving q max
free Find dE from repeated trials compare to
predicted ?E
s 1.63 keV
Grieb/RSR hep-ph/0609030
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• Science from Neutrino Flux Data
• Basic Dichotomy in Solar neutrino Research
• Measured Fluxes vs Unknown Original Fluxes in sun
  
• All science interpretations need ORIGINAL fluxes
• Usual Practice Appeal to predictions of Standard
  Solar Model
• How to make inferences completely free of models?
• First Breakthrough Made by SNO in the case of
  8B flux
• ?Single solar source? 8B
• ?SNO, SK
• ?Measured 8B NC flavor-blind flux?original flux
  in sun
• ?SK CCNC spectrum flavor survival independent
  of energy
• ?Kamland data with ANTINEUTRINOS
• ?LMA matter conversion at 8B neutrino energies
  (10 MeV)
• Major Questions
• Conclusion assumes CPT invariance. Is This
  Correct ?First opportunity to
• Test this for NEUTRINOS

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• Major Questions
• 1) CPT invariance for NEUTRINOS
• 2) LMA prediction of different type of
  conversion at LOW ENERGIES
• 3) Deviations from LMA predictions? Discovery
• Imperative tests
• HOW to attack the problem on a model independent
  basis?
• ? Model Independent Fluxes at LOW ENERGIES ?
• Basic Need Fluxes of
  single sources
• 
  ?Well identified and resolved Spectroscopic data
• 
  ?Removal of precisely measured background
• ? Requires CC based Low
  Energy Detection?Developed only in LENS

Bgd Est.
Bgd measured
Scattering Spectrum (CLEAN)
Absorption Spectrum (LENS)
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• Solar Luminosity from Low Energy Neutrino Flux
  data from LENS
• Use Best Known Neutrino Model (e.g. LMA) to
  reverse calculate original
• Fluxes from measured fluxes of INDIVIDUAL
  sources
• ?pp, Be, pep CNO, constitute 99 of solar
  neutrino flux
• ?Calculate Energy by weighting fluxes with
  coefficients of energy released
• in each solar reaction (Bahcall,
  Phys. Rev C 65 (2002), 025801)
• Solar Luminosity in Neutrinos L(? inferred)
• From Solar Constant
• Solar Luminosity in Photons L(h?)
• Energy Match from two probes
• L(?
  inferred) / L(h?) 1.00
• This tests if the neutrino model used is CORRECT
• No SSM used Inference only via measured
  quantities
• Present Status after 40 years of Solar nu
  research
• L(? inferred) / L(h?) 1.4 (0.2-0.3 1
  s)( 0.7-0.6 3s)
• Bahcall C. Penya-Garay, JHEP 4, 0311 (2003)

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• New Global Analysis using
• Data from LENS
• Measured v Fluxes of pp, Be, pep, CNO
• ?Solar Luminosity in Neutrinos
• Temperature of sun via Gamow shift
• Data from SNO
• 8B flux (CC and NC)
• SK data on spectrum
• Match to Measured Photon Luminosity by varying ?
  parameters
• (use the temperature shift to test SSM prediction
  of dependence of
• of pp flux on T (? (1-0.08(T/TSSM)-1.1) J. N.
  Bahcall A. Ulmer, Phys. Rev. D53, 4202 (1996).
• This global analysis ASSUMES
• 1) Nuclear Reactions SOLE source of Suns Energy
• 2) Quasi hydrostatic Equilibrium

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With Precise Model Independent pp, Be,pep
fluxes Energy Dependence of Survival
Probabilities Test LMA, NSI, MVA, Measure ?12
Precisely
e)
Be/pp 5 pep/pp9
LMA
Mass Var. Nus
Precision ?12
Sterile Nu
NSI
Be/pp 18 pep/pp40
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Conclusion
LENS TECHNOLOGY INTRODUCES Recipe
for Discovery in Particle Physics --CPT, NSI,
MVN, T12 , T13 from absolute energy Astrophysics
of Sun CNO,Hidden sources of energy, Past Sun vs
Present Sun, Temp of pp fusion (test SSM) A new
comprehensive approach for model independence
Measuring the Solar Luminosity in Neutrinos
and comparing it directly with the Photon
Luminosity
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