Measurement of the beta-neutrino correlation in laser trapped {sup 21}Na Metadata

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  • Main Title Measurement of the beta-neutrino correlation in laser trapped {sup 21}Na


  • Author: Scielzo, Nicholas David
    Creator Type: Personal


  • Sponsor: USDOE Director. Office of Science. Nuclear Physics (United States)
    Contributor Type: Organization


  • Name: Lawrence Berkeley National Laboratory
    Place of Publication: Berkeley, California
    Additional Info: Ernest Orlando Lawrence Berkeley National Laboratory, Berkeley, CA (United States)


  • Creation: 2003-06-01


  • English


  • Content Description: Trapped radioactive atoms are an appealing source for precise measurements of the beta-neutrino correlation coefficient, a, since the momentum of the neutrino can be inferred from the detection of the unperturbed low-energy recoil daughter nucleus. Sodium-21 is produced on-line at the 88'' cyclotron at Lawrence Berkeley National Laboratory, and 8e5 atoms have been maintained in a magneto-optical trap. A static electric field draws daughter Neon-21 ions to a microchannel plate detector and betas are detected in coincidence with a plastic scintillator beta detector. The Neon-21 time-of-flight distribution determines the beta neutrino correlation coefficient, a. The resulting charge-state distribution is compared to a simple model based on the sudden approximation which suggests a small but important contribution from nuclear recoil-induced ionization. A larger than expected fraction of the daughters are detected in positive charge-states, but no dependence on either the beta or recoil nucleus energy was observed. We find a = 0.5243 plus or minus 0.0092, which is in 3.6 sigma disagreement with the Standard Model prediction of a = 0.559 plus or minus 0.003. Aside from a deviation from the Standard Model, a possible explanation for the discrepancy is that the branching ratio to the first excited state is in error.
  • Physical Description: vp.


  • Keyword: Plastic Scintillators
  • Keyword: Charge States
  • Keyword: Forecasting
  • Keyword: Standard Model
  • Keyword: Laser Trap Magneto Optical Trap Beta Decay Beta Neutrino Correlation
  • STI Subject Categories: 43 Particle Accelerators
  • Keyword: Sodium 21
  • Keyword: Cyclotrons
  • Keyword: Atoms
  • Keyword: Neon 21
  • Keyword: Neutrinos
  • Keyword: Ionization
  • STI Subject Categories: 74 Atomic And Molecular Physics
  • Keyword: Excited States
  • Keyword: Electric Fields
  • STI Subject Categories: 72 Physics Of Elementary Particles And Fields
  • Keyword: Lasers
  • Keyword: Branching Ratio
  • STI Subject Categories: 73 Nuclear Physics And Radiation Physics
  • Keyword: Sudden Approximation Laser Trap Magneto Optical Trap Beta Decay Beta Neutrino Correlation


  • Other Information: TH: Thesis (Ph.D.); Submitted to Univ. of California, Berkeley, CA (US)


  • Name: Office of Scientific & Technical Information Technical Reports
    Code: OSTI


  • Name: UNT Libraries Government Documents Department
    Code: UNTGD

Resource Type

  • Thesis or Dissertation


  • Text


  • Report No.: LBNL--54350
  • Grant Number: AC03-76SF00098
  • Office of Scientific & Technical Information Report Number: 821455
  • Archival Resource Key: ark:/67531/metadc778693


  • Display Note: INIS; OSTI as DE00821455