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A Search for νₑ Appearance from Stopped π⁺ and µ⁺ Decay at LAMPF


Fujikawa, Brian Kurt (1990) A Search for νₑ Appearance from Stopped π⁺ and µ⁺ Decay at LAMPF. Dissertation (Ph.D.), California Institute of Technology. doi:10.7907/9e8k-2p03.


We report on a recent search for ν̅ₑ appearance from stopped π⁺ → µ⁺νµ and µ⁺ → e⁺νₑν̅µ decay made by the LAMPF experiment E645. The appearance of ν̅ₑ may occur from ν̅µ → ν̅ₑ, νₑ → ν̅ₑL, or νµ → ν̅ₑL oscillations. Appearance may also occur from rare µ⁺ → e⁺ν̅ₑνµ decay, which is allowed by a multiplicative lepton charge conservation law. The neutrino energies range from Eν to 52.8MeV. The neutrino detector, which is located 26.1 meters from the neutrino source, consists of a segmented liquid scintillator and proportional drift tube central detector surrounded by both active and passive shielding. The central detector detects ν̅ₑ through the ν̅ₑp → ne⁺ Charge Current (CC) reaction, which is signaled by the direct detection of the final state positron and neutron. The hydrogen-rich liquid scintillators act as free proton targets for the ν̅ₑp CC reaction. The neutrons are detected through radiative neutron capture on gadolinium. We find no evidence for ν̅ₑ appearance in the first year of running. New limits on the ν̅µ, ν̅ₑ, νµ → ν̅ₑ oscillation parameters and the rare µ⁺ → e⁺ν̅ₑνµ decay branching ratio are presented.

Item Type:Thesis (Dissertation (Ph.D.))
Subject Keywords:Physics
Degree Grantor:California Institute of Technology
Division:Physics, Mathematics and Astronomy
Major Option:Physics
Thesis Availability:Public (worldwide access)
Research Advisor(s):
  • McKeown, Robert D.
Thesis Committee:
  • McKeown, Robert D. (chair)
  • Vogel, Petr
  • Filippone, Bradley W.
  • Hitlin, David G.
Defense Date:26 September 1989
Record Number:CaltechETD:etd-06062007-121228
Persistent URL:
Default Usage Policy:No commercial reproduction, distribution, display or performance rights in this work are provided.
ID Code:2480
Deposited By: Imported from ETD-db
Deposited On:06 Jun 2007
Last Modified:11 Feb 2022 19:58

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