Weak Decays of Oxygen-14 and Boron-8

University Of Wisconsin-Madison, Madison WI

Investigators

Abstract

We plan to design and construct an electron spectrometer (a device for measuring electron energies) and to use the spectrometer to carry out two new experiments. The spectrometer will use superconducting magnet technology to generate precisely controlled magnetic fields which deflect and focus electrons emitted from a small radioactive source. This will permit us to measure the energy distribution of the electrons produced in the radioactive decay. The specific experiments to be performed involve studying the decays of the radioactive isotopes oxygen-14 and boron-8. The oxygen-14 experiment is designed to test what is referred to as the Conserved Vector Current (CVC) hypothesis, which is a fundamental component of the Standard Model of Weak Interactions. The Standard Model is the basis for understanding a wide variety of processes, including the beta-decay of nuclei, the process which produces the electrons in our experiments. The CVC hypothesis allows us to predict the electron energy distribution, and the experiment will test whether that prediction is correct. The purpose of the boron-8 experiment is to provide new information that will help physicists understand the spectrum of neutrinos from the sun. Boron-8 plays a critical role in solar neutrino studies. The neutrinos from decay of boron-8 in the sun are relatively high in energy, and most of the world's operating solar neutrino detectors primarily see the boron-8 neutrinos. Since the electron and the neutrino share the decay energy, we can obtain information about the expected neutrino spectrum from a measurement of the electron energies.