Tracking Tiny Particles: The Neutrino Expert

Rachel Meserole | February 25, 2010

A liquid argon neutrino detector. Image courtesy of Bonnie T. Fleming.

Bonnie T. Fleming, recently appointed Horace D. Taft Associate Profes­sor of Physics, focuses her research on experimentally defining the fundamen­tal behavior of the tiny elemental particles known as neutrinos. Her work has already achieved significant breakthroughs that could redefine numerous para­digms in particle physics.

Neutrinos, which read­ily penetrate matter at the speed of light, have been infamously difficult to study. Since their discovery in 1956, only a few reliable techniques have been developed to examine their core properties. As of late, there is still considerable debate as to the exact mass of the particle.

However, Fleming has been working to develop a type of neutrino detector that can begin answer­ing some of the difficult questions in her field. Fleming’s novel “bubble chambers” use a liquid argon compartment to discern disturbances caused by the movement of these particles. Through collaborations with the Fermi National Accelerator Laboratory in Batavia, Illinois, Flem­ing has brought Yale to the forefront of particle physics research, developing the first working liquid argon neutrino detector in the United States.

Fleming’s research in neu­trino detector development is part of the Mini Booster Neutrino Experiment (Mini­BooNE), a project that seeks to study neutrino oscilla­tions. Fleming hopes her findings will lead to the development of larger and more sensitive instruments that can be used to collect a wider range of relevant data.

In addition to studying neutrinos, Fleming also aims to determine experimen­tally an explanation for the matter-antimatter asymmetry. High-energy particle collisions lead to the production of equal amounts of matter and antimatter, but there appears to be more matter than antimatter in the universe. Fleming believes that further experimentation with increasingly sensitive instruments could lead to the solution of this particle physics mystery.

In addition to conducting ground-breaking research, Fleming is also a very active participant and leader in programs designed to encourage women to pursue education and careers in the sciences.

These programs include Girls’ Science Inves­tigations and the Undergraduate Conference for Women in Physics.