Chien-Shiung Wu
University of California, Berkeley
Physics
1940
nuclear physics, beta decay
Quantum Mechanics, Nuclear Physics, Statistical Mechanics, Particle Physics, Atomic Physics
https://en.wikipedia.org/wiki/Chien-Shiung_Wu
K12 , UGUD
Scientist Biography
Biographical information
Chien-Shiung Wu was a Chinese-American experimental physicist who made significant contributions in the field of nuclear physics. She is best known for her work on the Manhattan Project and the Wu experiment, which established that parity symmetry is violated in weak nuclear interactions.
Relevant Concepts
Parity Violation, Beta DecayResearch Areas:
nuclear physics, beta decayRelevant Courses:
Quantum Mechanics, Nuclear Physics, Statistical Mechanics, Particle Physics, Atomic PhysicsKey Contributions
Wu worked on the development of the process to separate uranium into U-235 and U-238 isotopes by gaseous diffusion.
If an interaction respects parity symmetry, it means that if left and right are swapped, the interaction would behave exactly the same. The Wu experiment studied whether parity is conserved in the weak nuclear interaction by looking at whether the decay products of cobalt-60 were being emitted preferentially in one direction or not. This would signify the violation of parity symmetry because if the weak interaction were parity conserving, the decay emissions should be emitted with equal probability in all directions. The experiment monitored the decay of cobalt-60 atoms that were aligned by a uniform magnetic field and cooled to near absolute zero. A cobalt-60 atom decays by emitting an electron and an electron antineutrino. They found that more electrons were emitted in the direction opposite to the spin than along the spin, indicating that parity is not conserved. The discovery set the stage for the development of the standard model, which is based on the symmetries of particles and forces and how they can sometimes be broken.