Professor Chen Yang ForMemRS
Chen-Ning Yang is a particle physicist whose research with Tsung-Dao Lee disproved the law of conservation of parity, concerning the interactions of fundamental nuclear particles. The pair shared the 1957 Nobel Prize in Physics for their theory, which led to important discoveries regarding elementary particles.
Conservation of parity assumes all atomic forces have ‘right–left symmetry’, such that an identical experiment carried out on an atom and its mirror should produce identical results. Chen-Ning and Tsung-Dao suggested that subatomic particles, called K mesons or kaons, did not however conserve parity. Their theory was tested by experiment, which showed that K mesons do indeed have nonsymmetric spin, decaying into different states resulting in the emission of alpha or beta particles.
Chen-Ning was the first Director of the Institute for Theoretical Physics at Stony Brook University, now known as the C. N. Yang Institute for Theoretical Physics. In 1963, he published Elementary Particles: A Short History of Some Discoveries in Atomic Physics, a history of research into the components of the atom, up to the 1950s.