The Abdus Salam International Centre for Theoretical Physics (ICTP) in Trieste has awarded its Dirac Medal this year to Stephen Adler of Princeton’s Institute for Advanced Study and Roman Jackiw of MIT. This medal, widely viewed by theorists as highly prestigious, is given each year to scientists who have made outstanding contributions to theoretical physics and mathematics.
Adler and Jackiw are honoured for their work on the “triangle anomaly”. CERN theoretician John Bell, who died in 1990, also played a major role in this work. It underlies the process by which a neutral pion transforms into two photons, the calculation of which was first carried out by Jack Steinberger in 1949. Such processes place severe strains on the underlying formalism hence “anomaly”. For the mathematics to work properly, several such anomalies should mutually cancel, placing important restrictions on modern grand unified theories.
