Jack Steinberger - Early Career

Early Career

After receiving his doctorate, Steinberger attended the Institute for Advanced Study in Princeton for a year. In 1949 he published a calculation of the lifetime of the neutral pion, which anticipated the study of anomalies in quantum field theory.

Following Princeton, Steinberger went to the Radiation Lab at the University of California at Berkeley, where he performed an experiment which demonstrated the production of neutral pions and their decay to photon pairs. This experiment utilized the 330 MeV synchrotron and the newly-invented scintillation counters. Despite this and other achievements, he was asked to leave the Radiation Lab at Berkeley due to his refusal to sign the so-called Non-Communist Oath.

Steinberger accepted a faculty position at Columbia in 1950. The newly commissioned meson beam at Nevis Labs provided the tool for several important experiments. Measurements of the production cross section of pions on various nuclear targets showed that the pion has odd parity. A direct measurement of the production of pions on a liquid hydrogen target, then not a common tool, provided the data needed to show that the pion has spin zero. The same target was used to observe the relative rare decay of neutral pions to a photon, an electron and a positron. A related experiment measured the mass difference between the charged and neutral pions based on the angular correlation between the neutral pions produced when the negative pion is captured by the proton in the hydrogen nucleus. Other important experiments studied the angular correlation between electron-positron pairs in neutral pion decays, and established the rare decay of a charged pion to an electron and neutrino; the latter required use of a liquid-hydrogen bubble chamber.