William J. Willis (15 September 1932, Fort Smith, Arkansas – 1 November 2012, Dobbs Ferry, New York)[1] was an American experimental particle physicist.
William Willis studied physics at Yale University, where he received his bachelor's degree in 1954 and his PhD in 1958 with advisor Earle Fowler and dissertation related to the development of hydrogen bubble chambers in Ralph P. Shutt's research group.
Willis was a postdoc at Brookhaven National Laboratory (BNL), where he observed weak decays of kaons and hyperons in bubble chambers.
He was essential for the development of the ISR's Axial Field Spectrometer, which detected the first high-pt jet events in hadronic collisions.
[2] He was a Fellow of the American Physical Society and in 2003 received the Panofsky Prize for "his leading role in the development and exploitation of innovative techniques now widely adopted in particle physics, including liquid argon calorimetry, electron identification by detection of transition radiation, and hyperon beams.