W K H Panofsky prize awarded for CP violation

Italo Mannelli (left) et Heinrich Wahl (right) at CERN after the announcement of the prize.

The American Physical Society has recently announced its 2007 winners of the W K H Panofsky prize to CERN's Heinrich Wahl (now at the University of Ferrara), Italo Mannelli from Scuola Normale Superiore di Pisa and Bruce Winstein of University of Chicago. These three physicists led experiments that resulted in a multitude of precision measurements of properties of neutral kaons, most notably the discovery of direct CP violation. The W K H Panofsky prize recognizes outstanding achievements in experimental particle physics.

Wahl and Mannelli's important work at CERN with CP violation and neutral kaons in the 1970s paved the way for the NA31 experiment in the 1980s. This experiment, of which Wahl was the spokesperson, focused on and found the first evidence for direct CP violation. Mannelli played a leading role, particularly in implementing his knowledge of calorimetry using liquefied noble gases, a technique originally developed by Bill Willis that provided good quality and stability of the signals for CP violation. The success of this experiment led to the NA48 and KTeV experiments at CERN and Fermilab, respectively. The NA48 experiment provided in 1999 the most precise measurement to date of CP violation in the decay of neutral kaons. Winstein is a leading member of the KTeV collaboration, which also investigated direct CP violation.