Giuseppe Paolo Stanislao "Beppo" Occhialini ForMemRS was an Italian physicist who contributed to the discovery of the pion or pi-meson decay in 1947 with César Lattes and Cecil Frank Powell, the latter winning the Nobel Prize in Physics for this work. At the time of this discovery, they were all working at the H. H. Wills Laboratory of the University of Bristol.

Cecil Frank Powell, FRS was a British physicist, and Nobel Prize in Physics laureate for heading the team that developed the photographic method of studying nuclear processes and for the resulting discovery of the pion (pi-meson), a subatomic particle.