The 2005 Benjamin Franklin medal in physics presented to Yoichiro Nambu

The Franklin Institute, Philadelphia, Pennsylvania, awarded the 2005 Benjamin Franklin medal in physics to Yoichiro Nambu for his seminal contributions which introduced the modern concept of broken symmetry to elementary particle physics, for his invention of the particle property called color which is the key to quark confinement, and for his ground-breaking work on the theory of string-like elementary particles.