Physics Colloquium

In 1975 the Cornell Electron Storage Ring (CESR) and the CLEO experiment were proposed. First collisions, at a center-of-mass energy of 10 GeV were recorded in 1979. A journey of discovery followed that included the first observations of the B meson and the Ds meson in 1983, the first b to u transition in 1989, and the first b to s transition in 1993. CLEO-c, the last incarnation of CLEO, was proposed in 2001. It became the first particle physics experiment to be approved in the 21st century. Operating at a center of mass energy of 4 GeV as a charm factory, CLEO-c opened a new window on the weak and strong interactions when it took data from 2003 until March 2008. After a brief review of some of the past highlights of the CLEO program the majority of the talk will focus on the latest results from CLEO-c including the most precise measurements to date of charm meson decay constants, and charm semileptonic form factors, and the CKM matrix elements Vcs and Vcd. These measurements allow the international flavor physics program to reach its full discovery potential, directly test the Standard Model of particle physics and significantly advance our understanding of strongly coupled non-perturbative quantum field theories which could be crucial to interpret new phenomena discovered at the Large Hadron Collider.