Mirza Abdul Baqi Bég (20 September 1934 – 30 January 1990), also known as MAB Bég or Baqi Bég, was a Pakistan theoretical physicist and a professor of physics at the Rockefeller University whose contributions were vital in string theory and particle physics.He is credited mainly with his role in laying down the theoretical foundations of the quark theory as well as development of the SU(6) model.