Alfred H. Mueller (born June 9, 1939) is an American theoretical physicist, and the Enrico Fermi Professor of Physics at Columbia University.
Mueller studied at Iowa State University, receiving a bachelor's degree in 1961 and in 1965 completed his PhD at MIT.
Mueller is a founding father of the field of parton saturation, a theoretically well established idea that the occupation numbers of small-x quarks and gluons cannot become arbitrarily large in the wave function of a hadron or nucleus.
In 2003 he received with George Sterman the Sakurai Prize for the development of concepts of perturbative QCD.
[1] Mueller is also a popular teacher amongst students at Columbia, where he currently teaches the graduate level Particle Physics course and the undergraduate Quantum Mechanics course.