Strong Interactions, Color Confinement, and Strings

Abstract: In the 1950s and 60s many strongly interacting particles were discovered. String theory was originally invented to describe them, but Quantum Chromodynamics (QCD) emerged as the precise theory of the strong nuclear force. A quarter century later it was understood that string theory and certain gauge theories akin to QCD are different descriptions of the same physics. I will review the relations between gauge theories and strings. Their formation in QCD is a manifestation of the confinement of colored quarks and gluons. While the color confinement is observed numerically using Lattice Gauge Theory, its analytic proof remains a deep unsolved problem in theoretical physics. I will conclude by discussing some surprises in lower-dimensional models.