String theory origins of supersymmetry

String Theory Origins of Supersymmetry

The string theory introduced in early 1971 by Ramond, Neveu, and myself has two-dimensional world-sheet supersymmetry. This theory, developed at about the same time that Golfand and Likhtman constructed the four-dimensional super-Poincaré algebra, motivated Wess and Zumino to construct supersymmetric field theories in four dimensions. Gliozzi, Scherk, and Olive conjectured the spacetime supersy...

1. Supersymmetry and String Theory

Splitting Supersymmetry in String Theory

We point out that type I string theory in the presence of internal magnetic fields provides a concrete realization of split supersymmetry. To lowest order, gauginos are massless while squarks and sleptons are superheavy. We build such realistic U(3) × U(2) × U(1) models on stacks of magnetized D9-branes. Though not unified into a simple group, these theories preserve the successful supersymmetr...

String Theory, Unification and Supersymmetry

One cannot yet point to any firm string prediction. While many approximate string ground states are known with interesting properties, we do not have any argument that one or another describes what we observe around us, and for reasons which appear fundamental we do not know how to systematically determine even any rough quantitative properties. I argue here that we should examine large classes...

Split Supersymmetry in String Theory

Type I string theory in the presence of internal magnetic fields provides a concrete realization of split supersymmetry. To lowest order, gauginos are massless while squarks and sleptons are superheavy. For weak magnetic fields, the correct Standard Model spectrum guarantees gauge coupling unification with sin2 θW = 3/8 at the compactification scale of MGUT ≃ 2× 1016 GeV. I discuss mechanisms f...