Speaker
Amit Sever
(Tel Aviv University)
Description
We consider weakly coupled theories of massive higher spin particles. This class of models
includes, for instance, tree-level String Theory and Large-N Yang-Mills theory. The S-matrix in
such theories is a meromorphic function obeying unitarity and crossing symmetry. We discuss
the (unphysical) regime s,t ≫ 1, in which we expect the amplitude to be universal and
exponentially large. We develop methods to study this regime and show that the amplitude
necessarily coincides with the Veneziano amplitude there. In particular, this implies that the
leading Regge trajectory, j(t), is asymptotically linear in Yang-Mills theory. Further, our analysis
shows that any such theory of higher spin particles has stringy excitations and infinitely many
asymptotically parallel daughter trajectories. More generally, we argue that any weakly coupled
theory with at least one higher spin particle must have strings.
