TH String Theory Seminar

# A toy model for light-by-light scattering

## by Simon Caron-Huot

Tuesday, 15 April 2014 from to (Europe/Zurich)
at CERN ( 4-3-006 - TH Conference Room )
 Description It is well-known that the classical Kepler problem possesses a non-obvious symmetry, related to the so-called Runge-Lenz vector and responsible for the periodicity of planetary orbits. I will review the role of this symmetry in the quantum formulation of the problem, revealing its most recent incarnation within a fully consistent relativistic quantum field theory, as a nontrivial generator of the dual conformal symmetry of (planar) N=4 super Yang-Mills. This connection is made visible by considering a natural analog of light-by-light scattering in this theory, with massive particles introduced through the Higgs mechanism. I will discuss recent progress in computing massive multi-loop integrals, where we succeeded in computing analytically this analog of light-by-light scattering to three-loop order by exploiting the Runge-Lenz symmetry. I will also present a novel way to calculate the spectrum of corresponding Hydrogen-like bound states, at all values of the coupling, exploiting old ideas from Regge theory. Organised by James Drummond