Hexagon Wilson loop = six-gluon MHV amplitude

by Emery Sokatchev (LAPTH, Universite de Savoie, Annecy)

Tuesday 22 Apr 2008, 14:00 → 15:00 Europe/Zurich

TH Theory Conference Room (CERN)

We review the new duality between gluon scattering amplitudes and Wilson loops in N=4 SYM, first proposed by Alday and Maldacena at strong coupling and then adapted to weak coupling. We explain the important role played by the dual conformal symmetry of the amplitudes/Wislon loops. It uniquely fixes the form of the finite part of the amplitude for 4 and 5 gluons, thus providing the explanation of the BDS conjecture in these special cases. However, starting with 6 gluons, an arbitrary function of conformal invariants can appear, which would invalidate the BDS conjecture. We report on the very recent parallel two-loop calculations of a hexagon Wilson loop and of a 6-gluon amplitude. They show that the BDS conjecture fails indeed, but in such a way that the duality gluon amplitudes/Wilson loops is maintained.