Scattering in AdS2/CFT1 and the BES phase

Abbott, Michael C; Murugan, Jeff; Sundin, Per; Wulff, Linus

Scattering in AdS2/CFT1 and the BES phase

Journal Article

2013

Journal Title

Journal of High Energy Physics

Link to Journal

https://dx.doi.org/10.1007/JHEP10(2013)066

Department

Department of Mathematics and Applied Mathematics

Faculty

Faculty of Science

Abstract

We study worldsheet scattering for the type IIA superstring in AdS 2 ×S 2 ×T 6. Using the Green-Schwarz action to quartic order in fermions we take the near-BMN limit, where as in the AdS3/CFT2 case there are both massive and massless excitations. For the massive excitations we compute all possible tree-level processes, and show that these agree with a truncated version of the exact AdS 5 × S 5 S-matrix. We also compute several S-matrix elements involving massless excitations. At one loop we find that the dressing phase is the same Hernándes-López phase appearing in AdS5/CFT4. We see the same phase when calculating this by semiclassical means using the PSU(1, 1 </td><td>2)/U(1)2 coset sigma model, for which we can also study the scattering of fermions. This supports the conjecture that the all-loop dressing phase is again the BES phase, rather than a new phase like that seen in AdS3/CFT2.