RESUMEN
We consider the Sudakov form factor in planar N=4 supersymmetric Yang-Mills theory in the off shell kinematical regime, which can be achieved by considering the theory on its Coulomb branch. We demonstrate that for up to three loops both the infrared-divergent as well as the finite terms do exponentiate, with the coefficient accompanying log^{2}(m^{2}) determined by the octagon anomalous dimension Γ_{oct}. This behavior is in stark contrast to previous conjectural accounts in the literature. Together with the finite terms we observe that for up to three loops the logarithm of the Sudakov form factor is identical to twice the logarithm of the null octagon O_{0}, which was recently introduced within the context of integrability-based approaches to four point correlation functions with infinitely large R charges. The null octagon O_{0} is known in a closed form for all values of the 't Hooft coupling constant and kinematical parameters. We conjecture that the relation between O_{0} and the off shell Sudakov form factor will hold to all loop orders.
RESUMEN
We present a new approach to computing energy-energy correlations in gauge theories that exploits their relation to correlation functions and bypasses the use of scattering amplitudes. We illustrate its power by calculating energy-energy correlations in the maximally supersymmetric Yang-Mills theory in the next-to-leading order approximation.
RESUMEN
The one-loop dilatation operator in Yang-Mills theory possesses a hidden integrability symmetry in the sector of maximal-helicity Wilson operators. We calculate two-loop corrections to the dilatation operator and demonstrate that, while integrability is broken for matter in the fundamental representation of the SU(3) gauge group, for the ajoint SU(N(c)) matter it survives the conformal symmetry breaking and persists in supersymmetric N=1, N=2, and N=4 Yang-Mills theories.
RESUMEN
We perform a perturbative QCD analysis of the nucleon's Pauli form factor F2(Q2) in the asymptotically large Q2 limit. We find that the leading contribution to F2(Q2) has a 1/Q6 power behavior, consistent with the well-known result in the literature. Its coefficient depends on the leading- and subleading-twist light-cone wave functions of the nucleon, the latter describing the quarks with one unit of orbital angular momentum. We also derive at the logarithmic accuracy the asymptotic scaling F2(Q2)/F(1)(Q2) approximately (log2Q2/Lambda2)/Q2 which describes recent Jefferson Lab data well.
RESUMEN
We suggest the measurement of exclusive electroproduction of lepton pairs as a tool to study interparton correlations in the nucleon via generalized parton distributions in the kinematical region where this process is light-cone dominated. We demonstrate how the single beam-spin asymmetry allows one to perform such a kind of analysis and give a number of predictions for several experimental setups. We comment on other observables which allow for a clean separation of different species of generalized parton distributions.
