TY - JOUR AU - Bargheer, Till TI - Systematics of the multi-Regge three-loop symbol JO - Journal of high energy physics VL - 2017 IS - 11 SN - 1029-8479 CY - Berlin PB - Springer M1 - PUBDB-2017-12764 M1 - DESY-16-115 M1 - arXiv:1606.07640 SP - 77 PY - 2017 AB - We review the systematics of Mandelstam cut contributions to planar scattering amplitudes in the multi-Regge limit. Isolating the relevant cut terms, we explain how the BFKL expansion can be used to construct the perturbative n-point multi-Regge limit amplitude in certain kinematic regions from a finite number of basic building blocks. At three loops and at leading logarithmic order, two building blocks are required. Their symbols are extracted from the known three-loop six-point and seven-point symbols for general kinematics. The new seven-point building block is constructed in terms of single-valued multiple polylogarithms to the extent it can be determined using the symbol as well as further symmetry and consistency constraints. Beyond the leading logarithmic order, the subleading and sub-subleading terms require two and one further building block, respectively. The latter could either be reconstructed from further perturbative data, or from BFKL integrals involving yet-unknown corrections to the central emission block. LB - PUB:(DE-HGF)16 UR - <Go to ISI:>//WOS:000415370900001 DO - DOI:10.1007/JHEP11(2017)077 UR - https://bib-pubdb1.desy.de/record/396563 ER -