Automatic calculation of massive twoloop selfenergies with XLOOPS
Abstract
Within the program package XLOOPS it is possible to calculate selfenergies up to the twoloop level for arbitrary massive particles. The program package — written in MAPLE (Char et al., Maple V Language Reference Manual (Springer, 1991); Char et al., Maple V Library Reference Manual (Springer, 1991)) — is designed to deal with the full tensor structure of the occurring integrals. This means that applications are not restricted to those cases where the reduction to scalars via equivalence theorem is allowed. The algorithms handle twoloop integrals analytically if this is possible. For those topologies where no analytic result for the general mass case is available, the diagrams are reduced to integral representations which encounter at most at twofold integration. These integral representations are numerically stable and can be performed easily using VEGAS (Lepage, J. Comp. Phys. 27 (1978) 192; Lepage, Cornell Univ. Preprint CLNS80/447 (1980)).
 Publication:

Nuclear Instruments and Methods in Physics Research A
 Pub Date:
 February 1997
 DOI:
 10.1016/S01689002(97)001216
 Bibcode:
 1997NIMPA.389..333F