Twoloop Feynman Diagrams in YangMills Theory from Bosonic String Amplitudes
Abstract
We present intermediate results of an ongoing investigation which attempts a generalization of the well known oneloop Bern Kosower rules of YangMills theory to higher loop orders. We set up a general procedure to extract the field theoretical limit of bosonic open string diagrams, based on the sewing construction of higher loop world sheets. It is tested with one and twoloop scalar field theory, as well as oneloop and twoloop vacuum YangMills diagrams, reproducing earlier results. It is then applied to twoloop twopoint YangMills diagrams in order to extract universal renormalization coefficients that can be compared to field theory. While developing numerous technical tools to compute the relevant contributions, we hit upon important conceptual questions: Do string diagrams reproduce YangMills Feynman diagrams in a certain preferred gauge? Do they employ a certain preferred renormalization scheme? Are four gluon vertices related to three gluon vertices? Unfortunately, our investigations remained inconclusive up to now.
 Publication:

arXiv eprints
 Pub Date:
 March 2000
 arXiv:
 arXiv:hepth/0003171
 Bibcode:
 2000hep.th....3171K
 Keywords:

 High Energy Physics  Theory
 EPrint:
 44 pages, 24 figures, LaTeX, axodraw