Four-Loop Cusp Anomalous Dimension From Obstructions
| dc.creator | Cachazo, Freddy | |
| dc.creator | Spradlin, Marcus | |
| dc.creator | Volovich, Anastasia | |
| dc.date | 2006-12-29 | |
| dc.date | 2007-05-11 | |
| dc.date.accessioned | 2026-07-07T11:23:33Z | |
| dc.date.available | 2026-07-07T11:23:33Z | |
| dc.description | We introduce a method for extracting the cusp anomalous dimension at L loops from four-gluon amplitudes in N=4 Yang-Mills without evaluating any integrals that depend on the kinematical invariants. We show that the anomalous dimension only receives contributions from the obstructions introduced in hep-th/0601031. We illustrate this method by extracting the two- and three-loop anomalous dimensions analytically and the four-loop one numerically. The four-loop result was recently guessed to be f^4 = - (4ζ^3_2+24ζ_2ζ_4+50ζ_6- 4(1+r)ζ_3^2) with r=-2 using integrability and string theory arguments in hep-th/0610251. Simultaneously, f^4 was computed numerically in hep-th/0610248 from the four-loop amplitude obtaining, with best precision at the symmetric point s=t, r=-2.028(36). Our computation is manifestly s/t independent and improves the precision to r=-2.00002(3), providing strong evidence in favor of the conjecture. The improvement is possible due to a large reduction in the number of contributing terms, as well as a reduction in the number of integration variables in each term. | |
| dc.description | 23 pages, revtex; v2,v3: minor typos fixed and references added | |
| dc.identifier | https://arxiv.org/abs/hep-th/0612309 | |
| dc.identifier | http://arxiv.org/abs/hep-th/0612309 | |
| dc.identifier | Phys.Rev.D75:105011,2007 | |
| dc.identifier | doi:10.1103/PhysRevD.75.105011 | |
| dc.identifier.uri | http://salesiana.dossiersoluciones.com/handle/123456789/194925 | |
| dc.subject | High Energy Physics - Theory | |
| dc.title | Four-Loop Cusp Anomalous Dimension From Obstructions | |
| dc.type | text |