The quark form factor at higher orders

By Sven-Olaf Moch, Jos Vermaseren, A. Vogt. 2005

246 citations recorded by the source corpus.

We study the electromagnetic on-shell form factor of quarks in massless perturbative QCD. We derive the complete pole part in dimensional regularization at three loops, and extend the resummation of the form factor to the next-to-next-to-leading contributions. These results are employed to evaluate the infrared finite absolute ratio of the time-like and space-like form factors up to the fourth order in the strong coupling constant. Besides for the pole structure of higher-loop QCD amplitudes, our new contributions to the form factor are also relevant for the high-energy limit of massive gauge theories like QED. The highest-transcendentality component of our results confirms a result recently obtained in = 4 Super-Yang-Mills theory.

Subfields: Nuclear and High Energy Physics

View Paper: https://www.semanticscholar.org/paper/766e8f44843581ff56308ae23c042d0ed5db58ef

How researchers see this paper

The researchers whose trusted networks rank it highest, strongest advocate first. Every researcher gets a different order.

In Nuclear and High Energy Physics

Citations in the corpus

On the resolution of singularities of multiple Mellin–Barnes integrals (2009, background): “Now, results of expansion up to ε(2) [11], up to ε(4) [12] and even a result for general ε [12] are available.”
The quark beam function at NNLL (2010, background): “divergences of the on-shell massless quark form factor which are known to three loops [30],”
Introduction to Soft-Collinear Effective Theory (2014, background): “The anomalous dimension γq = γ q̄ can be determined from the three-loop expression for the divergent part of the on-shell quark form factor in QCD [325].”
N-jettiness subtractions for NNLO QCD calculations (2015, background): “This is because the threeloop anomalous dimensions of jet and beam functions, the PDFs, and the hard function are known [90–97], which also fixes the three-loop soft anomalous dimension.”
Factorization at the LHC: From parton distribution functions to initial state jets (2010, background): “[147, 148], and for completeness the result is given in App.”
Factorization at the LHC: From PDFs to Initial State Jets (Ph.D. thesis) (2009, background): “r n2: (E.17) The MS non-cusp anomalous dimension for the hard function Hqq can be obtained [41, 118] from the IR divergences of the on-shell massless quark form factor which is known to three loops [148]. Similarly, the anomalous dimension for Hgg can be extracted [40] from the gluon form factor, wh”
Calculation of the quark and gluon form factors to three loops in QCD (2010, background): “[31] and provides the next term in the expansion.”
Erratum: On the structure of infrared singularities of gauge-theory amplitudes (2009, background): “The anomalous dimension γq = γ q̄ can be determined from the three-loop expression for the divergent part of the on-shell quark form factor in QCD [26].”