Warren Perkins
(Swansea University UK)
11/3/08, 2:00 PM
3. Computation in Theoretical Physics
Parallel Talk
Unitarity methods provide an efficient way of calculating 1-loop
amplitudes for which Feynman diagram techniques are impracticable.
Recently several approaches have been developed that apply these
techniques to systematically generate amplitudes. The 'canonical basis'
implementation of the unitarity method will be discussed in detail and illustrated using seven point QCD processes.
Johannes Bluemlein
(DESY)
11/3/08, 2:25 PM
3. Computation in Theoretical Physics
Parallel Talk
We present a method to unfold the complete functional dependence of single-scale quantities as
QCD splitting functions and Wilson coefficients from a finite number of moments. These quantities
obey recursion relations which can be found in an automated way. The exact functional form is obtained
solving the corresponding difference equations. We apply the algorithm to the QCD Wilson...
Dr
Mikhail Rogal
(DESY)
11/3/08, 2:50 PM
3. Computation in Theoretical Physics
Parallel Talk
will be sent later
Dr
Yoshimasa KURIHARA
(KEK)
11/3/08, 3:15 PM
3. Computation in Theoretical Physics
Parallel Talk
Automatic Feynman-amplitude calculation system, GRACE, has been extended to treat next-to-leading order (NLO) QCD calculations. Matrix elements of loop diagrams as well as those of tree level ones can be generated using the GRACE system. A soft/collinear singularity is treated using a leading-log subtraction method.
Higher order re-summation of the soft/collinear correction by the parton...
