ACAT 2016

Session

Track 3

19 Jan 2016, 13:55

UTFSM, Valparaíso (Chile)

Presentation materials

KMACAT2016.zip

177. Fun with higher-loop Feynman diagrams

York Schröder (UBB Chillán)

19/01/2016, 14:00

Computations in Theoretical Physics: Techniques and Methods

Oral

In high-energy physics experiments performed at current colliders such as the LHC, the flood of precision data requires matching theoretical efforts, in order extract the underlying event's structure. To this end, in this talk I will showcase a few techniques and results related to investigations of the structure of higher-loop Feynman integrals which provide one of the basic building...

248. Geometrical splitting and reduction of Feynman diagrams

Andrei Davydychev

19/01/2016, 14:25

A geometrical approach to the calculation of N-point Feynman diagrams is reviewed. It is shown that the geometrical splitting yields useful connections between Feynman integrals with different momenta and masses. It is demonstrated how these results can be used to reduce the number of variables in the occurring functions.

222. Alternative method of Reduction of the Feynman Diagrams to a set of Master Integrals

Igor Kondrashuk (UBB)

19/01/2016, 14:50

Computations in Theoretical Physics: Techniques and Methods

Oral

We propose a new set of Master Integrals which can be used as a basis for multiloop calculation in any gauge massless field theory. In these theories we consider three-point Feynman diagrams with arbitrary number of loops. The corresponding multiloop integrals may be decomposed in terms of this set of the Master Integrals. We construct a new reduction procedure which we apply to perform this...

247. Six loop beta function in $\phi^4$ model

Mikhail Kompaniets (St. Petersburg State University (RU))

19/01/2016, 15:45

Using R* operation, IBP and integration of hyperlogarithms we calculate the 6-loop beta function of the $\phi^4$ model. One of the remarkable features of this result is that the 6 loop term contains multiple zeta values. We discuss different aspects of this calculation as well as series resummation and predictions for the 6 loop term based on the 1979 paper by Kazakov, Shirkov and Tarasov.

149. Evaluation of the bottom quark mass from Upsilon(1S)

Dr Gorazd Cvetic (UTFSM, Valparaiso)

19/01/2016, 16:10

Computations in Theoretical Physics: Techniques and Methods

Oral

We present an extraction of the MSbar mass of bottom quark from the Upsilon(1S) system. We account for the leading renormalon effects in the extraction. We work in the renormalon subtracted scheme in order to control the divergence of the perturbation series coming from the pole mass renormalon, and we carefully take into account the charm quark effects.

224. Higgs boson production in association with jets in gluon-gluon fusion

Gionata Luisoni (CERN)

19/01/2016, 16:35

Computations in Theoretical Physics: Techniques and Methods

Oral

After the discovery of a Higgs boson during Run I at the LHC, Higgs physics has entered an era of precision measurements. Among the different production channels, gluon-gluon fusion (ggf) is the larges one, and constitutes also an irreducible background to the very important vector boson fusion process. A precise knowledge of the ggf channel is therefore fundamental. In this talk I will...

188. The flavour dependence for the four-loop QCD correction to the relation between pole and running heavy quark masses

Dr Andrei Kataev (Institute for Nuclear Research of the Russian Academy of Sciences)

19/01/2016, 17:00

Computations in Theoretical Physics: Techniques and Methods

Oral

The semi-analytical expressions for the flavour-dependence of the O(\alpha_s^4) QCD correction between pole and running heavy quark masses is obtained using the least square method. The results are compared with the estimates obtained with the help of different approaches. The asymptotic structure of the presnted perturbative series is discussed/ The necessity of performing extra analytical...