Speaker
Mr
Clayton mello
(ITA)
Description
In this work, we are studying the usual formalism of quantum field theory
of quantum field theory in Light-Front formalism, with the goal of applying
the properties of quantum chromodynamics (QCD) in the scheme nonperturbative.
The electromagnetic structure of the pion , wich is a pseudoscalar meson composed
of a quark-antiquark bound state with total spin zero, is our first object of study.
Our proposal is to obtain a wave function from QCD , wich describes the internal
structure of the pion. So that can in particular calculate such as the electromagnetic
form factorand meam square radius in energy low and intermediate.
In this case of the particle the wave function can be archieved using a model with
constituent quark. In this model the quark mass range (running mass) according to the
Dyson-Schwinger techniques. Specifically , we performed the calculations in the
Light-Front formalism with a model for the constituent quarks bound state of the
quark-antiquark pair.
The calculations will be compared with other models in the literature, wich on
the other hand, are different designs using different wave functions for the pion.
In the case of particles of spin-0 as the pion can obtain a wave function, separating
it in terms of the Dirac's matrices. In a first approximation we consider the function
wave without the Dirac's structure, and thus make the first estimateof how shouldbe the
behavior. The presence of poles in the Bethe-Salpeter amplitudecaused resortedthe Nakanish
representation. Due to presence of the poles at the vertex of the Bethe-Salpeter
amplitude, according to the proposal by reference hindered our attempt to use Nakanish
representation. For this reason we are analyzing the poles in the Bethe-Salpeter
amplitude in the Light-Front formalism, wich we integrate into terms of energy, via Cauchy's
theorem, and thus obtain a wave function analytically.
Author
Mr
Clayton mello
(ITA)
Co-authors
Prof.
João de Melo
(UNICSUL)
Prof.
Tobias Frederico
(ITA)
