A new method for computing the quark-gluon vertex

4th Symposium on Prospects in the Physics of Discrete Symmetries

Aguilar, A.C.^1

University of Campinas - UNICAMP, Institute of Physics Gleb Wataghin, Campinas, SP

CEP 13083-859, Brazil^1

关键词: Arbitrary values;    Background field;    Corresponding vertices;    Kinematical configurations;    Nonperturbative;    Numerical results;    Order relation;    Ward identities;   

Others  :  https://iopscience.iop.org/article/10.1088/1742-6596/631/1/012058/pdf
DOI  :  10.1088/1742-6596/631/1/012058

来源: IOP

【 摘 要 】

In this talk we present a new method for determining the nonperturbative quark-gluon vertex, which constitutes a crucial ingredient for a variety of theoretical and phenomenological studies. This new method relies heavily on the exact all-order relation connecting the conventional quark-gluon vertex with the corresponding vertex of the background field method, which is Abelian-like. The longitudinal part of this latter quantity is fixed using the standard gauge technique, whereas the transverse is estimated with the help of the so-called transverse Ward identities. This method allows the approximate determination of the nonperturbative behavior of all twelve form factors comprising the quark-gluon vertex, for arbitrary values of the momenta. Numerical results are presented for the form factors in three special kinematical configurations (soft gluon and quark symmetric limit, zero quark momentum), and compared with the corresponding lattice data.