Doctoral lecture on hadron physics and QCD
Title: "QCD Green's functions: from the gauge sector to phenomenology"
Lecturer: Pr. José Rodriquez Quintero, University of Huelva, Supported by D’Alembert program of
Université Paris-Saclay
Quantum Chromodynamics (QCD), the Standard Model's quantum field theory for the strong
interaction, remains fully determined by the behaviour of their Green's functions (n-point correlation
functions). Namely, the solutions of the equations of motion of the field theory, which can be derived
from the action and, within the context of a nonperturbative gauge field theory as QCD, are usually
named Dyson-Schwinger equations (DSEs). The behavior of QCD Green's functions, specially two-
and three-point correlation functions, have been thus far systematically explored by means of
continuum Schwinger methods, such as solving the DSEs or using the functional renormalization group
(FRG), and exploiting lattice QCD simulations (lQCD). Investigations capitalizing on the interplay of
DSEs and lQCD techniques have been revealed as very fruitful to scrutinize the properties of these
Green's functions; and especially in providing ample access to the dynamical mechanisms responsible
for key nonperturbative features of QCD. Remarkably important is the notion of the emergent hadron
mass (EHM), which relies on three basic pillars: the dynamical generation of gluon mass, that can be
triggered by the Schwinger mechanism; the construction of a process-independent effective charge
arising as a unique analogue of the QCD Gell-Mann-Low charge; and the dynamical chiral symmetry
breaking endowing the quarks with its constituent masses. Two of these three pillars stem from the
gauge sector of QCD, which encompasses both gluonic and ghost interactions. In these four lectures,
we will focus on the infrared behavior of two- and three-point QCD Green's functions, then on the two
gauge-sector EHM pillars and, finally, illustrate with some applications in hadron phenomenology.
Tentative planning:
Lecture 1: The behavior of QCD Green's function from lattice QCD. The strong running coupling and
the QCD vacuum.
Lecture 2: Low-momentum QCD Green's functions and the dynamical generation of gluon mass. The
Schwinger mechanism.
Lecture 3: The process-independent effective charge.
Lecture 4: All-orders evolution approach and its implications for hadron distribution functions and
form factors.
All lectures will take place at IJCLab, Building 210 room 114 on Orsay campus at the following time and dates:
Lecture 1: 19/11/2024 10:30-12:00
Lecture 2: 21/11/2024 10:30-12:00
Lecture 3: 26/11/2024 10:30-12:00
Lecture 4: 28/11/2024 14:00-15:30
