For the exploration of the phase diagram of QCD, effective Polyakov loop theories derived from lattice QCD provide a valuable tool in the heavy quark mass regime. In practice, the evaluation of these theories is complicated by the appearance of long-range and multipoint interaction terms. On the other hand, it is well known that for theories with such kind of interactions mean field approximations can be expected to yield reliable results. Here, we apply this framework to the critical endpoint of the deconfinement transition and results are compared to the literature. This treatment can also be used to investigate the phase diagram at non-zero baryon and isospin chemical potential.
The Yang-Mills gradient flow for QCD-like theories is generalized by including a fermionic matter term in the gauge field flow equation. We combine this with two different flow equations for the fermionic degrees of freedom. The solutions for the different gradient flow setups are used in the perturbative computations of the vacuum expectation value of the Yang-Mills Lagrangian density and the field renormalization factor of the evolved fermions up to next-to-leading order in the coupling. We find a one-parameter family of flow systems for which there exists a renormalization scheme in which t…
Deep insights into the possible infrared dynamics of strongly-coupled nonAbelian gauge theories such as QCD come from the analyses of ${\cal N}=1$ or ${\cal N}=2$ supersymmetric gauge theories. Central in the whole discussion will be the topological soliton monopoles and vortices and their quantum dynamics. We review the arguments that nonAbelian monopoles, free from the classic "difficulties", can be defined semi-classically via the topology and stability connection to the better understood nonAbelian vortices. Recent results on $CP^{N-1}$ models on $2D$ worldsheet of finite width, establish …
Exotic states have been predicted before and after the advent of QCD. In the last decades they have been observed at accelerator experiments in the sector with two heavy quarks, at or above the quarkonium strong decay threshold and called X Y Z states. These states offer a unique possibility for investigating the dynamical properties of strongly correlated systems in QCD. I will show how an alliance of nonrelativistic effective field theories and lattice can allow us to address these states in QCD. In particular I will explain what are the opportunities and challenges of lattice QCD in this re…
Soon after the formulation of Quantum Chromodynamics in 1972 its regularization on Euclidean space-time lattices had been introduced by Kenneth Wilson. This paved ground for numerical studies of non-perturbative aspects of QCD, first shown by Michael Creutz. Ever since these first lattice QCD calculations the exploration of the QCD phase diagram and the thermodynamics of strong-interaction matter at non-zero temperature and density was pursued vigorously. In this brief review I try to highlight some of the results on QCD thermodynamics obtain during the last 42 years through lattice QCD calcul…
I discuss recent results on the relation between the localisation of low-lying Dirac eigenmodes, the restoration of chiral symmetry, and deconfinement in QCD and QCD-like models, providing evidence of a close connection between the three phenomena.
QCDLAB is a set of programs, written in GNU Octave, for lattice QCD computations. Version 2.0 includes the generation of configurations for the SU(3) theory, computation of rectangle Wilson loops as well as the low lying meson spectrum with Wilson fermions. Version 2.1 includes also the computation of the low lying meson spectrum using minimally doubled chiral fermions. In this paper, we give a brief tutorial on lattice QCD computations using QCDLAB.
This talk is an overview of our recent investigations of supersymmetric and near conformal gauge theories. We have studied extensively $\mathcal{N}=1$ super Yang-Mills theory, most recently with the gauge group SU(3). In addition we have investigated theories that show indications for a conformal behavior at an infrared fixed point. We have included a mixed fundamental and adjoint fermion action setup in our studies. I will explain how this is related to the investigation of supersymmetric QCD on the lattice and present some first studies of the main obstacles that need to be addressed in the …
This document is one of a series of whitepapers from the USQCD collaboration. Here, we outline the opportunities for, prospects of and challenges to the lattice QCD calculations relevant for the understanding of the phases and properties of hot-dense QCD matter. This program of lattice QCD calculations is relevant to current and upcoming heavy-ion experimental programs at RHIC and LHC.
