Conveners
Talks: Monday - 1
- Orlando Oliveira (University of Coimbra)
Talks: Monday - 2
- Orlando Oliveira (University of Coimbra)
Talks: Monday - 3
- Marcela Peláez (Universidad de la República Uruguay)
Talks: Tuesday - 1
- Jon-Ivar Skullerud (National University of Ireland Maynooth)
Talks: Tuesday - 2
- Jon-Ivar Skullerud (National University of Ireland Maynooth)
Talks: Tuesday - 3
- GASTAO KREIN (Instituto de Física Teórica, Universidade Estadual Paulista)
Talks: Wednesday - 1
- There are no conveners in this block
Talks: Wednesday - 2
- There are no conveners in this block
Talks: Wednesday - 3
- There are no conveners in this block
Talks: Thursday - 1
- Maria Gomez Rocha (Universidad de Granada)
Talks: Thursday - 2
- Maria Gomez Rocha (Universidad de Granada)
Talks: Thursday - 3
- David Dudal (KU Leuven)
Talks: Friday - 1
- Leticia Faria Domingues Palhares (State University of Rio de Janeiro)
Talks: Friday - 2
- Leticia Faria Domingues Palhares (State University of Rio de Janeiro)
Talks: Closing
- There are no conveners in this block
Infrared-confining models such as the Curci-Ferrari and Refined Gribov-Zwanziger frameworks are known to provide modified gluon propagators that incorporate nonperturbative mass scales and/or complex analytic structures, while also yielding results compatible with benchmark nonperturbative approaches such as Lattice QCD. These models are largely evaluated through gluon, ghost and quark...
The Refined Gribov-Zwanziger (RGZ) scenario is one of the most well-developed frameworks to account for the existence of (infinitesimal) Gribov copies and further non-perturbative effects such as the formation of condensates. Most progress has been achieved in the Landau gauge. The theory features a tree-level gluon propagator that reaches a non-vanishing value at zero momentum and a...
We investigate the violation of the Bell-CHSH inequality in the vacuum state in the context of Quantum Field Theory. Summers and Werner showed in the eighties, using tools from algebraic quantum field theory and operator analysis, that test functions exist that lead to an asymptotic reaching of Tsirelson's upper bound violation of 2 \sqrt 2.
We propose a different strategy that allows to...
I will show results of a study* using continuum methods establishing a connection between center vortices and gluon mass generation in 3+ 1 dimensions Yang-Mills theory. I will show that such a connection can be established within the Hamiltonian framework by employing a vacuum wavefunctional peaked on center vortices — a framework originally introduced to explain the Wilson loop area law. We...
In gauge field theory, we follow the fundamental principle that physical observables must be gauge independent. The most straightforward way to ensure this is to work with gauge-invariant operators, since their correlation functions are expected to be gauge independent. In addition to this crucial property, in theories where the physical subspace has a semi-positive norm, correlation functions...
Lattice simulations have clearly established that the low- and high-temperature regimes of QCD are controlled by distinct active degrees of freedom, hadrons on the one side, and quarks and gluons on the other side. Yet, many continuum studies of the confinement/deconfinement transition rely on the Polyakov loop which measures how energetically costly it is to bring an external quark probe into...
Temperature has a significant effect on the properties of QFTs with spontaneously broken symmetries, in particular for the massless Goldstone bosons that exist in the vacuum state. In this talk I will discuss recent results which indicate that Goldstone modes persist at high temperatures, even if the symmetry is restored, and that they have the properties of screened massless excitations,...
During this talk we will present recent results on the Landau-gauge infrared gluon propagator in Euclidean space at finite temperatures and baryonic densities, as computed within the framework of the screened massive expansion of QCD by making use of a simple model for the infrared quark masses. We will discuss the behavior of the propagator and its sensitivity on the deconfinement phase...
The issue of analytically continuing Feynman integrals from Euclidean to Minkowski signature is revisited with complex momenta,which become relevant in theories where complex poles are observed. Although this continuation is well-known in terms of the Källén-Lehmann representation, some potential alternative takes, which are equivalent for real momenta, will lead to different results for...
I will present how the S-matrix formalism enables a model-independent description of hadronic matter by linking scattering phase shifts to an effective density of states. This approach naturally incorporates broad resonances and repulsive interactions, offering a robust framework for thermal QCD.
Applied to the LHC proton yield anomaly, it helps resolve the “proton puzzle” by capturing...
Fragmentation functions describe the number of hadrons inside a given parton in the light-front momentum-fraction range [z,z+dz]. They are ubiquitous, appearing in most of the factorisation formulae used to relate some given process to a structural hadron property. However, practically nothing is known about them. Results obtained via phenomenological fits are practitioner dependent and in...
Using available information from Drell-Yan data on pion and kaon structure functions, an approach is described which enables the development of pointwise profiles for all pion and kaon parton distribution functions without reference to theories of hadron structure. The key steps are construction of structure-function-constrained probability-weighted ensembles of valence DF replicas and use of...
After reviewing the Emergeht Hadrom Mass (EHM) framework I will discuss recent results onf the pion, kaon and nucleon electromagentic and gravitational form factors.
Understanding the internal structure of hadrons is a fundamental challenge in nonperturbative QCD, where the emergent phenomena of confinement and dynamical chiral symmetry breaking play central roles. In this talk, I present recent progress in the study of hadronic distribution functions using continuum Schwinger function methods formulated in Euclidean space. Focusing on the parton...
A nonperturbatively-improved, symmetry-\linebreak preserving approximation to the quantum field equations relevant in calculations of meson masses and interactions is used to deliver predictions for all distribution functions (DFs) of the ground state pion, $\pi_0$, and its first radial excitation, $\pi_1$, \emph{viz}.\ valence, glue, and sea. Regarding Mellin moments of the valence DFs, the...
A unified set of predictions for nucleon gravitational form factors is obtained using continuum Schwinger methods (CSMs). A crucial aspect of the study is the self-consistent characterization of the dressed quark-graviton vertices, applied when probing each quark flavor inside mesons or nucleons. The calculations reveal that each hadron’s mass radius is smaller than its charge radius, matching...
I will summarise some recent progress in studying hadrons using lattice QCD. The spectroscopy and interactions of hadrons probe the strongly-interacting regime of QCD, and in recent years experiments have observed a number of puzzling hadrons that challenge our understanding of the strong interaction. Lattice QCD provides a method for performing first-principles computations of the properties...
Dyson–Schwinger equations (DSEs) provide a non-perturbative framework for computing QCD Green’s functions. When constrained by lattice QCD data, these solutions—originally formulated in Euclidean space—can potentially be analytically continued to Minkowski space. Achieving this continuation enables the extraction of hadronic phenomenology directly from non-perturbative DSE...
Here we present first-principles lattice QCD calculations using comprehensive gauge ensembles that accurately predict ground state spin-1/2 and spin-3/2 baryon masses with light, strange, and charm quarks within 1\% of experimental values. At the (\overline{\mathrm{MS}}) 2 GeV scale, our results unveil two fundamental mass generation mechanisms for those baryon masses in QCD: 1) the...
I will discuss recent applications of functional methods, in particular the combination of Dyson-Schwinger and Bethe-Salpeter equations, to hadron spectroscopy. There are various ongoing efforts in investigating the properties of exotic hadrons and multiquark states such as tetraquarks, pentaquarks and hexaquarks. In this talk I will focus on four-quark states in the heavy-light sector and...
In the calculation of bound state properties, models for interactions play a crucial role in identifying underlying mechanisms and also in obtaining quantitative results. Their construction is typically not only guided by symmetries but also by the complexity one can computationally handle when using them in bound state and related equations. In this context, one advantage of models is that...
The internal structure of hadrons can be described in terms of structure functions that encode, for example, the momentum and spin distributions of their constituents. Parton distribution functions (PDFs) and Transverse Momentum Distributions (TMDs), for example, describe the quark and gluon momentum distributions inside a hadron. These distribution functions are, however, not easy to...
Problems of analytic continuation arise frequently in particle physics, especially in the context of lattice field theory calculations carried out in Euclidean time. This talk will describe recently developed methods for carrying out this procedure numerically, discussing the connection to scattering observables.
This contribution concerns the complexity of the Hamiltonian formulation of QCD in the Minkowski space-time. The talk will include suggestions for overcoming the issues using the front form of dynamics and eigenvalue equations for describing bound states of the quanta of quark and gluon fields, and a method for computing effective Hamiltonians in quantum field theory, called the...
We explore the QCD vacuum structure, using a novel semiclassical method on $\mathbb{R}^2×T^2$ with ‘t Hooft and baryon magnetic fluxes. In this setup, it is conjectured that no phase transition occurs when the size of $T^2$ is varied (adiabatic continuity). If this holds true, the analysis at small $T^2$ can predict qualitative features of the QCD vacuum structure on $\mathbb{R}^4$.
At small...