At sufficiently high baryon densities, such as those found in compact star cores, the internal quark-gluon wave functions of neighboring nucleons begin to overlap and delocalize, hinting at a percolation-like transition. Modeling such systems is particularly challenging, as nucleons gradually lose their identities and can no longer be treated as appropriate degrees of freedom. In this talk, I...
Recent Lattice QCD (LQCD) simulations have confirmed an attractive interaction in the isoscalar $DD^*$ channel, which is naturally associated with the $T_{cc}(3875)^+$ state observed by LHCb in the $D^0D^0\pi^+$ spectrum. However, the connection between the virtual bound state predicted by LQCD and the experimental signal remains an open question. In this talk, we present an Effective Field...
Hadronic form factors are around since Hofstadter proved the finite proton size in 1955 in electron scattering experiments, identified as matrix elements of the em current. Since then, the nucleon and other hadronic form factors have been measured or computed in lattice QCD using all sorts of currents: electromagnetic, axial or gravitational. In the time-like region analyticity, chiral...
The open quantum system framework allows one to compute quarkonium's evolution in a medium, keeping track of the needed quantum features. However, computing this evolution is a computationally demanding task. QTRAJ is an efficient code that allows one to simulate the behavior of quarkonium in a medium in the case in which the medium sees quarkonium as a small color dipole $rT\ll 1$. While this...
QCD Euclidean space path integrals of have a sign problem when a chemical potential is included; this inhibits our ability to calculate the equation of state (EOS) of nuclear matter. This sign problem goes away if the if the chemical potential is imaginary. Unfortunately imaginary chemical potentials are not physical; traditionally they have been used as the starting point for an analytic...
One of the main issues posed by the presence of hadrons in any reaction is their final-state interactions, which are formally expressed in terms of the unitarity of the amplitude. In two-body scattering, unitarity is usually imposed in the direct channel only, as one is not sensitive to the details of the crossed channels. This is certainly not the case for a three-body decay, where the three...
Current precision tests of the Standard Model show a deficit in the first row unitarity of the CKM matrix. At the current level of precision, the only relevant CKM matrix elements that contribute to first row unitarity are $V_{ud}$ and $V_{us}$. Without resorting on nuclear inputs, they can be extracted from the combination of the experimental decay width of kaon and pion leptonic decays along...
We present recent results from the FASTSUM collaboration, using anisotropic lattice QCD to study spectral properties of heavy quarkonia and open heavy flavour systems at high temperature. For heavy quarkonium, our results using a number of different suggest a small but significant and robust negative mass shift as well as an increasing thermal width. We present the first lattice results for...
The Belle and Belle II experiments have collected a 1.6 ab$^{-1}$ sample of $e^+e^-$ collision data at centre-of-mass energies near the $\Upsilon(nS)$ resonances. This provides a unique opportunity to study conventional hadronic states, such as charmed meson and baryons, charmonium and bottomonium. However, it also opens a window to the study of exotic hadron states, such as tetraquarks,...
We consider kaon-deuteron femtoscopy correlation functions using elementary kaon–nucleon scattering amplitudes within unitarized chiral effective field theory. The amplitudes are obtained through the impulse approximation, accounting for single kaon–nucleon scatterings, and through the fixed-center approximation to the Faddeev equations, which includes multiple re-scattering effects. The...
Charmonium production measurements are powerful tests of QCD. The models of charmonium production separate the quark pair production, well understood, and the hadronisation, which is non perturbative. The most successful model so far, non-relativistic QCD, requires input from experimental results to constrain the non-perturbative component. With its precise vertex reconstruction, powerful...
A precise description of low-energy pion-pion interactions is essential for many problems in hadronic physics. We present new global fits that satisfy dispersive constraints within uncertainties up to 1.6 GeV, while describing all available experimental data up to 1.8 GeV. Using continued-fraction expansions, we extract resonance pole parameters in a model-independent way from forward...
We study the momentum broadening of a high energy quark jet in the high-density gluon medium created right after the collision of two ultrarrelativistic heavy nuclei, the Glasma. Previous Glasma studies consider the jet as a classical probe particle, for which position and momentum are simultaneously determined. In this talk, we use the light-front QCD Hamiltonian formalism [1,2] to treat the...
The existence of the nucleonic pentaquark resonances $P_{c\bar{c}}(4312)^+$, $P_{c\bar{c}}(4380)^+$, $P_{c\bar{c}}(4440)^+$, $P_{c\bar{c}}(4457)^+$, $P_{c\bar{c}s}(4338)^0$ and $P_{c\bar{c}s}(4459)^0$, established by the LHCb collaboration, has been one of the major discoveries in hadron physics in the latest years. Most of these states (5 out of 6) can be understood as meson-baryon bound...
Various physical phenomena arise in QCD in the presence of strong magnetic fields. Some of them, such as magnetic catalysis and inverse magnetic catalysis, have already been well studied on the lattice, in QCD-like models, effective field theories, etc. Moreover, it has been proposed that an analog of the Kondo effect, which emerges in dense QCD, may also be present in magnetized QCD at zero...
Confinement and deconfinement of quarks and gluons can be understood in terms of the absence or presence of corresponding asymptotic states and/or quasi-particle-like excitations in the physical spectrum of QCD. In this talk, I will discuss our current knowledge of said spectrum, as encoded in the analytic structure of the QCD propagators, and I will report on recent results concerning the...
I will present a theoretical and experimental overview of the production of eta-pi and eta’-pi with pion beam (COMPASS) and photon beam (GlueX).
These two-meson systems are known to have odd angular waves with exotic quantum numbers.
The JPAC collaboration has been analyzing the COMPASS and GlueX data in order to extract the properties of the lightest exotic meson, the pi_1(1600). In this...
The formalism of Dyson-Schwinger equations is a powerful tool to study correlation functions in quantum field theory, but has also proved to yield an outstanding framework for the evaluation of hadron properties. Starting from state of the art continuum Schwinger calculations of pion's parton distribution function, we describe its extension to off-forward hadron kinematics, yielding the pion's...
In this talk, I will report on recent results concerning chiral and U(1)_A restoration, both from an analysis based on Ward identities, which are formally derived from QCD, and from effective field theories, which are provided by U(3) chiral perturbation theory.
These results lead to relevant conclusions about the behavior of chiral partners (in terms of susceptibilities) in the limit of...
The ALICE experiment at the LHC is focused on the investigation of the Quark-Gluon Plasma (QGP), a fundamental state of matter at high temperature in which quarks and gluons are deconfined, and which is generated in heavy-ion collisions at ultra-relativistic energies. One of the key experimental signatures to explore the structure and dynamics of the QGP is ‘jet quenching’, the modification of...
We present recent theoretical advances in the study of femtoscopic correlation functions (CFs) as tools to probe hadron interactions and the nature of hadronic resonances. We show the relation between femtoscopy and invariant mass distributions, and discuss modified both Koonin-Pratt and Lednicky-Lyuboshits formalisms. We also present the incorporation of Coulomb interactions into CF...
In a recent work, a novel approach to the physics of mesons has been put forth, which permits one to go beyond the traditional rainbow-ladder approach in a symmetry-preserving way. In this talk we review the salient features of the framework, and show in detail its applicability for the physics of massless pions.
One of the most anticipated applications of quantum information science is the simulation of complex systems. Those involving quarks and gluons are particularly compelling, as their real-time phenomenology remains elusive to computational techniques such as traditional Monte Carlo methods. Overcoming these challenges could provide unprecedented insights into the dynamics of partons.
In this...
In-medium parton splitting functions (PSFs) are a central ingredient in the description of the propagation of jets inside the quark-gluon plasma. Despite their critical importance, these objects have only been computed under a set of strong approximations concerning both the kinematics and the medium. In this talk, we present a novel approach so as to obtain the medium-induced modification...
We report on our ongoing lattice QCD computation of antistatic-antistatic-light-light potentials using the CLS $N_f=2$ gauge configurations and the OpenQ*D codebase. We improve on previous work by calculating the correlation matrices for all three attractive ground state potentials previously characterized, to mitigate excited state contributions and further probe the vague indication of...
Strong magnetic fields have a profound impact on the behavior of hot plasma, resulting in distinct correlations among charged particles in observed data. However, the corresponding theoretical prediction is complicated by a large uncertainty in the magnetic field. This presentation will delve into recent progress in deriving closed-form expressions for the one-loop photon polarization and...
The transport properties of the high-density matter found in neutron stars affect the gravitational wave signals observed from colliding neutron stars. In particular, the effects of bulk viscosity differ from quark and nuclear matter. I will discuss the general hydrodynamic evolution of relativistic and dense matter near equilibrium. Focussing on the case of unpaired quark matter, I address...
We study exotic baryon systems composed of anticharmed mesons and strange baryons using the extended local hidden gauge approach. By solving the coupled-channel Bethe-Salpeter equation with interaction kernels from vector meson exchange, we explore the formation of hadronic molecular states in sectors with strangeness S = −1, −2, −3 and −4.
We systematically consider all possible isospin...
Within the Bethe-Salpeter framework, we present a computation of space like electromagnetic form factors for pseudoscalar mesons, including light and heavy-light systems. Our approach employs a flavour-dependent variation of the standard Taylor effective charge, which contains key contributions from the quark-gluon vertices. This effective interaction is a common ingredient of all relevant...
With the increasing richness of neutron star observations and ongoing experiments on nuclear structure, a fertile ground has emerged for exploring QCD across a wide range of densities. In our previous studies of nuclear matter properties based on a baryonic extended linear model—where the delta meson is included in the equation of state—we found that the resulting parameter space differs...
We use NLO unitarized SU(3) Chiral Perturbation Theory (ChPT) to generate the lightest scalar and vector resonances,
in terms of the ChPT renormalized low-energy constants, with no additional parameters. By varying the quark masses, we follow the poles associated with each of these resonances through different Riemann sheets
until we reach the SU(3) and chiral limits. In a regime, resonance...
We present the first calculations of the masses of heavy and heavy–light tensor and axial-tensor mesons with total angular momentum up to J=3, obtained within the Covariant Spectator Theory (CST). This fully-relativistic Minkowski-space framework describes the quark–antiquark interaction through a covariant generalization of a one-gluon-exchange plus linear-confining potential. The CST...
In this talk I will discuss some recent advances in an effective theory of QCD at low energies, where nuclei and baryons are described by topological soliton solutions known as Skyrmions.
Following the great success of coupling the rho mesons to the Skyrme field (which provided more realistic nuclear binding energies for the model and the triggering of nuclear clustering), we have recently...
In quantum chromodynamics (QCD), the baryon number is a conserved quantity. It is traditionally assumed to be evenly distributed among valence quarks in nucleus. However, an alternative framework proposes that this number is carried by a non-perturbative, Y-shaped topology of gluons connecting to three quarks. While neither hypothesis has been conclusively verified experimentally, new...
We utilize the universality of pion--pion ($\pi\pi$) final-state interactions at small invariant masses to understand the enhanced local CP violation in $B^\pm\to K^\pm\pi^+\pi^-$, using a dispersive approach. From a fit to the integrated CP-asymmetry data, we successfully predict the Dalitz-plot kinematic distribution of the asymmetry in the low-energy $\pi\pi$ region, including the large...
The ALICE collaboration has recently reported $\pi^+K_S$ and $K^+ K_S$ femtoscopic correlations. Here we demonstrate that the data can be well reproduced using realistic interactions, and provide predictions for other light-hadron channels. This approach leads to an accurate description of the $\kappa/K^0(700), \rho(770)$ and $a_0(980)$ resonances. Moreover, we propose a novel framework to...
We investigate the core dynamics behind exotic matter formation via the TQ4Q1.1 set of collinear, variable-flavor-number-scheme fragmentation functions for fully charmed or bottomed tetraquarks in three quantum configurations: scalar ($0^{++}$), axial vector ($1^{+-}$), and tensor ($2^{++}$). We adopt single-parton fragmentation at leading power and implement a nonrelativistic QCD...
The theoretical interpretation of jet observables in heavy-ion collisions is a complex task due to the intricate interplay of perturbative and non-perturbative effects. One way to reduce this complexity is to groom away soft, wide-angle radiation so that perturbative dynamics dominates. Even in this simplified scenario, there are competing explanations for the physical origin of the measured...
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...
In this talk, I will discuss how the pattern of chiral symmetry breaking can be utilzied to compute vector and axial-vector pion matrix elements in a uniform magnetic field. The results are constructed within chiral perturbation theory and therefore model independent for a magnetic field, $\sqrt{eB}$, weaker the typical hadronic scale of $4\pi F_{\pi}\sim 1\ \rm{GeV}$. The matrix elements...
The quark mass dependence of the pseudoscalar meson decay consntants, $f_\pi, f_K$ and $f_\eta$, are determined from three-flavor ChPT till pion masses of around $750$ MeV, around the SU(3) limit. This is done by conducting an analysis of recent LQCD data using the LASSO method, a machine-learning technique which allows to pin down the relevant low-energy-constants with high precision. Since...
