The particle production at forward rapidities in hadronic collisions is one of the most promising processes to probe the QCD dynamics at small - x as well as to observe the breakdown of the collinear and kT factorization theorems, predicted to occur to high partonic densities. In this process, one has the interaction between projectile partons with large cone momentum fractions and target...
Conventional quantum mechanics relies on Hermitian Hamiltonians, which guarantee real and positive energy spectra while ensuring probability conservation through the Dirac inner product. However, $\mathcal{PT}$-symmetric Hamiltonians, which are invariant under parity $\mathcal{P}$ and time-reversal $\mathcal{T}$ transformations, naturally ensure a real and positive energy spectrum. By adopting...
The interest in systems with many correlated degrees of freedom is a central aspect of Quantum Field Theory (QFT) and Statistical Mechanics. These conditions mean that the effective long-range interactions between the particles in the system become highly non-trivial, and we therefore use the Renormalization-Group method to analyze the behavior around the critical point. This process is...
It is well established that the Schwinger mechanism generates a nonperturbative mass for gluons through the emergence of massless poles in the fundamental QCD vertices. In this work, we examine the pole structure of the three-gluon vertex, analyzing its patterns and residues using two complementary approaches: the Slavnov-Taylor identity, which encapsulates the vertex's symmetry properties,...
The Quark-Gluon Plasma produced in relativistic heavy-ion collisions allows the study of the QCD phase diagram through hydrodynamic phenomenology. An open question is the existence and location of a critical point.
At high energies, such as 200 GeV A at RHIC or a few TeV at LHC, the region of the QCD phase diagram being probed at mid-rapidity is characterized by high temperature and an...
Quantum electrodynamics (QED) is the gauge field theory that describes the interactions between photons and charged particles, characterized by gauge invariance under the group U (1) [1]. Understanding how QED works is essential to describe one of the fundamental forces of the universe, eletromagnetism,this can be investigated from various perspectives, including experimental, perturbative...
We present a Schwinger-Dyson analysis of the three- and four-gluon vertices in the soft-kinematic configuration, where one external momentum vanishes. The key assumption in our analysis is the validity of a ''planar degeneracy'', which states that the leading form factor for each vertex is well described by a single Bose-symmetric variable defining a plane in momentum space. We find that this...
The muon anomalous magnetic moment, $g-2$, is one of the most precisely measured quantities in physics. On the theoretical side, however, the Standard Model (SM) prediction does not achieve the same level of precision, primarily due to the uncertainty in the hadronic vacuum polarization (HVP) contribution. At energies between 2 and 3.7 GeV, perturbative QCD (pQCD) is often used for the...
We perform a detailed analysis of the key features of the transversely projected three-gluon vertex in the presence of two dynamical quarks, focusing on the soft-gluon limit, where one momentum vanishes. Our approach is based on the one-loop dressed Schwinger-Dyson equation derived from the 3PI effective action. A central assumption in our analysis is the validity of planar degeneracy, which...
The multiplicity distribution (MD) of charged particles in high-energy proton-proton collisions remains an intricate aspect of quantum chromodynamics (QCD). Traditional models, such as the Negative Binomial Distribution (NBD), were fitted and successfully described MDs at lower energies, but fail at higher energies, such as those probed by the Large Hadron Collider (LHC), where a...
The apparent onset of hydrodynamics in small systems necessitates a description of hydrodynamics independent of the many-particle limit, and the proper treatment of fluctuations in conditions of near-local equilibrium. We propose an algorithm for the dynamic description of such a few-particle fluctuating fluid. The procedure consists of defining a spacetime lattice in which each cell,...
We present a detailed study of the partial decay widths of a spin-parity resonance $J^P = 3/2^-$ $N^{โ}$ with a mass of $\simeq 2070$ MeV obtained from the coupled channel s wave vector-baryon $\rho N$, $\omega N$, $\phi N$, $K^{*} \Lambda$ and $K^{โ} \Sigma$ dynamics. This state, which couples strongly to the $K^{โ} \Sigma$ channel, corresponds to a nucleon with a hidden strange quark...
We use a recently developed explicitly flux conservative formalism for the causal and stable hydrodynamic equations developed by Bemfica, Disconzi, Noronha, and Kovtun (BDNK) with the goal of investigating shock formation in relativistic viscous fluids. It is well known that the relativistic Euler equations can give rise to discontinuous solutions called shock waves, and attempts to show...
In this work, we investigate the transverse Slavnov-Taylor identities as a means to constrain the nonperturbative structure of the transverse form factors of the quark-gluon vertex. These identities arise from the interplay between BRST symmetry and Lorentz invariance. While they provide a novel approach to studying the transverse component of the quark-gluon vertex, certain challenges arise,...
The effective cross section of double parton scattering in proton collisions has been measured by many experiments with rather different results. Motivated by this fact, we assumed that the parton correlations in the transverse plane are different whether we have valence or sea partons. With this simple approach, we were able to fit the available data and found that sea parton pairs are more...
The quark-gluon plasma is a state of matter where quarks and gluons, the fundamental components of protons and neutrons, are free and constantly interacting due to the properties of quantum chromodynamics, such as confinement and asymptotic freedom. This state can only be produced under extreme energy conditions, such as those that existed in the early universe after the Big Bang or in the...
We investigate the quark-gluon vertex in unquenched QCD with two degenerate light dynamical quarks in the Landau gauge. By solving its Schwinger-Dyson equation, derived from the 3PI effective action formalism, we determine the eight form factors of the transversely projected vertex in general kinematics. The analysis incorporates lattice data for key ingredients, including the gluon and quark...
In this work we study the higher-order QCD corrections of the Higgs decay into bottom quarks and into a pair of gluons. Our method consists of employing Padรฉ and D-log Padรฉ approximants considering the perturbative coefficients dependence on the number of flavors. We estimate, in a model-independent way, the yet unknown coefficient of order $\alpha_s^7$ of $\Gamma(H \to g g)$ in the...
Bayesian inference is a key tool in relativistic heavy-ion collision studies, enabling probabilistic constraints on model parameters through computational simulations and model-to-data comparison. The information obtained through these simulations, however, is limited to discrete parameter-space points (typically a few hundred to a few thousand design points).
To overcome this bottleneck,...
Exotic hadrons are particles that do not fit the traditional classification of hadrons, and their existence is compatible with our present understanding of Quantum Chromodynamics (QCD), the theory that describes how particles interact through the strong interaction, one of the four fundamental forces of Nature. In QCD, quarks and gluons interact via the strong force; quarks are the fundamental...
In the present work we investigate the source of azimuthal asymmetry for nuclear collision using a model that contemplates particles produced in the initial hard collisions and the collective effects described by a Blast-Wave like expansion. The latter is described by the relaxation time approximation of the Boltzmann transport equation. The parameters regarding collective flow and asymmetry...
The Standard Model describes the electromagnetic, strong, and weak interactions, but the treatment of gravitational interactions at the quantum level remains an open question. Such an aspect has motivated the proposition of various models for physics beyond the Standard Model, based on the existence of extra spatial dimensions. In these models, the production of black holes in hadronic...
In the last years the matter distribution inside the proton has become an important topic discussed by the international community. After the measurement of the proton mass and scalar radius, which revealed the extent of its gluon distribution, one important question remains: what is the shape of matter distribution inside it? One possible answer, which will be explored in this work, is the...
The particle production in photon-photon (ฮณฮณ) interactions present in electron-ion collisions is investigated. We present calculations for the total cross sections and event rates related to the production of light mesons [ฮท, ฮทโฒ, f0 and f2], charmonium [ ฮท_c and ฯ_c] and charmoniumlike [ X(3915), X(3940), X(4140) and X(6900)] states, considering the EIC, EicC, LHeC and FCC-eh energies. Our...
In ultraperipheral collisions, the electromagnetic fields can be approximated by a flux of quasi-real photons, according to the Equivalent Photon Approximation (EPA). This approach offers a powerful method for calculating physical observables in photo-induced processes.
Our goal is to predict the inclusive photoproduction of heavy hadronic states, including vector mesons and exotic states...
In this work, the excess of $J/\psi$ production in peripheral collisions, which was experimentally observed at the LHC (ALICE) and RHIC (STAR) at low transverse momentum ($p_{T}$), is investigated. We use the color dipole formalism to calculate the photoproduction cross section, employing the phenomenological dipole models bCGC and IP-SAT, which take into account saturation effects, and the...
We study the photoproduction of light vector mesons considering both
the proton and the nucleus as targets. Utilizing the dipole picture
and wave functions obtained via AdS/QCD, we were able to describe the
HERA $\gamma p$ data and extend the analysis to the nuclear case by
employing the GlauberโGribov formalism. This formalism is supplemented
by an effective nuclear suppression factor,...
In the forthcoming years, proton-oxygen ($pO$) and oxygen-oxygen ($OO$) collisions will be conducted at the LHC. The high luminosities of Run 3 will provide valuable insights into processes involving the collision of light and heavy ions. Such collisions present an opportunity to study the nuclear dependence and the transition regime of various phenomena, which are expected to exhibit distinct...
Exclusive diffractive processes offer a unique window into Quantum Chromodynamics (QCD) in the high-energy regime. The foundation for these studies, established by Lipatov and collaborators, introduced the QCD Pomeron and the Balitsky-Fadin-Kuraev-Lipatov (BFKL) equation, which governs gluon ladder exchanges. Recent investigations have highlighted the impact of BFKL evolution on observables in...
In this work we present a calculation of exotic charmonium production
in photo-induced processes, in which the exotic state is explicitly
treated as a meson molecule. Our formalism is general but we focus on the
lightest possible exotic charmonium state: a $D^+ D^-$ molecular bound state. Here we study the production of the open charm pair in the process $\gamma \gamma \to D^+ D^-$. Then...
Hydrodynamic models have been instrumental in uncovering the properties of quark-gluon plasma (QGP) in relativistic heavy-ion collisions, providing an effective framework to describe the system's evolution. However, their validity is challenged in scenarios where causality is violated, as such violations undermine their ability to represent the underlying relativistic quantum field theory...
The determination of the strong coupling, $\alpha_s$, from the theoretical description of inclusive hadronic tau decays in Quantum Chromodynamics (QCD), is one of the most precise extractions from experimental data. The theoretical description is dominated by perturbation theory but receives non-perturbative contributions from the Operator Product Expansion and duality violations, which...
Considering that the study of neutrino - nucleus interactions with incident neutrino energy ranges in the GeV - TeV range is feasible at the Large Hadron Collider, we investigate in this work the degree of polarization ${\cal{P}}$ of the (anti) tau lepton produced in (anti) tau neutrino - tungsten interactions. We include nuclear effects to examine their impact on ${\cal{P}}$. In this study...
This scientific initiation project involved the analysis of a Monte Carlo (MC) dataset of relativistic heavy-ion collisions using Machine Learning (ML) methods. The dataset was provided by the Experimental Hadronic Physics Group (HadrEx) in direct collaboration with the ALICE experiment at the Large Hadron Collider (LHC). The research focused specifically on multi-strange baryonsโsuch as ฮโป, ...
The exploration of fundamental particle physics has entered an era of data-driven discovery, characterized by unprecedented volumes of experimental data and advanced computational techniques. In our work, we strived to effectively quantifying and reducing uncertainties in Higgs boson detection using machine learning methodologies. Using public datasets, our study developed an machine learning...
We study the exclusive photoproduction of heavy vector mesons off nuclear targets using the color dipole model within the Glauber-Gribov formalism. We obtained the impact-parameter-dependent cross sections for both coherent and incoherent cases, with spatial correlations among nucleons to account for fluctuations in their positions. This approach aims to provide a more accurate description of...
We develop a neural network based on variational autoencoders to generate D0 meson kinematics, i.e., transverse momentum, pseudorapidity, and azimuthal angle. The input dataset is a Monte Carlo (MC) simulation of the D0 meson production and the CMS detector at the LHC in PbPb collisions at 5.02 TeV. For training the method, a n-tuple with the kinematics of the D0 meson daughters (in the decay...
The production cross sections and the number of events per year of mesons are estimated by considering photon-photon interactions in fixed-target collisions at the LHC energies of CERN. We consider several mesons with photon-photon partial decay widths well constrained by the experiment, and some mesons that are currently considered candidates for hadronic molecules and glueballs. Our results...
Neutron stars act as natural laboratories for probing nuclear matter under extreme densities, with their inner layers reaching values several times greater than those found in atomic nuclei. The detection of gravitational waves from neutron star mergers has provided unprecedented experimental data on tidal deformability during the final coalescence phase of binary systems. In this work, we...
We discuss how the passage of the universe through a pion condensed phase and a chiral symmetry breaking would affect its cosmic trajectory at the QCD era. A pion condensed phase could be achieved if large lepton asymmetries were reached at this epoch. To describe the QCD sector we employ a quark-meson model at finite temperature and finite baryon and charge chemical potentials. We show that,...
In this work, we generate a wide range of equations of state (EoS) for both quark matter and nucleonic matter. For nucleonic matter, we use the metamodeling approach due to its simplicity. The EoS generated using metamodeling must satisfy certain physical constraints: it must be causal, its symmetric properties must fall within experimental values, and it must support approximately 2 solar...
We use the recently developed resummation technique known as renormalization group optimized perturbation theory (RGOPT) to evaluate the equation of state (EoS) describing cold and dense quark matter at next-to-leading order (NLO). The technique is applied to non-strange quark matter ($N_f=2$) as well as strange quark matter ($N_f=2+1$) while ensuring thermodynamic consistency in both cases....
When massive stars (โณ 10Mโ) reach the end of their life cycle, the instability of their iron core leads to the collapse of the star. This collapse is halted upon reaching extreme densities, as the strong nuclear force prevents further contraction, resulting in the formation of a proto-neutron star (PNS). The collision of the starโs outer layers with the PNS generates a shock wave that expels...
In this work, we implement a neural network model introduced by Y. Fujimoto, K. Fukushima, and K. Murase (Phys. Rev. D 98, 023019 (2018)) to infer the neutron star equation of state (EoS) from mass and radius measurements. The Tolman-Oppenheimer-Volkoff equation allows for the derivation of a mass-radius (MR) relationship from a given EoS by solving a system of ordinary differential equations....
We constrain the nuclear matter equation of state by including the isoscalar-vector and isovector-vector coupling using the Bayesian approach. We use the recent observation GW190814 (R. Abbott et al 2020 ApJL 896 L44) for the compact star of mass 2.6 Mโ along with the nuclear saturation properties for finite and infinite nuclear matter at saturation properties at saturation and...
Quantum chromodynamics (QCD) is the fundamental theory of the strong interaction. Its equation of state at finite temperatures has been computed from first principles using lattice QCD simulations with Monte Carlo methods. At finite baryon densities, however, the known fermion sign problem prevents the application of these methods. In order to obtain results in this regime, which is relevant...
We present the extension for finite temperature of the Many-Body Forces Model (MBF Model) for the first time. The MBF Model describes nuclear matter in a relativistic quantum hadrodynamics formalism that takes many-body forces into account, by means of a field dependence of the nuclear interaction coupling constants in an adjustable derivative coupling framework. Assuming nuclear matter to be...
Quantum chromodynamics (QCD) is the theory that describes the nuclear strong interaction between quarks, mediated by gauge fields carrying color charge, the gluons. QCD has a very important and unsolved problem, which is finding a mechanism to explain why quarks are never seen alone in nature, but only forming bound states, such as protons and neutrons. This constitutes the color confinement...
We investigate the interactions of the deuteron with light mesons during the hadronic phase in heavy-ion collisions. For this purpose, we treat the deuteron as a bound state of two nucleons and analyze the evolution of the cross-sections in interactions between the deuteron and pions. We begin by using effective Lagrangians obtained through chiral perturbation theory to estimate the vacuum...
In this study, we investigate the interplay between chiral and diquark order parameters in cold, dense quark matter subjected to an external magnetic field, using an SU(2) version of the NambuโJona-Lasinio (NJL) model. We analyze the impact of the magnetic field on the phase diagram, addressing model divergences through various regularization strategies. These include the combined application...
The structure of the QCD phase diagram is a fundamental question in nuclear and particle physics. Recent works suggest the possibility of inhomogeneous phases, where key properties of quark matter such as the chiral condensate or number density adopt periodic spatial patterns. Although progress has been made in studying these phases within QCD-inspired models, direct analysis in full QCD...
We describe the total proton-air production cross section based on the inelastic proton-proton cross section derived from a QCD-inspired model. In this approach, the QCD contribution to the total cross section for the inclusive process $A+B \to jets$ is computed at the next-to-leading order.
Effective models to the quantum chromodynamics (QCD), like the Nambu--Jona-Lasinio (NJL) model, has been used to describe strong interaction for its simplicity. Regularization procedures can be applied to magnetized quark matter and describe the physics of peripheral heavy ion collisions and magnetars. The quark anomalous magnetic moment is a phenomena that has been calling attention in the...
The NambuโJona-Lasino model is modยญfied by the inclusion of a running-coupling that was obtained by a fractal approach to QCD. The coupling follows a ๐-exponential function and, in the context of high energy collisions, explains the origin of the Tsallis non-extensive statistics distributions. The parameter ๐ is completely determined in terms of the number of colours and the number of quark...
Recent developments in lattice calculations of thermodynamical properties of the QCD equation of state along the isospin axis at finite temperature and low baryon chemical potential have been successfully implemented (B. B. Brandt, F. Cuteri and G. Endrลdi, JHEP 07 (2023) 055 [2212.14016]). Lattice calculations provide reliable physical data on the thermodynamics of gauge theories such as QCD,...
In this work we use the Nambu--Jona-Lasinio model in its $SU(3)$ formulation, with the introduction of a six-point interaction given by the 't Hooft determinant to reproduce the breaking of the $U_A(1)$ symmetry.
Then, we apply the mean field approximation to obtain the effective quark masses and the stationary phase approximation in the bosonized NJL model to obtain the meson masses.
The...
Our aim is to study dynamically generated resonances on the multistrangess sector, using chiral unitary approach and hidden local symmetry. This work is an extension of ref [1] and the idea is to add s- and u-diagrams in the future for the pseudoscalar-baryon interactions, which is missing in ref [1]. Our work includes systems made of pseudoscalar and vector mesons, reproducing the calculation...
The only solution of the hydrodynamic equations that propagate in wave form, except for small perturbations, are shock waves. However, shock waves haven't been thoroughly studied in the ultrarelativist limit. In relativistic formulation of hydrodynamics, causality must be intrinsically preserved, which as a consequence limits the maximum group velocity of the theory. This will naturally affect...
