In this contribution, we study the inclusive and diffractive $\eta_{c}$ photoproduction in $pp$ and $pPb$ ultra-peripheral collisions (UPC's) at the LHC Run II energies. In a hadron-hadron UPC, is well known that the hadrons can act as sources of almost real photons allowing the study of photon-photon and photon-hadron interactions. Our goal is the study of the $\eta_{c}$ production in...
In heavy ion collisions after the quark-gluon plasma there is a hadronic gas phase. Using effective Lagrangians we study the interactions of charmed mesons which lead to $J/\psi$ production and absorption in this gas. We update and extend previous calculations introducing strange meson interactions and also including the interactions mediated by the recently measured exotic charmonium...
In the high energy regime, the proton structure consists of a very large number of parton that interact with each other according to the theory of strong interactions, Quantum Chromodynamics (QCD). Through QCD, the number of partons in the proton is described by equations of parton evolution that depend on kinematic variables. These equations can be linear, the DGLAP equations, and nonlinear ,...
In the present day, the theoretical description of the behavior of the cross section in the regime of high energies is still the focus of questioning. A proposal that is still valid, is that the slight growth of the cross section is associated with the exchange of an object with the quantum numbers of the vacuum, called Pomeron. Phenomenologically, via Regge's theory, it was possible to...
The behavior of charged pion masses in the presence of a static uniform magnetic field is studied in the framework of the two-flavor NJL model, using a magnetic field-independent regularization scheme. Analytical calculations are carried out employing the Ritus eigenfunction method, which allows us to properly take into account the presence of Schwinger phases in the quark...
The Covariant Spectator Quark Model, successful
in the description of the nucleon elastic
form factors revealed by the Jefferson Lab
polarization transfer experiments,
has been extended to the calculation
of transition form factors associated
to several light nucleon resonances $N^\ast$.
The electromagnetic structure of the $N^\ast$
are characterized by the
$\gamma^\ast N \to N^\ast$...
In this paper we study the double quarkonium production in single and double diffractive processes considering the Resolved Pomeron model. Based on the nonrelativistic QCD (NRQCD) factorization formalism for the quarkonium production mechanism we estimate the rapidity and transverse momentum dependence of the cross section for the $J/\Psi J/\Psi$ and $\Upsilon \Upsilon$ production in...
Double parton scattering (DPS) is a mechanism in which two partons from each proton initiate a scattering process. The cross section formula is described by a partonic distribution function (PDF), a double parton distribution (DPD) and scattering cross sections relative to more fundamental hard processes, i.e., the formula can be written in such a way that is possible to describe different...
Short-lived hadronic resonance production in high energy collisions is an important observable to investigate the properties of the system created in such collisions. Measurements of particle production yields have shown a suppression in the relative production of resonances with respect to non-resonance particles for high energy collisions in which a large amount of particles were produced....
In the present work we have obtained the equation of state and the population of baryons and leptons to the highly asymmetric dense stellar matter, with the purpose of studying the effects of hyperons on the structure of neutron stars. To this end, we adopted the Zimanyi-Moszkowski model in the mean field approximation. From the equation of state obtained with the model, we solve numerically...
The following work studies the effects of the interactions originated from scalars and vectors mesons exchanges in the interior of Neutron Stars. We analyze the differences that appears on masses and radii between stars sustained against gravitational collapse exclusively by the degeneracy pressure of matter and stars that have also the presence of interactions mediated by mesons. In the...
Since long the measurement of strange and multi-strange hadron production rates has demonstrated to be a key measurement in the investigation of the properties of nuclear matter created in high energy collisions. In particular, the observation of strangeness enhancement in collisions of large systems, such as Pb-Pb, is historically considered as a signature of the formation of a QGP phase in...
The exclusive photoproduction of the heavy vector mesons J/Ψ is investigated in the context of peripheral lead-lead collisions for the energies available at the LHC, s=2.76 TeV and s=5.02 TeV. Using the light-cone color dipole formalism, the rapidity distribution was calculated in two centrality bins at 50%–70% and 70%–90% in order to evaluate its robustness in extrapolating down to a...
At forward rapidities and high energies we expect to probe non-linear effects of the Quantum Chromodynamics (QCD). One of the most promising observables to constrain the QCD dynamics at this regime is the exclusive vector meson photoproduction (EVMP). We study the EVMP in association with a leading baryon (product of the proton dissociation) in photon-hadron interactions that take place in...
Establishing a description for confinement is not something simple. In order to try to understand a little about this phenomenon, we will explore the thermodynamics of models that try to describe it in terms of propagators with violation of positivity. In this work, "confinement'' is always understood in the sense of positivity violation of the propagator of the elementary fields. For...
In this work, we investigate the exclusive production of particles in scattering processes in the so-called saturation region. Within this scheme the phenomenon of geometric scaling takes place: cross sections are functions only of a dimensionless combination of the relevant kinematic variables, which happens both in inclusive and diffractive cases, as in the production of vector mesons. In...
The photon–induced interactions, as those present in the deep inelastic scattering (DIS) process and in ultraperipheral hadronic collisions, can be used to improve our understanding of the strong interactions in the high energy regime. In particular, the photon-induced interactions where one the incident hadrons fragments and only one rapidity gap is present in the final state, usually denoted...
We study the nucleon axial (Ga) form factor in symmetric nuclear matter in a light-front approach using the in-medium inputs calculated by the quark-meson coupling model, where the quarks interact with a flavor independent contact force. We found results comparable to the ones obtained with a confining interaction.
The recent data by the TOTEM Collaboration on $\sigma_{tot}$ and $\rho$ at 13 TeV, have shown agreement with a leading Odderon contribution at the highest energies, as demonstrated in the very recent analysis by Martynov and Nicolescu (MN). In order to investigate the same dataset by means of Pomeron dominance, we introduce a general class of forward scattering amplitude, with leading...
We investigate protoneutron star matter using the state-of-the-art perturbative equation of state for cold and dense QCD in the presence of a fixed lepton fraction in which both electrons and neutrinos are included. Besides computing the modifications in the equation of state due to the presence of trapped neutrinos, we show that stable strange quark matter has a more restricted parameter space.
Study of low energy interaction kaon-hyperon throw the nonlinear chiral invariant Lagragians considering kaons, ρ mesons, σ mesons, hyperons, and corresponding resonances. We calculate the total cross section, angular distributions, polarization, and the phase shifts in the center-of-mass frame to low energy S- and P-wave.
In this work, we study in detail the effects of many-body forces on the equation of state and the structure of magnetic neutron stars.
The stellar matter is described within a relativistic mean field formalism that takes into account many-body forces by means of a non-linear meson field dependence on the nuclear interaction coupling constants. We assume that matter is at zero temperature,...
The properties of color superconducting cold dense quark matter under compact star conditions are investigated using an SU(2) Nambu Jona-Lasinio (NJL) model in which the divergences are treated using "medium separation scheme" (MSS) as regularization scheme. We compare our results with the usual treatment of the divergent integrals (3D cutoff) that is referred to as the "traditional...
The dimension two gauge invariant non-local operator A2min, obtained through the minimization of ∫d4xA2 along the gauge orbit, allows to introduce a non-local gauge invariant configuration Ahμ which can be employed to built up a class of Euclidean massive Yang-Mills models useful to investigate non-perturbative infrared effects of confining theories. A fully local setup for both A2min and Ahμ...
The Parton Distribution Function measure the probability to find a parton inside a hadron, but these functions are of non-perturbative origin and, therefore, cannot be calculated from first principles in perturbative Quantum Chromodynamics. In this work we review how the parton distribution functions are determined, specifically the HERAPDF2.0, which is determined from deep inelastic...
The search for the existence of pasta phases
in the low density regions of nuclear and neutron star matter is performed within the context of the quark-meson
coupling (QMC) model, which incorporates quark
degrees of freedom.
Fixed proton fractions are considered, as well as nuclear matter in
beta equilibrium at zero temperature. We discuss the recent
attempts to better understand the...
In this work we present a theoretical approach to deal with radiative decays of meson molecules. This is a promising framework to understand mesons that lie near the production threshold of $D$ and $B$ mesons, and don't fit in the traditional quarkonia predictions. We apply this approach specifically to the meson $X(3872)$: considering it a $D D^*$ molecule, we deal with its radiative decays...
The sigma resonance has been a long standing puzzle in both, theory and experiment. Because its non-Breit Wigner shape, the extraction of its properties is not straightforward. Dispersive analysis techniques are needed to extract the properties of the resonance. Lately, several lattice data groups have performed a calculation of phase shifts for $\pi \pi$ scattering in the Isospin = 0, Spin =...
Using the light-front kaon wave function based on a Bethe-Salpeter amplitude model for the quark-antiquark bound state, we study the Electromagnetic Form Factor (EMFF) and other observables like charge radius and decay constant of the kaon in nuclear medium within the framework of light-front field theory. The kaon model we adopt is well constrained by previous and recent studies to explain...
We present finite temperature Dirac-Hartree-Bogoliubov (FTDHB) calculations
for the tin isotope chain to study the dependence of pseudospin on
the nuclear temperature. In the FTDHB calculation, the density dependence of the
self-consistent relativistic mean fields, the pairing, and the vapor phase
that takes into account the unbound nucleon states are considered
self-consistently. The...
We present a survey of electromagnetic form factors and mass spectra of light baryons obtained within a Poincaré covariant Faddeev equation framework, the ingredients of which are constrained by calculations in continuum QCD.
In 1979, Feynman and Veneziano had already proposed that multiparticle production can have a fractal structure, what could explain the complexity of the multiparticle processes in high energy collisions. In the next decades, multiparticle fractality was observed through the intermittence that appears in many distributions measured in different laboratories. Almost two decades before that,...
The compatibility of the results from the Gribov-Zwanziger tree level prediction and lattice simulations, using large statistical ensembles, for the Landau gauge gluon propagator are investigated, thereby complementing earlier work using small-scale statistics. Our results show that the data is well described by the tree level estimate only up to momenta p≲1 GeV while clearly favoring the...
Laboratories like JLAB, COMPASS and HERMES have dedicated programs focused on the investigations of Semi-inclusive DIS processes. Their results gives an opportunity to reconstruct the 3D structure of the hadron, in particular, the Transverse Momentum Distributions (TMDs). Their findings can give insights about the internal hadron dynamics as quark-gluon correlations and final-state...
The discrete Efimov scaling behavior, well-known in the low-energy spectrum of three-body bound systems for large scattering lengths (unitary limit), is identified in the energy dependence of atom-molecule elastic cross-section in mass imbalanced systems. That happens in the collision of a heavy atom with mass $m_H$ with a weakly-bound dimer formed by the heavy atom and a lighter one with mass...
