CARLOS BAHIA - Academia.edu (original) (raw)

Papers by CARLOS BAHIA

Research paper thumbnail of Energy-dependent dipole form factor in a QCD-inspired model

Journal of Physics: Conference Series, 2016

We consider the effect of an energy-dependent dipole form factor in the high-energy behavior of t... more We consider the effect of an energy-dependent dipole form factor in the high-energy behavior of the forward amplitude. The connection between the semihard parton-level dynamics and the hadron-hadron scattering is established by an eikonal QCD-based model. Our results for the proton-proton (pp) and antiproton-proton (pp) total cross sections, σ pp,pp tot (s), obtained using the CTEQ6L1 parton distribution function, are consistent with the recent data from the TOTEM experiment.

Research paper thumbnail of Nonperturbative QCD effects in forward scattering at the LHC

Physical Review D, 2015

We study infrared contributions to semihard parton-parton interactions by considering an effectiv... more We study infrared contributions to semihard parton-parton interactions by considering an effective charge whose finite infrared behavior is constrained by a dynamical mass scale. Using an eikonal QCD-based model in order to connect this semihard parton-level dynamics to the hadronhadron scattering, we obtain predictions for the proton-proton (pp) and antiproton-proton (pp) total cross sections, σ pp,pp tot , and the ratios of the real to imaginary part of the forward scattering amplitude, ρ pp,pp. We discuss the theoretical aspects of this formalism and consider the phenomenological implications of a class of energy-dependent form factors in the high-energy behavior of the forward amplitude. We introduce integral dispersion relations specially tailored to relate the real and imaginary parts of eikonals with energy-dependent form factors. Our results, obtained using a group of updated sets of parton distribution functions (PDFs), are consistent with the recent data from the TOTEM, AUGER and Telescope Array experiments.

Research paper thumbnail of The bosonic and fermionic propagators under an external electromagnetic field in a Euclidean manifold

Canadian Journal of Physics, 2021

In this paper, we will calculate the bosonic as well as fermionic propagators under classical hom... more In this paper, we will calculate the bosonic as well as fermionic propagators under classical homogeneous and constant magnetic and electric fields in a Euclidean space. For this, we will reassess the Ritus' method for calculating the Feynman propagator.

Research paper thumbnail of Análise fenomenológica dos espalhamentos elásticos próton-próton e antipróton-próton em altas energias na representação eiconal

We study the proton-proton (pp) and antiproton-proton (p̄p) elastic scattering in the eikonal rep... more We study the proton-proton (pp) and antiproton-proton (p̄p) elastic scattering in the eikonal representation by means of two formulations compatible with analyticity and unitarity constraints: a formulation inspired by Quantum Chromodynamics (QCD) and a formulation based upon Regge theory. In QCD-inspired models the increase of the total cross sections is associated with semihard scatterings of partons in the hadrons. The energy dependence of the cross sections is driven especially by gluon-gluon scattering processes which are potentially divergent at small transferred momenta. In this thesis we present an eikonal model in which these divergences are regulated by the introduction of a dynamical gluon mass. The model is built from the parton model using standard QCD cross sections for elementary parton-level processes, updated sets of quark and gluon distribution functions (CTEQ6L,CTEQ6L1 and MSTW), and physically-motivated cutoffs which restrict the elementary processes to semihard ...

Research paper thumbnail of Regge Phenomenology at LHC Energies

International Journal of Modern Physics: Conference Series

At high energies the Pomeron plays a crucial part in describing the soft interactions. In the lig... more At high energies the Pomeron plays a crucial part in describing the soft interactions. In the light of LHC (Large Hadron Collider) data we perform a detailed analysis of proton-proton ([Formula: see text]) and antiproton-proton ([Formula: see text]) forward scattering data in order to determine the intercept and the slope of the soft Pomeron trajectory. This analysis is performed based on Regge theory using Born-level amplitudes. We investigate the role of the proton-Pomeron vertex form and of the nearest [Formula: see text]-channel singularity. We give predictions for the total cross section and the ratio of the real part to the imaginary part of the elastic amplitude in [Formula: see text] collisions at LHC and cosmic-ray energies.

Research paper thumbnail of Regge Phenomenology at LHC Energies

International Journal of Modern Physics: Conference Series, 2017

At high energies the Pomeron plays a crucial part in describing the soft interactions. In the lig... more At high energies the Pomeron plays a crucial part in describing the soft interactions. In the light of LHC (Large Hadron Collider) data we perform a detailed analysis of protonproton (pp) and antiproton-proton (pp) forward scattering data in order to determine the intercept and the slope of the soft Pomeron trajectory. This analysis is performed based on Regge theory using Born-level amplitudes. We investigate the role of the proton-Pomeron vertex form and of the nearest t-channel singularity. We give predictions for the total cross section and the ratio of the real part to the imaginary part of the elastic amplitude in pp collisions at LHC and cosmic-ray energies.

Research paper thumbnail of Energy-dependent dipole form factor in a QCD-inspired model

Journal of Physics: Conference Series, 2016

We consider the effect of an energy-dependent dipole form factor in the high-energy behavior of t... more We consider the effect of an energy-dependent dipole form factor in the high-energy behavior of the forward amplitude. The connection between the semihard parton-level dynamics and the hadron-hadron scattering is established by an eikonal QCD-based model. Our results for the proton-proton (pp) and antiproton-proton (pp) total cross sections, σ pp,pp tot (s), obtained using the CTEQ6L1 parton distribution function, are consistent with the recent data from the TOTEM experiment.

Research paper thumbnail of Nonperturbative QCD effects in forward scattering at the LHC

Physical Review D, 2015

We study infrared contributions to semihard parton-parton interactions by considering an effectiv... more We study infrared contributions to semihard parton-parton interactions by considering an effective charge whose finite infrared behavior is constrained by a dynamical mass scale. Using an eikonal QCD-based model in order to connect this semihard parton-level dynamics to the hadronhadron scattering, we obtain predictions for the proton-proton (pp) and antiproton-proton (pp) total cross sections, σ pp,pp tot , and the ratios of the real to imaginary part of the forward scattering amplitude, ρ pp,pp. We discuss the theoretical aspects of this formalism and consider the phenomenological implications of a class of energy-dependent form factors in the high-energy behavior of the forward amplitude. We introduce integral dispersion relations specially tailored to relate the real and imaginary parts of eikonals with energy-dependent form factors. Our results, obtained using a group of updated sets of parton distribution functions (PDFs), are consistent with the recent data from the TOTEM, AUGER and Telescope Array experiments.

Research paper thumbnail of The bosonic and fermionic propagators under an external electromagnetic field in a Euclidean manifold

Canadian Journal of Physics, 2021

In this paper, we will calculate the bosonic as well as fermionic propagators under classical hom... more In this paper, we will calculate the bosonic as well as fermionic propagators under classical homogeneous and constant magnetic and electric fields in a Euclidean space. For this, we will reassess the Ritus' method for calculating the Feynman propagator.

Research paper thumbnail of Análise fenomenológica dos espalhamentos elásticos próton-próton e antipróton-próton em altas energias na representação eiconal

We study the proton-proton (pp) and antiproton-proton (p̄p) elastic scattering in the eikonal rep... more We study the proton-proton (pp) and antiproton-proton (p̄p) elastic scattering in the eikonal representation by means of two formulations compatible with analyticity and unitarity constraints: a formulation inspired by Quantum Chromodynamics (QCD) and a formulation based upon Regge theory. In QCD-inspired models the increase of the total cross sections is associated with semihard scatterings of partons in the hadrons. The energy dependence of the cross sections is driven especially by gluon-gluon scattering processes which are potentially divergent at small transferred momenta. In this thesis we present an eikonal model in which these divergences are regulated by the introduction of a dynamical gluon mass. The model is built from the parton model using standard QCD cross sections for elementary parton-level processes, updated sets of quark and gluon distribution functions (CTEQ6L,CTEQ6L1 and MSTW), and physically-motivated cutoffs which restrict the elementary processes to semihard ...

Research paper thumbnail of Regge Phenomenology at LHC Energies

International Journal of Modern Physics: Conference Series

At high energies the Pomeron plays a crucial part in describing the soft interactions. In the lig... more At high energies the Pomeron plays a crucial part in describing the soft interactions. In the light of LHC (Large Hadron Collider) data we perform a detailed analysis of proton-proton ([Formula: see text]) and antiproton-proton ([Formula: see text]) forward scattering data in order to determine the intercept and the slope of the soft Pomeron trajectory. This analysis is performed based on Regge theory using Born-level amplitudes. We investigate the role of the proton-Pomeron vertex form and of the nearest [Formula: see text]-channel singularity. We give predictions for the total cross section and the ratio of the real part to the imaginary part of the elastic amplitude in [Formula: see text] collisions at LHC and cosmic-ray energies.

Research paper thumbnail of Regge Phenomenology at LHC Energies

International Journal of Modern Physics: Conference Series, 2017

At high energies the Pomeron plays a crucial part in describing the soft interactions. In the lig... more At high energies the Pomeron plays a crucial part in describing the soft interactions. In the light of LHC (Large Hadron Collider) data we perform a detailed analysis of protonproton (pp) and antiproton-proton (pp) forward scattering data in order to determine the intercept and the slope of the soft Pomeron trajectory. This analysis is performed based on Regge theory using Born-level amplitudes. We investigate the role of the proton-Pomeron vertex form and of the nearest t-channel singularity. We give predictions for the total cross section and the ratio of the real part to the imaginary part of the elastic amplitude in pp collisions at LHC and cosmic-ray energies.