arXiv subjects

B. D. Moreira

Publications and source records attributed to B. D. Moreira.

At least 19 recordsLinked to original sources

arXiv2021

Photoproduction of relativistic QED bound states in hadronic collisions

In this paper we investigate the photoproduction of QED bound states in proton -- proton, proton -- nucleus and nucleus -- nucleus collisions at RHIC, LHC and FCC energies considering an accurate treatment of the absorptive corrections and for the nuclear form factor. The total cross sections for the production of singlet and triplet $(l^+ l^-)$ states, with $l = e,\, μ, \, τ$, are estimated and a detailed analysis of the photoproduction of singlet QED bound states is performed considering the rapidity ranges covered by central and forward detectors. The impact of the Coulomb corrections on the parapositronium production in heavy ion collisions is estimated. We predict a large number of events associated to the production of ($e^+ e^-$) and ($μ^+ μ^-$) states in hadronic collisions.

hep-ph↗

arXiv2020

Dark photons from pions produced in ultraperipheral $PbPb$ collisions

In this letter we propose the search of dark photons in the decay of pions produced by $γγ$ interactions in ultraperipheral $PbPb$ collisions. The cross section is estimated considering an accurate treatment for the absorptive corrections and for the nuclear form factor. Predictions for the event rates are presented considering the expected luminosities for the LHC, High -- Luminosity LHC and High -- Energy LHC as well as for the Future Circular Collider. Our results indicate that a future experimental analysis of the pion production in ultraperipheral heavy ion collisions can be useful to probe the dark photon production and constrain its properties.

hep-ph↗

arXiv2020

True muonium production in ultraperipheral $PbPb$ collisions

In this paper we investigate the production of a true muonium state, which is an atom consisting of a $μ^+ μ^-$ bound state, by $γγ$ interactions in ultraperipheral $PbPb$ collisions considering an accurate treatment of the absorptive corrections and for the nuclear form factor. The rapidity distributions and cross sections are estimated considering the RHIC, LHC and FCC energies. Our results indicate that the experimental analysis can be useful to observe, for the first time, the true muonium state.

hep-ph↗

arXiv2020

A phenomenological analysis of the nonperturbative QCD contributions for the photon wave function

The photon -- induced interactions, present in $ep$, $eA$, $pp$, $pA$, $AA$ and $e^+ e^-$ collisions, are expressed within the color dipole approach in terms of the photon wave function, which describes the transition of the photon into a quark -- antiquark color dipole. Such quantity is usually calculated using perturbation theory assuming that long distance corrections associated to strong interactions can be neglected. In this paper we investigate the impact of these nonperturbative QCD (npQCD) corrections to the description of the photon wave function for dipoles of large size in several observables measured at HERA, LEP and LHC. We assume a phenomenological ansatz for the treatment of these npQCD corrections and constrain the free parameters of our model using the experimental data for the photoproduction cross section. The predictions for the $γγ$ cross section, exclusive $ρ$ production in $ep$ collisions and the rapidity distribution for the $ρ$ production in $PbPb$ collisions are compared with the data. We demonstrate that the inclusion of the nonperturbative QCD corrections improves the description of processes that are dominated by large dipoles.

hep-ph↗

arXiv2019

Exclusive dilepton production in ultraperipheral $PbPb$ collisions at the LHC

In this paper we perform a systematic study of the exclusive dilepton production by $γγ$ interactions in $PbPb$ collisions at the LHC Run 2 energies considering different levels of precision for the treatment of the absorptive corrections and for the nuclear form factor. The rapidity and invariant mass distributions are estimated taking into account the experimental cutoffs and a comparison with the recent ALICE and ATLAS data for the $e^+ e^-$ and $μ^+ μ^-$ production is presented.

hep-ph↗

arXiv2018

Probing the $X(4350)$ in $γγ$ interactions at the LHC

The production of $X(4350)$ in the $γγ$ interactions that occur in proton-proton, proton-nucleus and nucleus-nucleus collisions at the CERN Large Hadron Collider (LHC) is investigated and predictions for the kinematical ranges probed by the ALICE and LHCb Collaborations are presented. We focus on the $γγ\rightarrow ϕJ/Ψ$ process, which have been measured by the Belle Collaboration, and present parameter free predictions for the total cross sections at the LHC energies. Our results demonstrate that the experimental study of this process is feasible and can be used to confirm or not the existence of the $X(4350)$ state. Finally, for completeness, we present predictions for the production of the $X(3915)$ state in the $γγ\rightarrow ωJ/Ψ$ process and show that this exotic state can also be probed in $γγ$ interactions at the LHC.

hep-ph↗

arXiv2018

Investigating the exclusive vector meson photoproduction in nuclear collisions at Run 2 LHC energies

We investigate the theoretical uncertainty on the predictions for the photoproduction of $ρ$ and $J/Ψ$ states in nucleus-nucleus collisions at Run 2 LHC energies using the Color Dipole formalism. The results for rapidity distributions and total cross sections are presented. Moreover, we compare directly the theoretical results to the recent preliminary data from ALICE collaboration on $ρ$ production in $PbPb$ collisions at central rapidity.

hep-ph↗

arXiv2018

$η_c$ photoproduction at LHC energies

In this contribution, we study the inclusive and diffractive $η_{c}$ photoproduction in $pp$ and $pPb$ ultra-peripheral collisions (UPC's) at the LHC Run 2 energies. The quarkonium production is studied using nonrelativistic quantum chromodynamics (NRQCD) formalism. We present predictions for rapidity and transverse momentum distributions for the $η_c$ photoproduction and present our estimate for the total cross sections at the Run 2 energies.

hep-ph↗

arXiv2018

$η_c$ production in photon - induced interactions at the LHC

In this paper we investigate the $η_c$ production by photon - photon and photon - hadron interactions in $pp$ and $pA$ collisions at the LHC energies. The inclusive and diffractive contributions for the $η_c$ photoproduction are estimated using the nonrelativistic quantum chromodynamics (NRQCD) formalism. We estimate the rapidity and transverse momentum distributions for the $η_c$ photoproduction in hadronic collisions at the LHC and present our estimate for the total cross sections at the Run 2 energies. A comparison with the predictions for the exclusive $η_c$ photoproduction, which is a direct probe of the Odderon, also is presented.

hep-ph↗

arXiv2017

Color dipole predictions for the exclusive vector meson photoproduction in $pp/pPb/PbPb$ collisions at Run 2 LHC energies

In this paper we present a comprehensive analysis of exclusive vector meson photoproduction in $pp$, $pPb$ and $PbPb$ collisions at Run 2 LHC energies using the Color Dipole formalism. The rapidity distributions and total cross sections for the $ρ$, $ϕ$, $J/Ψ$, $Ψ(2S)$ and $Υ$ production are estimated considering the more recent phenomenological models for the dipole - proton scattering amplitude, which are based on the Color Glass Condensate formalism and are able to describe the inclusive and exclusive $ep$ HERA data. Moreover, we also discuss the impact of the modelling of the vector meson wave functions on the predictions. The current theoretical uncertainty in the Color Dipole predictions is estimated and a comparison with the experimental results is performed.

hep-ph↗

arXiv2017

Diffractive quarkonium photoproduction in $pp$ and $pA$ collisions at the LHC: Predictions of the Resolved Pomeron model for the Run 2 energies

The inclusive diffractive quarkonium photoproduction in $pp$ and $pA$ collisions is investigated considering the Resolved Pomeron Model to describe the diffractive interaction. We estimate the rapidity and transverse momentum distributions for the $J/Ψ$, $Ψ(2S)$ and $Υ$ photoproduction in hadronic collisions at the LHC and present our estimate for the total cross sections at the Run 2 energies. A comparison with the predictions associated to the exclusive production also is presented. Our results indicate that the inclusive diffractive production is a factor $\gtrsim 10$ smaller than the exclusive one in the kinematical range probed by the LHC.

hep-ph↗

arXiv2016

Exclusive heavy vector meson photoproduction in hadronic collisions at the LHC: predictions of the Color Glass Condensate model for Run 2 energies

In this letter we update our predictions for exclusive $J/Ψ$ and $Υ$ photoproduction in proton-proton and nucleus - nucleus collisions at the Run 2 LHC energies obtained with the color dipole formalism and considering the impact parameter Color Glass Condensate model (bCGC) for the forward dipole - target scattering amplitude. A comparison with the LHCb data on rapidity distributions and photon - hadron cross sections is presented. Our results demonstrate that the current data can be quite well described by the bCGC model, which takes into account nonlinear effects in the QCD dynamics and reproduces the very precise HERA data, without introducing any additional effect or free parameter.

hep-ph↗

arXiv2016

Production of exotic charmonium in $γγ$ interactions at hadronic colliders

In this paper we investigate the Exotic Charmonium (EC) production in $γγ$ interactions present in proton-proton, proton-nucleus and nucleus-nucleus collisions at the CERN Large Hadron Collider (LHC) energies as well as for the proposed energies of the Future Circular Collider (FCC). Our results demonstrate that the experimental study of these processes is feasible and can be used to constrain the theoretical decay widths and shed some light on the configuration of the considered multiquark states.

hep-ph↗

arXiv2016

Double vector meson production in photon - hadron interactions at hadronic colliders

In this paper we analyse the double vector meson production in photon -- hadron ($γh$) interactions at $pp/pA/AA$ collisions and present predictions for the $ρρ$, $J/ΨJ/Ψ$ and $ρJ/Ψ$ production considering the double scattering mechanism. We estimate the total cross sections and rapidity distributions at LHC energies and compare our results with the predictions for the double vector meson production in $γγ$ interactions at hadronic colliders. We present predictions for the different rapidity ranges probed by the ALICE, ATLAS, CMS and LHCb Collaborations. Our results demonstrate that the $ρρ$ and $J/ΨJ/Ψ$ production in $PbPb$ collisions is dominated by the double scattering mechanism, while the two - photon mechanism dominates in $pp$ collisions. Moreover, our results indicate that the analysis of the $ρJ/Ψ$ production at LHC can be useful to constrain the double scattering mechanism.

hep-ph↗

arXiv2016

Exclusive vector meson production with a leading neutron in photon - hadron interactions at hadronic colliders

In this paper we study leading neutron production in photon - hadron interactions which take place in $pp$ and $pA$ collisions at large impact parameters. Using a model that describes the recent leading neutron data at HERA, we consider exclusive vector meson production in association with a leading neutron in $pp/pA$ collisions at RHIC and LHC energies. The total cross sections and rapidity distributions of $ρ$, $ϕ$ and $J/Ψ$ produced together with a leading neutron are computed. Our results indicate that the study of these processes is feasible and that it can be used to improve the understanding of leading neutron processes and of exclusive vector meson production.

hep-ph↗

arXiv2015

Double vector meson production in $γγ$ interactions at hadronic colliders

In this paper we revisit the double vector meson production in $γγ$ interactions at heavy ion collisions and present, by the first time, predictions for the $ρρ$ and $J/ΨJ/Ψ$ production in proton -- nucleus and proton -- proton collisions. In order to obtain realistic predictions for rapidity distributions and total cross sections for the double vector production in ultra peripheral hadronic collisions we take into account of the description of $γγ\rightarrow VV$ cross section at low energies as well as its behaviour at large energies, associated to the gluonic interaction between the color dipoles. Our results demonstrate that the double $ρ$ production is dominated by the low energy behaviour of the $γγ\rightarrow VV$ cross section. In contrast, for the double $J/Ψ$ production, the contribution associated to the description of the QCD dynamics at high energies contributes significantly, mainly in $pp$ collisions. Predictions for the RHIC, LHC, FCC and CEPC - SPPC energies are shown.

hep-ph↗

arXiv2015

Double vector meson production in the International Linear Collider

In this paper we study double vector meson production in $γγ$ interactions at high energies and, using the color dipole picture, estimate the main observables which can be probed at the International Linear Collider (ILC). The total $γ(Q_1^2) + γ(Q_2^2) \rightarrow V_1 + V_2$ cross-sections for $V_i = ρ$, $ϕ$, $J/ψ$ and $Υ$ are computed and the energy and virtuality dependencies are studied in detail. Our results demonstrate that the experimental analysis of this process is feasible at the ILC and it can be useful to constrain the QCD dynamics at high energies.

hep-ph↗

arXiv2015

Exclusive $Υ$ photoproduction in hadronic collisions at CERN LHC energies

The exclusive $Υ$ photoproduction in proton-proton and proton - nucleus collisions at LHC energies is investigated using the color dipole formalism and considering different models for the $Υ$ wave function and forward dipole - target scattering amplitude. Our goal is to update the color dipole predictions and estimate the theoretical uncertainty present in these predictions. We present predictions for the kinematical ranges probed by the ALICE, CMS and LHCb Collaborations.

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