arXiv subjects

M. L. L. da Silva

Publications and source records attributed to M. L. L. da Silva.

At least 19 recordsLinked to original sources

arXiv2026

Phenomenology of $f_2(1270)$ photoproduction at energies measured with the CLAS facility

We investigate the photoproduction of the tensor meson $f_2(1270)$ on the proton within a Regge-based framework, focusing on the reaction $γp \to p f_2(1270)$ in the few-GeV energy region. The production mechanism is modeled through the exchange of vector-meson Regge trajectories in the $t$-channel, including both $ρ$ and $ω$ exchanges with phenomenologically motivated couplings. The scattering amplitudes are derived using Reggeized propagators and effective hadronic vertices, allowing for the calculation of differential cross sections in the narrow-width approximation. We further extend the analysis to the $π^+π^-$ invariant mass distribution by incorporating a relativistic Breit--Wigner description of the $f_2(1270)$ resonance.

hep-ph↗

arXiv2020

Strong decays of strange quarkonia in a corrected 3P0 model

Extensively applied to both light and heavy meson decay and standing as one of the most successful strong decay models is the $^{3}P_{0}$ model, in which $q\bar{q}$ pair production is the dominant mechanism. In this paper we evaluate strong decay amplitudes and partial widths of strange $S$ and $D$ state mesons, namely $ ϕ(1020)$, $ϕ(1680) $, $ ϕ(2050) $, $ϕ_1 (1850) $, $ϕ_2 (1850) $ and $ ϕ_3 (1850) $, in the bound-state corrected $^{3}P_{0}$ decay model (C$^{3}P_{0}$). The C$^{3}P_{0}$ model is obtained in the context of the Fock-Tani formalism, which is a mapping technique.

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arXiv2019

Investigating the glue content of $f_1(1285)$

The radiative decay of $f_1(1285)$ to vector mesons $ρ$ and $ϕ$ is calculated in a non-relativistic approach. The results obtained are compared to experimental data to estimate the glue content of $f_1$. We find a small or nonexistent glue content when our results are compared to the PDG data. However a large glue content for $f_1(1285)$ was found when we compared our results to the CLAS data.

hep-ph↗

arXiv2017

Fine-tuning in scalar meson decay with bound-state corrections

The glueball-quarkonia mixture decay amplitude has been evaluated, in the literature, by diagrammatic techniques for drawing quark lines and the quark-gluon vertex. In this paper we use an alternative approach which consists in a mapping technique, the Fock-Tani formalism, in order to obtain an effective Hamiltonian starting from microscopic interactions. An extra effect is present in this formalism associated to the extended nature of mesons: bound-state corrections, which introduces an additional decay amplitude and sets a fine-tuning procedure for general meson decay calculations. The $f_0(1500) \to ππ$ channel shall be considered as numerical example of the procedure.

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arXiv2015

Analysis Tools for Next-Generation Hadron Spectroscopy Experiments

The series of workshops on New Partial-Wave Analysis Tools for Next-Generation Hadron Spectroscopy Experiments was initiated with the ATHOS 2012 meeting, which took place in Camogli, Italy, June 20-22, 2012. It was followed by ATHOS 2013 in Kloster Seeon near Munich, Germany, May 21-24, 2013. The third, ATHOS3, meeting is planned for April 13-17, 2015 at The George Washington University Virginia Science and Technology Campus, USA. The workshops focus on the development of amplitude analysis tools for meson and baryon spectroscopy, and complement other programs in hadron spectroscopy organized in the recent past including the INT-JLab Workshop on Hadron Spectroscopy in Seattle in 2009, the International Workshop on Amplitude Analysis in Hadron Spectroscopy at the ECT*-Trento in 2011, the School on Amplitude Analysis in Modern Physics in Bad Honnef in 2011, the Jefferson Lab Advanced Study Institute Summer School in 2012, and the School on Concepts of Modern Amplitude Analysis Techniques in Flecken-Zechlin near Berlin in September 2013. The aim of this document is to summarize the discussions that took place at the ATHOS 2012 and ATHOS 2013 meetings. We do not attempt a comprehensive review of the field of amplitude analysis, but offer a collection of thoughts that we hope may lay the ground for such a document.

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arXiv2014

Deciphering charmoniumlike exotic states in photon - hadron interactions at RHIC and LHC energies

In this paper we propose the study of the photoproduction of charmoniumlike states in $pp$ collisions at RHIC and LHC energies and estimate the rapidity distribution and total cross sections for the production of the exotic hadrons $Y(3940)$, $X(3915)$, $Z(4430)$ and $Z_c(3900)$. We demonstrate that the experimental analysis of this process can provide complementary and independent checks on these states, and help to understand their underlying nature.

hep-ph↗

arXiv2014

Scalar photoproduction on the proton at CLAS and GlueX energies

In this work we present the results of a theoretical analysis of the data on photoproduction of $f_0(980)$ meson in the laboratory photon energy between $3.0$ GeV and $3.8$ GeV. A comparison is done to the measurements performed by the CLAS collaboration at JLab accelerator for the exclusive reaction $γp \to p f_0(980)$. The differential and integrated total cross sections are also computed for the cases of the mesons $f_0(1500)$, and $f_0(1710)$, focusing on the GlueX energy regime with photon energy $E_γ= 9$ GeV.

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arXiv2013

Probing the Color Glass Condensate in $pp$ collisions at forward rapidities and very low transverse momenta

The description of the hadron production at very forward rapidities and low transverse momentum is usually made using phenomenological models based on nonperturbative physics. However, at high energies and large rapidities the wave function of one of the projectiles is probed at very small Bjorken $x$, being characterized by a large number of gluons. In this kinematical regime, a new state of matter - the Color Glass Condensate (CGC) - is expected to be formed. One the main characteristics of such system is the presence of a new dynamical momentum scale, the saturation scale $Q_s$, which can assume values very larger than the QCD confinement scale $Λ_{QCD}$ and give the scale of the running coupling constant. In this paper we assume that in particular kinematical region probed by LHC forward (LHCf) experiment the saturation scale can be considered the hard momentum scale present in the process and calculate the forward neutral pion production at very low-$p_T$ using a perturbative approach. We demonstrate that the CGC formalism is able to successfully describe the LHCf data, which can be considered as a compelling indication of the presence of non-linear QCD effects at LHC energies.

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arXiv2013

Phenomenology of $f_0(980)$ photoproduction on the proton at energies measured with the CLAS facility

In this work we present the results of a theoretical analysis of the data on photoproduction of $f_0(980)$ meson in the laboratory photon energy between 3.0 and 3.8 GeV. A comparison is done to the measurements performed by the CLAS collaboration at JLab accelerator for the exclusive reaction $γp\rightarrow pf_0(980)$. In the analysis the partial S-wave differential cross section is described by a model based on Regge approach with reggeized exchanges and distinct scenarios for the $f_0(980)\rightarrow Vγ$ coupling are considered. It is shown that such a process can provide information on the resonance structure and production mechanism.

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arXiv2012

Glueball-glueball potential in a constituent gluon model

In this work we use a mapping technique to derive in the context of a constituent gluon model an effective Hamiltonian that involves explicit gluon degrees of freedom. We study glueballs with two gluons using the Fock-Tani formalism. In the present work we calculate the glueball-glueball potential, in the context of the constituent gluon model, with gluon interchange.

hep-ph↗

arXiv2012

Investigating photoproduction of scalar mesons at medium energies

In this letter we study the photoproduction of scalar mesons in the intermediate energies considering distinct mixing scenarios in the description of meson physical states. The differential and integrated total cross section are computed for the cases of the mesons a_0(980), f_0(1500) and f_0(1710) focusing the GlueX energy regime with photon energy equal to 9 GeV. Our results indicate that light-quark scalar meson photoproduction is well suited for studying hybrid mesons structure.

hep-ph↗

arXiv2011

Exclusive glueball production at the LHC

In this contribution we summarize recent results on the computation of cross sections for glueball candidates production in quasi-real photon-photon collisions and on central diffraction processes, i.e. double Pomeron exchange, in heavy ion interactions at the LHC are computed. In particular, we provide predictions for the production of exotic mesons f0(1500), f0(1710) and X(1835). The rates for these distinct production channels are compared.

hep-ph↗

arXiv2010

Exclusive glueball production in high energy nucleus-nucleus collisions

The cross sections for the glueball candidates production in quasi-real photon-photon collisions and on central diffraction processes, i.e. double Pomeron exchange, in heavy ion interactions at RHIC and LHC are computed. The rates for these distinct production channels are compared and they may be a fruitful approach to the investigation of glueballs.

hep-ph↗

arXiv2008

Meson decay in a corrected $3^P_0$ model

Extensively applied to both light and heavy meson decay and standing as one of the most successful strong decay models is the $3^P_0$ model, in which $q\bar{q}$ pair production is the dominant mechanism. The pair production can be obtained from the non-relativistic limit of a microscopic interaction Hamiltonian involving Dirac quark fields. The evaluation of the decay amplitude can be performed by a diagrammatic technique for drawing quark lines. In this paper we use an alternative approach which consists in a mapping technique, the Fock-Tani formalism, in order to obtain an effective Hamiltonian starting from same microscopic interaction. An additional effect is manifest in this formalism associated to the extended nature of mesons: bound-state corrections. A corrected $3^P_0$ is obtained and applied, as an example, to $b_{1}\toωπ$ and $a_{1}\toρπ$ decays.

hep-ph↗

arXiv2006

Do glueballs contribute in heavy ion collisions?

In heavy ion collision simulations many hadron states and/or parton degrees of freedom are included in order to obtain the observables. Meson spectroscopy, for example, considers the $0^{++}$ meson as a mixture of $q\bar{q}$ and glue. This fact is usually not considered in heavy ion collision physics. In the present work we consider two extreme possibilities for the constitution of the $0^{++}$ meson, either as a pure glueball or as $q\bar{q}$-meson. The scattering amplitude and cross-sections with constituent interchange are determined for the two situations. The comparison showed that the glueball-glueball elastic scattering cross-section for a color singlet state is between one to two orders of magnitude smaller than the corresponding $q\bar{q}$ state. The $2^{++}$ glueball-glueball interaction is also evaluated with similar behavior. Thus, glueball-glueball scattering is not very likely to introduce significant changes in heavy ion collision observables.

hep-ph↗

arXiv2005

Glueball decay in the Fock-Tani formalism

We investigate the two-meson decay modes for $f_0(1500)$. In this calculation we consider this resonance as a glueball. The Fock-Tani formalism is introduced to calculate the decay width.

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arXiv2005

Meson decay in the Fock-Tani Formalism

The Fock-Tani formalism is a first principle method to obtain effective interactions from microscopic Hamiltonians. Usually this formalism was applied to scattering, here we introduced it to calculate partial decay widths for mesons.

hep-ph↗

arXiv2004

Glueball-glueball scattering in a constituent gluon model

In this work we use a mapping technique to derive in the context of a constituent gluon model an effective Hamiltonian that involves explicit gluon degrees of freedom. We study glueballs with two gluons using the Fock-Tani formalism. In the present work we consider two possibilities for $0^{++}$: (i) as a pure $s\bar{s}$ and calculate, in the context of a quark interchange picture, the cross-section; (ii) as a glueball where a new calculation for this cross-section is made, in the context of the constituent gluon model, with gluon interchange.

hep-ph↗