Rapport sur les contributions - XV Hadron Physics 2020
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XV Hadron Physics 2020
Rapport sur les
contributions
https://indico.in2p3.fr/e/19502XV Hadron Physi … / Rapport sur les contributions Gravitational waves signatures an …
Contribution ID: 5 Type: Seminar
Gravitational waves signatures and magnetars
A neutron star was first detected as a pulsar in 1967. It is one of the most mysterious objects in the
universe, with a radius of the order of 10 km and masses that can reach two solar masses. In 2017,
a gravitational wave was detected (GW170817) and its source was identified as the merger of two
neutron stars. The same event was seen in X-ray, gamma-ray, UV, IR, radio frequency and even
in the optical region of the electromagnetic spectrum, starting the new era of multi-messenger
astronomy [1]. To understand neutron stars, an appropriate equation of state that satisfies bulk
nuclear matter properties has to be used [2] and GW170817 has provided some extra constraints
to determine it [3].
On the other hand, some neutron stars have strong magnetic fields up to 1015 Gauss on the surface
as compared with the usual 1012 Gauss normally present in ordinary pulsars. They are called
magnetars. While the description of ordinary pulsars is not completely established, describing
magnetars poses a real challenge because the magnetic fields can produce an anisotropic equation
of state. One elegant way to circumvent this problem is the use of the chaotic field approximation
[4].
It is also known that low magnetic fields do not affect the equation of state and the resulting
star macroscopic properties but they do affect the crust-core transition and the crust thickness [5]
with many consequences, as the explanation of glitches and the calculation of the Love number that
enter the quadrupole tidal polarisabilities. Moreover, just before the merging, tidal interactions can
excite the star crust fluid modes by resonance and the fundamental mode can be greatly excited
with a strong influence on the gravitational wave emission [6].
I will talk about the importance of the new constraints imposed by GW170817 in the determination
of appropriate equations of state, in the calculation of the fundamental mode and possible ways to
describe hadronic and quark matter subject to strong magnetic fields.
[1] P. S. Cowperthwaite et al. (Ligo Scientific Collaboration and Virgo Collaboration), Astrophys.
Jour. Lett. 848: L12 (2017).
[2] M.Dutra, O.Lourenço, S.S.Avancini, B.V.Carlson, A. Delfino, D. P. Menezes, C. Providência, S.
Typel, and J. R. Stone, Phys. Rev. C 90, 055203 (2014).
[3] Odilon Lourenço, Mariana Dutra, César H. Lenzi, Cesar V. Flores and Débora P. Menezes, Phys.
Rev. C 99, 045202 (2019).
[4] L. Lopes and D. Menezes, Journal of Cosmology and Astroparticle Physics 08 (2015) 002; D.
P. Menezes and L. L. Lopes, Eur. Phys. J. A 52 (2016) 17; Luiz L. Lopes and D.P. Menzes, arXiv
1909.05400.
[5] Debarati Chatterjee, Francesca Gulminelli and Débora P. Menezes, Journal of Cosmology and
Astroparticle Physics 03 (2019) 035.
[6] Cesar V. Flores, Luiz L. Lopes, Luis B. Castro and D.P. Menezes, arXiv:1905.11170.
Auteur principal: Prof. P. MENEZES, Débora (UFSC)
Orateur: Prof. P. MENEZES, Débora (UFSC)
Session Classification: Seminars
September 1, 2020 Page 1XV Hadron Physi … / Rapport sur les contributions Strong Interactions and Fundamen … Contribution ID: 6 Type: Seminar Strong Interactions and Fundamental Symmetries Effective field theories allow us to track the violation of symmetries across energy scales. I will dis- cuss the manifestation in nuclei of the lowest-dimension interactions beyond the Standard Model which violate lepton number, baryon number, and time reversal. Specific processes/quantities in- volved include neutrinoless double-beta decay, the deuteron lifetime, and electric dipole moments of the neutron and light nuclei. Auteur principal: Dr VAN KOLCK, U. (IPN Orsay) Orateur: Dr VAN KOLCK, U. (IPN Orsay) Session Classification: Seminars September 1, 2020 Page 2
XV Hadron Physi … / Rapport sur les contributions Low energy constituent quark cou …
Contribution ID: 7 Type: Seminar
Low energy constituent quark couplings from a
dynamical approach
Recent work on the derivation of light quark-antiquark mesons couplings to baryon’s constituent
quarks will be presented by starting from a quark-quark interaction mediated by one non-nonperturbative
gluon exchange. Some well known methods are considered and they provide complete well known
effective models with their parameters such as coupling constants, and also form factors and av-
eraged quadratic radii. These quantities are written in terms of components of quark and non per-
turbative gluon propagators, of the quark-gluon (running) coupling constant and u and d quark
masses. Among the resuling couplings there is a whole constituent quark Large Nc EFT proposed
by Weinberg with its electromagnetic couplings. Light vector and axial mesons couplings to con-
stituent quarks and to the photon are also obtained in such dynamical way. Some effects of a
relatively weak magnetic field on all these couplings may be shortly addressed. The constituent
quark-level Goldberger Treiman and the GellMann Oakes Renner relations are obtained among
other new relations.
Auteur principal: Dr BRAGHIN, Fabio L. (IF-UFG)
Orateur: Dr BRAGHIN, Fabio L. (IF-UFG)
Session Classification: Seminars
September 1, 2020 Page 3XV Hadron Physi … / Rapport sur les contributions NN short-ranged correlations: Fro …
Contribution ID: 9 Type: Lecture
NN short-ranged correlations: From Theory to
Experiment in 65 Years
The physics of short-ranged correlations is reviewed from a pedagogical standpoint that is aimed
to provide background sufficient for students to do research in the field. The lectures discuss:
1) how the earliest efforts allowed physicists to understand the qualitative features of nuclear
binding and saturation.
2) the technical improvements, including relativistic effects
3) short-range correlations in the context of effective field theory
4) recent experimental findings related to short range correlations
5) future prospects
Auteur principal: Prof. MILLER, Gerald (University of Washington)
Orateur: Prof. MILLER, Gerald (University of Washington)
Session Classification: Lectures
September 1, 2020 Page 4XV Hadron Physi … / Rapport sur les contributions Pion off-shell electromagnetic for …
Contribution ID: 10 Type: Seminar
Pion off-shell electromagnetic form factors from
data analysis
The light mesons, like pion, play special rules in try to understanting QCD, between another moti-
vation, the pion is the Goldstone boson, and, is central to symmetry breaking and partial current
conservation
(PCAC). The most general way to take informations about the hadronic substructure, i.e.; in terms
of the degrees of freedom from QCD, quarks and gluons, are the study of the electromagnetic form
factors. The electromagnetic form factors play also, fundamental importance in order to studing
processes involving hadrons and virtual photons. Because the pion have spin zero, and, with the
time-reverse invariance, we need only one electromagnetic form factor to describe the pion. Still,
general approaches about electromagnetic form factors for pseudoscalar particles, not take in ac-
count off-shell effects.
But in order to be more consistent, and go beyond on-shell,
the off-shell effects is need be included at the electromagnetic interactions [1].
The possible off-shell effects, also appear in meson pion
exchange current [2], because in that case, the exchanged pion is
not on-mass shell. The most general electromagnetic description for the pion, need two electro-
magnetic form factors, F1 (q 2 , t), and, F2 (q 2 , t),
wich are related the Ward-Takahashi identity [3].
Ward-Takahashi identity was explore some years ago for the boson case in the
reference [4] with the light-front approach.
The electromagnetic off-shell form factors was been calculated for the boson
bound state, and, in that work, is realized, the zero modes inclusion
is crucial to preserve the Ward-Takahashi indentities with the
Light-front Field Theory. However, microscopic model
is not already made to incorpore off-shel effects at the vertex,
and extract the off-shell form factors.
In the present work, we explore the electromagnetic off-shell effects for the
pion meson and extract the off-shell electromagnetic form factors,
F1 (q 2 , t) and F2 (q 2 , t), from experimental electroproduction cross section data [5,6].
However, the extraction of the electromagnetic form factor
with the reaction 1 H(e, e′ , π + )n, need some model for the GπN N (t) form factor,
here, we explore some possibilities for this form factor.
The differents models are explored, in order to see the power predictions for that models, with
respect the pion observables, like, electromagnetic form factors, electromagnetic radius and, also,
the pion electroweak decay constant.
References
1. H. M. Choi, T. Frederico, C. R.~Ji and J. P. B. C. de Melo.
Pion off-shell electromagnetic form factors: data extraction and model. arXiv:1908.01185
[hep-ph].
2. F.Gross and D. O. Riska, Phys. Rev. C36, 1928 (1987).
3. Lewis H. Ryder, Quantum Field Theory, Cambridge University Press.
4. H. W. L. Naus, J. P. B. C. de Melo and T.Frederico, Few Body Syst. 24, 99 (1998).
5. H. P. Blok et al., [Jefferson Lab Collaboration], Phys. Rev. C78, 045202 (2008).
6. G. M. Huber et al., [Jefferson Lab Collaboration],
Phys. Rev. C78, 045203 (2008).
September 1, 2020 Page 5XV Hadron Physi … / Rapport sur les contributions Pion off-shell electromagnetic for … Auteurs principaux: DE MELO, João Pacheco (Laboratório de Física Teórica e Computacional - UCS - UNICID); Dr CHOI, Ho-Meoyng (Kyungpook Natl. U., Daegu); JI, Chueng (North Carolina State University); Prof. FREDERICO, Tobias Orateur: DE MELO, João Pacheco (Laboratório de Física Teórica e Computacional - UCS - UNI- CID) Session Classification: Seminars September 1, 2020 Page 6
XV Hadron Physi … / Rapport sur les contributions Heavy ion and fixed target physics …
Contribution ID: 11 Type: Seminar
Heavy ion and fixed target physics at the LHCb
experiment
The LHCb experiment explores the heavy ion and fixed target physics using some of its specific
features. Particle production of particles, notably heavy flavour states, can be studied at LHC
energies in the forward rapidity region, providing complementary measurements to the other LHC
experiments. An overview of these results obtained on the LHCb heavy ion program will be given.
Auteurs principaux: RANGEL, Murilo (LAL); COLLABORATION , LHCb
Orateur: RANGEL, Murilo (LAL)
Session Classification: Seminars
September 1, 2020 Page 7XV Hadron Physi … / Rapport sur les contributions Mixing and quark mass dependenc …
Contribution ID: 12 Type: Seminar
Mixing and quark mass dependence of axial vector
mesons in the Coulomb gauge QCD model
We discuss properties of axial-vector mesons within an effective version of Quantum Chromody-
namics in the Coulomb gauge. While recent studies have put emphasis in configuration mixing
with open meson-meson channels, we here concentrate on the simpler closed-channel problem
and follow the 1+ mixing through a wide range of quark masses. We also examine their radial
excitations
and discuss with them the concept of insensitivity to chiral symmetry breaking.
Auteur principal: ABREU, Luciano (Federal University of Bahia (Brazil))
Orateur: ABREU, Luciano (Federal University of Bahia (Brazil))
Session Classification: Seminars
September 1, 2020 Page 8XV Hadron Physi … / Rapport sur les contributions Multiquark state: from meson and …
Contribution ID: 14 Type: Seminar
Multiquark state: from meson and baryons to exotic
tetraquarks and pentaquarks.
I will review quark models for baryons and mesons and the experimental results as starting tools
to understand hadron spectroscopy and structure. Then I will focus on the evolving theoretical
methods and on the experiments planned at future hadron and lepton colliders, to explore this very
lively field of research initiated fifteen years ago with the discovery of Ds0(2317) and X(3872) and
in particular to review recent theoretical work on Exotic Hadrons (tetraquarks and pentaquarks)
and original contributions from several groups. Finally, particular attention will be devoted to the
emerging field of hadrons with heavy quarks (non-exotic and exotic).
Auteur principal: SANTOPINTO, Elena (INFN)
Orateur: SANTOPINTO, Elena (INFN)
Session Classification: Seminars
September 1, 2020 Page 9XV Hadron Physi … / Rapport sur les contributions The interaction of bottomonium ϒ …
Contribution ID: 15 Type: Poster
The interaction of bottomonium ϒ with a hadronic
medium
Abstract: Heavy mesons play an important role to understand the properties of strongly interact-
ing matter. Quarkonia that survived after the quark-gluon plasma phase are expected to collide
with other particles that constitute hadronic matter. In this work, we present a study on the inter-
actions of the Υ meson with a hadronic medium. The meson-meson interactions are described by
an effective Lagrangian that is based on SU(4) symmetry, within the framework of unitarized cou-
pled channels projected onto s-waves. The symmetry is explicitly broken to SU(3) by suppression
of the interactions driven by bottomed mesons. We calculate the cross sections for Υ scattering
by light pseudoscalar and vector mesons, as well as their inverse processes. The most relevant
channels are evaluated and a comparison of the findings with existing literature is performed.
Auteur principal: M. VIEIRA, Hildeson (Universidade Federal da Bahia)
Co-auteur: ABREU, Luciano (Federal University of Bahia (Brazil))
Orateur: M. VIEIRA, Hildeson (Universidade Federal da Bahia)
Session Classification: Posters
September 1, 2020 Page 10XV Hadron Physi … / Rapport sur les contributions Diffusion of conserved charges in …
Contribution ID: 16 Type: Seminar
Diffusion of conserved charges in relativistic heavy
ion collisions
The bulk nuclear matter produced in heavy ion collisions carries a multitude of conserved quan-
tum numbers: electric charge, baryon number and strangeness. Therefore, the diffusion processes
associated to these conserved charges cannot occur independently and must be described in terms
of a set of coupled diffusion equations. This physics is implemented by replacing the traditional
diffusion coefficients for each conserved charge by a diffusion coefficient matrix, which quantifies
the coupling between the conserved quantum numbers. The diagonal coefficients of this matrix
are the usual charge diffusion coefficients, while the off-diagonal entries describe the diffusive
coupling of the charge currents. In this seminar, we provide the first calculation of this diffusion
coefficient matrix for a hadron resonance gas and a gas of partons. In order to provide some in-
sight on the influence that the coupling between the net charge diffusion currents can have on
heavy ion observables, we present first results for the diffusive evolution of a hadronic system in
a simple (1+1)D-fluid dynamics approach.
Auteur principal: SILVEIRA DENICOL, Gabriel (Universidade Federal Fluminense)
Orateur: SILVEIRA DENICOL, Gabriel (Universidade Federal Fluminense)
Session Classification: Seminars
September 1, 2020 Page 11XV Hadron Physi … / Rapport sur les contributions Self-consistent Modelling of Nucle …
Contribution ID: 17 Type: Poster
Self-consistent Modelling of Nuclear Processes in
Solar Flares using FLUKA
We use the Monte Carlo particle physics code FLUKA to calculate gamma-ray spectra expected
from solar flare energetic ion distributions. The FLUKA code includes robust physics-based models
for electromagnetic, hadronic and nuclear interactions, sufficiently detailed for it to be a useful
tool for calculating nuclear de-excitation, positron annihilation and neutron capture line fluxes
and shapes, as well as ~GeV continuum radiation from pion decay products. We show nuclear
de-excitation gamma-ray line model spectra from a range of assumed primary accelerated ion
distributions and find them to be in good agreement with those found using the code built by
Ramaty and collaborators, currently one of the main tools for the analysis of solar flare gamma-
ray data. We also show full gamma-ray model spectra which exhibit all the typical structures of
gamma-ray spectra observed in solar flares. From these model spectra we build templates which
are incorporated into the software package Objective Spectral Executive (OSPEX) and used to fit
the combined Fermi Gamma-ray Burst Monitor (GBM)/Large Area Telescope (LAT) spectrum of
the 2010 June 12 solar flare, providing a statistically acceptable result. To the best of our knowledge,
the fit carried out with the FLUKA templates for the full gamma-ray spectrum can be regarded as
the first attempt to use a single code to implement a self-consistent treatment of the several spectral
components in the energy range from ~ 100s keV to ~100s MeV.
Auteur principal: Dr SZPIGEL, Sergio (Centro de Rádio-Astronomia e Astrofísica Mackenzie
(CRAAM), Escola de Engenharia, Universidade Presbiteriana Mackenzie)
Co-auteurs: Dr MACKINNON, Alexander (School of Physics and Astronomy, University of Glas-
gow, Glasgow); GIMÉNEZ DE CASTRO, Carlos Guillermo (Centro de Rádio-Astronomia e Astrofísica
Mackenzie (CRAAM), Escola de Engenharia, Universidade Presbiteriana Mackenzie); Dr SIMÕES, Paulo
José Aguiar (Centro de Rádio-Astronomia e Astrofísica Mackenzie (CRAAM), Escola de Engenharia, Uni-
versidade Presbiteriana Mackenzie); Dr TUSNSKI, Daneele Saraçol
Orateur: Dr SZPIGEL, Sergio (Centro de Rádio-Astronomia e Astrofísica Mackenzie (CRAAM), Escola
de Engenharia, Universidade Presbiteriana Mackenzie)
Session Classification: Seminars
September 1, 2020 Page 12XV Hadron Physi … / Rapport sur les contributions Hyperon electromagnetic form fac …
Contribution ID: 18 Type: Seminar
Hyperon electromagnetic form factors at large q 2
We present calculation of the hyperon elastic form factors
for the baryon octet for large four-momentum transfer squared,
q 2 , in the timelike region (q 2 > 0).
Our calculations are based on a covariant quark model
developed in the spacelike region (q 2 < 0)
and on asymptotic relations between the
spacelike and the timelike regions.
Those asymptotic relations are derived based on
analyticity and unitarity.
Our estimates compare well with the integrated
cross section data measured at BaBar, BES III and CLEO.
Auteurs principaux: Dr RAMALHO, Gilberto (Universidade Cruzeiro do Sul); Prof. PEÑA, Maria
Teresa (Universidade de Lisboa); Prof. TSUSHIMA, Kazuo (Universidade Cruzeiro do Sul)
Orateur: Dr RAMALHO, Gilberto (Universidade Cruzeiro do Sul)
Session Classification: Seminars
September 1, 2020 Page 13XV Hadron Physi … / Rapport sur les contributions Low-Q2 parametrizations of the …
Contribution ID: 19 Type: Poster
Low-Q2 parametrizations of the γ ∗N → N ∗ transition
amplitudes
The electromagnetic structure of the nucleon resonances N ∗ are
usually parametrized by γ ∗ N → N ∗ helicity amplitudes,
at the resonance rest frame.
Those amplitudes are, however, constrained by kinematic conditions
in the limit where the photon three-momentum vanishes
(pseudothreshold limit).
Although the pseudothreshold limit is below the photon point (Q2 = 0)
it has an impact on the structure of the helicity amplitudes
at low-Q2 .
Most of the empirical parametrizations of the data ignore those constraints.
In our work we study the effect of the pseudothreshold constraints
on some analytic parametrizations of the data,
be performing analytic continuations of
these parametrizations to the Q2 < 0 region.
We conclude that the pseudothreshold constraints are
fundamental for some resonances.
Auteur principal: Dr RAMALHO, Gilberto (Universidade Cruzeiro do Sul)
Orateur: Dr RAMALHO, Gilberto (Universidade Cruzeiro do Sul)
Session Classification: Posters
September 1, 2020 Page 14XV Hadron Physi … / Rapport sur les contributions Effective approaches to hadronic s …
Contribution ID: 20 Type: Seminar
Effective approaches to hadronic systems
We review some results in quark matter and few nucleon systems using effective models for QCD
and the nuclear force.
Auteur principal: SALVADOR TIMÓTEO, Varese (Universidade Estadual de Campinas)
Orateur: SALVADOR TIMÓTEO, Varese (Universidade Estadual de Campinas)
Session Classification: Seminars
September 1, 2020 Page 15XV Hadron Physi … / Rapport sur les contributions Mass spectra and Regge trajectorie …
Contribution ID: 21 Type: Poster
Mass spectra and Regge trajectories of meson states
in a effective QCD model
This work is devoted to the discussion of the ground state and the orbitally and radially excited
states of quark-antiquark mesons within the Tamm-Dancoff approximation of the Coulomb-gauge
QCD model. The Regge trajectories for angular and radial excitations are constructed, and their
properties are analyzed. The calculated meson masses and their quantum numbers are used as
basis to attribute experimentally observed states to Regge trajectories.
Auteurs principaux: COSTA, FRANCISCO MIGUEL (FRANCISCO MIGUEL); ABREU, Luciano
(Federal University of Bahia (Brazil)); Mme FAVERO, Aline G.
Orateur: COSTA, FRANCISCO MIGUEL (FRANCISCO MIGUEL)
Session Classification: Posters
September 1, 2020 Page 16XV Hadron Physi … / Rapport sur les contributions Neutrino oscillation with decay
Contribution ID: 22 Type: Poster
Neutrino oscillation with decay
For many years, the Standard Model has described neutrinos as massless particles. In 2015, Takaaki
Kajita and Arthur B. McDonald received the Nobel Prize for the discovery of neutrino oscillations,
which shows that they have mass. In this paper, we discuss the theory of this phenomenon, making
a brief historical introduction to the neutrino’s existence proposal and the solar neutrino problem,
for which the oscillation model was proposed as a solution, and describing the standard oscillation
in vacuum, in two and three flavors, and oscillation with invisible decay, also in two and three
flavors. The calculation of the first shows immediately that neutrinos must indeed have mass for
oscillation to occur. We also obtain the transition probability from muonic to electronic neutrinos
in matter, investigated by the NOνA experiment. We see that the effect of matter in this transition
is obtained by changing the mixing angle θ13 and the squared-mass difference ∆m231 to their
effective values in matter. We simulate the survival and transition probabilities, which lead to
important discussions, such as the validity of the two-flavor model, order of magnitude of the
decay parameter and modification of the transition νµ → νe in matter.
Auteur principal: M. MOREIRA, Thiago Henrique (Universidade Federal de Goiás)
Orateur: M. MOREIRA, Thiago Henrique (Universidade Federal de Goiás)
Session Classification: Posters
September 1, 2020 Page 17XV Hadron Physi … / Rapport sur les contributions Thermodynamically consistent qu …
Contribution ID: 23 Type: Poster
Thermodynamically consistent quark matter model
with density dependent mass
Abstract
Nearly half a century ago the existence of an absolute stable strange quark matter was conjectured
[1] and it was based on a simple model known as the MIT bag model [2]. More recently, different
versions of density dependent quark models were proposed, but they lack thermodynamic consis-
tency [3]. The main goal of the present work is to use a more sophisticated model called quasi
particle model [4], based on a density dependent mass that takes into account the confinement
and leading-order perturbative interactions, and that is also thermodynamically consistent. Our
results will be compared with the ones obtained from the MIT bag model. For this purpose, the
equations of state of both models were derived and they will be soon implemented numerically.
References
[1] E. Witten, Phys. Rev. D 30,272 (1984).
[2] CHODOS, Ao et al. New extended model of hadrons. Physical Review D, v. 9, n. 12, p. 3471,
1974.
[3] AGUDELO, David Felipe Tamayo. Matéria de Quarks à Temperatura Finita. 2013. Dissertação
(Mestrado em Física) - Universidade Federal de Santa Catarina, Florianópolis, 2013.
[4] C. J. Xia, G. X. Peng, S. W. Chen, Z. Y. Lu, and J. F. Xu, Phys. Rev. D 89,105027 (2014).
Auteur principal: MARZOLA, Isabella
Co-auteurs: Mme BACKES, Betânia (Federal university of Santa Catarina); PERES MENEZES, Deb-
ora (Federal University of Santa Catarina (UFSC))
Orateur: MARZOLA, Isabella
Session Classification: Posters
September 1, 2020 Page 18XV Hadron Physi … / Rapport sur les contributions Effective models and phase transit …
Contribution ID: 25 Type: Poster
Effective models and phase transitions in QCD
In the present work the phase diagram of QCD is obtained by means of two effective models. For
the description of the quarks matter we make use of the MIT bag model, and for the description
of the hadronic matter we make use of the non-linear Walecka model (NLWM).
The Gibbs conditions are used to establish the crossing points of the pressures in function of the
chemical potentials obtained in both phases.
Some restrictions are imposed when choosing models. The MIT model is used only with constant
values satisfying the Bodmer-Witten conjuncture. The NLWM, in turn, is restricted to parameter-
izations that satisfy several nuclear and astrophysical properties.
Two situations are considered for the description of the hadronic matter; in the first one the condi-
tions of matter of compact stars are imposed and the model is extrapolated to finite temperatures,
and in the second situation we consider symmetrical matter.
Auteurs principaux: Mlle BIESDOF, Carline (Universidade Federal de Santa Catarina (UFSC)); Prof.
PERES MENEZES, Debora (Universidade Federal de Santa Catarina (UFSC))
Orateur: Mlle BIESDOF, Carline (Universidade Federal de Santa Catarina (UFSC))
Session Classification: Posters
September 1, 2020 Page 19XV Hadron Physi … / Rapport sur les contributions Quark-antiquark potentials in non …
Contribution ID: 26 Type: Poster
Quark-antiquark potentials in nonperturbative
models
Many models have tried to explain some non-perturbative aspects of the strong interactions, in
particular, the color confinement hypothesis of quantum chromodynamics (QCD), but actually,
they do not fully explain it. In this work, we investigate some of these non-perturbative models
for QCD with the purpose of testing its validity in the perturbative region of nuclear interactions
where the perturbative predictions with quasi-free quarks are in agreement with the experimental
data, as well as to explore its behavior in the infrared region. In particular, we focused on the calcu-
lations and analysis of the potentials between heavy quarks and antiquarks, since this observable
might reveal the appearance of confinement properties in non-perturbative models through a lin-
ear growth at large and intermediate distances. We calculated the potentials associated with the
Massive Gluon (Yukawa), Gribov-Zwanziger and Gribov-Zwanziger Refined models at tree level
for the non-relativistic case. In addition, we have included the flux of the Renormalization Group
in the QCD coupling constant, which allowed us to study the energy-scale dependence of the pa-
rameters of the potentials treated here. Our results indicate that, in the tree-level approximation,
all potentials we have obtained can reproduce the perturbative result at high energies and some
of them bring significant non-perturbative corrections. We also present one-loop corrections and
discuss the two-loop modifications in the case of the Curci-Ferrari model.
Auteur principal: MENA , Carlos (UERJ)
Co-auteur: Prof. PALHARES, Letícia (UERJ)
Orateur: MENA , Carlos (UERJ)
Session Classification: Posters
September 1, 2020 Page 20XV Hadron Physi … / Rapport sur les contributions Thermodynamically consistent qu …
Contribution ID: 27 Type: Poster
Thermodynamically consistent quark matter model
with density dependent mass
Abstract
Nearly half a century ago, the existence of an absolute stable strange quark matter (SQM) was con-
jectured [1] and it was based on a simple model known as the MIT bag model [2]. More recently,
different versions of density dependent quark models were proposed, but they lack thermody-
namic consistency [3]. The main goal of the present work is to use a more sophisticated model
[4], based on a density dependent mass that takes into account the confinement and leading-order
perturbative interactions, and that is also thermodynamically consistent. The equations of state
were derived and implemented numerically. Our results show explicitly the thermodynamic con-
sistency of the model, along with it’s stability window at zero temperature.
References
[1] E. Witten, Phys. Rev. D 30, 272 (1984).
[2] A. Chodos, R. L.Jaffe, K. Johnson, C. B. Thorn and V. F. Weisskopf, Phys. Rev. D 9,3471 (1974).
[3] AGUDELO, David Felipe Tamayo. Matéria de Quarkas à Temperatura Finita. 2013. Dissertação
(Mestrado em Física) - Universidade Federal de Santa Catarina, Florianópolis, 2013.
[4] C. J. Xia, G. X. Peng, S. W. Chen, Z. Y. Lu, and J. F. Xu, Phys. Rev. D 89,105027 (2014).
Auteur principal: BACKES, Betânia
Co-auteurs: HAFEMANN, Eduardo (UFSC); MARZOLA, Isabella; PERES MENEZES, Debora (Fed-
eral University of Santa Catarina (UFSC))
Orateur: BACKES, Betânia
Session Classification: Posters
September 1, 2020 Page 21XV Hadron Physi … / Rapport sur les contributions An analysis on the exclusive produ …
Contribution ID: 28 Type: Poster
An analysis on the exclusive production of light
mesons at the LHC
The central diffractive production of mesons f0 (980) and f2(1270) at the energy of CERN-Large
Hadron Collider experiment on proton-proton collisions is investigated. The processes initiated
by quasireal photon-photon collisions and by central diffraction processes are considered. The
role played by the photon-Odderon production channel is also studied. The cross sections for
these distinct production channels are compared and analyzed.
Auteur principal: MACHADO, Magno (IF-UFRGS)
Orateur: MACHADO, Magno (IF-UFRGS)
Session Classification: Posters
September 1, 2020 Page 22XV Hadron Physi … / Rapport sur les contributions Measuring the speed of sound of t …
Contribution ID: 29 Type: Poster
Measuring the speed of sound of the quark-gluon
plasma in ultracentral nucleus-nucleus collisions
We show that, within the hydrodynamic framework of heavy-ion collisions, the mean transverse
momentum of charged hadrons (⟨pt ⟩) rises as a function of the multiplicity in ultra-central nucleus-
nucleus collisions. The relative increase is proportional to the speed of sound squared (c2s ) of the
quark-gluon plasma, that is therefore accessible experimentally using ultra-central data. Based on
the value of c2s calculated in lattice QCD, we predict that ⟨pt ⟩ increases by ≈ 18 MeV between 1%
√
and 0.001% centrality in Pb+Pb collisions at sN N = 5.02 TeV.
Auteurs principaux: GARDIM, Fernando G (Federal University of Alfenas - BRA); Dr OLLI-
TRAULT, Jean-Yves (Saclay); Mlle GIACALONE, Giuliano (SACLAY)
Orateur: GARDIM, Fernando G (Federal University of Alfenas - BRA)
Session Classification: Posters
September 1, 2020 Page 23XV Hadron Physi … / Rapport sur les contributions Anisotropic Compact Stars in …
Contribution ID: 30 Type: Poster
Anisotropic Compact Stars in Rastall-Rainbow
Gravity
We have investigated anisotropic neutron stars in the framework of Rastall-Rainbow gravity. Our
calculations were computed using the IU-FSU realistic equation of state (EoS), in which was con-
sidered two cases: standard nucleonic composition and the one with the eight lightest baryons.
From the neutron star masses and radii obtained we conclude that when Rastall-Rainbow gravity
and anisotropy are simultaneously considered, they provide the best results for mass and radius
values, including important astrophysical objects such as the LMXB NGC 6397 and the extremely
massive pulsar millisecond MSP J0740 + 6620. Although the expected inclusion of hyperons in
the nuclear model reproduces stellar masses smaller than those produced by standard nucleonic
matter, we shown that the hyperon puzzle problem can be circumvented by including anisotropic
effects on compact stars in the context of the Rastall-Rainbow gravity.
Auteurs principaux: M. EVANGELISTA MOTA, Clésio (Universidade Federal de Santa Catarina
- UFSC); CÉSAR NUNES DOS SANTOS, Luis (UFPB); MANOEL DA SILVA, Franciele (UFSC); OS-
WALDO VASQUEZ FLORES, Cesar (UFSC); JOSÉ NUNES DA SILVA, Tiago (UFSC); PERES MENEZES,
Débora (UFSC)
Orateur: M. EVANGELISTA MOTA, Clésio (Universidade Federal de Santa Catarina - UFSC)
Session Classification: Posters
September 1, 2020 Page 24XV Hadron Physi … / Rapport sur les contributions Statistical fluctuations in the pasta …
Contribution ID: 31 Type: Poster
Statistical fluctuations in the pasta phase
Exotic shapes of nuclei exist which are known as pasta phase. These are possible to occur at high
densities, such as the crust of neutron stars, and are due to the competition between the strong
and electromagnetic forces, resulting in a frustrated system. Calculations of such shapes usually
assume a crystalline structure described by repetitions of the same Wigner-Seitz cells for fixed
temperature, density and proton fraction. Such approximation is unrealistic since the difference
in free energy for each pasta configuration is very small, allowing for different configurations to
exist in equilibrium.
In this work we utilize mean field theory with the Non-linear Walecka Model to calculate the
probability distribution for the pasta configurations using the free energy of a single Wigner-Seitz
cell and the approximation of phase-coexistence.
Auteur principal: M. PELICER, Mateus (Universidade Federal de Santa Catarina)
Orateur: M. PELICER, Mateus (Universidade Federal de Santa Catarina)
Session Classification: Posters
September 1, 2020 Page 25XV Hadron Physi … / Rapport sur les contributions Neutron stars: The journey from b …
Contribution ID: 32 Type: Lecture
Neutron stars: The journey from birth to death.
Neutron star observations, including those from Chandra, LIGO and anticipated results from the
NICER mission, continue to provide unique insight into the role that neutron stars play in stellar
evolution and the nature of the dense matter in the neutron star core. After being created in a core-
collapse supernova explosion, the neutron star’s first minute (as a “proto-neutron star) is critical.
It is during this brief time that the neutron star’s final mass, composition, and fate are decided.
Depending upon its distance from earth, the supernovae explosion can, in favourable cases, be
observed in photons, neutrinos, and gravitational waves: the manifest promise of multi-messenger
astronomy.
One of the critical uncertainties in neutron star structure and discussion of the maximum pos-
sible neutron star mass is the composition of matter in the core. However, most simulations of
core-collapse supernovae and neutron star mergers do not take into account this compositional
uncertainty. Many assume that the core is composed only of neutrons, protons and electrons.
This omission is particularly problematic for the evolution of the proto-neutron star, when exotic
degrees of freedom, such as de-confined quarks, are most likely to appear.
In this talk I will discuss properties of high density matter in the cores of cold and hot (proto)neutron
stars as predicted by the Quark-Meson-Coupling (QMC) Model [1]. This model, which self-consistently
relates the dynamics of the internal quark structure of a hadron to the relativistic mean fields aris-
ing in nuclear matter, provides a natural answer to many open questions in low energy nuclear
physics. These include the origin of many-body nuclear forces and their saturation, the spin–orbit
interaction and properties of hadronic matter at a wide range of densities up to those occurring
in the cores of neutron stars. The QMC energy density functional depends on a single set of
four adjustable parameters which are narrowly constrained. The same QMC formalism, without
introducing additional parameters, can be applied to any particles composed of quarks, such as
hyperons. The forces between hyperons and between hyperons and nucleons are calculated in
mean field approximation within the model without the need for an external calibration.
I will report results on the Equation of State, masses, radii, baryon and lepton content and its
distribution inside the star. In addition, rotation, tidal deformation and the I-Love-Q relation at
finite temperature will be discussed. A comparison with other selected models will be made.
Auteur principal: Prof. STONE, Jirina (Department of Physics and Astronomy, University of Ten-
nessee, Knoxville, US)
Orateur: Prof. STONE, Jirina (Department of Physics and Astronomy, University of Tennessee,
Knoxville, US)
Session Classification: Lectures
September 1, 2020 Page 26XV Hadron Physi … / Rapport sur les contributions Non-Perturbative Information fro …
Contribution ID: 33 Type: Lecture
Non-Perturbative Information from QCD Green
Functions
We review the computation of the two-point (propagators) and the quark-gluon vertex using non-
perturbative first principle methods. Topics concerned with quark and gluon confinement together
with chiral symmetry breaking and there relation with the propagators and vertex are also ad-
dressed.
Auteur principal: OLIVEIRA, Orlando (University of Coimbra)
Orateur: OLIVEIRA, Orlando (University of Coimbra)
Session Classification: Lectures
September 1, 2020 Page 27XV Hadron Physi … / Rapport sur les contributions Parton distribution functions from …
Contribution ID: 34 Type: Seminar
Parton distribution functions from lattice QCD
Parton Distribution Functions (PDFs) are the fundamental objects containing information on the
flavour structure of hadrons, and on how the hadron spin and momentum are distributed among
its constituents, quarks and gluons. Because they are non-perturbation quantities, we must rely
on non-perturbative methods for their computation. Lattice QCD (LQCD) is the most successful
method to access the non-perturbative physics. Even so, in the case of PDFs LQCD is, essentially,
not useful because PDFs are given by light-cone correlations, while LQCD is applicable to real-time
correlations. However, several years ago Ji proposed a new method to compute PDFs in LQCD
based on Large Momentum Effective Theory. Within this method, one computes purely spatial
correlations, accessible to LQCD, which can be related, upon a suitable perturbative calculation,
to the light-cone correlations. The Fourier transform of the purely spatial matrix elements are
called quasi-PDFs. In this talk, we will give an overview of the quasi-PDF approach, showing
how to obtain light-cone PDFs from quasi-PDFs. We will present the state-of-art of the lattice
computations of PDFs as well as discussing future directions to this field.
Auteur principal: STEFFENS, Fernanda (University of Bonn)
Orateur: STEFFENS, Fernanda (University of Bonn)
Session Classification: Seminars
September 1, 2020 Page 28XV Hadron Physi … / Rapport sur les contributions Few-body physics in Minkowski s …
Contribution ID: 35 Type: Seminar
Few-body physics in Minkowski space
In recent years, it is becoming more and more attractive the possibility of exploring the dynamics
inside few-body systems directly in Minkowski space. A fully quantum-field treatment of the
dynamics together with the adoption of the physical space open a new path for investigating the
relativistic effects on the momentum distribution as well as the approach to critical regimes.
Auteur principal: SALME’, Giovanni (Istituto Nazionale di Fisica Nucleare)
Orateur: SALME’, Giovanni (Istituto Nazionale di Fisica Nucleare)
Session Classification: Seminars
September 1, 2020 Page 29XV Hadron Physi … / Rapport sur les contributions Photon induced processes from …
Contribution ID: 36 Type: Seminar
Photon induced processes from semi-central to
ultraperipheral heavy-ion collisions
Ultrarelativistic heavy ions are accompanied by a large flux of quasi-real Weizsäcker-Williams
photons. This opens a broad range of research possibilities, as the Weizsäcker-Williams photons
can be used to study photon-photon fusion reactions as well as photonuclear reactions in a wide
range of energies, see for example the review [1].
Of special interest here are diffractive photoproduction reactions, which appear in two major
classes: the coherent diffraction in which the target nucleus stays intact and the incoherent (or
quasielastic) diffraction in which the nucleus breaks up, but no additional particles are produced
in the nuclear
fragmentation region.
We will discuss the coherent and incoherent diffractive photoproduction of heavy vector mesons
J/ψ and Υ based on our recent papers [2, 3]. Good agreement with available experimental data by
the ALICE and LHCb collaborations can be obtained within a color-dipole approach. Diffractive
photoproduction of heavy-flavour vector mesons has long been discussed as a probe of the target’s
gluon distribution, and we will discuss implications for the nuclear glue.
Very recently, the role of Weizsäcker-Williams photons in peripheral, inelastic, heavy ion collisions
has come under scrutiny. Recent measurements of dilepton production of the STAR collaboration
in √sNN =200 GeV Au-Au collisions indicate an excess at small pair pT most notably in peripheral
collisions. We show, that it can be that has attributed to the initial photon fusion which is most
significant at small pair transverse momenta [4].
[1] C. A. Bertulani, S. R. Klein and J. Nystrand, “Physics of ultra-peripheral nuclear collisions,” Ann.
Rev. Nucl. Part. Sci. 55 (2005) 271 [nucl-ex/0502005].
[2] A. Luszczak and W. Schäfer, “Incoherent diffractive photoproduction of J/ψ and Υ on heavy
nuclei in the color dipole approach,” Phys. Rev. C 97 (2018) no.2, 024903 [arXiv:1712.04502 [hep-
ph]].
[3] A. Luszczak and W. Schäfer, “Coherent photoproduction of J/ψ in nucleus-nucleus collisions in
the color dipole approach,” Phys. Rev. C 99 (2019) no.4, 044905 [arXiv:1901.07989 [hep-ph]].
[4] M. Klusek-Gawenda, R. Rapp, W. Schäfer and A. Szczurek, “Dilepton Radiation in Heavy-Ion
Collisions at Small Transverse Momentum,” Phys. Lett. B 790 (2019) 339 [arXiv:1809.07049 [nucl-
th]].
Auteur principal: SCHAEFER, Wolfgang (Institute of Nuclear Physics PAN, Krakow)
Orateur: SCHAEFER, Wolfgang (Institute of Nuclear Physics PAN, Krakow)
Session Classification: Seminars
September 1, 2020 Page 30XV Hadron Physi … / Rapport sur les contributions FSI in 3-body decay: challenges an …
Contribution ID: 38 Type: Seminar
FSI in 3-body decay: challenges and future
Three-body decays of heavy-flavoured hadrons into light particles are sequential processes, dom-
inated by intermediate resonant states that requires a full amplitude analysis to be determined.
These decays are a natural source of information about two-body scattering amplitudes, as an al-
ternative to the early scattering data. However, the determination of the two-body amplitudes
requires the understanding of the role of final-state interactions (FSI) and strong phases from the
primary weak vertex. This is also a crucial step to understand the massive localized CP violation
observed in B + → h− 1 h2 h3 (hi ≡ π, K) decays from LHCb.
+ +
The gigantic samples of B and D decays collected by the LHCb, BES-III and, in the near future,
Belle II experiments motivated theoretical efforts in the past decade towards building models that
are based on more solid grounds. These models improve essentially the description of FSI by us-
ing coupled-channels formalism and imposing two-body unitarity, in the framework of dispersion
relations and chiral perturbation theory. Most models are based on the quasi-two-body (2+1) ap-
proximation, in which interactions with the third particle are neglected. Three-body FSI, however,
may play significant role, especially in D decays as for the D+ → K − π + + π + decay.
In this talk an overview of these models will be presented. In particular, two important results will
be discussed, namely D+ → K − K + K + and B + → K − K + K + . In the first case, the focus is on
the determination of the K − K + scattering amplitudes, whilst in the second decay, the focus is on
the underlying mechanisms of the CP asymmetries pattern observed in the Dalitz plot.
Auteur principal: MAGALHAES, Patricia (University of Bristol)
Orateur: MAGALHAES, Patricia (University of Bristol)
Session Classification: Seminars
September 1, 2020 Page 31XV Hadron Physi … / Rapport sur les contributions Relativistic Landau levels via …
Contribution ID: 39 Type: Poster
Relativistic Landau levels via Feynman-Gell-Mann
formulation
The planar motion of spin-1/2 fermions under the influence of a homogeneous magnetic field is
described by the Feynman-Gell-Mann formulation of the Dirac equation. The axially symmetric
gauge is used for the vector potential in such a way that the Dirac spinor is written in terms
of eigenstates of the quiral operator and the third component of the total angular momentum
operator. The spinors are split in eigenstates of the third component of the spin operator and
the corresponding radial functions obey uncoupled second-order equations similar to the singular
harmonic oscillator in the nonrelativistic theory.
Auteur principal: M. MENDROT, Vitor (UNESP)
Orateur: M. MENDROT, Vitor (UNESP)
Session Classification: Posters
September 1, 2020 Page 32XV Hadron Physi … / Rapport sur les contributions Diffractive gauge boson productio …
Contribution ID: 40 Type: Poster
Diffractive gauge boson production at the LHC as a
probe of the flavor content of the Pomeron
The production of the W and Z bosons in single diffractive processes at the LHC is investigated
taking into account the ATLAS, CMS and LHCb acceptances and considering different assumptions
for the flavour content of the Pomeron. The total cross sections and pseudorapidity distributions
are estimated for pp collisions at √s=13 TeV. Our results indicate that a future experimental analysis
of the ratio between the W and Z cross sections can be used to probe the flavour content of the
Pomeron.
Auteur principal: ERNANI MARTINS NETO, Daniel (UFRJ)
Co-auteurs: GONCALVES, Victor (Universidade Federal de Pelotas); RANGEL, Murilo (LAL)
Orateur: ERNANI MARTINS NETO, Daniel (UFRJ)
Session Classification: Posters
September 1, 2020 Page 33XV Hadron Physi … / Rapport sur les contributions Rescattering in exclusive photopro …
Contribution ID: 41 Type: Poster
Rescattering in exclusive photoproduction of
quarkonia in UPCs
In the exclusive production of vector mesons in nuclear collisions
(\gamma A), we have to take into account two main nuclear effects in
order to make a precise calculation of the scattering amplitude: the
gluon shadowing and the finite coherence length. The first deals with
the main source of rescattering in the production of heavy quark
pairs, making the gluon density in a nuclei to be suppressed compared
to a free nucleon due to interference among the multiuple scatterings.
The second is the dependence on the finite lifetime of the photon
fluctuation into q-qbar pair inside the nucleus and is particularly
important in low energy regimes. This banner aims to study the
theoretical tools (and possible improvements to them) used to predict
the exclusive vector meson production (i.e. J/Psi or Upsilon) in high
energy nuclear collisions.
Auteurs principaux: MELCHIORS TREBIEN, Haimon Otto (UFSC); DE OLIVEIRA, Emmanuel
(UFSC)
Orateur: MELCHIORS TREBIEN, Haimon Otto (UFSC)
Session Classification: Posters
September 1, 2020 Page 34XV Hadron Physi … / Rapport sur les contributions Exclusive vector meson productio …
Contribution ID: 42 Type: Poster
Exclusive vector meson production in UPC
A good way to describe the production of vector mesons is by the color dipole model. In this
approach, the interaction of the photon with the target is described by a phenomenologically pa-
rameterized dipole cross section. The photon and meson wave functions, which can be obtained
by solving the Schröedinger equation for different potentials, with the inclusion of Melosh spin ro-
tation, can not only describe the quarkonia ground states but also the excited states. In this work,
these ingredients are used to calculate the γp cross section for the production of bottommonia
and charmonia and compared with some newly available data. Then this formalism is extended to
ultraperipheral AA collisions, where some interesting effects need to be included, such as gluon
shadowing and finite coherent length.
Auteurs principaux: HENKELS DE SOUZA, Cheryl (UFSC); DE OLIVEIRA, Emmanuel (UFSC)
Orateur: HENKELS DE SOUZA, Cheryl (UFSC)
Session Classification: Posters
September 1, 2020 Page 35XV Hadron Physi … / Rapport sur les contributions The Quantum Chromodynamics P …
Contribution ID: 43 Type: Poster
The Quantum Chromodynamics Phase Diagram
within Effective Models Frameworks
Different extensions of the Nambu-Jona-Lasinio model, known to satisfy expected QCD chiral
symmetry aspects, are presented and used to investigate a possible hadron-quark phase transition
at zero temperature. In special, one version of these NJL-type models, suitable to describe both
nucleonic and hyperonic matter, is partially developed in this work. In an early exploratory study,
it is shown that the transition point is very sensitive to the model parameters and that both pressure
and chemical potential increase drastically with the increase of the vector interaction strength in
the quark sector.
Auteur principal: MARQUEZ, Kauan (Federal University of Santa Catarina, Brazil)
Co-auteur: PERES MENEZES, Debora (Federal University of Santa Catarina (UFSC))
Orateur: MARQUEZ, Kauan (Federal University of Santa Catarina, Brazil)
Session Classification: Posters
September 1, 2020 Page 36XV Hadron Physi … / Rapport sur les contributions Orbital Properties and Gravitation …
Contribution ID: 44 Type: Seminar
Orbital Properties and Gravitational Waves
Signatures of Strange Crystal Planets
In this work we consider the possibility that strange quark matter may be manifested in the form of
strange crystal planets. These planet-like objects are made up of nuggets of strange quark matter
(SQM), organized in a crystalline structure. We consider the so–called strange matter hypothesis
proposed by Bodmer, Witten and Terazawa, in that, strange quark matter may be the absolutely
stable state of matter. {\bf In this context, we analyze planets made up} entirely of strangelets
arranged in a crystal lattice. Furthermore we propose that a solar system with a host compact
star may be orbited by strange crystal planets. Under this assumption we calculate the relevant
quantities that could potentially be observable, such as the planetary tidal disruption radius, and
the gravitational waves signals that may arise from potential star-planet merger events. Our results
show that strange crystal planets could potentially be used as an indicator for the the existence of
SQM.
Auteurs principaux: NEGREIROS, Rodrigo (Universidade Federal Fluminense); Mlle ZAPATA,
Joás (Universidade Federal Fluminense)
Orateur: NEGREIROS, Rodrigo (Universidade Federal Fluminense)
Session Classification: Seminars
September 1, 2020 Page 37XV Hadron Physi … / Rapport sur les contributions Dynamical vs. Explicit Dynamical …
Contribution ID: 45 Type: Seminar
Dynamical vs. Explicit Dynamical Chiral Symmetry
Breaking
The relative contributions of explicit and dynamical chiral symmetry breaking in QCD models of
the quark-gap equation are studied in dependence of frequently employed Ansätze for the dressed
interaction and quark-gluon vertex. In a naive quark picture, explicit symmetry breaking contribu-
tions are defined by a constituent-quark sigma term whereas the combined effects of explicit and
dynamical symmetry breaking are described by a Euclidean constituent-mass solution. We extend
this study of the gap equation to a quark-gluon vertex derived from longitudinal and transverse
Slavnov-Taylor identities and complemented with numerical gluon- and ghost-dressing functions
from lattice QCD. In comparison, we discuss the dynamical chiral symmetry breaking contribu-
tions to the mass of light baryons in the limit of vanishing quark masses.
Auteur principal: Prof. EL-BENNICH, Bruno (Cruzeiro do Sul University)
Orateur: Prof. EL-BENNICH, Bruno (Cruzeiro do Sul University)
Session Classification: Seminars
September 1, 2020 Page 38XV Hadron Physi … / Rapport sur les contributions Dynamic gluon mass generation fr …
Contribution ID: 46 Type: Seminar
Dynamic gluon mass generation from the effective
potential of the Gribov-Zwanziger theory
The Gribov-Zwanziger theory takes into account the effect of Gribov gauge copies and may provide
an effective description of the infrared regime of QCD. The success of this approach is based on the
compatibility of its predictions with the available lattice data for correlation functions, especially
gluon and ghost propagators, which point towards a dynamic mass generation in the form of
dimension-2 condensates of the gluon and auxiliary fields. In this talk, we address the task of
computing explicitly these condensates within the Gribov-Zwanziger framework by minimizing
the corresponding one-loop effective potential in a fully BRST-invariant setting.
Auteur principal: Prof. PALHARES, Letícia (UERJ)
Orateur: Prof. PALHARES, Letícia (UERJ)
Session Classification: Seminars
September 1, 2020 Page 39XV Hadron Physi … / Rapport sur les contributions Continuum Limit of Gluon and Gh …
Contribution ID: 47 Type: Seminar
Continuum Limit of Gluon and Ghost Propagators in
Minimal Landau Gauge
We study the continuum limit of SU(2) Landau-gauge gluon and ghost propagators, obtained from
numerical simulations performed on lattice volumes of up to 192⁴, in the scaling region.
Auteur principal: MENDES, Tereza
Orateur: MENDES, Tereza
Session Classification: Seminars
September 1, 2020 Page 40XV Hadron Physi … / Rapport sur les contributions Limiting Fragmentation in Hadron …
Contribution ID: 48 Type: Seminar
Limiting Fragmentation in Hadronic and Nuclear
collisions
We discuss limiting fragmentation within a few currently popular phenomenological models. We
show that popular Glauber-inspired models of particle production in heavy ion collisions gener-
ally fail to reproduce limiting fragmentation when all energies and system sizes experimentally
available are considered, due to the energy-dependence of number of participants and number of
collisions. We quantify this violation in terms of the model parameters. We also make the same
calculation within a Color Glass Condensate scenario and show that the dependence of the satu-
ration scale on the number of participants generally leads to violation of limiting fragmentation.
We further argue that wounded parton models, provided the nucleon size and parton density vary
predominantly with Bjorken x, could in principle reproduce both multiplicity dependence with
energy and limiting fragmentation. We suggest, therefore, that an experimental measurement of
deviation from limiting fragmentation in heavy ion collisions, for different system sizes and in-
cluding the experimentally available range of energies, is a powerful test of initial state models.
Auteur principal: TORRIERI, Donato Giorgio (Unicamp)
Orateur: TORRIERI, Donato Giorgio (Unicamp)
Session Classification: Seminars
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