arXiv subjects

M. B. Gay Ducati

Publications and source records attributed to M. B. Gay Ducati.

At least 19 recordsLinked to original sources

arXiv2022

Snowmass 2021/22 Letter of Interest: A Forward Calorimeter at the LHC

A forward electromagnetic and hadronic calorimeter (FoCal) was proposed as an upgrade to the ALICE experiment, to be installed during LS3 for data-taking in 2027--2029 at the LHC. The FoCal extends the scope of ALICE, which was designed for the comprehensive study of hot and dense partonic matter, by adding new capabilities to explore the small-$x$ parton structure of nucleons and nuclei. The primary objective of the FoCal is high-precision inclusive measurement of direct photons and jets, as well as coincident gamma-jet and jet-jet measurements, in pp and p--Pb collisions. These measurements by FoCal constitute an essential part of a comprehensive small-$x$ program at the LHC down to $x\sim10^{-6}$ and over a large range of $Q^2$ with a broad array of complementary probes, comprising -- in addition to the photon measurements by FoCal and LHCb -- Drell-Yan and open charm measurements planned by LHCb, as well as photon-induced reactions performed by all LHC experiments.

hep-ex↗

arXiv2021

Establishing limits for the monopole production in pp accelerators

The spin 1/2 magnetic monopole pair production and the spin 0 monopolium production are studied in proton-proton collisions. For the pair production, the velocity-dependent coupling model and the additional effective coupling with a magnetic moment parameter are used for the calculation of photon fusion and Drell Yan cross sections. Since the monopole mass is unknown, the mass range employed is based on the last results of ATLAS and the MoEDAL experiment, which set a minimal value of around 2 TeV. The cross sections are calculated for the center of mass energies of the LHC, for its successor, the HE-LHC and for the future collider FCC. As a result, the estimated mass limits for observation in LHC and the other accelerators are obtained and the advantages in using both effective couplings and the monopolium as an indirect measure are discussed.

hep-ph↗

arXiv2020

Central exclusive $χ_{c,b}$ production at high energy colliders and gluon saturation approach

The central exclusive production of $χ_{c}$ and $χ_{b}$ at the LHC, RHIC and Tevatron energies is analyzed, using the recent unintegrated parton distribution (UGDs) functions available in the package TMDlib. Comparison with data is performed, which tests the underlying assumptions basing the theoretical approach and it can constrain the unintegrated gluon distribution function at the small-$x$ region. Predictions for LHC energies using recent UGDs based in CCFM formalism are provided. It is explored the underlying uncertainties on this production as the choice for the unintegrated gluon distribution and factorization scale is done. Moreover, based on the parton saturation model for the gluon distribution, analytical expressions for the rapidity distributions are proposed. The prompt production of $J/ψ+γ$ and $Υ+γ$ is computed for the first time for LHC energies within the very same formalism used for $χ$ production.

hep-ph↗

arXiv2018

Exclusive Photoproduction $J/ψ$ in Peripheral Pb-Pb

The exclusive photoproduction of the $J/ψ$ state is investigated in peripheral AA collisions for the energies available at the LHC, $\sqrt{s}=2.76$ TeV and $\sqrt{s}=5.02$ TeV. In order to evaluate the robustness of the light-cone color dipole formalism, previously tested in the ultraperipheral regime, the rapidity distribution and the nuclear modification factor ($R_{AA}$) were calculated for three centrality classes: 30%-50%, 50%-70% and 70%-90%. In the peripheral regime, three scenarios were considered. In the scenario 1, a similar formalism adopted in the UPC regime is used; in the scenario 2, one considers that only the spectators in the target are the ones that interact coherently with the photon; in the scenario 3, the photonuclear cross section is modified using the same geometrical constraints applyed in the scenario 2. The results obtained from the three scenarios were compared with the ALICE measurements (only $J/ψ$ at the moment), showing a better agreement in the more complete approach (scenario 3), mainly in the more central regions (30%-50% and 50%-70%) where the incertainty is smaller.

hep-ph↗

arXiv2018

Heavy Mesons Photoproduction in Peripheral AA Collisions

The exclusive photoproduction of the heavy vector mesons $ψ$'s and $Y$'s is investigated in peripheral lead-lead collisions for the energies available at the LHC, $\sqrt{s}=2.76$ TeV and $\sqrt{s}=5.02$ TeV. In order to evaluate the robustness of the light-cone color dipole formalism, previously tested in the ultraperipheral regime. It was calculated the rapidity distribution as well as the nuclear modification factor ($R_{AA}$) for the three centrality classes: 30%-50%, 50%-70% and 70%-90%. The transition from ultraperipheral to peripheral regime was carried out sophisticating the photon flux description and the photonuclear cross section, taking into account the effective interaction area. In our calculations, three scenarios were considered: (scenario 1) the direct application of the usual photon flux and of the photonuclear cross section without any relevant change in relation to the UPC's, (scenario 2) the application of an effective photon flux keeping the photonuclear cross section unchanged and (scenario 3) where it was also considered an effective photonuclear cross section. The results obtained from the three scenarios were compared with the ALICE measurements (only $J/ψ$ at the moment), showing a better agreement with the data in the more complete approach (scenario 3), mainly in the more central regions (30%-50% and 50%-70%) where the incertainty is smaller.

hep-ph↗

arXiv2017

LHC Forward Physics

The goal of this report is to give a comprehensive overview of the rich field of forward physics, with a special attention to the topics that can be studied at the LHC. The report starts presenting a selection of the Monte Carlo simulation tools currently available, chapter 2, then enters the rich phenomenology of QCD at low, chapter 3, and high, chapter 4, momentum transfer, while the unique scattering conditions of central exclusive production are analyzed in chapter 5. The last two experimental topics, Cosmic Ray and Heavy Ion physics are presented in the chapter 6 and 7 respectively. Chapter 8 is dedicated to the BFKL dynamics, multiparton interactions, and saturation. The report ends with an overview of the forward detectors at LHC. Each chapter is correlated with a comprehensive bibliography, attempting to provide to the interested reader with a wide opportunity for further studies.

hep-ph↗

arXiv2017

$J/Ψ$ Photoproduction in Peripheral AA Collisions

The exclusive photoproduction of the heavy vector mesons $J/Ψ$ is investigated in the context of peripheral lead-lead collisions for the energies available at the LHC, $\sqrt{s}=2.76$ TeV and $\sqrt{s}=5.02$ TeV. Using the light-cone color dipole formalism, it was calculated the rapidity distribution in two centrality bins 50\%-70\% and 70\%-90\% in order to evaluate its robustness in extrapolating down to smaller impact parameter. It is introduced a modified photon flux, without change in the photonuclear cross section in relation to the ultraperipheral (UPC) case. Results were obtained for the two regions analized, which presented a maximum difference of 27\% in frontal rapidity for the two regions. Comparing the results for $\sqrt{s}=2.76$ TeV and $\sqrt{s}=5.02$ TeV, it was verified an increase of approximately half the one obtained in ultraperipheral regime in the central rapidity region.

hep-ph↗

arXiv2017

Coherent and incoherent Upsilon production in ultraperipheral collisions at the Large Hadron Collider

The exclusive photoproduction of $Υ(nS)$ states were calculated in ultra-peripheral collisions for coherent and incoherent process in PbPb at $\sqrt{s_{NN}}$= 5.5 TeV. Different dipole models were compared in the theoretical framework of light-cone color dipole formalism. Moreover, it was calculated the differential cross section for the Upsilon states and their total cross section for two intervals of rapidity: $|y|\leq 4$ 4 and $ 2 \le$ y $\le 4.5$. A systematic study is done on the theoretical uncertainties associated to the production and predictions are presented for the first time for the incoherent cross section of the radially excited states.

hep-ph↗

arXiv2016

Photoproduction of Upsilon states in ultraperipheral collisions at the CERN Large Hadron Collider within the color dipole approach

The exclusive photoproduction of upsilon states $Υ(1S)$ and its radially excited states $Υ(2S,3S)$ is investigated in the context of ultra-peripheral collisions at the LHC energies. Predictions are presented for their production in proton-proton, proton-nucleus and nucleus-nucleus collision at the energies available at the LHC run 2. The rapidity and transverse momentum distributions are shown, and the robustness of the model is tested against the experimental results considering $ψ(1S,2S)$ and $Υ(1S)$ states. The theoretical framework considered in the analysis is the light-cone color dipole formalism, which includes consistently parton saturation effects and nuclear shadowing corrections.

hep-ph↗

arXiv2014

Diffractive Photoproduction of Psi(2S) in Photon-Pomeron Reactions in PbPb Collisions at the CERN LHC

This work investigates the exclusive photoproduction of $ψ(2S)$ meson off nuclei evaluating the coherent and the incoherent contributions. The theoretical framework used in the present analysis is the light-cone dipole formalism and predictions are done for PbPb collisions at the CERN-LHC energy of 2.76 TeV. A comparison is done to the recent ALICE Collaboration data for the $ψ(1S)$ state photoproduction.

hep-ph↗

arXiv2014

Diffractive photoproduction of radially excited psi(2S) mesons in photon-Pomeron reactions in PbPb collisions at the CERN LHC

In this work we investigate the photoproduction of radially excited vector mesons off nuclei in heavy ion relativistic collisions. In particular, we analyze the exclusive photoproduction of psi(2S) off nuclei, evaluating the coherent and the incoherent contributions to that process. The theoretical framework used in the present analysis is the light-cone dipole formalism and predictions are done for PbPb collisions at the CERN-LHC energy of 2.76 TeV. The theoretical uncertainties are analyzed and comparison is also done to the recent ALICE Collaboration data for the psi(1S) state photoproduction.

hep-ph↗

arXiv2014

Exclusive photoproduction of J/psi and psi(2S) states in proton-proton collisions at the CERN LHC

In this work we investigate the exclusive photoproduction of J/psi and the radially excited psi(2S) state off nucleon in proton-proton collisions. The theoretical framework considered in the analysis is the light-cone dipole formalism and predictions are done for proton-proton collisions at the CERN-LHC energy of 7 TeV. The theoretical uncertainties are investigated and comparison is done to the recent LHCb Collaboration data for the exclusive charmonium production.

hep-ph↗

arXiv2014

A study on the low mass Drell-Yan production at the CERN LHC within the dipole formalism

We present results for the low mass Drell-Yan (DY) production in proton-proton collisions at the LHC in the color dipole formalism. The DY differential cross sections at 7 TeV as a function of dilepton rapidity, transverse momentum and invariant mass are discussed. We have imposed kinematical cuts related to the low mass DY production investigated by ATLAS and LHCb collaborations.

hep-ph↗

arXiv2013

Inclusive hadron and photon production at LHC in dipole momentum space

Using a momentum space model for the dipole scattering amplitude we present an analysis of the saturation effects at LHC energies, describing the data on proton-proton and proton-lead collisions. The model is based on the asymptotic solutions of the Balitsky-Kovchegov equation, being ideal in the saturation domain where the target wave function has a high occupation number. We also make predictions for the nuclear modification ratios on charged hadron and prompt photon production in the forward region, where the high parton density effects are important.

hep-ph↗

arXiv2012

Running coupling and pomeron loop effects on inclusive and diffractive DIS cross sections

Within the framework of a (1+1)--dimensional model which mimics high energy QCD, we study the behavior of the cross sections for inclusive and diffractive deep inelastic $γ^*h$ scattering cross sections. We analyze the cases of both fixed and running coupling within the mean field approximation, in which the evolution of the scattering amplitude is described by the Balitsky-Kovchegov equation, and also through the pomeron loop equations, which include in the evolution the gluon number fluctuations. In the diffractive case, similarly to the inclusive one, the suppression of the diffusive scaling, as a consequence of the inclusion of the running of the coupling, is observed.

hep-ph↗

arXiv2011

Estimations for the Higgs boson production with QCD and EW corrections in exclusive events at the LHC

The Higgs boson production is investigated in proton-proton collisions at next-to-leading-order accuracy in central exclusive diffractive processes at the LHC. The production process by the double Pomeron exchange is analyzed in the diffractive factorization through the Ingelman-Schlein approach, taking into account the parton content of the Pomeron by the diffractive partonic distribution function provided by the H1 Collaboration. Hence, we estimate the production cross section of the Higgs boson as well as its rapidity distribution for distinct energies of the LHC. Also, we include the gap survival probability in our calculation, which is studied in recent works and expected to lie in the range between 1% and 5% for the energy regime of 14 TeV. As a result, we found a production cross section of about 0.3--0.8 (1.2--3.7) fb at 7 (14) TeV, being of the same order as predicted by the two-photon and the Balitsky-Fadin-Kuraev-Lipatov Pomeron mechanisms. Therefore, assuming the selection rules of spin-parity properties, the exclusive production is a promising channel for the Higgs boson detection in the LHC.

hep-ph↗

arXiv2011

Estimations for the Single Diffractive production of the Higgs boson at the Tevatron and the LHC

The single diffractive production of the standard model Higgs boson is computed using the diffractive factorization formalism, taking into account a parametrization for the Pomeron structure function provided by the H1 Collaboration. We compute the cross sections at next-to-leading order accuracy for the gluon fusion process, which includes QCD and electroweak corrections. The gap survival probability ($<\!|S|^2\!>$) is also introduced to account for the rescattering corrections due to spectator particles present in the interaction, and to this end we compare two different models for the survival factor. The diffractive ratios are predicted for proton-proton collisions at the Tevatron and the LHC for the Higgs boson mass of $M_H$ = 120 GeV. Therefore, our results provide updated estimations for the diffractive ratios of the single diffractive production of the Higgs boson in the Tevatron and LHC kinematical regimes.

hep-ph↗

arXiv2011

Momentum space saturation model for deep inelastic scattering and single inclusive hadron production

We show how the AGBS model, originally developed for deep inelastic scattering applied to HERA data on the proton structure function, can also describe the RHIC data on single inclusive hadron yield for $d+Au$ and $p+p$ collisions through a new simultaneous fit. The single inclusive hadron production is modeled through the color glass condensate, which uses the quark(and gluon)--condensate amplitudes in momentum space. The AGBS model is also a momentum space model based on the asymptotic solutions of the BK equation, although a different definition of the Fourier transform is used. This aspect is overcome and a description entirely in transverse momentum of both processes arises for the first time. The small difference between the simultaneous fit and the one for HERA data alone suggests that the AGBS model describes very well both kind of processes and thus emerges as a good tool to investigate the inclusive hadron production data. We use this model for predictions at LHC energies, which agree very well with available experimental data.

hep-ph↗