Search

The Electron-Ion Collider, a next generation electron-hadron and electron-nuclei scattering facility, will be built at Brookhaven National Laboratory. The wealth of new data will shape research in hadron physics, from nonperturbative QCD techniques to perturbative QCD improvements and global QCD analyses, for the decades to come. With the present proposal, Latin America based physicists, whose expertise lies on the theory and phenomenology side, make the case for the past and future efforts of a growing community, working hand-in-hand towards developing theoretical tools and predictions to analyze, interpret and optimize the results that will be obtained at the EIC, unveiling the role of the glue that binds us all. This effort is along the lines of various initiatives taken in the U.S., and supported by colleagues worldwide, such as the ones by the EIC User Group which were highlighted during the Snowmass Process and the Particle Physics Project Prioritization Panel (P5)., Comment: White Paper contribution to the Latin American Strategy Forum for Research Infrastructure (III LASF4RI

We investigate the multiplicity dependence of the transverse momentum $p_T$ spectra of hadrons produced in high-energy collisions. We propose that the partonic distribution be parameterized by its non-extensive entropy and the parton saturation scale $Q_s(x)$. These two variables can be identified from the produced charged hadron distributions and provide important information on the gluon dynamics at the moment of interaction. From this perspective we interpret data from different ALICE multiplicity classes at $\sqrt{s}= 13$ TeV and $\sqrt{s}= 5.02$ TeV. A multiplicity dependent scaling function is presented and the dependence of the interaction area on multiplicity is also investigated., Comment: 11 pages, 7 figures. Version to be published in Physical Review D

In this work we analyze the application of the analytical gluon distribution based on the double asymptotic scaling for the photoproduction of vector mesons in coherent $pp$, $pA$ and $AA$ collisions at the LHC energies using the color dipole formalism. Predictions for the rapidity distribution are presented for $\rho^0$ and $J/ \psi$, $\psi (2S)$ and $\Upsilon (1S)$ photoproduction. An analysis on the uncertainties associated to different implementations of the dipole-proton amplitude is performed. The vector meson photoproduction accompanied by electromagnetic dissociation is also analyzed., Comment: 12 pages, 12 figures, 2 tables

A study of double charmed meson production in proton-proton and proton-nucleus collisions at the LHC energies is performed. Based on the color dipole formalism developed in the transverse momentum representation and the double parton scattering mechanism, predictions are made for the transverse momentum differential cross section for different pairs of $D$-mesons. The theoretical results consider the center-of-mass energy and forward rapidities associated to the measurements by the LHCb Collaboration. The results considering different unintegrated gluon distributions are presented and compared to data and predictions for proton-nucleus collisions are provided., Comment: 20 pages, 4 figures

We outline the physics opportunities provided by the Electron Ion Collider (EIC). These include the study of the parton structure of the nucleon and nuclei, the onset of gluon saturation, the production of jets and heavy flavor, hadron spectroscopy and tests of fundamental symmetries. We review the present status and future challenges in EIC theory that have to be addressed in order to realize this ambitious and impactful physics program, including how to engage a diverse and inclusive workforce. In order to address these many-fold challenges, we propose a coordinated effort involving theory groups with differing expertise is needed. We discuss the scientific goals and scope of such an EIC Theory Alliance., Comment: 44 pages, ReVTeX, White Paper on EIC Theory Alliance

By using the Reggeometric Pomeron model for vector meson production which successfully describes the high energy lepton-nucleon data, we analyse the light meson production in ultra-peripheral heavy ion collisions at the Large Hadron Collider (LHC). The rapidity distributions for $\rho$ and $\phi$ photoproduction in lead-lead, xenon-xenon and oxygen-oxygen collisions are investigated., Comment: Proceedings IWARA 2022

The elastic differential and integrated total cross section for the exclusive $\rho^0$ photoproduction in electron-proton ($ep$) collisions are evaluated taking into account nonperturbative Pomeron exchange approach. By using three different models based on Regge phenomenology the results are compared to recent measurements by H1 Collaboration in $ep$ collisions and by the CMS collaboration from ultraperipheral proton-lead collisions. The analysis is expanded by calculating the coherent nuclear cross section, $\sigma (\gamma A\rightarrow \rho^0 A)$, which is applied to $\rho^0$ production in ultraperipheral lead-lead and xenon-xenon collisions. The predictions are compared to the measurements performed by ALICE Collaboration. Aspects of the theoretical uncertainties and limitations of the formalism are scrutinized.

In this paper, dedicated to the memory of the late Prof. Jean Cleymans, the nuclear modification factors, $R_{xA}$, are investigated for pion production in small system collisions, measured by PHENIX experiment at RHIC (Relativistic Heavy Ion Collider). The theoretical framework is the transverse momentum $k_T$-factorization formalism for hard processes at small momentum fraction, $x$. Evidence for collective expansion and thermal effects for pions, produced at equilibrium, is studied based on phenomenological parametrization of blast-wave type in the relaxation time approximation. The dependencies on the centrality and on the projectile species are discussed in terms of the behavior of Cronin peak and the suppression of $R_{xA}$ at large transverse momentum, $p_T$. The multiplicity of produced particles, which is sensitive to the soft sector of the spectra, is also included in the present analysis., Comment: 12 pages, 4 figures. Contribution to MDPI Physics Special Issue "Jean Cleymans: A Life for Physics", dedicated to the memory of Professor Jean Cleymans

We present an analysis of the most precise set of HERA data within the color dipole formalism, by using an analytical gluon density, based on the double-logarithm approximation of the DGLAP equations in the asymptotic limit of the scaling variable, $\sigma=\log{(1/x)}\log{(\log{(Q^2/Q_ 0^2)})}\rightarrow \infty$. Fits to data, including charm and bottom quarks are performed and demonstrate the efficiency of the model in describing the reduced cross section, $\sigma_{r}$, in the wide range $Q^2:(1.5,500)$ GeV$^2$ for two dipole models including parton saturation effects. We also give predictions to $F_{2}^{c\bar{c}}$ , $F_{2}^{b\bar{b}}$ and $F_{L}$, all describing the data reasonably well in the range $Q^2:(2.5,120)$ GeV$^2$. Total cross sections of exclusive photoproduction of $J/\psi$ and $\rho$ are also calculated and successfully compared to HERA data and recent measurements at LHCb., Comment: 17 pages, 9 figures, 6 tables. Matches published version

The $D$-meson production is investigated by considering the unintegrated gluon distribution within the dipole approach in the momentum representation. We analyze the $D$-meson spectrum accounting for the effects of nonlinear behavior of the QCD dynamics which can be accordingly addressed in the dipole framework. The unintegrated gluon distribution is obtained by using geometric scaling property and the results are compared to the Glauber-Gribov framework. The absolute transverse momentum spectra and the nuclear modification ratios are investigated. Predictions are compared with the experimental measurements by the ALICE and LHCb Collaborations in $pA$ collisions for different rapidity bins., Comment: 23 pages, 9 figures, 1 table

In this work the $k_{\perp}$-factorization formalism is applied to compute the exclusive $Z^0$ boson photoproduction in $ep$ and $eA$ collisions. The study is also extended to $pp$ and $AA$ processes. The nuclear effects are investigated considering heavy and light ions. Analytical models for the unintegrated gluon distribution are taken into account and the corresponding theoretical uncertainty is quantified. The analysis is done for electron-ion collisions at the Large Hadron-Electron Collider (LHeC), its high-energy upgrade (HE-LHeC) and at the Future Circular Collider (FCC) in lepton-hadron mode. Additionally, ultra-peripheral heavy ion collisions at future runs of the Large Hadron Collider (LHC) and at the FCC (hadron-hadron mode) are also considered., Comment: 8 pages, 5 figures

The dynamical entropy of dense gluonic states in proton-proton collisions at high energies is studied by using phenomenological models for the unintegrated gluon distribution. The corresponding transverse momentum probability distributions are evaluated in terms of rapidity. The dynamical entropy density is obtained in the rapidity range relevant for the collisions at the Large Hadron Collider. The total entropy density for the dense system is computed as a function of the rapidity evolution $\Delta Y = Y-Y_0$ given an initial rapidity $Y_0$. The theoretical uncertainties are investigated and comparison with related approaches in literature is done., Comment: 08 pages, 4 figures

By using models based on Regge phenomenology we analyse the coherent photoproduction of charmonium in peripheral heavy-ion collisions at the Large Hadron Collider (LHC). The centrality dependence is investigated and compared to the experimental results for coherent $J/\psi$ production in lead-lead LHC runs at the energies of 2.76 and 5.02 TeV. Theoretical uncertainties and possible limitations of the formalism are also discussed., Comment: 12 pages, 7 figures

Transverse momentum broadening of a parton propagating through a large nucleus is evaluated in the color dipole approach using different models for the dipole cross section or unintegrated gluon distribution, which lead to different values of the coefficient $C_{\mathcal{F}}(0,s)$. Numerical calculations are compared to data extracted from LHCb and ALICE experiments for nuclear broadening of $J/\psi$. We find that different models which describe the small-$x$ data predict values of $\Delta p_T^2$ that agree reasonably well with experiment, specially for forward rapidity. The centrality dependence was also analysed and the models are consistent with the ALICE measurements., Comment: 6 pages, 2 figure, 2 tables

By using a Regge-pole model for vector meson production (VMP), successfully describing the HERA data, we analyse the correlation between VMP cross sections in photon-induced reactions at HERA and those in ultra-peripheral collisions at the Large Hadron Collider (LHC). The rapidity distributions of proton-proton collisions at 13~TeV and lead-lead collisions at 2.76 and 5.02 TeV are investigated. The transverse momentum distribution in nuclear coherent vector meson production is also addressed. Predictions for future experiments on production of $J/\psi$ and $\psi(2S)$ are presented., Comment: 14 pages, 9 figures. arXiv admin note: text overlap with arXiv:1408.0530

The production of $D$-mesons in high-energy $pp$ collisions at the LHC kinematic regime is analyzed with the dipole approach in the momentum representation. We present predictions for the $D$-meson differential cross section in terms of the transverse momentum and rapidity distributions taking into account the nonlinear behavior of the QCD dynamics. Comparison between our results and the corresponding experimental measurements reported by the ALICE and LHCb Collaborations in different rapidity bins is performed. We show that the $D$-meson production in the high energy limit can be properly addressed by using the QCD dipole transverse momentum distributions., Comment: 16 pages, 5 figures

We describe the energy distribution of hard gluons travelling through a dense quark-gluon plasma whose temperature increases linearly with time, within a probabilistic perturbative approach. The results were applied to the thermalization problem in heavy ion collisions, in the third stage of the bottom-up picture, to estimate the initial time for the third stage of the bottom-up scenario. We then look at the entropy density and average temperature of the soft thermal bath, as the system approaches (local) thermal equilibrium., Comment: 6 pages, 5 figures; corrected for updated references and acknowledgements

In the present work, $k_T$-factorization formalism is applied to compute the exclusive dilepton production by timelike Compton scattering (TCS) in $eA$, $pA$ and $AA$ collisions. The nuclear effects are investigated considering heavy and light ions. The production cross section in terms of invariant mass and rapidity distribution of the lepton pair is shown. The analysis is done for electron-ion collisions at the Large Hadron-Electron Collider (LHeC), its high-energy upgrade (HE-LHeC) and at the Future Circular Collider (FCC) in lepton-hadron mode. Additionally, ultraperipheral heavy ion collisions at future runs of the Large Hadron Collider (LHC) and at the FCC (hadron-hadron mode) are also considered., Comment: 9 pages, 4 figures. To be published in Physical Review D

The study of how fast thermalization in heavy ion collisions occurs has been one of the central topics in the heavy ion community. In the weak coupling picture this thermalization occurs from "the bottom up": high energy partons, formed early in the collision, radiate low energy gluons which then proceed to equilibrate among themselves, forming a thermal bath that brings the high energy sector to equilibrium. In this scheme we apply a model on parton energy loss to discuss the effects of medium expansion on the thermalization problem and estimate the average transverse momentum diffusivity for thermalization in a Bjorken expanding medium., Comment: 8 pages, 4 figures. Current version includes updated references and a more detailed discussion on the underlying assumptions

The transverse momentum spectra of hadrons is calculated from the unintegrated gluon distribution (UGD) within the $k_T$-factorization framework at small $x$. Starting from $pp$ collisions, the modification caused by the nuclear medium is incorporated in the UGD at high energies, which is related to the nuclear shadowing phenomenon. Moreover, we consider that particle production from minijet decaying is not enough to explain the $p_T$ spectra in $AA$ collisions due to collective phenomena that take place after the hard collision. The Boltzmann-Gibbs Blast Wave (BGBW) distribution is utilized in order to evaluate the distribution of particle production in equilibrium. Data from ALICE collaboration for $PbPb$ collisions at $\sqrt{s}=2.76$ TeV are analyzed and the nuclear modification factor for pion production is computed., Comment: 8 pages, 5 figures

An analysis of prompt photon production in high energy nuclear collisions at the LHC energy regime is performed within the parton saturation picture taking into account the updated phenomenological color dipole models. The results are confronted with the measurements made by the ALICE, ATLAS, and CMS experiments in terms of photon transverse momentum at different rapidity bins. As a result, we show that the prompt photon production exhibits distinct scalings in $AA$ events associated to geometrical properties of the collision and can be properly addressed in the color dipole formalism., Comment: 17 pages, 5 figures

In this work we consider the dilepton production via timelike Compton scattering (TCS) in electron-proton and proton-proton collisions. In particular, the differential cross section in terms of the dilepton invariant mass and rapidity is computed within the $k_T$-factorization approach. Besides, we utilize distinct unintegrated gluon distributions (UGD) in order to compare their impact on the differential cross section of TCS in $pp$ ($ep$) collisions evaluated at the LHC (LHeC), HL-LHC (LHeC), HE-LHC (LHeC) and FCC-hh (eh) center-of-mass energies., Comment: 9 pages, 4 figures

The entanglement entropy of two-body elastic scattering at high energies is studied by using the model-independent L\'evy imaging method for investigating the hadron structure. It is considered the finite entropy in the momentum Hilbert space properly regularized and results are compared to recent evaluation using the diffraction peak approximation. We present the entropy for RHIC, Tevatron and LHC energies pointing out the underlying uncertainties., Comment: 9 pages, 1 figure, 1 table. Version to be published in Physical Review D

Prompt photon production in hadronic collisions at the RHIC and the LHC energies is investigated within the QCD color dipole approach. Predictions for the nuclear modification factor in $pA$ collisions are evaluated based on parton saturation framework and the results are compared to the experimental measurements as a function of the photon transverse momentum at different rapidity bins. The reliability of the models is performed with the data from PHENIX, ATLAS, and ALICE Collaborations. Moreover, we show that the observed $x_T$-scaling of prompt photon production in $pp$ and $pA$ collisions can positively be addressed in the QCD color dipole formalism., Comment: 17 pages, 10 figures

In this paper we review and update the Amaral-Gay Ducati-Betemps-Soyez saturation model, by testing it against the recent H1-ZEUS combined data on deep inelastic scattering, including heavy quarks in the dipole amplitude. We obtain that this model, which is based on traveling wave solutions of the Balitsky-Kovchegov equation and built in the momentum space framework, yields very accurate descriptions of the reduced cross section, $\sigma_{r}(x,y,Q^{2})$, as well as DIS structure functions such as $F_{2}(x,Q^{2})$ and $F_{L}(x,Q^{2})$, all measured at HERA. Additionally, it provides good descriptions of heavy quark structure functions, $F_{2}^{cc}$ and $F_{2}^{bb}$ at small-$x$ and $Q^{2}\lesssim 60$ GeV$^{2}$. We also use the improved model to make predictions for structure functions to be measured in the near future at LHeC., Comment: 13 pages, 7 figures

The presence of geometric scaling within the $p_T$ spectra of produced hadrons at high energy $pp$ collisions using small-$x$ $k_T$-factorization is investigated. It is proposed a phenomenological parameterization for the unintegrated gluon distribution in the scaling range which reproduces the features of the differential cross section both in the saturated and dilute perturbative QCD regimes. As the saturation scale acts as an effective regulator of the infrared region (IR), the extension of the model to quantities usually associated to soft physics is studied. The approach is applied to compute the average $p_T$ and the rapidity distribution of produced gluons at high energies., Comment: 11 pages, 9 figures

A study on the prompt photon production within the QCD color dipole picture with emphasis in $pp$ and $pA$ collisions at the LHC energy regimes is performed. We present predictions for the differential cross section as a function of photon transverse momentum at different rapidity bins considering updated phenomenological color dipole models, which take into account the QCD gluon saturation physics. The results are directly compared to the recent experimental measurements provided by CMS and ATLAS Collaborations, showing a reasonable agreement in all rapidity bins with no free parameters. Special attention is given to the IPSAT model given its good description of the data in all rapidity bins from low- to high-$p_{T}$ ranges. As a result, a free-parameter approach has succeeded in describing the LHC data for prompt photon production, while new predictions for the 13-TeV data is presented in view of new data to confirm such prospect., Comment: 12 pages, 18 figures

We study the diffractive jet production in electron-ion collisions in the kinematical region where the mass $M_X$ of the diffractive final state is larger than $Q^2$. Based on parton saturation framework predictions are done for the kinematics of future or possible $eA$ machines as the EIC, LHeC, HE-LHeC and FCC-eA. We analyze the differential cross section as a function of jet (gluon) transverse momentum and from the experimental point of view this observable could be used to extract the saturation scale as a function of $x_{I\!\!P}$., Comment: 8 pages, 5 figures. To be published in Physical Review C

The central exclusive production of $\chi_{c}$ and $\chi_{b}$ 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 $J/\psi+\gamma$ and $\Upsilon+\gamma$ is computed for the first time for LHC energies within the very same formalism used for $\chi$ production., Comment: 9 pages, 8 figures and 2 tables. Final version to be published in Physics Letters B

In this work we analyse the entanglement entropy in deep inelastic scattering off protons and nuclei. It is computed based on the formalism where the partonic state at small-x is maximally entangled with proton being constituted by large number of microstates occuring with equal probabilities. We consider analytical expressions for the number of gluons, N_{gluon}, obtained from gluon saturation models for the dipole-target amplitudes within the QCD color dipole picture. In particular, the nuclear entanglement entropy per nucleon is studied. We also study the underlying uncertainties on these calculations and compare the results to similar investigations in literature., Comment: 11 pages, 5 figures and 1 table (revised, conclusions unchanged). Extended version to be published in Physical Review D

In this work we consider the QCD parton saturation models to describe soft interactions at the high energy limit. The total and elastic cross sections as well as the elastic slope parameter are obtained for proton-proton and pion-proton collisions and compared to recent experimental results. The analyses are done within the color dipole formalism taking into account saturation models which have been tested against DIS data. The main point is that the match between soft and hard interaction occurs in the saturation region which can be described by high density QCD approaches. Discussion is performed on the main theoretical uncertainties associated with calculations., Comment: 12 pages, 6 figures. Final version to be published in Physical Review D

In this paper we analyse the exclusive vector meson photoproduction in the recent run using Xenon-ions at energy of 5.44 TeV performed by the Large Hadron Collider. We focus on the ultraperipheral collisions and provide theoretical predictions for coherent and incoherent cross sections within the color dipole approach and gluon saturation framework. The rapidity distribution is investigated in both cases and comparison to other approaches available at literature is done. We show that the expected yields are enough to perform reliable cross section measurements for light mesons as $\rho^0$ and $\phi$., Comment: 6 figures, 7 pages, accepted to be published in PRD. arXiv admin note: text overlap with arXiv:1708.08546

We investigate the theoretical uncertainty on the predictions for the photoproduction of $\rho$ and $J/\Psi$ 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 $\rho$ production in $PbPb$ collisions at central rapidity., Comment: 4 pages, 2 figures, 1 table. Poster presented by G. Sampaio dos Santos at the XIV International Workshop on Hadron Physics, Florianopolis, Brazil, March 2018

In this work, we investigate the exclusive production of particles in scattering processes in the so-called saturation region. Within this scheme the phenomenon of geometric scaling takes place: cross sections are functions only of a dimensionless combination of the relevant kinematic variables, which happens both in inclusive and diffractive cases, as in the production of vector mesons. In particular, the scaling variable is given in general by $\tau = Q^2/Q_s^2$, where $Q^2$ is the photon virtuality and $Q_s$ represents the saturation scale, which drives the energy dependence and the corresponding nuclear effects. Based on the scaling property, we are able to derive a universal expression for the cross sections for the exclusive vector meson production and deeply virtual Compton scattering (DVCS) in both photon-proton and photon-nucleus interactions. This phenomenological result describes all available data from DESY-HERA for $\rho$, $\phi$ and $J/\psi$ production and DVCS measurements. A discussion is also carried out on the size of nuclear shadowing corrections on photon-nucleus interaction., Comment: Poster presented at the XIV International Workshop on Hadron Physics, Florian\'opolis, Brazil, March 2018

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 $\rho$, $\phi$, $J/\Psi$, $\Psi (2S)$ and $\Upsilon$ 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., Comment: 11 pages, 6 figures, 1 table

The experimental results of the future electron -- ion ($e A$) collider are expected to constrain the dynamics of the strong interactions at small values of the Bjorken -- $x$ variable and large nuclei. Recently it has been suggested that Coulomb corrections can be important in inclusive and diffractive $eA$ interactions. In this paper we present a detailed investigation of the impact of the Coulomb corrections to some of the observables that will be measured in the future $eA$ collider. In particular, we estimate the magnitude of these corrections for the charm and longitudinal cross sections in inclusive and diffractive interactions. Our results demonstrate that the Coulomb corrections for these observables are negligible, which implies that they can be used to probe the QCD dynamics., Comment: 9 pages, 6 figures. Improved version to be published in Physical Review C

The exclusive photoproduction of $\Upsilon (nS)$ 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., Comment: 6 pages, 3 figures, 2 tables. Version to be published in Physical Review D

We provide a universal expression of cross sections for the exclusive vector meson production and Deeply Virtual Compton Scattering (DVCS) in photon-proton and photon-nucleus interactions based on the geometric scaling phenomenon. The theoretical parameterization based on the scaling property depends only on the single variable $\tau_A = Q^2/Q_{\mathrm{sat}}^2$, where the saturation scale, $Q_{\mathrm{sat}}$, drives the energy dependence and the corresponding nuclear effects. This phenomenological result describes all available data from DESY-HERA for $\rho,\,\phi,\,J/\psi$ production and DVCS measurements. A discussion on the size of nuclear shadowing corrections on photon-nucleus interaction is also done., Comment: 8 pages, 3 figures and 2 tables. Extended version to be published in Physical Review D. Title has been changed

We present some of the topics covered in two lectures under the same title that were given at the "Summer School on High Energy Physics at the LHC: New trends in HEP" in Natal, Brazil. In this contribution we give a brief review on the application of perturbative QCD to the hard diffractive processes. Some examples of phenomenology for the diffractive production of $W/Z$, heavy $Q\bar{Q}$ and quarkonium in hadron-hadron reactions are presented. It is also discussed the exclusive diffractive processes in $ep$ interactions. They are in general driven by the gluon content of proton which is strongly subject to parton saturation effects in the very high energy limit. These saturation effects are well described within the color dipole formalism. We present some examples of corresponding phenomenology as the elastic vector meson production and the DVCS relying on the color dipole approach., Comment: 35 pages, 4 figures (new references added). Proceedings of the Summer School and Workshop on High Energy Physics at the LHC: New trends in HEP, October 21- November 6 2014, Natal, Brazil. arXiv admin note: substantial text overlap with arXiv:hep-ph/0511047, arXiv:hep-ph/9909362, arXiv:hep-ph/0102093 by other authors

The exclusive photoproduction of upsilon states $\Upsilon(1S)$ and its radially excited states $\Upsilon(2S,3S)$ 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 $\psi(1S,2S)$ and $\Upsilon(1S)$ 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., Comment: 7 pages, 5 figures , Version to be published in phydical Review D

We investigate the theoretical uncertainty on the predictions for the photoproduction of J/psi and Upsilon states in the proton-nucleus and nucleus-nucleus collisions at the LHC within the color dipole formalism. Predictions for the rapidity distributions are presented and the dependence on the meson wavefunction, heavy quark mass as well as the models for the dipole cross section are analyzed. We compare directly the theoretical results to the recent data from ALICE collaboration on J/psi production in pPb collisions at a centre-of-mass energy per nucleon pair of 5.02 TeV and in PbPb collisions at a centre-of-mass energy per nucleon pair of 2.76 TeV. Predictions are also performed for $\Upsilon$ state in PbPb and pPb and pp collisions at the LHC energies, including the coherent and incoherent contributions., Comment: 08 pages, 06 figures. Final version to be published in J. Phys. G: Nucl. Part. Phys

By using a Regge-pole model for vector meson production (VMP), that successfully describes the HERA data, we analyze the connection of VMP cross sections in photon-induced reactions at HERA with those in ultra-peripheral collisions at the Large Hadron Collider (LHC). The role of the low-energy behaviour of VMP cross sections in {\gamma}p collisions is scrutinized., Comment: "Presented at "Diffraction 2014", Primosten" conference (Croatia), to be published by the American Institute of Physics"

This work investigates the exclusive photoproduction of $\psi(2S)$ 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 $\psi(1S)$ state photoproduction., Comment: To appear in proceedings of The Second Annual Conference Large Hadron Collider on Physics Columbia University, New York, U.S.A. June 2-7, 2014. Based on arXiv:1305.2407

In this work we analyse the theoretical uncertainties on the predictions for the photoproduction of light vector mesons in coherent pp, pA and AA collisions at the LHC energies using the color dipole approach. In particular, we present our predictions for the rapidity distribution for rh0 and phi photoproduction and perform an analysis on the uncertainties associated to the choice of vector meson wavefunctionand the phenomenological models for the dipole cross section. Comparison is done with the recent ALICE analysis on coherent production of rho at 2.76 TeV in PbPb collisions., Comment: 07 pages, 6 figures. Version to be published in Phys. Rev. C

The cross section for the nuclear diffractive dissociation in proton-lead collisions at the LHC is estimated. Based on the current theoretical uncertainties for the single (target) diffactive cross section in hadron-hadron reactions one obtains sigma_SD(5.02 TeV) = 19.67 \pm 5.41 mb and sigma_SD(8.8 TeV) = 18.76 \pm 5.77 mb, respectively. The invariant mass M_X for the reaction pPb -> pX is also analyzed. Discussion is performed on the main theoretical uncertainties associated to the calculations., Comment: 04 pages, 2 figures. Final version to be published in European Physical Journal A - "Hadrons and Nuclei"

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 $\gamma p \to p f_0(980)$. 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 $E_\gamma = 9$ GeV., Comment: 6 pages, 2 figures, 1 table. Presented at the Workshop 'Excited QCD 2014'

In this work we investigate the coherent photoproduction of psi(1S), psi(2S) and Upsilon (1S) states in the proton-nucleus collisions in the LHC energies. Predictions for the rapidity distributions are presented using the color dipole formalism and including saturation effects that are expected to be relevant at high energies. Calculations are done at the energy 5.02 TeV and also for the next LHC run at 8.8 TeV in proton-lead mode. Discussion is performed on the main theoretical uncertainties associated to the calculations., Comment: 05 pages, 5 figures. Version to be published in Phys. Rev. C

In this contribution we report on the investigations of the exclusive production of J/psi and psi(2S) states in proton-proton and nucleus-nucleus reactions at the LHC using the theoretical framework of light-cone dipole formalism., Comment: Presented at EDS Blois 2013 (arXiv:1309.5705)

In this contribution we report on the investigation of the photoproduction of W and Z bosons in the planned electron-proton/nucleus collider, the LHeC. The production cross sections and the number of events are provided and theoretical uncertainties are discussed. We also analyze the sensitivity of the LHeC experiment to physics beyond Standard Model by studying the role played by anomalous WWgamma coupling in the presented process., Comment: Contribution to the proceedings of the XXI International Workshop on Deep-Inelastic Scattering and Related Subjects (DIS2013), Marseille, 22-26 April 2013

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., Comment: 05 pages. 3 figures. Version to be published in Phys. Rev. D. arXiv admin note: text overlap with arXiv:0704.0642 by other authors