Vento, V. (2018). Skyrmions at high density. Phys. Part. Nuclei Lett., 15(4), 367–370.
Abstract: The phase diagram of quantum chromodynamics is conjectured to have a rich structure containing at least three forms of matter: hadronic nuclear matter, quarkyonic matter and quark gluon plasma. We describe its formulation in terms of Skyrme crystals and justify the origin of the quarkyonic phase transition in a chiral-quark model.
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Kiesewetter, S., & Vento, V. (2010). eta-eta '-glueball mixing. Phys. Rev. D, 82(3), 034003–13pp.
Abstract: We have revisited glueball mixing with the pseudoscalar mesons in the MIT bag model scheme. The calculation has been performed in the spherical cavity approximation to the bag using two different fermion propagators, the cavity and the free propagators. We obtain probabilities of mixing for the eta at the level of 0.006%-2.0%, while for the eta' one at the level of 0.6%-40%, depending on the choice of bag radius and, therefore, of the strong coupling constant. Our results differ from previous calculations. The origin of our difference stems from the treatment of the time integrations. The comparison of our calculation with experimental data, which is consistent with small eta – eta' – G mixing, implies that the pseudoscalar glueball is small, R similar to 0.5-0.6 fm and has a large mass, M-G similar to 2000-2500 MeV.
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Mathieu, V., & Vento, V. (2010). Pseudoscalar glueball and eta-eta ' mixing. Phys. Rev. D, 81(3), 034004–12pp.
Abstract: We have performed a dynamical analysis of the mixing in the pseudoscalar channel with the goal of understanding the existence and behavior of the pseudoscalar glueball. Our philosophy has not been to predict precise values of the glueball mass but to exploit an adequate effective theory to the point of breaking and to analyze which kind of mechanisms restore compatibility with data. Our study has led to analytical solutions which allow a clear understanding of the phenomena. The outcome of our calculation leads to a large mass glueball M-Theta > 2000 MeV, to a large glue content of the eta ', and to mixing angles in agreement with previous numerical studies.
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Kochelev, N. I., & Vento, V. (2010). Gluonic components of the pion and the transition form factor gamma*gamma* -> pi(0). Phys. Rev. D, 81(3), 034009–5pp.
Abstract: We propose an effective Lagrangian for the coupling of the neutral pion with gluons whose strength is determined by a low-energy theorem. We calculate the contribution of the gluonic components arising from this interaction to the pion transition form factor gamma*gamma* -> pi(0) using the instanton liquid model to describe the quantum chromodynamics vacuum. We find that this contribution is large and might explain the anomalous behavior of the form factor at large virtuality of one of the photons, a feature which was recently discovered by the BABAR Collaboration.
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Gonzalez, P., Mathieu, V., & Vento, V. (2011). Heavy meson interquark potential. Phys. Rev. D, 84(11), 114008–7pp.
Abstract: The resolution of Dyson-Schwinger equations leads to the freezing of the QCD running coupling (effective charge) in the infrared, which is best understood as a dynamical generation of a gluon mass function, giving rise to a momentum dependence which is free from infrared divergences. We calculate the interquark static potential for heavy mesons by assuming that it is given by a massive One Gluon Exchange interaction and compare with phenomenologyical fits inspired by lattice QCD. We apply these potential forms to the description of quarkonia and conclude that, even though some aspects of the confinement mechanism are absent in the Dyson-Schwinger formalism, the spectrum can be reasonably reproduced. We discuss possible explanations for this outcome.
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Rinaldi, M., Scopetta, S., & Vento, V. (2013). Double parton correlations in constituent quark models. Phys. Rev. D, 87(11), 114021–9pp.
Abstract: Double parton correlations, having effects on the double parton scattering processes occurring in high-energy hadron-hadron collisions, for example at the LHC, are studied in the valence quark region by means of constituent quark models. In this framework, two particle correlations are present without any additional prescription, at variance with what happens, for example, in independent particle models, such as the MIT bag model in its simplest version. From the present analysis, conclusions similar to the ones obtained recently in a modified version of the bag model can be drawn: correlations in the longitudinal momenta of the active quarks are found to be sizable, while those in transverse momentum are much smaller. However, the framework used allows us to understand clearly the dynamical origin of the correlations. In particular, it is shown that the small size of the correlations in transverse momentum is a model-dependent result, which would not occur if models with sizable quark orbital angular momentum were used to describe the proton. Our analysis permits us, therefore, to clarify the dynamical origin of the double parton correlations and to establish which, among the features of the results, are model independent. The possibility of testing the studied effects experimentally is discussed.
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Rinaldi, M., & Vento, V. (2021). Meson and glueball spectroscopy within the graviton soft wall model. Phys. Rev. D, 104(3), 034016–17pp.
Abstract: The graviton soft wall (GSW) model provides a unified description of the scalar glueball and meson spectra with a unique energy scale. This success has led us to extend the analysis to the description of the spectra of other hadrons. We use this model to calculate masses of the odd and even ground states of glueballs for various spins, and show that the GSW model is able to reproduce the Regge trajectory of these systems. In addition, the spectra of the rho, a(1 )and eta mesons will be addressed. Results are in excellent agreement with current experimental data. Furthermore such an achievement is obtained without any additional parameters. Indeed, the only two parameters appearing in these spectra are those that were previously fixed by the light scalar meson and glueball spectra. Finally, in order to describe the pi meson spectrum, a suitable modification of the dilaton profile function has been included in the analysis to properly take into account the Goldstone realisation of chiral symmetry. The present investigation confirms that the GSW model provides an excellent description of the spectra of mesons and glueballs with only a small number of parameters unveiling a relevant predicting power.
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Rinaldi, M., & Vento, V. (2023). Phase transition in the holographic hard-wall model. Phys. Rev. D, 108(11), 114020–10pp.
Abstract: A Hawking-Page phase transition between anti-de Sitter (AdS) thermal and AdS black hole was presented as a mechanism for explaining the QCD deconfinement phase transition within holographic models. In order to implement temperature dependence in the confined phase we use a hard-wall AdS/QCD model, where the geometry at low temperatures is described also by a black hole metric. We then investigate the temperature dependence of glueball states described as gravitons propagating in deformed background spaces. Finally, we use potential models to physically describe the implications of our study.
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MoEDAL Collaboration(Acharya, B. et al), Bernabeu, J., Garcia, C., Mamuzic, J., Mitsou, V. A., Ruiz de Austri, R., et al. (2017). Search for Magnetic Monopoles with the MoEDAL Forward Trapping Detector in 13 TeV Proton-Proton Collisions at the LHC. Phys. Rev. Lett., 118(6), 061801–6pp.
Abstract: MoEDAL is designed to identify new physics in the form of long-lived highly ionizing particles produced in high-energy LHC collisions. Its arrays of plastic nuclear-track detectors and aluminium trapping volumes provide two independent passive detection techniques. We present here the results of a first search for magnetic monopole production in 13 TeV proton-proton collisions using the trapping technique, extending a previous publication with 8 TeV data during LHC Run 1. A total of 222 kg of MoEDAL trapping detector samples was exposed in the forward region and analyzed by searching for induced persistent currents after passage through a superconducting magnetometer. Magnetic charges exceeding half the Dirac charge are excluded in all samples and limits are placed for the first time on the production of magnetic monopoles in 13 TeV pp collisions. The search probes mass ranges previously inaccessible to collider experiments for up to five times the Dirac charge.
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MoEDAL Collaboration(Acharya, B. et al), Bernabeu, J., Mamuzic, J., Mitsou, V. A., Papavassiliou, J., Ruiz de Austri, R., et al. (2019). Magnetic Monopole Search with the Full MoEDAL Trapping Detector in 13 TeV pp Collisions Interpreted in Photon-Fusion and Drell-Yan Production. Phys. Rev. Lett., 123(2), 021802–7pp.
Abstract: MoEDAL is designed to identify new physics in the form of stable or pseudostable highly ionizing particles produced in high-energy Large Hadron Collider (LHC) collisions. Here we update our previous search for magnetic monopoles in Run 2 using the full trapping detector with almost four times more material and almost twice more integrated luminosity. For the first time at the LHC, the data were interpreted in terms of photon-fusion monopole direct production in addition to the Drell-Yan-like mechanism. The MoEDAL trapping detector, consisting of 794 kg of aluminum samples installed in the forward and lateral regions, was exposed to 4.0 fb(-1) of 13 TeV proton-proton collisions at the LHCb interaction point and analyzed by searching for induced persistent currents after passage through a superconducting magnetometer. Magnetic charges equal to or above the Dirac charge are excluded in all samples. Monopole spins 0, 1/2, and 1 are considered and both velocity-independent and-dependent couplings are assumed. This search provides the best current laboratory constraints for monopoles with magnetic charges ranging from two to five times the Dirac charge.
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