Catálogo de publicaciones - revistas

<jats:title>Abstract</jats:title> <jats:p>We study the quark-antiquark scattering phase shift and meson spectral function in the pion superfluid described by the Nambu-Jona-Lasinio model. Meson mixing in the pion superfluid dramatically changes the full scattering phase shift and significantly broadens the spectral function of some collective modes.</jats:p>

<jats:title>Abstract</jats:title> <jats:p>A quark coalescence model, based on semi-relativistic molecular dynamics with color interactions among quarks, is presented and applied to <jats:italic>pp</jats:italic> collisions. A phenomenological potential with two tunable parameters is introduced to describe the color interactions between quarks and antiquarks. The interactions drive the process of hadronization that finally results in different color neutral clusters, which can be identified as hadrons based on some criteria. A Monte Carlo generator PYTHIA is used to generate quarks in the initial state of hadronization, and different values of tunable parameters are used to study the final state distributions and correlations. Baryon-to-meson ratio, transverse momentum spectra, pseudorapidity distributions and forward-backward multiplicity correlations of hadrons produced in the hadronization process, obtained from this model with different parameters, are compared with those from PYTHIA. </jats:p>

<jats:title>Abstract</jats:title> <jats:p>This study investigates the optimal projectile/target combination for the production of new neutron-deficient isotopes of superheavy nuclei (SHN). To this end, the dependence of the evaporation residue cross-section (ERCS) used to synthesize SHN on the mass asymmetry and the isospin of colliding nuclei are analyzed within the dinuclear system (DNS) concept. The predicted ERCSs for the production of new neutron-deficient isotopes of SHN were found to be quite large with the <jats:sup>36</jats:sup>S projectile, and the cross-section of SHN decreases slowly with the charge of compound nuclei owing to the increase in their survival probability, <jats:inline-formula> <jats:tex-math><?CDATA $ W_{{\rm sur}} $?></jats:tex-math> <jats:inline-graphic xmlns:xlink="http://www.w3.org/1999/xlink" xlink:href="cpc_43_5_054105_M2.jpg" xlink:type="simple" /> </jats:inline-formula>. W<jats:sub>sur</jats:sub> is not canceled by the decreasing probability, PCN, that the system will evolve from a touching configuration to the compound nucleus in competition with the quasifission process. </jats:p>

<jats:title>Abstract</jats:title> <jats:p>Within the framework of the UrQMD model, by tracing the number of initial quarks in protons, we study the elliptic flow of protons with 3, 2, 1, 0 initial quarks and anti-protons in Au+Au collisions at <jats:inline-formula> <jats:tex-math><?CDATA $ \sqrt{s_{{\rm NN}}} $?></jats:tex-math> <jats:inline-graphic xmlns:xlink="http://www.w3.org/1999/xlink" xlink:href="cpc_43_5_054106_M1.jpg" xlink:type="simple" /> </jats:inline-formula> = 7.7, 11.5, 39, 200 GeV. The difference of elliptic flow between protons with 2, 1, 0 initial quarks and anti-protons is smaller than 0, or consistent with 0, respectively. The difference of elliptic flow between transported protons (with 3 initial quarks) and anti-protons is larger than 0 at 7.7, 11.5 and 39 GeV. This is in good agreement with the STAR results at 7.7 and 11.5 GeV, but overestimates the STAR results at 39 GeV. The yield of transported protons with 3 initial quarks is smaller than of protons with 2 and 1 initial quarks, and <jats:inline-formula> <jats:tex-math><?CDATA $ v_{2} $?></jats:tex-math> <jats:inline-graphic xmlns:xlink="http://www.w3.org/1999/xlink" xlink:href="cpc_43_5_054106_M2.jpg" xlink:type="simple" /> </jats:inline-formula> of all protons is much smaller than the STAR results. The observation of the difference of elliptic flow between transported protons and anti-protons in the UrQMD model partly explains the <jats:inline-formula> <jats:tex-math><?CDATA $ v_{2} $?></jats:tex-math> <jats:inline-graphic xmlns:xlink="http://www.w3.org/1999/xlink" xlink:href="cpc_43_5_054106_M3.jpg" xlink:type="simple" /> </jats:inline-formula> difference between protons and anti-protons observed in the Beam Energy Scan program at the Relativistic Heavy Ion Collider (RHIC). </jats:p>

<jats:title>Abstract</jats:title> <jats:p>The particle-number-conserving method based on the cranked shell model is used to investigate the antimagnetic rotation band in <jats:sup>104</jats:sup>Pd. The experimental moments of inertia and reduced <jats:italic>B</jats:italic>(<jats:italic>E</jats:italic>2) transition probabilities are reproduced well. The <jats:italic>J</jats:italic> <jats:sup>(2)</jats:sup>/<jats:italic>B</jats:italic>(<jats:italic>E</jats:italic>2) ratios are also discussed. The occupation probability of each orbital close to the Fermi surface and the contribution of each major shell to the total angular momentum alignment as function of rotational frequency are analyzed. The backbending mechanism of the ground state band in <jats:sup>104</jats:sup>Pd is understood clearly and the configuration of the antimagnetic rotation after backbending is clarified. In addition, the crossing of a four quasiparticle state with this antimagnetic rotation band is also predicted. By examining the closing of the angular momenta of four proton holes towards the neutron angular momentum, the " two-shears-like” mechanism for this antimagnetic rotation is investigated and two stages of antimagnetic rotation in <jats:sup>104</jats:sup>Pd are clearly seen. </jats:p>

<jats:title>Abstract</jats:title> <jats:p>Inasmuch as the hydrostatic structure of the interior of neutron stars uniquely depends on the equation of state (EOS), the inverse constraints on EOS from astrophysical observations have been an important method for revealing the properties of high density matter. Currently, most EOS for neutron star matter are given in tabular form, but these numerical tables can have quite different resolution. To guarantee both the accuracy and efficiency in computing the Tolman-Oppenheimer-Volkoff equations, a concise standard for generating EOS tables with suitable resolution is investigated. It is shown that EOS tables with 50 points logarithmic-uniformly distributed in the supra-nuclear density segment [ <jats:inline-formula> <jats:tex-math><?CDATA $ \rho_{0}, 10 \rho_{0} $?></jats:tex-math> <jats:inline-graphic xmlns:xlink="http://www.w3.org/1999/xlink" xlink:href="cpc_43_5_054108_M1.jpg" xlink:type="simple" /> </jats:inline-formula>], where <jats:inline-formula> <jats:tex-math><?CDATA $ \rho_{0} $?></jats:tex-math> <jats:inline-graphic xmlns:xlink="http://www.w3.org/1999/xlink" xlink:href="cpc_43_5_054108_M2.jpg" xlink:type="simple" /> </jats:inline-formula> is the nuclear saturation density, correspond to the interpolation induced errors of ~0.02% for the gravitational mass <jats:inline-formula> <jats:tex-math><?CDATA $ M $?></jats:tex-math> <jats:inline-graphic xmlns:xlink="http://www.w3.org/1999/xlink" xlink:href="cpc_43_5_054108_M4.jpg" xlink:type="simple" /> </jats:inline-formula> and ~0.2% for the tidal deformability <jats:inline-formula> <jats:tex-math><?CDATA $ \Lambda $?></jats:tex-math> <jats:inline-graphic xmlns:xlink="http://www.w3.org/1999/xlink" xlink:href="cpc_43_5_054108_M6.jpg" xlink:type="simple" /> </jats:inline-formula>. </jats:p>

<jats:title>Abstract</jats:title> <jats:p>We discuss the sign and energy dependence of second to tenth order susceptibilities of the baryon number, charge number, and strangeness for the analysis of critical conditions in heavy ion collisions in the LHC and RHIC by applying a modified Nambu-Jona-Lasinio model. This model is fitted to the quark condensate of the lattice QCD result at finite temperature and zero baryon chemical potential. The presence of a critical point made these susceptibilities deviate considerably from a Hadron-Resonance-Gas model that shows no criticality. The sign, magnitude, and energy dependence of these higher order fluctuations hint towards the existence and location of a critical point that could be discovered in future heavy ion collision experiments.</jats:p>

<jats:title>Abstract</jats:title> <jats:p>Jet shape measurements are employed to explore the microscopic evolution mechanisms of parton-medium interaction in ultra-relativistic heavy-ion collisions. In this study, jet shape modifications are quantified in terms of the fragmentation function <jats:inline-formula> <jats:tex-math><?CDATA $ F(z) $?></jats:tex-math> <jats:inline-graphic xmlns:xlink="http://www.w3.org/1999/xlink" xlink:href="cpc_43_5_054110_M1.jpg" xlink:type="simple" /> </jats:inline-formula>, relative momentum <jats:inline-formula> <jats:tex-math><?CDATA $ p_{T}^{\rm rel} $?></jats:tex-math> <jats:inline-graphic xmlns:xlink="http://www.w3.org/1999/xlink" xlink:href="cpc_43_5_054110_M2.jpg" xlink:type="simple" /> </jats:inline-formula>, density of charged particles <jats:inline-formula> <jats:tex-math><?CDATA $ \rho(r) $?></jats:tex-math> <jats:inline-graphic xmlns:xlink="http://www.w3.org/1999/xlink" xlink:href="cpc_43_5_054110_M3.jpg" xlink:type="simple" /> </jats:inline-formula>, jet angularity <jats:inline-formula> <jats:tex-math><?CDATA $ girth $?></jats:tex-math> <jats:inline-graphic xmlns:xlink="http://www.w3.org/1999/xlink" xlink:href="cpc_43_5_054110_M4.jpg" xlink:type="simple" /> </jats:inline-formula>, jet momentum dispersion <jats:inline-formula> <jats:tex-math><?CDATA $ p_{T}^{\rm disp} $?></jats:tex-math> <jats:inline-graphic xmlns:xlink="http://www.w3.org/1999/xlink" xlink:href="cpc_43_5_054110_M5.jpg" xlink:type="simple" /> </jats:inline-formula>, and <jats:inline-formula> <jats:tex-math><?CDATA $ LeSub $?></jats:tex-math> <jats:inline-graphic xmlns:xlink="http://www.w3.org/1999/xlink" xlink:href="cpc_43_5_054110_M6.jpg" xlink:type="simple" /> </jats:inline-formula> for proton-proton (pp) collisions at 0.9, 2.76, 5.02, 7, and 13 TeV, as well as for lead-lead collisions at 2.76 TeV and 5.02 TeV by JEWEL. A differential jet shape parameter <jats:inline-formula> <jats:tex-math><?CDATA $ D_{girth} $?></jats:tex-math> <jats:inline-graphic xmlns:xlink="http://www.w3.org/1999/xlink" xlink:href="cpc_43_5_054110_M7.jpg" xlink:type="simple" /> </jats:inline-formula> is proposed and studied at a smaller jet radius <jats:inline-formula> <jats:tex-math><?CDATA $ r \lt 0.3 $?></jats:tex-math> <jats:inline-graphic xmlns:xlink="http://www.w3.org/1999/xlink" xlink:href="cpc_43_5_054110_M8.jpg" xlink:type="simple" /> </jats:inline-formula>. The results indicate that the medium has the dominant effect on jet shape modification, which also has a weak dependence on the center-of-mass energy. Jet fragmentation is enhanced significantly at very low <jats:inline-formula> <jats:tex-math><?CDATA $ z \lt 0.02 $?></jats:tex-math> <jats:inline-graphic xmlns:xlink="http://www.w3.org/1999/xlink" xlink:href="cpc_43_5_054110_M9.jpg" xlink:type="simple" /> </jats:inline-formula>, and fragmented jet constituents are linearly spread to larger jet-radii for <jats:inline-formula> <jats:tex-math><?CDATA $ p_{T}^{\rm rel} \lt 1 $?></jats:tex-math> <jats:inline-graphic xmlns:xlink="http://www.w3.org/1999/xlink" xlink:href="cpc_43_5_054110_M10.jpg" xlink:type="simple" /> </jats:inline-formula>. The waveform attenuation phenomena is observed in <jats:inline-formula> <jats:tex-math><?CDATA $ p_{T}^{\rm rel} $?></jats:tex-math> <jats:inline-graphic xmlns:xlink="http://www.w3.org/1999/xlink" xlink:href="cpc_43_5_054110_M11.jpg" xlink:type="simple" /> </jats:inline-formula>, <jats:inline-formula> <jats:tex-math><?CDATA $ girth $?></jats:tex-math> <jats:inline-graphic xmlns:xlink="http://www.w3.org/1999/xlink" xlink:href="cpc_43_5_054110_M12.jpg" xlink:type="simple" /> </jats:inline-formula>, and <jats:inline-formula> <jats:tex-math><?CDATA $ D_{girth} $?></jats:tex-math> <jats:inline-graphic xmlns:xlink="http://www.w3.org/1999/xlink" xlink:href="cpc_43_5_054110_M13.jpg" xlink:type="simple" /> </jats:inline-formula> distributions. The results obtained for <jats:inline-formula> <jats:tex-math><?CDATA $ D_{girth} $?></jats:tex-math> <jats:inline-graphic xmlns:xlink="http://www.w3.org/1999/xlink" xlink:href="cpc_43_5_054110_M14.jpg" xlink:type="simple" /> </jats:inline-formula>from <jats:inline-formula> <jats:tex-math><?CDATA ${\rm pp} $?></jats:tex-math> <jats:inline-graphic xmlns:xlink="http://www.w3.org/1999/xlink" xlink:href="cpc_43_5_054110_M15.jpg" xlink:type="simple" /> </jats:inline-formula> to <jats:inline-formula> <jats:tex-math><?CDATA $ {\rm Pb+Pb} $?></jats:tex-math> <jats:inline-graphic xmlns:xlink="http://www.w3.org/1999/xlink" xlink:href="cpc_43_5_054110_M16.jpg" xlink:type="simple" /> </jats:inline-formula>, where the wave-like distribution in <jats:inline-formula> <jats:tex-math><?CDATA $ {\rm pp} $?></jats:tex-math> <jats:inline-graphic xmlns:xlink="http://www.w3.org/1999/xlink" xlink:href="cpc_43_5_054110_M17.jpg" xlink:type="simple" /> </jats:inline-formula> collision is ahead of <jats:inline-formula> <jats:tex-math><?CDATA $ {\rm Pb+Pb} $?></jats:tex-math> <jats:inline-graphic xmlns:xlink="http://www.w3.org/1999/xlink" xlink:href="cpc_43_5_054110_M18.jpg" xlink:type="simple" /> </jats:inline-formula> collisions at small jet-radii, indicates a strong medium effect. </jats:p>

<jats:title>Abstract</jats:title> <jats:p>Within the framework of the Dyson-Schwinger equations and by means of Multiple Reflection Expansion, we study the effect of finite volume on the chiral phase transition in a sphere, and discuss in particular its influence on the possible location of the critical end point (CEP). According to our calculations, when we take a sphere instead of a cube, the influence of finite volume on phase transition is not as significant as previously calculated. For instance, as the radius of the spherical volume decreases from infinite to 2 fm, the critical temperature <jats:inline-formula> <jats:tex-math><?CDATA $T_{c}$?></jats:tex-math> <jats:inline-graphic xmlns:xlink="http://www.w3.org/1999/xlink" xlink:href="cpc_43_6_063101_M1.jpg" xlink:type="simple" /> </jats:inline-formula> , at zero chemical potential and finite temperature, drops only slightly. At finite chemical potential and finite temperature, the location of CEP shifts towards smaller temperature and higher chemical potential, but the amplitude of the variation does not exceed 20%. As a result, we find that not only the size of the volume but also its shape have a considerable impact on the phase transition. </jats:p>

<jats:title>Abstract</jats:title> <jats:p>One of the main problems in particle physics is to understand the origin and nature of dark matter. An exciting possibility is to consider that dark matter belongs to a new complex but hidden sector. In this paper, we assume the existence of a strongly interacting dark sector consisting of a new scalar doublet and new vector resonances, in accordance with the model recently proposed by our group. Since it was found in the previous work that it is very challenging to find the new vector resonances at the LHC, here we study the possibility of finding them at the future Compact Linear Collider (CLIC) running at <jats:inline-formula> <jats:tex-math><?CDATA $\sqrt{s}=3$?></jats:tex-math> <jats:inline-graphic xmlns:xlink="http://www.w3.org/1999/xlink" xlink:href="cpc_43_6_063102_M1.jpg" xlink:type="simple" /> </jats:inline-formula> TeV. We consider two distinct scenarios. In the first, when the non-standard scalars are heavy, the dark resonance is intense enough to make its discovery possible at CLIC when the resonance mass is in the range [2000, 3000] GeV. In the second scenario, when the non-standard scalars are light, the new vector boson is too broad to be recognized as a resonance, and is not detectable except when the mass of the scalars is close to (but smaller than) half of the resonance mass and the scale of the dark sector is high. In all positive cases, less than a tenth of the maximum integrated luminosity is needed to reach the discovery level. Finally, we also comment on the mono- <jats:inline-formula> <jats:tex-math><?CDATA $Z$?></jats:tex-math> <jats:inline-graphic xmlns:xlink="http://www.w3.org/1999/xlink" xlink:href="cpc_43_6_063102_M2.jpg" xlink:type="simple" /> </jats:inline-formula> production. </jats:p>