Catálogo de publicaciones - revistas

<jats:title>Abstract</jats:title> <jats:p>Heavy quarks play an important role in probing the properties of strongly interacting quark-gluon plasma (QGP) created in ultra-relativistic heavy-ion collisions. We study the interactions of single heavy (charm) quarks and correlated charm and anticharm ( <jats:inline-formula> <jats:tex-math><?CDATA $c\bar c$?></jats:tex-math> <jats:inline-graphic xmlns:xlink="http://www.w3.org/1999/xlink" xlink:href="cpc_44_5_054102_M1.jpg" xlink:type="simple" /> </jats:inline-formula>) quark pairs with the medium constituents of QGP by performing fireball+Langevin simulations of the pertinent Brownian motion with elastic collisions. Besides studying the traditional observables, the nuclear modification factor and the elliptic flow of single heavy quarks in QGP for different thermal relaxation rates, we also study the broadening of the azimuthal correlations of charm and anticharm quark pairs in the QGP medium for different relaxation rates and transverse momenta classes. We quantified the smearing of <jats:inline-formula> <jats:tex-math><?CDATA $c\bar c$?></jats:tex-math> <jats:inline-graphic xmlns:xlink="http://www.w3.org/1999/xlink" xlink:href="cpc_44_5_054102_M2.jpg" xlink:type="simple" /> </jats:inline-formula> pair azimuthal correlations with an increasing thermal relaxation rate: while the (nearly) back-to-back correlations among <jats:inline-formula> <jats:tex-math><?CDATA $c\bar c$?></jats:tex-math> <jats:inline-graphic xmlns:xlink="http://www.w3.org/1999/xlink" xlink:href="cpc_44_5_054102_M3.jpg" xlink:type="simple" /> </jats:inline-formula> pairs are almost completely washed out at low transverse momentum (<jats:italic>p<jats:sub>T</jats:sub> </jats:italic>), these correlations at high <jats:italic>p<jats:sub>T</jats:sub> </jats:italic> largely survive the pair diffusion. This provides a novel observable for diagnosing the properties of QGP. </jats:p>

<jats:title>Abstract</jats:title> <jats:p>The complex-scaled Green's function (CGF) method is employed to explore the single-proton resonance in <jats:sup>15</jats:sup>F. Special attention is paid to the first excited resonant state 5/2<jats:sup>+</jats:sup>, which has been widely studied in both theory and experiments. However, past studies generally overestimated the width of the 5/2<jats:sup>+</jats:sup> state. The predicted energy and width of the first excited resonant state 5/2<jats:sup>+</jats:sup> by the CGF method are both in good agreement with the experimental value and close to Fortune's new estimation. Furthermore, the influence of the potential parameters and quadruple deformation effects on the resonant states are investigated in detail, which is helpful to the study of the shell structure evolution. </jats:p>

<jats:title>Abstract</jats:title> <jats:p>We investigate the <jats:inline-formula> <jats:tex-math><?CDATA $ \eta \bar{K}K^* $?></jats:tex-math> <jats:inline-graphic xmlns:xlink="http://www.w3.org/1999/xlink" xlink:href="cpc_44_5_054104_M2.jpg" xlink:type="simple" /> </jats:inline-formula> three-body system in order to look for possible <jats:inline-formula> <jats:tex-math><?CDATA $ I^G(J^{PC}) = 0^+(1^{-+}) $?></jats:tex-math> <jats:inline-graphic xmlns:xlink="http://www.w3.org/1999/xlink" xlink:href="cpc_44_5_054104_M3.jpg" xlink:type="simple" /> </jats:inline-formula> exotic states in the framework of the fixed-center approximation of the Faddeev equation. We assume the scattering of <jats:inline-formula> <jats:tex-math><?CDATA $ \eta $?></jats:tex-math> <jats:inline-graphic xmlns:xlink="http://www.w3.org/1999/xlink" xlink:href="cpc_44_5_054104_M4.jpg" xlink:type="simple" /> </jats:inline-formula> on a clusterized system <jats:inline-formula> <jats:tex-math><?CDATA $ \bar{K}K^* $?></jats:tex-math> <jats:inline-graphic xmlns:xlink="http://www.w3.org/1999/xlink" xlink:href="cpc_44_5_054104_M5.jpg" xlink:type="simple" /> </jats:inline-formula>, which is known to generate <jats:inline-formula> <jats:tex-math><?CDATA $ f_1(1285) $?></jats:tex-math> <jats:inline-graphic xmlns:xlink="http://www.w3.org/1999/xlink" xlink:href="cpc_44_5_054104_M6.jpg" xlink:type="simple" /> </jats:inline-formula>, or a <jats:inline-formula> <jats:tex-math><?CDATA $ \bar{K} $?></jats:tex-math> <jats:inline-graphic xmlns:xlink="http://www.w3.org/1999/xlink" xlink:href="cpc_44_5_054104_M7.jpg" xlink:type="simple" /> </jats:inline-formula> in a clusterized system <jats:inline-formula> <jats:tex-math><?CDATA $ \eta K^* $?></jats:tex-math> <jats:inline-graphic xmlns:xlink="http://www.w3.org/1999/xlink" xlink:href="cpc_44_5_054104_M8.jpg" xlink:type="simple" /> </jats:inline-formula>, which is shown to generate <jats:inline-formula> <jats:tex-math><?CDATA $ K_1(1270) $?></jats:tex-math> <jats:inline-graphic xmlns:xlink="http://www.w3.org/1999/xlink" xlink:href="cpc_44_5_054104_M9.jpg" xlink:type="simple" /> </jats:inline-formula>. In the case of <jats:inline-formula> <jats:tex-math><?CDATA $ \eta $?></jats:tex-math> <jats:inline-graphic xmlns:xlink="http://www.w3.org/1999/xlink" xlink:href="cpc_44_5_054104_M10.jpg" xlink:type="simple" /> </jats:inline-formula>- <jats:inline-formula> <jats:tex-math><?CDATA $ (\bar{K}K^*)_{f_1(1285)} $?></jats:tex-math> <jats:inline-graphic xmlns:xlink="http://www.w3.org/1999/xlink" xlink:href="cpc_44_5_054104_M11.jpg" xlink:type="simple" /> </jats:inline-formula> scattering, we find evidence of a bound state <jats:inline-formula> <jats:tex-math><?CDATA $ I^G(J^{PC}) = 0^+(1^{-+}) $?></jats:tex-math> <jats:inline-graphic xmlns:xlink="http://www.w3.org/1999/xlink" xlink:href="cpc_44_5_054104_M12.jpg" xlink:type="simple" /> </jats:inline-formula> below the <jats:inline-formula> <jats:tex-math><?CDATA $ \eta{f_1(1285)} $?></jats:tex-math> <jats:inline-graphic xmlns:xlink="http://www.w3.org/1999/xlink" xlink:href="cpc_44_5_054104_M13.jpg" xlink:type="simple" /> </jats:inline-formula> threshold with a mass of around 1700 MeV and a width of about 180 MeV. Considering <jats:inline-formula> <jats:tex-math><?CDATA $ \bar{K} $?></jats:tex-math> <jats:inline-graphic xmlns:xlink="http://www.w3.org/1999/xlink" xlink:href="cpc_44_5_054104_M14.jpg" xlink:type="simple" /> </jats:inline-formula>- <jats:inline-formula> <jats:tex-math><?CDATA $ (\eta K^*)_{K_1(1270)} $?></jats:tex-math> <jats:inline-graphic xmlns:xlink="http://www.w3.org/1999/xlink" xlink:href="cpc_44_5_054104_M15.jpg" xlink:type="simple" /> </jats:inline-formula> scattering, we obtain a bound state <jats:inline-formula> <jats:tex-math><?CDATA $ I(J^{P}) = 0(1^{-}) $?></jats:tex-math> <jats:inline-graphic xmlns:xlink="http://www.w3.org/1999/xlink" xlink:href="cpc_44_5_054104_M16.jpg" xlink:type="simple" /> </jats:inline-formula> just below the <jats:inline-formula> <jats:tex-math><?CDATA $ \bar{K}{K_1(1270)} $?></jats:tex-math> <jats:inline-graphic xmlns:xlink="http://www.w3.org/1999/xlink" xlink:href="cpc_44_5_054104_M17.jpg" xlink:type="simple" /> </jats:inline-formula> threshold with a mass of around 1680 MeV and a width of about 160 MeV. </jats:p>

<jats:title>Abstract</jats:title> <jats:p>We analyze the transverse momentum dependence of HBT radii in relativistic heavy-ion collisions using several source models. Results indicate that the single-particle space-momentum angle distribution plays an important role in the transverse momentum dependence of HBT radii. In a cylinder source, we use several formulas to describe the transverse momentum dependence of HBT radii and the single-particle space-momentum angle distribution. We also make a numerical connection between them in the transverse plane.</jats:p>

<jats:title>Abstract</jats:title> <jats:p>We derive a simple Woods-Saxon-type form for potentials between <jats:inline-formula> <jats:tex-math><?CDATA $Y=\Xi, \Omega$?></jats:tex-math> <jats:inline-graphic xmlns:xlink="http://www.w3.org/1999/xlink" xlink:href="cpc_44_5_054106_M1.jpg" xlink:type="simple" /> </jats:inline-formula>, and <jats:inline-formula> <jats:tex-math><?CDATA $\alpha$?></jats:tex-math> <jats:inline-graphic xmlns:xlink="http://www.w3.org/1999/xlink" xlink:href="cpc_44_5_054106_M2.jpg" xlink:type="simple" /> </jats:inline-formula> using a single-folding potential method, based on a separable <jats:italic>Y</jats:italic>-nucleon potential. The potentials <jats:inline-formula> <jats:tex-math><?CDATA $\Xi+\alpha$?></jats:tex-math> <jats:inline-graphic xmlns:xlink="http://www.w3.org/1999/xlink" xlink:href="cpc_44_5_054106_M3.jpg" xlink:type="simple" /> </jats:inline-formula> and <jats:inline-formula> <jats:tex-math><?CDATA $\Omega+\alpha$?></jats:tex-math> <jats:inline-graphic xmlns:xlink="http://www.w3.org/1999/xlink" xlink:href="cpc_44_5_054106_M4.jpg" xlink:type="simple" /> </jats:inline-formula> are accordingly obtained using the ESC08c Nijmegens <jats:inline-formula> <jats:tex-math><?CDATA $\Xi N$?></jats:tex-math> <jats:inline-graphic xmlns:xlink="http://www.w3.org/1999/xlink" xlink:href="cpc_44_5_054106_M5.jpg" xlink:type="simple" /> </jats:inline-formula> potential (in <jats:inline-formula> <jats:tex-math><?CDATA $^{3}S_{1}$?></jats:tex-math> <jats:inline-graphic xmlns:xlink="http://www.w3.org/1999/xlink" xlink:href="cpc_44_5_054106_M6.jpg" xlink:type="simple" /> </jats:inline-formula> channel) and HAL QCD collaboration <jats:inline-formula> <jats:tex-math><?CDATA $\Omega N$?></jats:tex-math> <jats:inline-graphic xmlns:xlink="http://www.w3.org/1999/xlink" xlink:href="cpc_44_5_054106_M7.jpg" xlink:type="simple" /> </jats:inline-formula> interactions (in lattice QCD), respectively. In deriving the potential between <jats:italic>Y</jats:italic> and <jats:inline-formula> <jats:tex-math><?CDATA $\alpha$?></jats:tex-math> <jats:inline-graphic xmlns:xlink="http://www.w3.org/1999/xlink" xlink:href="cpc_44_5_054106_M8.jpg" xlink:type="simple" /> </jats:inline-formula>, the same potential between <jats:italic>Y</jats:italic> and <jats:italic>N</jats:italic> is employed. The binding energy, scattering length, and effective range of the <jats:italic>Y</jats:italic> particle on the alpha particle are approximated by the resulting potentials. The depths of the potentials in <jats:inline-formula> <jats:tex-math><?CDATA $\Omega \alpha $?></jats:tex-math> <jats:inline-graphic xmlns:xlink="http://www.w3.org/1999/xlink" xlink:href="cpc_44_5_054106_M9.jpg" xlink:type="simple" /> </jats:inline-formula> and <jats:inline-formula> <jats:tex-math><?CDATA $\Xi \alpha $?></jats:tex-math> <jats:inline-graphic xmlns:xlink="http://www.w3.org/1999/xlink" xlink:href="cpc_44_5_054106_M10.jpg" xlink:type="simple" /> </jats:inline-formula> systems are obtained at <jats:inline-formula> <jats:tex-math><?CDATA $-61$?></jats:tex-math> <jats:inline-graphic xmlns:xlink="http://www.w3.org/1999/xlink" xlink:href="cpc_44_5_054106_M11.jpg" xlink:type="simple" /> </jats:inline-formula> MeV and <jats:inline-formula> <jats:tex-math><?CDATA $-24.4$?></jats:tex-math> <jats:inline-graphic xmlns:xlink="http://www.w3.org/1999/xlink" xlink:href="cpc_44_5_054106_M12.jpg" xlink:type="simple" /> </jats:inline-formula> MeV, respectively. In the case of the <jats:inline-formula> <jats:tex-math><?CDATA $\Xi \alpha$?></jats:tex-math> <jats:inline-graphic xmlns:xlink="http://www.w3.org/1999/xlink" xlink:href="cpc_44_5_054106_M13.jpg" xlink:type="simple" /> </jats:inline-formula> potential, a fairly good agreement is observed between the single-folding potential method and the phenomenological potential of the Dover-Gal model. These potentials can be used in 3-,4- and 5-body cluster structures of <jats:inline-formula> <jats:tex-math><?CDATA $ \Omega$?></jats:tex-math> <jats:inline-graphic xmlns:xlink="http://www.w3.org/1999/xlink" xlink:href="cpc_44_5_054106_M14.jpg" xlink:type="simple" /> </jats:inline-formula> and <jats:inline-formula> <jats:tex-math><?CDATA $\Xi$?></jats:tex-math> <jats:inline-graphic xmlns:xlink="http://www.w3.org/1999/xlink" xlink:href="cpc_44_5_054106_M15.jpg" xlink:type="simple" /> </jats:inline-formula> hypernuclei. </jats:p>

<jats:title>Abstract</jats:title> <jats:p>We used the cluster structure properties of the <jats:sup>212</jats:sup>Po to estimate the neutron skin thickness of <jats:sup>208</jats:sup>Pb. For this purpose, we considered two important components: (a) alpha decay is a low energy phenomenon; therefore, one can expect that the mean-field, which can explain the ground state properties of <jats:sup>212</jats:sup>Po, does not change during the alpha decay process. (b) <jats:sup>212</jats:sup>Po has a high alpha cluster-like structure, two protons and two neutrons outside its core nucleus with a double magic closed-shell, and the cluster model is a powerful formalism for the estimation of alpha decay preformation factor of such nuclei. The slope of the symmetry energy of <jats:sup>208</jats:sup>Pb is estimated to be <jats:inline-formula> <jats:tex-math><?CDATA $75\pm25$?></jats:tex-math> <jats:inline-graphic xmlns:xlink="http://www.w3.org/1999/xlink" xlink:href="cpc_44_5_054107_M6.jpg" xlink:type="simple" /> </jats:inline-formula> MeV within the selected same mean-fields and Skyrme forces, which can simultaneously satisfy the ground-state properties of parent and daughter nuclei, as their neutron skin thicknesses are consistent with experimental data. </jats:p>

<jats:title>Abstract</jats:title> <jats:p>To explain the experimental observation that the fusion cross-section of a proton-halo nucleus with a heavy target nucleus is not enhanced as expected, the shielding hypothesis was proposed, where the proton-halo nucleus is polarized and the valence proton shielded by the core. In the frame of the improved quantum molecular dynamics model, the fusion reaction <jats:sup>17</jats:sup>F on <jats:sup>208</jats:sup>Pb around the Coulomb barrier is simulated. The existence of the shielding effect is verified by the microscopic dynamics simulations. Its influence on the effective interaction potential is also investigated. </jats:p>

<jats:title>Abstract</jats:title> <jats:p>A microscopic approach is employed to study the optical potential for the <jats:sup>7</jats:sup>Li-nucleus interaction system without any free parameters. It is obtained by folding the microscopic optical potentials of the constituent nucleons of <jats:sup>7</jats:sup>Li over their density distributions. We employ an isospin-dependent nucleon microscopic optical potential, which is based on the Skyrme nucleon-nucleon effective interaction and derived using the Green's function method, as the nucleon optical potential. The harmonic oscillator shell model is used to describe the internal wave function of <jats:sup>7</jats:sup>Li and obtain the nucleon density distribution. The <jats:sup>7</jats:sup>Li microscopic optical potential is used to predict the reaction cross-sections and elastic scattering angular distributions for the target range from <jats:sup>27</jats:sup>Al to <jats:sup>208</jats:sup>Pb and energy range below 450 MeV. Generally, the results can reproduce the measured data reasonably well. In addition, the microscopic optical potential is comparable to a global phenomenological optical potential by fitting the presently existing measured data. </jats:p>

<jats:title>Abstract</jats:title> <jats:p>The energy per particle <jats:italic>B<jats:sub>A</jats:sub> </jats:italic> in nuclear matter is calculated up to high baryon density in the whole isospin asymmetry range from symmetric matter to pure neutron matter. The results, obtained in the framework of the Brueckner-Hartree-Fock approximation with two- and three-body forces, confirm the well-known parabolic dependence on the asymmetry parameter <jats:italic>β</jats:italic> = (<jats:italic>N</jats:italic> − <jats:italic>Z</jats:italic>)/<jats:italic>A</jats:italic> (<jats:italic>β</jats:italic> <jats:sup>2</jats:sup>law) that is valid in a wide density range. To investigate the extent to which this behavior can be traced back to the properties of the underlying interaction, aside from the mean field approximation, the spin-isospin decomposition of <jats:italic>B<jats:sub>A</jats:sub> </jats:italic> is performed. Theoretical indications suggest that the <jats:italic>β</jats:italic> <jats:sup>2</jats:sup>law could be violated at higher densities as a consequence of the three-body forces. This raises the problem that the symmetry energy, calculated according to the <jats:italic>β</jats:italic> <jats:sup>2</jats:sup>law as a difference between <jats:italic>B<jats:sub>A</jats:sub> </jats:italic> in pure neutron matter and symmetric nuclear matter, cannot be applied to neutron stars. One should return to the proper definition of the nuclear symmetry energy as a response of the nuclear system to small isospin imbalance from the <jats:italic>Z</jats:italic> = <jats:italic>N</jats:italic> nuclei and pure neutron matter. </jats:p>

<jats:title>Abstract</jats:title> <jats:p>We study the prospects of using the low-redshift and high-redshift black hole shadows as new cosmological standard rulers for measuring cosmological parameters. We show that, using the low-redshift observation of the black hole shadow of <jats:inline-formula> <jats:tex-math><?CDATA ${\rm M87}^\star$?></jats:tex-math> <jats:inline-graphic xmlns:xlink="http://www.w3.org/1999/xlink" xlink:href="cpc_44_5_055101_Z-20200317145709.jpg" xlink:type="simple" /> </jats:inline-formula>, the Hubble constant can be independently determined with a precision of about 13% as <jats:inline-formula> <jats:tex-math><?CDATA $H_0=70\pm 9$?></jats:tex-math> <jats:inline-graphic xmlns:xlink="http://www.w3.org/1999/xlink" xlink:href="cpc_44_5_055101_M2.jpg" xlink:type="simple" /> </jats:inline-formula> km <jats:inline-formula> <jats:tex-math><?CDATA ${\rm s}^{-1}$?></jats:tex-math> <jats:inline-graphic xmlns:xlink="http://www.w3.org/1999/xlink" xlink:href="cpc_44_5_055101_M3.jpg" xlink:type="simple" /> </jats:inline-formula> <jats:inline-formula> <jats:tex-math><?CDATA ${\rm Mpc}^{-1}$?></jats:tex-math> <jats:inline-graphic xmlns:xlink="http://www.w3.org/1999/xlink" xlink:href="cpc_44_5_055101_M4.jpg" xlink:type="simple" /> </jats:inline-formula>. The high-redshift observations of super-massive black hole shadows may accurately determine a combination of parameters <jats:inline-formula> <jats:tex-math><?CDATA $H_0$?></jats:tex-math> <jats:inline-graphic xmlns:xlink="http://www.w3.org/1999/xlink" xlink:href="cpc_44_5_055101_M5.jpg" xlink:type="simple" /> </jats:inline-formula> and <jats:inline-formula> <jats:tex-math><?CDATA ${\Omega_{m}}$?></jats:tex-math> <jats:inline-graphic xmlns:xlink="http://www.w3.org/1999/xlink" xlink:href="cpc_44_5_055101_M6.jpg" xlink:type="simple" /> </jats:inline-formula>, and we show by a simple simulation that combining them with the type Ia supernovae observations would give precise measurements of the cosmological parameters. </jats:p>