Catálogo de publicaciones - revistas

<jats:title>Abstract</jats:title> <jats:p>We investigate the mass-shift of <jats:italic>P</jats:italic>-wave charmonium ( <jats:inline-formula> <jats:tex-math><?CDATA $ {\chi_c}_0 $?></jats:tex-math> <jats:inline-graphic xmlns:xlink="http://www.w3.org/1999/xlink" xlink:href="cpc_43_12_124109_M1.jpg" xlink:type="simple" /> </jats:inline-formula>, <jats:inline-formula> <jats:tex-math><?CDATA $ {\chi_c}_1 $?></jats:tex-math> <jats:inline-graphic xmlns:xlink="http://www.w3.org/1999/xlink" xlink:href="cpc_43_12_124109_M2.jpg" xlink:type="simple" /> </jats:inline-formula>), and <jats:italic>S</jats:italic> and <jats:italic>P</jats:italic>-wave bottomonium ( <jats:inline-formula> <jats:tex-math><?CDATA $ \eta_b $?></jats:tex-math> <jats:inline-graphic xmlns:xlink="http://www.w3.org/1999/xlink" xlink:href="cpc_43_12_124109_M3.jpg" xlink:type="simple" /> </jats:inline-formula>, <jats:inline-formula> <jats:tex-math><?CDATA $ \Upsilon $?></jats:tex-math> <jats:inline-graphic xmlns:xlink="http://www.w3.org/1999/xlink" xlink:href="cpc_43_12_124109_M4.jpg" xlink:type="simple" /> </jats:inline-formula>, <jats:inline-formula> <jats:tex-math><?CDATA $ {\chi_b}_0 $?></jats:tex-math> <jats:inline-graphic xmlns:xlink="http://www.w3.org/1999/xlink" xlink:href="cpc_43_12_124109_M5.jpg" xlink:type="simple" /> </jats:inline-formula>, and <jats:inline-formula> <jats:tex-math><?CDATA $ {\chi_b}_1 $?></jats:tex-math> <jats:inline-graphic xmlns:xlink="http://www.w3.org/1999/xlink" xlink:href="cpc_43_12_124109_M6.jpg" xlink:type="simple" /> </jats:inline-formula>) states in magnetized hot asymmetric nuclear matter using the unification of QCD sum rules (QCDSR) and the chiral <jats:inline-formula> <jats:tex-math><?CDATA $ SU(3) $?></jats:tex-math> <jats:inline-graphic xmlns:xlink="http://www.w3.org/1999/xlink" xlink:href="cpc_43_12_124109_M7.jpg" xlink:type="simple" /> </jats:inline-formula> model. Within QCDSR, we use two approaches, i.e., the moment sum rule and the Borel sum rule. The magnetic field induced scalar gluon condensate <jats:inline-formula> <jats:tex-math><?CDATA $ \left\langle \frac{\alpha_{s}}{\pi} G^a_{\mu\nu} {G^a}^{\mu\nu} \right\rangle $?></jats:tex-math> <jats:inline-graphic xmlns:xlink="http://www.w3.org/1999/xlink" xlink:href="cpc_43_12_124109_M9.jpg" xlink:type="simple" /> </jats:inline-formula> and the twist-2 gluon operator <jats:inline-formula> <jats:tex-math><?CDATA $ \left\langle \frac{\alpha_{s}}{\pi} G^a_{\mu\sigma} {{G^a}_\nu}^{\sigma} \right\rangle $?></jats:tex-math> <jats:inline-graphic xmlns:xlink="http://www.w3.org/1999/xlink" xlink:href="cpc_43_12_124109_M10.jpg" xlink:type="simple" /> </jats:inline-formula> calculated in the chiral <jats:inline-formula> <jats:tex-math><?CDATA $ SU(3 $?></jats:tex-math> <jats:inline-graphic xmlns:xlink="http://www.w3.org/1999/xlink" xlink:href="cpc_43_12_124109_M11.jpg" xlink:type="simple" /> </jats:inline-formula>) model are utilised in QCD sum rules to calculate the in-medium mass-shift of the above mesons. The attractive mass-shift of these mesons is observed, which is more sensitive to magnetic field in the high density regime for charmonium, however less so for bottomonium. These results may be helpful to understand the decay of higher quarkonium states to the lower quarkonium states in asymmetric heavy ion collision experiments. </jats:p>

<jats:title>Abstract</jats:title> <jats:p>The electric quadrupole moment <jats:inline-formula> <jats:tex-math><?CDATA $Q$?></jats:tex-math> <jats:inline-graphic xmlns:xlink="http://www.w3.org/1999/xlink" xlink:href="cpc_43_12_124110_M1.jpg" xlink:type="simple" /> </jats:inline-formula> and the magnetic moment <jats:inline-formula> <jats:tex-math><?CDATA $\mu$?></jats:tex-math> <jats:inline-graphic xmlns:xlink="http://www.w3.org/1999/xlink" xlink:href="cpc_43_12_124110_M2.jpg" xlink:type="simple" /> </jats:inline-formula> (or the <jats:inline-formula> <jats:tex-math><?CDATA $g$?></jats:tex-math> <jats:inline-graphic xmlns:xlink="http://www.w3.org/1999/xlink" xlink:href="cpc_43_12_124110_M3.jpg" xlink:type="simple" /> </jats:inline-formula> factor) of low-lying states in even-even nuclei <jats:sup>72-80</jats:sup>Ge and odd-mass nuclei <jats:sup>75-79</jats:sup>Ge are studied in the framework of the nucleon pair approximation (NPA) of the shell model, assuming the monopole and quadrupole pairing plus quadrupole-quadrupole interaction. Our calculations reproduce well the experimental values of <jats:inline-formula> <jats:tex-math><?CDATA $Q(2_1^{+})$?></jats:tex-math> <jats:inline-graphic xmlns:xlink="http://www.w3.org/1999/xlink" xlink:href="cpc_43_12_124110_M6.jpg" xlink:type="simple" /> </jats:inline-formula> and <jats:inline-formula> <jats:tex-math><?CDATA $g(2_1^+)$?></jats:tex-math> <jats:inline-graphic xmlns:xlink="http://www.w3.org/1999/xlink" xlink:href="cpc_43_12_124110_M7.jpg" xlink:type="simple" /> </jats:inline-formula> for <jats:sup>72,74,76</jats:sup>Ge, as well as the yrast energy levels of these isotopes. The structure of the <jats:inline-formula> <jats:tex-math><?CDATA $2_1^+$?></jats:tex-math> <jats:inline-graphic xmlns:xlink="http://www.w3.org/1999/xlink" xlink:href="cpc_43_12_124110_M9.jpg" xlink:type="simple" /> </jats:inline-formula> states and the contributions of the proton and neutron components in <jats:inline-formula> <jats:tex-math><?CDATA $Q(2_1^{+})$?></jats:tex-math> <jats:inline-graphic xmlns:xlink="http://www.w3.org/1999/xlink" xlink:href="cpc_43_12_124110_M10.jpg" xlink:type="simple" /> </jats:inline-formula> and <jats:inline-formula> <jats:tex-math><?CDATA $g(2_1^+)$?></jats:tex-math> <jats:inline-graphic xmlns:xlink="http://www.w3.org/1999/xlink" xlink:href="cpc_43_12_124110_M11.jpg" xlink:type="simple" /> </jats:inline-formula> are discussed in the <jats:inline-formula> <jats:tex-math><?CDATA $SD$?></jats:tex-math> <jats:inline-graphic xmlns:xlink="http://www.w3.org/1999/xlink" xlink:href="cpc_43_12_124110_M12.jpg" xlink:type="simple" /> </jats:inline-formula>-pair truncated shell-model subspace. The overall trend of <jats:inline-formula> <jats:tex-math><?CDATA $Q(2_1^{+})$?></jats:tex-math> <jats:inline-graphic xmlns:xlink="http://www.w3.org/1999/xlink" xlink:href="cpc_43_12_124110_M13.jpg" xlink:type="simple" /> </jats:inline-formula> and <jats:inline-formula> <jats:tex-math><?CDATA $g(2_1^+)$?></jats:tex-math> <jats:inline-graphic xmlns:xlink="http://www.w3.org/1999/xlink" xlink:href="cpc_43_12_124110_M14.jpg" xlink:type="simple" /> </jats:inline-formula> as a function of the mass number <jats:inline-formula> <jats:tex-math><?CDATA $A$?></jats:tex-math> <jats:inline-graphic xmlns:xlink="http://www.w3.org/1999/xlink" xlink:href="cpc_43_12_124110_M15.jpg" xlink:type="simple" /> </jats:inline-formula>, as well as their signs, are found to originate essentially from the proton contribution. The negative value of <jats:inline-formula> <jats:tex-math><?CDATA $Q(2^+_1)$?></jats:tex-math> <jats:inline-graphic xmlns:xlink="http://www.w3.org/1999/xlink" xlink:href="cpc_43_12_124110_M16.jpg" xlink:type="simple" /> </jats:inline-formula> in <jats:sup>72,74</jats:sup>Ge is suggested to be due to the enhanced quadrupole-quadrupole correlation and configuration mixing. </jats:p>

<jats:title>Abstract</jats:title> <jats:p>Considering the cosmological constant as the pressure, this study addresses the laws of thermodynamics and weak cosmic censorship conjecture in the Reissner-Nordström-AdS black hole surrounded by quintessence dark energy under charged particle absorption. The first law of thermodynamics is found to be valid as a particle is absorbed by the black hole. The second law, however, is violated for the extremal and near-extremal black holes, because the entropy of these black hole decrease. Moreover, we find that the extremal black hole does not change its configuration in the extended phase space, implying that the weak cosmic censorship conjecture is valid. Remarkably, the near-extremal black hole can be overcharged beyond the extremal condition under charged particle absorption. Hence, the cosmic censorship conjecture could be violated for the near-extremal black hole in the extended phase space. For comparison, we also discuss the first law, second law, and the weak cosmic censorship conjecture in normal phase space, and find that all of them are valid in this case.</jats:p>

<jats:title>Abstract</jats:title> <jats:p>We test the possible dipole anisotropy of the Finslerian cosmological model and the other three dipole-modulated cosmological models, i.e. the dipole-modulated ΛCDM, <jats:italic>w</jats:italic>CDM and Chevallier–Polarski–Linder (CPL) models, by using the recently released Pantheon sample of SNe Ia. The Markov chain Monte Carlo (MCMC) method is used to explore the whole parameter space. We find that the dipole anisotropy is very weak in all cosmological models used. Although the dipole amplitudes of four cosmological models are consistent with zero within the <jats:inline-formula> <jats:tex-math><?CDATA $1\sigma$?></jats:tex-math> <jats:inline-graphic xmlns:xlink="http://www.w3.org/1999/xlink" xlink:href="cpc_43_12_125102_M1.jpg" xlink:type="simple" /> </jats:inline-formula> uncertainty, the dipole directions are close to the axial direction of the plane of the SDSS subsample in Pantheon. This may imply that the weak dipole anisotropy in the Pantheon sample originates from the inhomogeneous distribution of the SDSS subsample. A more homogeneous distribution of SNe Ia is necessary to constrain the cosmic anisotropy. </jats:p>

<jats:title>Abstract</jats:title> <jats:p>The high-precision measurement of Higgs boson properties is one of the primary goals of the Circular Electron Positron Collider (CEPC). The measurements of <jats:inline-formula> <jats:tex-math><?CDATA $H \to b\bar b/c\bar c/gg$?></jats:tex-math> <jats:inline-graphic xmlns:xlink="http://www.w3.org/1999/xlink" xlink:href="cpc_44_1_013001_M3.jpg" xlink:type="simple" /> </jats:inline-formula> decay branching fraction in the CEPC experiment is presented, considering a scenario of analysing 5000 fb<jats:sup>-1</jats:sup> <jats:inline-formula> <jats:tex-math><?CDATA $ e^+e^-$?></jats:tex-math> <jats:inline-graphic xmlns:xlink="http://www.w3.org/1999/xlink" xlink:href="cpc_44_1_013001_L01.jpg" xlink:type="simple" /> </jats:inline-formula> collision data with the center-of-mass energy of 250 GeV. In this study the Higgs bosons are produced in association with a pair of leptons, dominantly mediated by the <jats:italic>ZH</jats:italic> production process. The statistical uncertainty of the signal cross section is estimated to be about 1% in the <jats:inline-formula> <jats:tex-math><?CDATA $H \to b\bar b$?></jats:tex-math> <jats:inline-graphic xmlns:xlink="http://www.w3.org/1999/xlink" xlink:href="cpc_44_1_013001_M4.jpg" xlink:type="simple" /> </jats:inline-formula> final state, and approximately 5%-10% in the <jats:inline-formula> <jats:tex-math><?CDATA $H \to c\bar c/gg$?></jats:tex-math> <jats:inline-graphic xmlns:xlink="http://www.w3.org/1999/xlink" xlink:href="cpc_44_1_013001_M5.jpg" xlink:type="simple" /> </jats:inline-formula> final states. In addition, the main sources of the systematic uncertainties and their impacts to the measurements of branching fractions are discussed. This study demonstrates the potential of precise measurement of the hadronic final states of the Higgs boson decay at the CEPC, and will provide key information to understand the Yukawa couplings between the Higgs boson and quarks, which are predicted to be the origin of quarks’ masses in the standard model. </jats:p>

<jats:title>Abstract</jats:title> <jats:p>Measurements of decay asymmetry parameters of charmed baryons, e.g., <jats:inline-formula> <jats:tex-math><?CDATA $ \Xi_c$?></jats:tex-math> <jats:inline-graphic xmlns:xlink="http://www.w3.org/1999/xlink" xlink:href="cpc_44_1_013002_M2.jpg" xlink:type="simple" /> </jats:inline-formula>, provide more data to test the <jats:italic>W</jats:italic>-emission and <jats:italic>W</jats:italic>-exchange mechanisms controlled by strong and weak interactions. Taking advantage of the spin polarization in charmed baryon decays, we investigate the possibility to measure weak decay asymmetry parameters in the <jats:inline-formula> <jats:tex-math><?CDATA $ e^{+}e^{-}\to \Xi_c^0\bar\Xi_c^0$?></jats:tex-math> <jats:inline-graphic xmlns:xlink="http://www.w3.org/1999/xlink" xlink:href="cpc_44_1_013002_M3.jpg" xlink:type="simple" /> </jats:inline-formula> process. We analyze the transverse polarization spontaneously produced in this process and the spin transfer in the subsequent <jats:inline-formula> <jats:tex-math><?CDATA $ \Xi_c$?></jats:tex-math> <jats:inline-graphic xmlns:xlink="http://www.w3.org/1999/xlink" xlink:href="cpc_44_1_013002_M4.jpg" xlink:type="simple" /> </jats:inline-formula> decays. The sensitivity to measure the asymmetry parameters is estimated for the decay <jats:inline-formula> <jats:tex-math><?CDATA $ \Xi_c\to\Xi \pi$?></jats:tex-math> <jats:inline-graphic xmlns:xlink="http://www.w3.org/1999/xlink" xlink:href="cpc_44_1_013002_M5.jpg" xlink:type="simple" /> </jats:inline-formula>. </jats:p>

<jats:title>Abstract</jats:title> <jats:p>The heavy quark effective field theory (HQEFT) provides an effective way to deal with heavy meson decays. In this paper, we adopt two different correlators to derive the light-cone sum rules (LCSR) for the <jats:inline-formula> <jats:tex-math><?CDATA $ B \to \pi $?></jats:tex-math> <jats:inline-graphic xmlns:xlink="http://www.w3.org/1999/xlink" xlink:href="cpc_44_1_013101_M2.jpg" xlink:type="simple" /> </jats:inline-formula> transition form factors (TFFs) in the framework of HQEFT. We label the two LCSR results as LCSR- <jats:inline-formula> <jats:tex-math><?CDATA $ {\cal U} $?></jats:tex-math> <jats:inline-graphic xmlns:xlink="http://www.w3.org/1999/xlink" xlink:href="cpc_44_1_013101_M3.jpg" xlink:type="simple" /> </jats:inline-formula> and LCSR- <jats:inline-formula> <jats:tex-math><?CDATA $ {\cal R} $?></jats:tex-math> <jats:inline-graphic xmlns:xlink="http://www.w3.org/1999/xlink" xlink:href="cpc_44_1_013101_M4.jpg" xlink:type="simple" /> </jats:inline-formula>, which stand for the conventional correlator and the right-handed correlator. We observe that the correlation parameter <jats:inline-formula> <jats:tex-math><?CDATA $ |\rho_{\rm RU}| $?></jats:tex-math> <jats:inline-graphic xmlns:xlink="http://www.w3.org/1999/xlink" xlink:href="cpc_44_1_013101_M5.jpg" xlink:type="simple" /> </jats:inline-formula> for the branching ratio <jats:inline-formula> <jats:tex-math><?CDATA $ {\cal B}(B \to \pi l \nu_{l}) $?></jats:tex-math> <jats:inline-graphic xmlns:xlink="http://www.w3.org/1999/xlink" xlink:href="cpc_44_1_013101_M6.jpg" xlink:type="simple" /> </jats:inline-formula> is <jats:inline-formula> <jats:tex-math><?CDATA $ \sim 0.85 $?></jats:tex-math> <jats:inline-graphic xmlns:xlink="http://www.w3.org/1999/xlink" xlink:href="cpc_44_1_013101_M7.jpg" xlink:type="simple" /> </jats:inline-formula>, implying a consistency of LCSRs with the other correlators. Furthermore, we obtain <jats:inline-formula> <jats:tex-math><?CDATA $ |V_{ub}| _{{\rm LCSR}-{\cal U}} = (3.45^{+0.28}_{-0.20}\pm{0.13}_{\rm{exp}})\times10^{-3} $?></jats:tex-math> <jats:inline-graphic xmlns:xlink="http://www.w3.org/1999/xlink" xlink:href="cpc_44_1_013101_M8.jpg" xlink:type="simple" /> </jats:inline-formula> and <jats:inline-formula> <jats:tex-math><?CDATA $ |V_{ub}| _{{\rm LCSR}-\cal{R}} = (3.38^{+0.22}_{-0.16} \pm{0.12}_{\rm{exp}})\times10^{-3} $?></jats:tex-math> <jats:inline-graphic xmlns:xlink="http://www.w3.org/1999/xlink" xlink:href="cpc_44_1_013101_M9.jpg" xlink:type="simple" /> </jats:inline-formula>. We also obtain <jats:inline-formula> <jats:tex-math><?CDATA $ {\cal{R}}_{\pi}| _{{\rm LCSR}-\cal{U}} = 0.68^{+0.10}_{-0.09} $?></jats:tex-math> <jats:inline-graphic xmlns:xlink="http://www.w3.org/1999/xlink" xlink:href="cpc_44_1_013101_M10.jpg" xlink:type="simple" /> </jats:inline-formula> and <jats:inline-formula> <jats:tex-math><?CDATA $ {\cal{R}}_{\pi}| _{{\rm LCSR}-\cal{R}} = 0.65^{+0.13}_{-0.11} $?></jats:tex-math> <jats:inline-graphic xmlns:xlink="http://www.w3.org/1999/xlink" xlink:href="cpc_44_1_013101_M11.jpg" xlink:type="simple" /> </jats:inline-formula>, both of which agree with the lattice QCD predictions. Thus, HQEFT provides a useful framework for studying <jats:italic>B</jats:italic> meson decays. Moreover, by using the right-handed correlator, the twist-2 terms are dominant in TFF <jats:inline-formula> <jats:tex-math><?CDATA $ f^+(q^2) $?></jats:tex-math> <jats:inline-graphic xmlns:xlink="http://www.w3.org/1999/xlink" xlink:href="cpc_44_1_013101_M12.jpg" xlink:type="simple" /> </jats:inline-formula>, as their contribution is over ~97% in the whole <jats:inline-formula> <jats:tex-math><?CDATA $ q^2 $?></jats:tex-math> <jats:inline-graphic xmlns:xlink="http://www.w3.org/1999/xlink" xlink:href="cpc_44_1_013101_M13.jpg" xlink:type="simple" /> </jats:inline-formula> region, while the large twist-3 uncertainty of the conventional correlator is greatly suppressed. Hence, the LCSR- <jats:inline-formula> <jats:tex-math><?CDATA $ {\cal R} $?></jats:tex-math> <jats:inline-graphic xmlns:xlink="http://www.w3.org/1999/xlink" xlink:href="cpc_44_1_013101_M14.jpg" xlink:type="simple" /> </jats:inline-formula> predictions can be used to test the properties of the various models for the pion twist-2 distribution amplitudes. </jats:p>

<jats:title>Abstract</jats:title> <jats:p>Mass spectra and wave functions of the doubly heavy baryons are computed assuming that the two heavy quarks inside a baryon form a compact heavy ‘diquark core’ in a color anti-triplet, and bind with the remaining light quark into a colorless baryon. The two reduced two-body problems are described by the relativistic Bethe-Salpeter equations (BSEs) with the relevant QCD inspired kernels. We focus on the doubly heavy baryons with <jats:inline-formula> <jats:tex-math><?CDATA $1^+$?></jats:tex-math> <jats:inline-graphic xmlns:xlink="http://www.w3.org/1999/xlink" xlink:href="cpc_44_1_013102_M2.jpg" xlink:type="simple" /> </jats:inline-formula> heavy diquark cores. After solving BSEs in the instantaneous approximation, we present the mass spectra and the relativistic wave functions of the diquark cores, and of the low-lying baryon states <jats:inline-formula> <jats:tex-math><?CDATA $J^P=\frac{1}{2}^+$?></jats:tex-math> <jats:inline-graphic xmlns:xlink="http://www.w3.org/1999/xlink" xlink:href="cpc_44_1_013102_M3.jpg" xlink:type="simple" /> </jats:inline-formula> and <jats:inline-formula> <jats:tex-math><?CDATA $\frac{3}{2}^+$?></jats:tex-math> <jats:inline-graphic xmlns:xlink="http://www.w3.org/1999/xlink" xlink:href="cpc_44_1_013102_M4.jpg" xlink:type="simple" /> </jats:inline-formula> with flavors <jats:inline-formula> <jats:tex-math><?CDATA $(ccq)$?></jats:tex-math> <jats:inline-graphic xmlns:xlink="http://www.w3.org/1999/xlink" xlink:href="cpc_44_1_013102_M5.jpg" xlink:type="simple" /> </jats:inline-formula>, <jats:inline-formula> <jats:tex-math><?CDATA $(bcq)$?></jats:tex-math> <jats:inline-graphic xmlns:xlink="http://www.w3.org/1999/xlink" xlink:href="cpc_44_1_013102_M6.jpg" xlink:type="simple" /> </jats:inline-formula> and <jats:inline-formula> <jats:tex-math><?CDATA $(bbq)$?></jats:tex-math> <jats:inline-graphic xmlns:xlink="http://www.w3.org/1999/xlink" xlink:href="cpc_44_1_013102_M7.jpg" xlink:type="simple" /> </jats:inline-formula>. A comparison with other approaches is also made. </jats:p>

<jats:title>Abstract</jats:title> <jats:p>Theta-dependent gauge theories can be studied using holographic duality through string theory in certain spacetimes. By this correspondence we consider a stack of <jats:italic>N</jats:italic> <jats:sub>0</jats:sub> dynamical D0-branes as D-instantons in the background sourced by <jats:italic>N</jats:italic> <jats:sub>c</jats:sub> coincident non-extreme black D4-branes. According to the gauge-gravity duality, this D0-D4 brane system corresponds to Yang-Mills theory with a theta angle at finite temperature. We solve the IIA supergravity action by taking account into a sufficiently small backreaction of the Dinstantons and obtain an analytical solution for our D0-D4-brane configuration. Subsequently, the dual theory in the large <jats:italic>N</jats:italic> <jats:sub>c</jats:sub> limit can be holographically investigated with the gravity solution. In the dual field theory, we find that the coupling constant exhibits asymptotic freedom, as is expected in QCD. The contribution of the theta-dependence to the free energy gets suppressed at high temperatures, which is basically consistent with the calculation using the Yang-Mills instanton. The topological susceptibility in the large <jats:italic>N</jats:italic> <jats:sub>c</jats:sub> limit vanishes, and this behavior remarkably agrees with the implications from the simulation results at finite temperature. Moreover, we finally find a geometrical interpretation of the theta-dependence in this holographic system. </jats:p>