118367915
Constraint on nuclear symmetry energy from nuclear charge dependent neutron skin thickness of nuclei
An alternative way to constrain the density dependence of the symmetry energy with the slope of the neutron skin thickness of nuclei which shows a linear relation to both the isospin asymmetry and the nuclear charge with a form of Z^{2/3} is proposed. The linear dependence of the neutron skin thickness on the nuclear charge and isospin asymmetry is systematically studied with the data from antiprotonic atom measurement experimentally and the extended Thomas-Fermi approach incorporated the Skyrme energy density functional theoretically. An obviously linear relationship between the slope parameter L of the symmetry energy and the slope of the neutron skin thickness on the isospin asymmetry can be found by adopting 66 Skyrme interactions in the calculation. Combining the available experimental data, the constraint of 16<L<66 MeV on the slope parameter of the symmetry energy is obtained. The Skyrme interactions satisfying the constraint are selected.
124137012
Study of in-medium Delta Delta elastic scattering cross section
121143863
THE DYNAMICAL ISOSPIN EFFECT ON PROTON-INDUCED REACTIONS ON Sn ISOTOPES
In this talk we present a model, Improved Quantum Molecular Dynamics (ImQMD05) model incorporated with a Statistical Decay Model (SDM), to describe intermediate energy proton induced spallation reactions. A good agreement with experimental data of double differential cross sections of emitted neutrons is obtained. We further apply this model to study the isospin effect in proton induced spallation reactions on a series Sn isotope targets. We find that the systematic behavior of the reaction cross sections for Sn isotope targets deviates from the empirical expression obtained by fitting the experimental data for proton induced spallation reactions on target nuclei along β-stability line. The extent of the deviation depends on the density dependence of the symmetry energy strongly. We also find an obvious shift of the elastic scattering angular distribution of emitted protons when the symmetry energy is taken into account for neutron-rich Sn isotope targets and the angle shifted strongly depends on the stiffness of the symmetry energy. The attractive effect of the symmetry potential of target on incident proton directly influences the motion of the incident proton leading to strong isospin effect on the reaction dynamics and thus on these reaction observables. We conclude that the measurement of reaction cross sections and the elastic scattering angular distributions in proton induced spallation reactions on Sn isotopes can provide clear constraint for the density dependence of symmetry energy.
119408968
Isospin dependence of nucleon-nucleon elastic cross section
The in-medium neutron-proton, proton-proton (neutron-neutron) scattering cross sections (sigma(np)*, sigma(pp(nn))*) are studied based on QHD-II type Lagangian within the framework of the microscopic transport theory. The results demonstrate that, for free nucleon-nucleon scattering cross sections, the isospin dependence is dominantly caused by the rho meson field. The medium correction of nucleon-nucleon scattering cross sections is also isospin dependent, sigma(np)*, depends on the baryon density weakly and sigma(pp(nn))* depends on the baryon density significantly, which is due to the different effects of the medium correction of nucleon mass and rho meson mass on sigma(np) and sigma(pp(nn)), respectively.
9051613
Mass and isotope dependence of limiting temperatures for hot nuclei
The mass and isotope dependence of limiting temperatures for hot nuclei are investigated. The predicted mass dependence of limiting temperatures is in good agreement with data derived from the caloric curve data. The predicted isotope distribution of limiting temperatures appears to be a parabolic shape and its centroid is not located at the isotope on the beta-stability line (T=0) but at neutron-rich side. Our study shows that the mass and isotope dependence of limiting temperatures depend on the interaction and the form of surface tension and its isospin dependence sensitively.
55892113
In-medium NN cross sections determined from stopping and collective flow in intermediate-energy heavy-ion collisions
In-medium nucleon-nucleon scattering cross sections are explored by comparing results of quantum molecular dynamics simulations to data on stopping and on elliptic and directed flow in intermediate-energy heavy-ion collisions. The comparison points to in-medium cross sections which are suppressed at low energies but not at higher energies. Positive correlations are found between the degree of stopping and the magnitudes of elliptic and directed flows. PACS numbers: 25.70.-z, 24.10.Lx, 21.65.+f
4046382
Nuclear symmetry potential in the relativistic impulse approximation
Using the relativistic impulse approximation with the Love-Franey NN scattering amplitude developed by Murdock and Horowitz, we investigate the low-energy (100{<=}E{sub kin}{<=}400 MeV) behavior of the nucleon Dirac optical potential, the Schroedinger-equivalent potential, and the nuclear symmetry potential in isospin asymmetric nuclear matter. We find that the nuclear symmetry potential at fixed baryon density decreases with increasing nucleon energy. In particular, the nuclear symmetry potential at saturation density changes from positive to negative values at nucleon kinetic energy of about 200 MeV. Furthermore, the obtained energy and density dependence of the nuclear symmetry potential is consistent with those of the isospin- and momentum-dependent MDI interaction with x=0, which has been found to describe reasonably well both the isospin diffusion data from heavy-ion collisions and the empirical neutron-skin thickness of {sup 208}Pb.
126298053
Soft nonfactorizable contribution to anti-B0 ---> D0 pi0
121598302
QCD resummation for jet profiles
We predict the energy profiles of light-quark and gluon jets in the framework of perturbative QCD. Resumming large logarithmic contributions to all orders in the coupling constant, our predictions are shown to agree well with Tevatron CDF and Large-Hadron-Collider CMS data. We also extend our resummation formalism to the invariant mass distributions of light-quark and gluon jets produced in hadron collisions.
119444616
Reexamined radiative decay B*(q) ---> B(q gamma) in light cone QCD
The radiative decay $ B_{q}^*\to B_{q}\gamma(q=u,d, or s) $ is reexamined with a modified light-cone QCD sum rule method, in which adequate chiral operators are chosen as the interpolating fields in the correlators used for a sum rule estimate of the relevant coupling $ g_{B_{q}^*B_{q}\gamma} $. The resulting sum rules not only show the physical picture consistent with the underlying physics in $ B_{q}^*\to B_{q}\gamma $ but also avoid the pollution by the nonlocal matrix element $ $, which starts with twist-3 and thus may bring a large uncertainty to the sum rule predictions. Also, a comparison is made with the previous results from light-cone QCD sum rules and chiral perturbation theory.
59931380
Relativistic energy density functionals: Low-energy collective states ofPu240andEr166
The empirical relativistic density-dependent, point-coupling energy density functional, adjusted exclusively to experimental binding energies of a large set of deformed nuclei with A ≈ 150-180 and A ≈ 230-250, is tested with spectroscopic data for 166 Er and 240 Pu. Starting from constrained self-consistent triaxial relativistic Hartree-Bogoliubov calculations of binding energy maps as functions of the quadrupole deformation in the β-γ plane, excitation spectra and E2 transition probabilities are calculated as solutions of the corresponding microscopic collective Hamiltonian in five dimensions for quadrupole vibrational and rotational degrees of freedom and compared with available data on low-energy collective states.