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
119234168
Sensitive dependence of isotope and isobar distributions of limiting temperatures on the symmetry energy
The mass, isotope, and isobar distributions of limiting temperatures for finite nuclei are investigated by using a thermodynamics approach together with the Skyrme energy density functional. The relationship between the width of the isotope (isobar) distribution of limiting temperatures and the stiffness of the density dependence of the symmetry energy clearly is observed. The nuclear symmetry energy with smaller slope parameter Lsym causes a wider isotope (isobar) distribution of limiting temperatures. The widths of the isotope (isobar) distributions of limiting temperatures could be useful observables for exploring the information of the density dependence of the nuclear symmetry energy at finite temperatures.
124137012
Study of in-medium Delta Delta elastic scattering cross section
118197616
Transition to Delta matter from hot, dense nuclear matter within a relativistic mean field formulation of the nonlinear sigma and omega model
An investigation of the transition to $\ensuremath{\Delta}$ matter is performed based on a relativistic mean field formulation of the nonlinear $\ensuremath{\sigma}$ and $\ensuremath{\omega}$ model. We demonstrate that in addition to the $\ensuremath{\Delta}$-meson coupling, the occurrence of the baryon resonance isomer also depends on the nucleon-meson coupling. Our results show that for the favored phenomenological value of ${m}^{*}$ and $K$, the $\ensuremath{\Delta}$ isomer exists at baryon density $\ensuremath{\sim}2$--3${\ensuremath{\rho}}_{0}$ if $\ensuremath{\beta}$=1.31 is adopted. For universal coupling of the nucleon and $\ensuremath{\Delta}$, the $\ensuremath{\Delta}$ density at baryon density $\ensuremath{\sim}2$--3${\ensuremath{\rho}}_{0}$ and temperature $\ensuremath{\sim}0.4$--0.5 fm${}^{\ensuremath{-}1}$ is about normal nuclear matter density, which is in accord with a recent experimental finding.
119441908
Dynamical isospin effects in nucleon-induced reactions
The isospin effects in proton-induced reactions on isotopes of $^{112\ensuremath{-}132}\mathrm{Sn}$ and the corresponding $\ensuremath{\beta}$-stable isobars are studied by means of the improved quantum molecular dynamics model and some sensitive probes for the density dependence of the symmetry energy at subnormal densities are proposed. The beam energy range is chosen to be 100\char21{}300 MeV. Our study shows that the system size dependence of the reaction cross sections for $p+{}^{112\ensuremath{-}132}\mathrm{Sn}$ deviates from the Carlson's empirical expression obtained by fitting the reaction cross sections for proton on nuclei along the $\ensuremath{\beta}$-stability line and sensitively depends on the stiffness of the symmetry energy. We also find that the angular distribution of elastic scattering for $p+{}^{132}\mathrm{Sn}$ at large impact parameters is very sensitive to the density dependence of the symmetry energy, which is uniquely due to the effect of the symmetry potential with no mixture of the effect from the isospin dependence of the nucleon-nucleon cross sections. The isospin effects in neutron-induced reactions are also studied and it is found that the effects are just opposite to that in proton-induced reactions. We find that the difference between the peaks of the angular distributions of elastic scattering for $p+{}^{132}\mathrm{Sn}$ and $n+{}^{132}\mathrm{Sn}$ at ${E}_{p,n}=100$ MeV and $b=7.5$ fm is positive for soft symmetry energy ${U}_{\mathrm{sym}}^{\mathrm{sf}}$ and negative for super-stiff symmetry energy ${U}_{\mathrm{sym}}^{\mathrm{nlin}}$ and close to zero for linear density dependent symmetry energy ${U}_{\mathrm{sym}}^{\mathrm{lin}}$, which seems very useful for constraining the density dependence of the symmetry energy at subnormal densities.
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.
14686040
The heavy-to-light transitions in the light-cone QCD sum rules
We have analyzed the $B\to \pi $ and $B_{s}\to K$ semileptonic form factors and $B\to V\gamma (V=K^*,\rho,\omega)$ processes in the light-cone QCD sum rules. In order to enhance the predictivity and reliability of numerical results the chiral-current correlator is employed and the twist-3 light-cone wavefunction can be effectively eliminated from the sum rules.
121145994
Nuclear matter saturation point and symmetry energy with modern nucleon-nucleon potentials
We determine the saturation properties of nuclear matter within the Brueckner-Hartree-Fock approach based on a large set of modern nucleon-nucleon potentials and confirm the validity of the Coester band. The improvement of the saturation point when including nuclear three-body forces is pointed out and comparison with the Dirac-Brueckner-Hartree-Fock results is made.
118612358
THE CARNEGIE-IRVINE GALAXY SURVEY. III. THE THREE-COMPONENT STRUCTURE OF NEARBY ELLIPTICAL GALAXIES
Motivated by recent developments in our understanding of the formation and evolution of massive galaxies, we explore the detailed photometric structure of a representative sample of 94 bright, nearby elliptical galaxies, using high-quality optical images from the Carnegie-Irvine Galaxy Survey. The sample spans a range of environments and stellar masses, from M * = 1010.2 to 1012.0 M ☉. We exploit the unique capabilities of two-dimensional image decomposition to explore the possibility that local elliptical galaxies may contain photometrically distinct substructure that can shed light on their evolutionary history. Compared with the traditional one-dimensional approach, these two-dimensional models are capable of consistently recovering the surface brightness distribution and the systematic radial variation of geometric information at the same time. Contrary to conventional perception, we find that the global light distribution of the majority (75%) of elliptical galaxies is not well described by a single Sersic function. Instead, we propose that local elliptical galaxies generically contain three subcomponents: a compact (Re 1 kpc) inner component with luminosity fraction f 0.1-0.15; an intermediate-scale (Re 2.5 kpc) middle component with f 0.2-0.25; and a dominant (f = 0.6), extended (Re 10 kpc) outer envelope. All subcomponents have average Sersic indices n 1-2, significantly lower than the values typically obtained from single-component fits. The individual subcomponents follow well-defined photometric scaling relations and the stellar mass-size relation. We discuss the physical nature of the substructures and their implications for the formation of massive elliptical galaxies.
119264529
Next-to-leading order QCD effects in associated charged Higgs and W boson production in the MSSM at the CERN Large Hadron Collider
We present the calculations of the next-to-leading order (NLO) QCD corrections to the inclusive total cross sections for the associated production of the ${W}^{\ifmmode\pm\else\textpm\fi{}}{H}^{\ensuremath{\mp}}$ through $b\overline{b}$ annihilation in the minimal supersymmetric standard model at the CERN Large Hadron Collider. The NLO QCD corrections can either enhance or reduce the total cross sections, but they generally efficiently reduce the dependence of the total cross sections on the renormalization/factorization scale. The magnitude of the NLO QCD corrections is about 10% in most of the parameter space and can reach 15% in some parameter regions. We also show the Monte Carlo simulation results for the $2j+{\ensuremath{\tau}}_{\mathrm{jet}}+{\mathrm{p\ensuremath{\llap{\not\;}}}}_{T}$ signature from the ${W}^{\ifmmode\pm\else\textpm\fi{}}$ and the ${H}^{\ensuremath{\mp}}$ decays including the NLO QCD effects, and find an observable signal at a $5\ensuremath{\sigma}$ level in some parameter region of the minimal supergravity model.