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The -delayed particle emission from the exotic nucleus Si has been studied using a detection system with silicon array and clover-type high-purity germanium (HPGe) detectors. The -delayed charged-particle spectrum and -ray spectrum were identified. The half-life of Si has been determined. A new -delayed proton branch with an energy of 3811keV was observed. The -delayed two-proton emission was confirmed. [ABSTRACT FROM AUTHOR]

Hard photon emitted from energetic heavy ion collisions is of very interesting since it does not experience the late-stage nuclear interaction, therefore it is useful to explore the early-stage information of matter phase. In this work, we investigated the directed flow and elliptic flow for proton-neutron bremsstrahlung hard photons in intermediate energy heavy-ion collisions. The positive directed flow and negative elliptic flow of directed photons are illustrated and they seem to be anti-correlated to the free proton's flow. Also we calculated the two-photon correlation functions from which the information of photon source was extracted, and while two-photon azimuthal correlations are presented as a good method to extract the elliptic flow parameter v2 of direct hard photons. [ABSTRACT FROM AUTHOR]

The deformed projectiles and targets are expected to play different roles in heavy-ion collisions (HICs) at intermediate energy compared with spherical ones. With an isospin dependent quantum molecular dynamics (IDQMD) model, in despite of averaging all the orientations of axisymmetric deformed 24Mg + 24Mg collisions, it is still found that NN collision number, nuclear stopping power (R) and multiplicity of fragments have considerable differences compared with spherical 24Mg + 24Mg collisions. [ABSTRACT FROM AUTHOR]

Fragment yields for Z ≥ 5 from projectile fragmentation using primary beams of 36,40Ar at 50 MeV/nucleon on 64Ni target have been measured in RIBLL fragment separator. We compare the fragment cross sections with the predictions of the empirical EPAX parametrization of fragmentation cross-sections and Statistical Abration-Ablation model (SAA) by considering the RIBLL separator transmission rate. Isotope yield ratios between these two reactions were calculated and isoscaling parameters α and β are extracted, their dependences on fragment atomic number Z and neutron number N were presented. [ABSTRACT FROM AUTHOR]

An experiment of 22Mg and 20Ne beams bombarding on a 12C target at an energy of 60~70 A MeV has been performed at the RIKEN projectile fragment separator (RIPS) in the RIKEN Ring Cyclotron Facility to study the two-proton correlated emission from 22Mg and 20Ne excited states. The two-protons momentum correlation functions have been obtained for 22Mg and 20Ne, respectively. The trajectories of the 22Mg decayed products (20Ne + p + p) were also measured to get the angular correlations between the two protons in Center of Mass of decaying system by relativistic-kinematics reconstruction. The results exhibit that 22Mg has the features of 2He cluster decay mechanism. [ABSTRACT FROM AUTHOR]

Experiments of 23Al and 22Mg radioactive beams bombarding a 12C target at an energy of 60 ~70 A MeV have been performed at the projectile fragment separator beamline (RIPS) in the RIKEN Ring Cyclotron Facility to study the two-proton emission from 23Al and 22Mg excited states, respectively. The trajectorie of the decay products, namely 21Na + p + p from 23Al and 20Ne + p + p from 22Mg, are clean identified. The relative momentum and opening angle between two protons in the rest frame of three body decay channels are obtained by relativistic-kinematics reconstruction. The results demonstrate that there are some di-proton emission components from 2He cluster for the excited 23Al and 22Mg. [ABSTRACT FROM AUTHOR]

The excited states of some odd A nuclei near the stability line have been systematically investigated from light to intermediate mass with the spherical relativistic mean field (RMF) model. The ratio between the valence nucleon root-mean-square (RMS) radius and the core rms radius, the separation energy and the density distribution have been deduced as signatures for halo or skin structure. We have presented the scaling laws of the ratio of valence particle rms radii and square-potential radii versus the scaled separation energies. The probability for a valence particle being out of the binding potential has also been extracted. We proposed a relaxed necessary condition for nuclear halo occurrence. [ABSTRACT FROM AUTHOR]

We have studied the isospin effect and isoscaling behavior in projectile fragmentation using a modified statistical abrasion-ablation (SAA) model. The relationship between neutron skin thickness (δnp) and neutron abrasion cross section (σnabr) has also been investigated. We find the normalized peak differences and reduced isoscaling parameters decrease with (Zproj - Z)/Zproj or the excitation energy per nucleon and have no significant dependence on the size of the reaction systems. The excitation energy dependence of the symmetry energy coefficients are tentatively extracted from α and β. Assuming Fermi-type density distributions for proton and neutron and introducing a parameter to adjust the diffuseness of the neutron density distribution for neutron-rich nucleus, δnp and σnabr for neutron-rich nucleus were found to have a linear correlation. It is suggested that σnabr could be used as an observable to extract the neutron skin thickness for neutron-rich nucleus. [ABSTRACT FROM AUTHOR]

Isoscaling properties of the primary and final products are studied via isospin dependent quantum molecular dynamics (IQMD) model and the followed sequential decay model GEMINI, respectively. Both primary and final products isoscaling parameter α keeps no significant change for light fragments, but increases with the mass for intermediate and heavy products. The dynamical effect on isoscaling is reflected on the α decreasing a little with the evolution time of the system, and opposite trend for the heavy products. The secondary decay effect on isoscaling is reflected on the increasing of the α value for the final products which experienced secondary decay process. Furthermore the density dependence of the symmetry energy has also been explored for the primary and secondary products, the symmetry energy coefficient can be expressed by the form of Csym(ρ) ~ C0(ρ/ρ0)γ, C0 and γ extracted from the primary products are consistent with the input parameters, but C0 and γ extracted from the final products deviate the input values. In the paper we also suggest that it might be more reasonable to describe the density dependence of the symmetry energy coefficient by the Csym(ρ/ρ0) ≈ C1(ρ/ρ0)γsoft + C2(ρ/ρ0)γstiff with γsoft ≤ 1, γstiff ≥ 1 and C1, C2 constant parameters. [ABSTRACT FROM AUTHOR]

Anisotropic flows of light nuclear clusters and hard photons are studied by nucleonic transport models in intermediate energy heavy ion collisions. The transverse momentum and rapidity dependences of the directed flow (v1) and elliptic flow (v2) are studied for light nuclear clusters and their scaling behaviors are found. The ratio of $v_4/v_2^2$ of nuclear clusters show a constant value of 1/2. Proton-neutron bremsstrahlung hard photon shows non-zero flows with the contrary sign of proton's flows. [ABSTRACT FROM AUTHOR]

In the framework of a modified statistical abrasion-ablation (SAA) model, the isospin effect and isoscaling behavior in projectile fragmentation have been systematically investigated. The normalized peak differences and reduced isoscaling parameters are found to decrease with (Zproj-Z)/Zproj and have no significant dependence on the size of reaction systems. The linear dependence of α and |β| on $\Delta[(\frac{Z}{A})^2]$ or $\Delta[(\frac{N}{A})^2]$ for projectile-like fragments is demonstrated, which is obtained for light fragments from multifragmentation in the grand-canonical limit. Assuming a Fermi-gas behavior, the excitation energy dependence of the symmetry energy coefficients are tentatively extracted from α and β which looks consistent with the experimental data. It is pointed out that the reduced isoscaling parameters can be used as an observable to study the excitation extent of system and asymmetric nuclear equation of state in heavy ion collisions. [ABSTRACT FROM AUTHOR]

The longitudinal momentum (p//) distributions of fragments after one-proton removal and reaction cross sections (σR) for several N = 10 isotones at intermediate energy (~ 70A MeV) have been measured simultaneously at the RIken Projectile fragment Separator (RIPS). p// was measured using a direct time-of-flight (TOF) technique, while σR was determined using a transmission method. An enhanced σR is observed for 23Al comparing with its neighbors. The p// distribution for 22Mg fragments from 23Al one-proton removal reaction has been obtained for the first time. The experimental data are discussed within a Few Body Glauber (FBG) framework. Analysis of p// indicates a dominant d-wave component in the ground state of 23Al. This agrees with recent experimental results. We also suggest the possibility of an enlarged 22Mg core for proton-rich nucleus 23Al. [ABSTRACT FROM AUTHOR]