Nuclear Physics A最新文献

The coefficients of modified macroscopic-microscopic mass formula have been adjusted on 2267 experimental atomic masses extracted from the AME2012 atomic mass evaluation. Same as the Weizsäcker-Skyrme model the influence of the nuclear deformation on the macroscopic energy and the mirror nuclei constraint are also taken into account, and for the sake of the consistency of the model parameters between the macroscopic and the microscopic parts we approximate the isospin-dependent component of the macroscopic energy to the depth of the Woods-Saxon potential. Inspired by Kruppa prescription the continuum states are considered in the calculation of shell correction. Then the root-mean square (rms) deviation with respect to 2267 measured nuclear masses is 0.46 MeV. We predict the remaining 988 nuclei from the AME2012 with $Z,N>7$ for which the mass is still unknown or known with a higher uncertainty. In addition the α−decay energies of seven chains in the superheavy nuclei region with $Z=117,118$ are evaluated.

The ⁶Li+⁸⁹Y experiment was conducted at the Legnaro National Laboratory in Italy to explore the influence of breakup and transfer reactions on the fusion process induced by the weakly bound projectiles. Due to the competition between neutron and proton evaporation, complete and incomplete fusion might produce identical residues, leading to the difficulties in identification of different reaction process. In this work, the High-Purity-Germanium (HPGe) detector array (GALILEO) was employed to measure γ rays, and the silicon detector array (EUCLIDES) was utilized to capture light charged particles. Exclusive measurements of prompt γ rays from residuals with various light charged particles at an energy near the Coulomb barrier are reported. In the $p-\gamma$ coincident measurements, observed ⁹¹Nb, ⁹²Nb, and ⁹³Nb is considered from neutron evaporation channel in complete fusion reaction, and ⁹⁰Y is generated through 1n stripping reaction. A two-step, breakup followed by fusion, in case of the capture of α is inferred to be the dominant mechanism to yield the ⁹²Nb and ⁹¹Nb in the deutron coincident exclusive measurement.

By using the fact that the Gamow states in the momentum representation are square integrable, we obtain the differential and the total decay width of a two-body, non-relativistic decay. The resulting Gamow Golden Rule is well suited to describe both energy and angular decay distributions, and it becomes the Fermi Golden Rule when the resonance is long-lived and far from the energy threshold. We also show that the correct density of states and phase space factors arise naturally from the Gamow Golden Rule. The upshot is that the Gamow states and the Golden Rule can be combined into a unified description of quantum resonances.

Hamiltonian theory for collective longitudinally polarized gluon excitations (plasmons) interacting with classical high-energy test color-charged particle propagating through a high-temperature gluon plasma is developed. A generalization of the Lie-Poisson bracket to the case of a continuous medium involving bosonic normal field variable $a_k^{\phantom{⁎}a}$ and a non-Abelian color charge $Q^a$ is performed and the corresponding Hamilton equations are presented. The canonical transformations including simultaneously both bosonic degrees of freedom of the soft collective excitations and degree of freedom of hard test particle connecting with its color charge in the hot gluon plasma are written out. A complete system of the canonicity conditions for these transformations is derived. The notion of the plasmon number density $N_k^{a{a}_{\phantom{1}}^{\prime }}$, which is a nontrivial matrix in the color space, is introduced. An explicit form of the effective fourth-order Hamiltonian describing the elastic scattering of a plasmon off a hard color particle is found and the self-consistent system of Boltzmann-type kinetic equations taking into account the time evolution of the mean value of the color charge of the hard particle is obtained. On the basis of these equations, a model problem of the interaction of two infinitely narrow wave packets is considered. A system of nonlinear first-order ordinary differential equations defining the dynamics of the interaction of the colorless $N_k^l$ and color $W_k^l$ components of the plasmon number density is derived. The problem of determining the third- and fourth-order coefficient functions entering into the canonical transformations of the original bosonic variable $a_k^{\phantom{⁎}a}$ and color charge $Q^a$ is discussed. With the help of the coefficient functions obtained, a complete effective amplitude of the elastic scattering of plasmon off hard test particle is written out.

Based on analyses of the mass and the strong decay features, $D_{s0}{\left(2590\right)}^{+}$ observed by LHCb collaboration is identified as a radial excitation of the pseudoscalar $D_s$, and $D_{sJ}{\left(3040\right)}^{+}$ observed by BaBar collaboration is identified as a radial excitation of $D_{s1}{\left(2536\right)}^{\pm }$. $D_{s0}{\left(2590\right)}^{+}$ is possibly a pure $D_s\left(2{}^{1}S_0\right)$ meson, both basic $D_{s1}{\left(2536\right)}^{\pm }$ and radially excited $D_{sJ}{\left(3040\right)}^{+}$ are possibly the mixtures $D_s\left(n{P}_1\right)$ between spin triplet $D_s\left(n{}^{3}P_1\right)$ and spin singlet $D_s\left(n{}^{1}P_1\right)$. In this arrangement, their masses meet the linear behavior of the radial Regge trajectory very well. In the ${}^{3}P_0$ strong decay model, the decay channels of $D_{s0}{\left(2590\right)}^{}$