The relativistic mean field（RMF） FSUGold model extended to include hyperons is employed to study the properties of neutron stars with strong magnetic fields.The chaotic magnetic field approximation is utilized.The effect of anomalous magnetic moments（AMMs） is also investigated.It is shown that the equation of state（EOS）of neutron star matter is stiffened by the presence of the magnetic field,which increases the maximum mass of a neutron star by around 6%.The AMMs only have a small influence on the EOS of neutron star matter,and increase the maximum mass of a neutron star by 0.02M（sun）.Neutral particles are spin polarized due to the presence of the AMMs.
Recently,we analyze the α-decay data of even-Z nuclei and propose the new Geiger-Nuttall law where the effects of the quantum numbers of α-core relative motion are naturally embedded in the law [Physical Review C 85,044608(2012)].In this paper,we firstly test whether the new law without any change of parameters can be applied to the α-decays of odd-Z nuclei which are more complicated than those of even-even nuclei.Then the nuclear shell effect around N=126 is analyzed for very proton-rich nuclei with Z=85-92 based on the data of α-decay energies and half-lives.A long-lived island beyond the stable line is proposed where the half-lives of nuclei on this island are abnormally long.The mechanism of the appearance of the island and its significance to other mass ranges are discussed.
Very neutron-deficient nuclei are investigated with Woods-Saxon potentials,especially the newly measured A =2Z-1 nucleus 65As [X.L.Tu et al.,Phys.Rev.Lett.106,112501（2011）],where the experimental proton separation energy is obtained as-90（85） keV for the first time.Careful consideration is given to quasibound protons with outgoing Coulomb wave boundary conditions.The observed proton halos in the first excited state of 17F and in the ground states of 26,27,28P are reproduced well,and predictions of proton halos are made for the ground states of 56,57Cu and 65As.The sensitivity of the results to the proton separation energy is discussed in detail,together with the effect of the l=1 centrifugal barrier on proton halos.
In this paper,a general method of data transmission system design on PXI platform is proposed.It can be used in readout system design for physical experiments.It aims at providing reusable and general interfaces for customized design of PXI while maintaining the transmission performance.It has three main features:(1)universal logic hardware interface,(2)ethernet based socket software interface,and(3)specific and simple data transmission protocol.Data transmission on PXI bus can be realized with the said two universal interfaces coordinated by this specific protocol.Test shows that this method is feasible and stable.This method can be easily reused in readout system designs for different experiments.
The precise determination of neutron distribution has important implications for both nuclear structure and nuclear astrophysics. The purpose of this paper is to study the characteristics of neutron distribution of^208 Pb by parity-violating electron scattering（PVS）. Parity-violating asymmetries of^208 Pb with different types of neutron skins are systematically calculated and compared with the experimental data of PREx. The results indicate that the PVS experiments are very sensitive to the nuclear neutron distributions. From further PVS measurements, detailed information on nuclear neutron distributions can be extracted.
Nuclear double β^--decays with two neutrinos were observed for many years and a systematic law describing the relation between their half-lives and decay energies was also proposed recently [Phys Rev C, 2014, 89： 064603]. However, double β^＋ -decay （β^＋β^＋） with emission of both two positrons and two neutrinos has not been observed up to date. In this article, we pcrform a systematic analysis on the candidates of double β^＋-decay, based on the 2012 nuclear mass table. Eight nuclei are found to be the good candidates for double β^＋-decay and their half-lives are predicted according to the generalization of the systematic law to double β^＋-decay. As far as we know, there is no theoretical result on double β^＋-decay of nucleus ^154Dy and our result is the first prediction on this nucleus. This is also the first complete research on eight double β^＋-decay candidates based on the available data of nuclear masses. It is expected that the calculated half-lives of double β^＋-decay in this article will be useful for future experimental search of double β^＋-decay.
We study a non-periodically driven kicked rotor based on the one-dimensional quantum relativistic kicked rotor(QRKR). In our model, we add a small constant to the interval of the one-dimensional QRKR after each kick process.It is found that the momentum spreading is stable in finite kicked times, it then jumps up or down and becomes stable again.This interesting phenomenon is understood by quantum resonance. Moreover, the stable-jump–stable-jump phenomenon persists, even though the interval of kick process is randomly increased. This result means that the quantum resonance is independent of the periodic perturbation in the QRKR model.
The a-preformation factors of medium and heavy-mass nuclei are calculated by using the cluster-formation model.The obtained preformation factors of even–even,odd-A,and odd–odd nuclei consist in both magnitude and trend with the general features predicted by standard calculations.The variation of a clustering affected by the evolution of nuclear structure is observed from different behaviors of preformation factors.We typically analyze the variation of preformation factors in the closed-shell N =126 and Z =82 regions,and discuss in detail the structural effects on a-cluster formation.This work shows the strong correlation between a-preformation factors and the shell structure,which would be a useful reference for microscopic cluster-model calculations of a-decay half-lives.
In this paper,the nuclear longitudinal form factors are systematically studied from the intrinsic charge multipoles.For axially deformed nuclei,two different types of density profiles are used to describe their charge distributions.For the same charge distributions expanded with different basis functions,the corresponding longitudinal form factors are derived and compared with each other.Results show the multipoles C_λ of longitudinal form factors are independent of the basis functions of charge distributions.Further numerical calculations of longitudinal form factors of^（12）C indicates that the C_0 multipole reflects the contributions of spherical components of all nonorthogonal basis functions.For deformed nuclei,their charge RMS radii can also be determined accurately by the C_0 measurement.The studies in this paper examine the model-independent properties of electron scattering,which are useful for interpreting electron scattering experiments on exotic deformed nuclei.
