arXiv subjects

Zhen-Xiang Xu

Publications and source records attributed to Zhen-Xiang Xu.

3 recordsLinked to original sources

arXiv2013

Novel Monte Carlo representation for shell model in the complex energy plane

A Monte Carlo method is presented to evaluate quantum states with many particles moving in the continuum. The scattering state is generated at each time by a Monte Carlo random sampling algorithm. The same calculation are repeated until the average energies of all calculations converge. For systems with one and a few particles, our calculations show that the exact solution can be approached with around only one hundred iterations. As examples, we apply the approach to study the structure of neutron-rich oxygen isotopes.

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arXiv2013

Shell evolution and its indication on the isospin dependence of the spin-orbit splitting

The available experimental data on shell evolution indicate that the strength of the spin-orbit (SO) single-particle potential may be enhanced in neutron-rich nuclei. We observe that such a simple scheme destroys the Harmonic Oscillator (HO) magic numbers N=8 and 20 and generates new SO magic numbers like N=6, 14, 16, 32 and 34. The traditional SO magic numbers like N=28 and 50 and N=14 seen in $^{22}$O are eroded somehow in neutron-rich nuclei due to the sensitivity of larger-$l$ orbitals to the depth of the central potential but they are more robust than the HO magic numbers. The N=82 shell closure persists in neutron-rich nuclei while HO shell closures like N=40 and 70 do not emerge. Both mechanisms contribute to enhancing the N=56 and 90 gaps by splitting the $1d_{5/2}$ and $0g_{7/2}$ and the $0h_{9/2}$ and $1f_{7/2}$ orbitals.

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arXiv2011

Multistep shell model description of spin-aligned neutron-proton pair coupling: The formalism

The multistep shell model was extended recently to incorporate both neutron and proton degrees of freedom and applied to study the structure of $N=Z$ systems with four, six and eight particles [arXiv:1108.0269]. In this work we give a brief introduction to the formalism thus developed. A more detailed explanation with applications will be updated later.

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