Narrow Results

We investigate the tensor correlations in He and Li isotopes systematically. We propose the tensor-optimized shell model (TOSM) to describe the strong tensor correlation arising from the bare nuclear force in nuclei. Using TOSM for Li isotopes, we investigate the anomalous structures of ^9,10,11Li based on the ⁹Li+n+n model where the ⁹Li cluster is described by TOSM. As a result, the couplings between the tensor correlation in ⁹Li and the extra two neutrons emerge Pauli-blocking, which naturally increases the s² component to develop the halo structure in ¹¹Li. We further describe the short-range correlation arising from the repulsive core in the bare nuclear force by the unitary correlation operator method (UCOM). We propose the new framework of TOSM+UCOM for the nuclear structure study starting from the bare nuclear force.

We propose a new theoretical approach to calculate nuclear structure using bare nuclear interaction, in which the tensor and short-range correlations are described by using the tensor optimized shell model (TOSM) and the unitary correlation operator method (UCOM), respectively. We compare the obtained results using TOSM+UCOM for ⁴He with the rigorous calculation.

We propose a new method to describe nuclear structure using bare nuclear interaction, in which the tensor and short-range correlations are described by using the tensor optimized shell model (TOSM) and the unitary correlation operator method (UCOM), respectively.

The pion plays an important role for the structure of nucleus and nuclear matter. We propose a new theoretical framework, named the tensor optimized shell model (TOSM) to calculate the tensor interaction together with the unitary correlation operator method (UCOM) for the short range repulsion. We are able to handle the pion exchange interaction directly in the proposed framework. We compare the calculated results for ⁴He with the rigorous calculation to show the power of TOSM to treat the tensor interaction.

The pion plays an important role for the structure of nucleus and nuclear matter. We propose a new theoretical framework, named the tensor optimized shell model (TOSM) to calculate the tensor interaction together with the unitary correlation operator method (UCOM) for the short range repulsion. We are able to handle the pion exchange interaction directly in the proposed framework. We compare the calculated results for ⁴He with the rigorous calculation to show the power of TOSM to treat the tensor interaction. We then discuss the important role of pion in hypernuclei due to excitation of Σ baryon from Λ state.

Autoregressive processes (AR) have typical short-range memory. Detrended Fluctuation Analysis (DFA) was basically designed to reveal long-range correlations in non stationary processes. However DFA can also be regarded as a suitable method to investigate both long-range and short-range correlations in non stationary and stationary systems. Applying DFA to AR processes can help understanding the non-uniform correlation structure of such processes. We systematically investigated a first order autoregressive model AR(1) by DFA and established the relationship between the interaction constant of AR(1) and the DFA correlation exponent. The higher the interaction constant the higher is the short-range correlation exponent. They are exponentially related. The investigation was extended to AR(2) processes. The presence of an interaction between distant terms with characteristic time constant in the series, in addition to a near by interaction will increase the correlation exponent and the range of correlation while the effect of a distant negative interaction will significantly decrease the range of interaction, only. This analysis demonstrate the possibility to identify an AR(1) model in an unknown DFA plot or to distinguish between AR(1) and AR(2) models.

Series of coding sequence lengths extracted from the chromosome of Bacillus subtilis were subjected to detrended fluctuation analysis (DFA). The non-linear characteristic of the DFA plot was interpreted in terms of short-range correlation. The analysis was performed on series consisting of the whole chromosome coding sequences, as well as on the leading and lagging strands. These were compared to the same series subjected to a randomization procedure. The series were divided into two halves, which also revealed different short-range characteristics. Similar results were noticed for seven strains of Escherichia coli. Therefore, the short-range correlation characteristics are sensitive to species and strains and could be used for comparative investigations of microbial genome organization.

The pion plays an important role for the structure of nucleus and nuclear matter. We propose a new theoretical framework, named the tensor optimized shell model (TOSM) to calculate the tensor interaction together with the unitary correlation operator method (UCOM) for the short range repulsion. We are able to handle the pion exchange interaction directly in the proposed framework. We compare the calculated results for ⁴He with the rigorous calculation to show the power of TOSM to treat the tensor interaction. We then discuss the important role of pion in hypernuclei due to excitation of Σ baryon from Λ state.

We propose a new theoretical approach to calculate nuclear structure using bare nuclear interaction, in which the tensor and short-range correlations are described by using the tensor optimized shell model (TOSM) and the unitary correlation operator method (UCOM), respectively. We compare the obtained results using TOSM+UCOM for ⁴He with the rigorous calculation.

Nuclear matter is studied by using beyond relativistic Hartree-Fock (RHF) model with the realistic nucleon-nucleon (NN) interaction. We use the unitary correlation operator method (UCOM) to treat the strong repulsive interaction in the short-range region between two nucleons. We find that the equation of state (EOS) of pure neutron matter is completely comparable with the results of Dirac-Brueckner-Hartree-Fock (DBHF) theory. However, for the symmetric nuclear matter, the EOS is largely different from the DBHF result particularly in the low density region.

We propose a new theoretical approach to describe nucleus using bare nuclear interaction, in which the tensor and short-range correlations are described with the tensor optimized shell model (TOSM) and the unitary correlation operator method (UCOM), respectively. We show the obtained results of He isotopes using TOSM+UCOM, such as the importance of the pn-pair correlated by the tensor force, and the structure differences in the LS partner states of ⁵He.