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Haozhao Liang - One of the best experts on this subject based on the ideXlab platform.

  • resonant continuum relativistic mean field plus bcs in complex Momentum Representation
    Physical Review C, 2018
    Co-Authors: Kemeng Ding, Jian-you Guo, Min Shi, Zhong-ming Niu, Haozhao Liang
    Abstract:

    To develop methods for open quantum systems is one of the most important tasks in theoretical studies. We develop the resonant-continuum relativistic mean-field theory in complex Momentum Representation with the BCS approximation for pairing correlations in weakly bound nuclei. The bound states and resonant states are treated on the same footing and the physical resonant states are considered self-consistently in the present calculations. The Zr isotopes are chosen as illustrative examples. The calculated binding energies, two-neutron separation energies, and root-mean-square radii are in excellent agreement with the available data as well as the relativistic Hartree-Bogoliubov calculations. Especially, several resonant states lying near the continuum threshold are found to play important roles in the formation of exotic phenomena and support the prediction of giant halo in the Zr isotopes.

  • Combination of complex Momentum Representation and Green's function methods in relativistic mean-field theory
    Physical Review C, 2018
    Co-Authors: Min Shi, Zhong-ming Niu, Haozhao Liang
    Abstract:

    We have combined the complex Momentum Representation method with the Green's function method in the relativistic mean-field framework to establish the RMF-CMR-GF approach. This new approach is applied to study the halo structure of $^{74}$Ca. All the continuum level density of concerned resonant states are calculated accurately without introducing any unphysical parameters, and they are independent of the choice of integral contour. The important single-particle wave functions and densities for the halo phenomenon in $^{74}$Ca are discussed in detail.

  • Probing resonances in the Dirac equation with quadrupole-deformed potentials with the complex Momentum Representation method
    Physical Review C, 2017
    Co-Authors: Zhi Fang, Jian-you Guo, Min Shi, Zhong-ming Niu, Haozhao Liang, Shi-sheng Zhang
    Abstract:

    Resonance plays critical roles in the formation of many physical phenomena, and many techniques have been developed for the exploration of resonance. In a recent letter [Phys. Rev. Lett. 117, 062502 (2016)], we proposed a new method for probing single-particle resonances by solving the Dirac equation in complex Momentum Representation for spherical nuclei. Here, we extend this method to deformed nuclei with theoretical formalism presented. We elaborate numerical details, and calculate the bound and resonant states in $^{37}$Mg. The results are compared with those from the coordinate Representation calculations with a satisfactory agreement. In particular, the present method can expose clearly the resonant states in complex Momentum plane and determine precisely the resonance parameters for not only narrow resonances but also broad resonances that were difficult to obtain before.

  • Probing Resonances of the Dirac Equation with Complex Momentum Representation.
    Physical Review Letters, 2016
    Co-Authors: Min Shi, Jian-you Guo, Zhong-ming Niu, Haozhao Liang
    Abstract:

    Resonance plays critical roles in the formation of many physical phenomena, and several methods have been developed for the exploration of resonance. In this work, we propose a new scheme for resonance by solving the Dirac equation in the complex Momentum Representation, in which the resonant states are exposed clearly in the complex Momentum plane and the resonance parameters can be determined precisely without imposing unphysical parameters. Combined with the relativistic mean-field theory, this method is applied to probe the resonances in ^{120}Sn with the energies, widths, and wave functions being obtained. Compared to other methods, this method is not only very effective for narrow resonances, but also can be reliably applied to broad resonances.

Jian-you Guo - One of the best experts on this subject based on the ideXlab platform.

  • Investigation of exotic structure in 34 Na by complex Momentum Representation combined with Green’s function method
    Journal of Physics G: Nuclear and Particle Physics, 2020
    Co-Authors: Yu-xuan Luo, Quan Liu, Jian-you Guo, Yan-yun Yang
    Abstract:

    The study of exotic nuclei is one of the most interesting topics in nuclear physics. 34Na has attracted additional attentions for an odd-odd nucleus with special structure. Here, we combine the complex Momentum Representation (CMR) and Green's function (GF) to establish the CMR-GF method for the exploration of exotic structure, such as halo, skin, the level inversion and so on, in 34Na. The available density distributions, the configuration occupations, and the root mean square radius for the orbit occupied by the last valence neutron suggest a pwave single-neutron halo or skin structure in 34Na.

  • investigation of exotic structure in 34 na by complex Momentum Representation combined with green s function method
    Journal of Physics G, 2020
    Co-Authors: Yu-xuan Luo, Quan Liu, Jian-you Guo, Yan-yun Yang
    Abstract:

    The study of exotic nuclei is one of the most interesting topics in nuclear physics. 34Na has attracted additional attentions for an odd-odd nucleus with special structure. Here, we combine the complex Momentum Representation (CMR) and Green's function (GF) to establish the CMR-GF method for the exploration of exotic structure, such as halo, skin, the level inversion and so on, in 34Na. The available density distributions, the configuration occupations, and the root mean square radius for the orbit occupied by the last valence neutron suggest a pwave single-neutron halo or skin structure in 34Na.

  • Probing the resonance of Dirac particle in the relativistic point-coupling model by complex-Momentum-Representation method
    Journal of Physics G: Nuclear and Particle Physics, 2019
    Co-Authors: Yu Wang, Zhong-ming Niu, Min Shi, Jian-you Guo
    Abstract:

    The complex-Momentum-Representation (CMR) method is applied to investigate the single-particle resonant states in the relativistic point-coupling model. Taking Sn isotopes as examples, the resonant energies and widthes are systematically calculated and compared with those from the Green's function method. It is found that the resonant states are predicted accurately with the CMR method even for those lying near the continuum threshold. The predicted resonant energies and widths generally decrease with the increase of neutron number, which are mainly induced by the different potentials of Sn isotopes. It is also found that the wave functions in the Momentum space are relatively localized for the resonant states especially for the broad resonances, while they have long tails in the coordinate space, which indicates the advantage of CMR method in studying the properties of resonant states.

  • Interpretation of halo in 19C with complex Momentum Representation method
    Journal of Physics G: Nuclear and Particle Physics, 2018
    Co-Authors: Xue-neng Cao, Quan Liu, Jian-you Guo
    Abstract:

    The extremely neutron-rich nucleus 19C has attracted much attention for its exotic properties. The most interesting is that the ground state of 19C behaves like a one-neutron halo. In order to understand this peculiar characteristic, we apply the complex Momentum Representation method to explore the weakly bound structure of 19C. We have calculated the single-particle energies for the bound and resonant states together with their evolutions to deformation, and checked the occupation probabilities of major configurations in the level occupied by the valance neutron. The result suggests that 19C is a prolate halo formed by a dominant s-wave configuration.

  • resonant continuum relativistic mean field plus bcs in complex Momentum Representation
    Physical Review C, 2018
    Co-Authors: Kemeng Ding, Jian-you Guo, Min Shi, Zhong-ming Niu, Haozhao Liang
    Abstract:

    To develop methods for open quantum systems is one of the most important tasks in theoretical studies. We develop the resonant-continuum relativistic mean-field theory in complex Momentum Representation with the BCS approximation for pairing correlations in weakly bound nuclei. The bound states and resonant states are treated on the same footing and the physical resonant states are considered self-consistently in the present calculations. The Zr isotopes are chosen as illustrative examples. The calculated binding energies, two-neutron separation energies, and root-mean-square radii are in excellent agreement with the available data as well as the relativistic Hartree-Bogoliubov calculations. Especially, several resonant states lying near the continuum threshold are found to play important roles in the formation of exotic phenomena and support the prediction of giant halo in the Zr isotopes.

Leonid V. Poluyanov - One of the best experts on this subject based on the ideXlab platform.

V. M. Volokhov - One of the best experts on this subject based on the ideXlab platform.

  • Method of Momentum Representation in the Relativistic Jan–Teller Effect G_ g [3/2] × (t_2g + e_ g )
    Russian Journal of Physical Chemistry B, 2017
    Co-Authors: Leonid V. Poluyanov, V. M. Volokhov
    Abstract:

    The relativistic multimode Jahn-Teller effect G _ g [3/2] × ( t _2 g + e _ g ), which takes place in cubic and octahedral molecular systems containing heavy atoms, is considered. The changeover from to the Momentum Representation in the vibronic Schrödinger equation, equivalent to the five-dimensional Fourier transform, makes it possible to lower the order of the differential operators, thereby achieving significant simplifications. The main result of this work is a quantum-mechanical calculation of the nonadiabatic transition probability in a system that does not admit a complete separation of the variables in the vibronic Schrödinger equation.

  • method of Momentum Representation in the relativistic jan teller effect g g 3 2 t 2 g e g
    Russian Journal of Physical Chemistry B, 2017
    Co-Authors: L V Poluyanov, V. M. Volokhov
    Abstract:

    The relativistic multimode Jahn-Teller effect G g [3/2] × (t2g + e g ), which takes place in cubic and octahedral molecular systems containing heavy atoms, is considered. The changeover from to the Momentum Representation in the vibronic Schrodinger equation, equivalent to the five-dimensional Fourier transform, makes it possible to lower the order of the differential operators, thereby achieving significant simplifications. The main result of this work is a quantum-mechanical calculation of the nonadiabatic transition probability in a system that does not admit a complete separation of the variables in the vibronic Schrodinger equation.

  • Method of Momentum Representation in the Relativistic Jan–Teller Effect G g [3/2] × ( t 2 g + e g )
    Russian Journal of Physical Chemistry B, 2017
    Co-Authors: Leonid V. Poluyanov, V. M. Volokhov
    Abstract:

    The relativistic multimode Jahn-Teller effect G g [3/2] × (t2g + e g ), which takes place in cubic and octahedral molecular systems containing heavy atoms, is considered. The changeover from to the Momentum Representation in the vibronic Schrodinger equation, equivalent to the five-dimensional Fourier transform, makes it possible to lower the order of the differential operators, thereby achieving significant simplifications. The main result of this work is a quantum-mechanical calculation of the nonadiabatic transition probability in a system that does not admit a complete separation of the variables in the vibronic Schrodinger equation.

J. Serreau - One of the best experts on this subject based on the ideXlab platform.

  • Physical Momentum Representation of scalar field correlators in de Sitter space
    Physical Review D, 2013
    Co-Authors: R. Parentani, J. Serreau
    Abstract:

    We propose a new approach to compute correlators of quantum fields in de Sitter space. It is based on nonequilibrium field theory techniques, and exploits de Sitter symmetries so as to partially reduce the number of independent variables of n-point functions in a manner that preserves the usefulness of a Momentum Representation, e.g., for writing spatial convolution integrals as simple products. In this Representation, the two-point function of a scalar field only depends on two physical momenta, and the corresponding Schwinger-Dyson evolution equations take the form of Momentum flow equations. Moreover, standard diagrammatic rules can be entirely formulated in this Representation. The method is suitable for analytical approximations as well as numerical implementations. In forthcoming publications, we apply it to resum infrared logarithmic terms appearing in the perturbative calculation of vertex and correlation functions.

  • Physical Momentum Representation of scalar field correlators in de Sitter space
    Physical Review D, 2013
    Co-Authors: R. Parentani, J. Serreau
    Abstract:

    We propose a new approach to compute correlators of quantum fields in de Sitter space. It is based on nonequilibrium field theory techniques, and exploits de Sitter symmetries so as to partially reduce the number of independent variables of n-point functions in a manner that preserves the usefulness of a Momentum Representation, e.g., for writing spatial convolution integrals as simple products. In this Representation, the two-point function of a scalar field only depend on two physical momenta, and the corresponding Schwinger-Dyson evolution equations take the form of Momentum flow equations. Moreover, standard diagrammatic rules can be entirely formulated in this Representation. The method is suitable for analytical approximations as well as numerical implementations. In a forthcoming publication, we apply it to resum infrared logarithmic terms appearing in perturbative calculation of the four-point vertex function.