Semimicroscopic modeling of heavy-ion fusion reactions with multireference covariant density functional theory

Hagino, K.; Yao, J. M.

doi:10.1103/physrevc.91.064606

Cited by 12 publications

(6 citation statements)

References 52 publications

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“…Numerical applications using Eqs. (85) and (87) lead to almost identical results [109]. In fact, the application of Eq.…”

Section: Particle Number Projection Techniquementioning

confidence: 80%

“…Anharmonicities can be studied by investigating, e.g., non-linear response in TDHF [71,75,83] or boson mapping techniques [84]. An alternative approach based on the multireference covariant density functional theory (MCDFT) has also been used to compute the properties of low-lying collective excitations and their effect on fusion via coupled-channel calculations [85,86].…”

Section: Couplings To Collective Vibrationsmentioning

confidence: 99%

“…This suggests that other beyond mean-field correlations may be important. Unlike expression (85), the number of determinants to compute in Eq. ( 87) only depends on the number of discretised gauge angles θ.…”

Section: Particle Number Projection Techniquementioning

confidence: 99%

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Heavy-ion collisions and fission dynamics with the time-dependent Hartree–Fock theory and its extensions

Simenel

Umar

2018

Progress in Particle and Nuclear Physics

169

103

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Microscopic methods and tools to describe nuclear dynamics have considerably been improved in the past few years. They are based on the time-dependent Hartree-Fock (TDHF) theory and its extensions to include pairing correlations and quantum fluctuations. The TDHF theory is the lowest level of approximation of a range of methods to solve the quantum many-body problem, showing its universality to describe manyfermion dynamics at the mean-field level. The range of applications of TDHF to describe realistic systems allowing for detailed comparisons with experiment has considerably increased. For instance, TDHF is now commonly used to investigate fusion, multi-nucleon transfer and quasi-fission reactions. Thanks to the inclusion of pairing correlations, it has also recently led to breakthroughs in our description of the saddle to scission evolution, and, in particular, the non-adiabatic effects near scission. Beyond mean-field approaches such as the time-dependent random-phase approximation (TDRPA) and stochastic meanfield methods have reached the point where they can be used for realistic applications. We review recent progresses in both techniques and applications to heavy-ion collision and fission. Introduction: nuclear quantum many-body dynamicsThe quantum many-body problem is vital to many areas of physics. Indeed, the description of complex quantum objects of interacting particles is of interests for many physical systems, from quarks and gluons in a nucleon to macromolecules, such as fullerenes, to Bose-Einstein condensates. Consequently, major developments in the description of quantum many-body systems are often of interest to many different fields. For instance, the BCS theory introduced to describe superconductivity [1] is also widely used in nuclear physics to incorporate the effect of pairing correlations. Similarly, the tools used to study low-energy fusion with multi-channel tunneling [2] are also used to describe dissociative adsorption of molecules on a surface [3].The similarity between dynamical processes in quantum many-body systems, whether their constituents are nucleons, electrons, or atoms, is quite striking. It is possible to make such systems vibrate, rotate, fuse, transfer particles, fission and break up. This is of course true for nuclear systems, where each of these processes can be used to learn about specific aspects of quantum many-body dynamics. For instance, the study of nuclear vibrations tells us how single-particles can produce collective motion, what is its interplay with the underlying shell structure, what are the source of non-linearities leading to anharmonicities, and how collective modes get damped and decay. These concepts and many others can also be studied via heavy-ion collisions:1 In the case of a time-independent Hamiltonian, we haveF H (t) = e iĤt/ F e −iĤt/ . 2 Of course, nucleons are indistinguishable fermions and there is no guarantee that the nucleon which is annihilated is the same as the one which is created. In fact, the question of "which one" is created or a...

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“…Numerical applications using Eqs. (85) and (87) lead to almost identical results [109]. In fact, the application of Eq.…”

Section: Particle Number Projection Techniquementioning

confidence: 80%

Section: Couplings To Collective Vibrationsmentioning

confidence: 99%

See 1 more Smart Citation

Heavy-ion collisions and fission dynamics with the time-dependent Hartree–Fock theory and its extensions

Simenel

Umar

2018

Progress in Particle and Nuclear Physics

169

103

View full text Add to dashboard Cite

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“…These methods have been applied already in the 1970s [83]. Although lacking dissipative interactions, they still belong to the standard approaches for theoretical studies of nuclear fusion [84][85][86][87] and fission [88,89] reactions.…”

Section: Introductionmentioning

confidence: 99%

Self-consistent methods for structure and production of heavy and superheavy nuclei

et al. 2021

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Self-consistent methods for the structure of heavy and superheavy nuclei are reviewed. The construction and application of energy-density functionals are discussed. The relationship between the self-consistent methods and microscopic-macroscopic approaches is considered on the mean-field level. The extraction of single-particle potentials from the energy-density functional is described. The isotopic dependence of nucleon distributions and its influence on the nucleus-nucleus interaction is analyzed. As a new additional condition we introduce that the energy-density functional must describe the heights of the Coulomb barriers in nucleusnucleus interaction potentials, thus imposing constraints on the properties of the functional at low matter densities. The self-consistent methods are applied to describe the quasiparticle structure, cluster radioactivity, and fission of the heaviest nuclei. These methods are used to predict the probabilities of β-delayed multi-neutron emission and half-lives of β-decays and electron captures in heavy and superheavy nuclei. The predicted properties of superheavy nuclei are used to estimate the production cross-sections of superheavy nuclei in complete fusion reactions. Contents

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“…This novel picture of rotationinduced octupole shape stabilization provides a natural explanation for the spin-dependent parity splitting in the excitation energies and is expected to be a common phenomenon in some actinides and rare-earth nuclei. Finally, we point out that with our microscopic results as the inputs of the coupled-channel calculation for nuclear fusion [41], one may observe some interesting differences on the barrier distribution compared with that based on rotational or vibrational limits [42]. Moreover, octupole deformed odd-mass nuclei have enhanced time-reversal violating nuclear Schiff moments and thus are relevant for measuring atomic electric-dipole moments [43].…”

mentioning

confidence: 99%

Beyond relativistic mean-field approach for nuclear octupole excitations

Yao

Zhou

2015

Phys. Rev. C

Self Cite

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We report the first beyond-mean-field study of low-lying parity-doublet states in 224 Ra by extending the multireference relativistic energy density functional method to include dynamical correlations related to symmetry restoration and quadrupole-octupole shape fluctuation with a generator coordinate method combined with parity, particle-number, and angular-momentum projections. We clarify full microscopically that the origin of spin-dependent parity splitting in low-spin states is related to the octupole shape stabilization of positive-parity states, the dominated shapes of which drift gradually to that of negative-parity ones. The existence of octupole shaped nuclei in intrinsic frame has been suggested very early from the observed low-lying parity doublets connected with strong electric odd-multipole (Eλ) transition strengths [1,2]. Among them, 224 Ra was recently suggested to be a stable pear shaped nucleus based on the measured Eλ transitions [3]. Nevertheless, as pointed out early [4] and shown in this paper that the effects stemming from static octupole shapes on Eλ transitions can be almost equally well described by including dynamical octupole deformations around the equilibrium shape. Moreover, the spectroscopy of reflection-asymmetric diatomic molecules suggests the existence of a rotational band with alternating parity, which has indeed been found in some candidates of octupole shaped nuclei at high-spin states. However, an evident energy splitting is observed in the odd and even parity states of these nuclei at low-spin region. In particular, this parity splitting is gradually increased with the decrease of spin. This peculiar feature indicates the possible existence of large quantum shape fluctuation in octupole shapes at low-spin states. Therefore, whether atomic nuclei possess dynamical or stable octupole shapes in low-spin states remains an open question, which is relevant not only for deepening our understanding on nuclear structure at low energy, but also in searching for CP-violating Schiff moment which is expected to be amplified in octupole deformed nuclei [5].Numerous studies have been performed to search for octupole deformed nuclei with selfconsistent meanfield approaches [6][7][8][9][10][11][12], and to understand nuclear collective octupole excitations with energy density functional (EDF) based collective Hamiltonian [13][14][15][16], EDF mapped interacting boson model [17], and generator coordinate method (GCM) [18][19][20]. These studies have greatly deepened our understanding on the structure of octupole candidate nuclei. However, the onset of unusual spin-dependent parity splitting has not been clarified.The combination of energy density functional approach with GCM provides a powerful tool to study nuclear shape fluctuations. Unfortunately, angular-momentum projection has not yet been implemented in this framework for octupole nuclei and the stabilization of nuclear octupole shape against rotation remains to be examined.In the meantime, cranked mean-field approaches have also be...

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Semimicroscopic modeling of heavy-ion fusion reactions with multireference covariant density functional theory

Cited by 12 publications

References 52 publications

Heavy-ion collisions and fission dynamics with the time-dependent Hartree–Fock theory and its extensions

Heavy-ion collisions and fission dynamics with the time-dependent Hartree–Fock theory and its extensions

Self-consistent methods for structure and production of heavy and superheavy nuclei

Beyond relativistic mean-field approach for nuclear octupole excitations

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