A5063716161- Nuclear physics research studies
- Advanced Chemical Physics Studies
- Atomic and Molecular Physics
- Quantum Chromodynamics and Particle Interactions
- Astronomical and nuclear sciences
- Rare-earth and actinide compounds
- Nuclear Physics and Applications
- Building Energy and Comfort Optimization
- Solar Radiation and Photovoltaics
- Cold Atom Physics and Bose-Einstein Condensates
- Advanced NMR Techniques and Applications
- Quantum, superfluid, helium dynamics
- Impact of Light on Environment and Health
- High-pressure geophysics and materials
- Astro and Planetary Science
- Pulsars and Gravitational Waves Research
- Atomic and Subatomic Physics Research
- Nuclear reactor physics and engineering
- Neutrino Physics Research
- Quantum chaos and dynamical systems
- Superconducting Materials and Applications
- Gamma-ray bursts and supernovae
- Urban Heat Island Mitigation
- Particle accelerators and beam dynamics
- Solar Thermal and Photovoltaic Systems
Universidad Autónoma de Madrid
2016-2025
Universidad Politécnica de Madrid
2009-2025
Instituto de Física Fundamental
2025
Kuwait University
2021
Universitat de Barcelona
2021
University of Washington
2018-2019
Istituto Nazionale di Fisica Nucleare, Sezione di Catania
2017
Gamma Medica (United States)
2015
University of Jyväskylä
2009
Instituto de Estructura de la Materia
2009
There has been much recent interest in nuclear fission, due part to a new appreciation of its relevance astrophysics, stability superheavy elements, and fundamental theory neutrino interactions. At the same time, there have important developments on conceptual computational level for theory. The promising theoretical avenues were subject workshop held at University York October 2019; this report summarises findings recommendations.
The equal filling approximation, a procedure widely used in mean-field calculations to treat the dynamics of odd nuclei time-reversal invariant way, is justified as consequence variational principle over an average energy functional. ideas statistical quantum mechanics are employed justification. As illustration method, ground and lowest-lying states some octupole deformed radium isotopes computed.
We present a computational methodology for theory of the lowest octupole excitations applicable to all even-even nuclei beyond lightest. The is well-known generator-coordinate extension (GCM) Hartree-Fock-Bogoliubov self-consistent mean field (HFB). use discrete-basis Hill-Wheel method (HW) compute wave functions with an interaction from Gogny family Hamiltonians. Comparing compiled experimental data on excitations, we find that performance depends deformation characteristics nucleus. For...
The evolution of the ground-state nuclear shapes in neutron-rich Sr, Zr, and Mo isotopes, including both even-even odd-A nuclei, is studied within a self-consistent mean-field approximation based on D1S–Gogny interaction. Neutron separation energies charge radii are calculated compared with available data. A correlation between shape transition discontinuity those observables found microscopically. While Sr Zr isotopes steep behavior observed isotopic dependence consequence sharp...
The relevance of coupling quadrupole and octupole collective degrees freedom in physical observables is explored calculations with the Gogny force for light radon, radium, thorium isotopes. results generator coordinate method properties negative parity states show an improvement over traditional ones that consider just moment.
A new version of the Barcelona-Catania-Paris energy functional is applied to a study nuclear masses and other properties. The largely based on calculated ab initio neutron matter equations state. Compared typical Skyrme functionals having 10--12 parameters apart from spin-orbit pairing terms, has only 2 or 3 adjusted parameters, fine tuning binding fixing surface finite nuclei. An rms value 1.58 MeV obtained fit these three 579 measured reported in Audi Wapstra [Nucl. Phys. 729, 337 (2003)]...
Despite the more than 1 order of magnitude difference between measured dipole moments in ^{144}Ba and ^{146}Ba, octupole correlations ^{146}Ba are found to be as strong those with a similarly large value B(E3;3^{-}→0^{+}) determined 48(+21-29) W.u. The new results not only establish unambiguously presence region deformation centered on these neutron-rich Ba isotopes, but also manifest dependence electric occupancy different neutron orbitals nuclei enhanced strength, revealed by fully...
We computed a new set of static fission properties suited for $r$-process calculations. The potential energy surfaces and collective inertias 3640 nuclei in the superheavy region are obtained from self-consistent mean-field calculations using Barcelona-Catania-Paris-Madrid density functional. path is as function quadrupole moment by minimizing exploring octupole hexadecapole deformations. spontaneous lifetimes evaluated employing different schemes vibrational corrections. This allows us to...
Ground-state properties of neutron-rich $N\ensuremath{\approx}28$ nuclei are described in the framework relativistic Hartree plus Bogoliubov (RH+B) theory. The model uses NL3 effective interaction mean-field Lagrangian, and describes pairing correlations by part finite range Gogny D1S. Two-neutron separation energies ground-state quadrupole deformations that result from fully self-consistent RH+B solutions compared with available experimental data. predicts a strong suppression spherical...
The fission barriers of the nuclei ${}^{254}\mathrm{Fm},$ ${}^{256}\mathrm{Fm},$ ${}^{258}\mathrm{Fm},$ ${}^{258}\mathrm{No}$, and ${}^{260}\mathrm{Rf}$ are investigated in a fully microscopic way up to scission point. analysis is based on constrained Hartree-Fock-Bogoliubov theory Gogny's D1S force. quadrupole, octupole, hexadecapole moments as well number nucleons neck region used constraints. Two paths, corresponding bimodal fission, found. decrease with isotope mass half-life times heavy...
The collective yrast band of the nucleus ${}^{48}\mathrm{Cr}$ is studied using spherical shell model and Hartree-Fock-Bogoliubov (HFB) method. Both approaches produce basically same axially symmetric intrinsic state up to the---accurately reproduced---observed backbending. Agreement between both calculations extends most observables. only significant discrepancy comes from static moments inertia can be attributed need a more refined treatment pairing correlations in HFB calculation.
The problem of how to compute accurately and efficiently the sign overlap between two general Hartree-Fock-Bogoliubov (HFB) wave functions is addressed. results obtained can easily be extrapolated evaluation trace a density operator exponential one body operators.
Cluster radioactivity is the emission of a fragment heavier than an $\ensuremath{\alpha}$ particle and lighter mass 50. The range clusters observed in experiments goes from ${}^{14}$C to ${}^{32}$Si while heavy residue always nucleus neighborhood doubly-magic ${}^{208}$Pb nucleus. described this paper as very asymmetric nuclear fission. A new fission valley leading decay with large asymmetry matching cluster products found. octupole moment found be more convenient standard quadrupole...
Self-consistent axially symmetric Skyrme Hartree-Fock plus BCS calculations are performed to study the evolution of shapes with number nucleons in various chains Yb, Hf, W, Os, and Pt isotopes from neutron $N=110$ up $N=122$. Potential energy curves analyzed a search for signatures oblate-prolate phase shape transitions, results pairing forces considered. Comparisons obtained Gogny interaction as well relativistic mean field presented. The role \ensuremath{\gamma} degree freedom is also discussed.
We present a pfaffian formula for projection and symmetry restoration wave functions of the general Bogoliubov form, including quasiparticle excited states linear combinations them. This solves long-standing problem in calculating good symmetry, arising from sign ambiguity commonly used determinant formula. A simple example is given projecting particle number angular momentum function Fock space single j-shell.
A computer code is presented for solving the equations of Hartree-Fock-Bogoliubov (HFB) theory by gradient method, motivated need efficient and robust codes to calculate configurations required extensions HFB such as generator coordinate method. The organized with a separation between parts that are specific details Hamiltonian generic This permits total flexibility in choosing symmetries be imposed on solutions. solves both even odd particle number ground states, choice determined input...
The structure of even-even neutron-rich Ru, Mo, Zr and Sr nuclei in the $A\approx 100$ mass region is studied within interacting boson model (IBM) with microscopic input from self-consistent mean-field approximation based on Gogny-D1M energy density functional. deformation surface quadrupole space $(\beta,\gamma)$, computed constrained Hartree-Fock-Bogoliubov framework, mapped onto expectation value appropriately chosen IBM Hamiltonian configuration mixing condensate state. used to study...
The neutron-rich nuclei 94,96Kr were studied via projectile Coulomb excitation at the REX-ISOLDE facility CERN. Level energies of first excited 2(+) states and their absolute E2 transition strengths to ground state are determined discussed in context E(2(1)(+)) B(E2;2(1)(+)→0(1)(+)) systematics krypton chain. Contrary previously published results no sudden onset deformation is observed. This experimental result supported by a new proton-neutron interacting boson model calculation based on...
The properties of dynamic (least action) fission paths are analyzed and compared to the ones more traditional static energy) paths. Both Barcelona-Catania-Paris-Madrid Gogny D1M energy density functionals used in calculation Hartree-Fock-Bogoliubov (HFB) constrained configurations providing potential collective inertias. action is computed as Wentzel-Kramers-Brillouin method. A full variational search least-action path over complete space HFB wave functions cumbersome probably unnecessary if...
Spectroscopic observables such as electromagnetic transition strengths can be related to the properties of intrinsic mean-field wave function when latter are strongly deformed, but standard rotational formulas break down deformation decreases. Nevertheless there is a well-defined, nonzero, spherical limit that evaluated in terms overlaps deformed functions. We examine between and for range nuclei, comparing two limiting with exact projection results. find simple criterion validity formula...