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DOE OSTI · 3019932

Computing nuclear response functions with time-dependent coupled-cluster theory

Bonaiti, Francesca [Michigan State University, East Lansing, MI (United States); Oak Ridge National Laboratory (ORNL), Oak Ridge, TN (United States)] (ORCID:0000000239261609)·Balos, Cody [Lawrence Livermore National Laboratory (LLNL), Livermore, CA (United States)] (ORCID:0000000191380720)·Godbey, Kyle [Michigan State University, East Lansing, MI (United States)] (ORCID:0000000306223646)·Hagen, Gaute [Oak Ridge National Laboratory (ORNL), Oak Ridge, TN (United States); University of Tennessee, Knoxville, TN (United States)]·Papenbrock, Thomas [Oak Ridge National Laboratory (ORNL), Oak Ridge, TN (United States); University of Tennessee, Knoxville, TN (United States)] (ORCID:0000000187332849)·Woodward, Carol S. [Lawrence Livermore National Laboratory (LLNL), Livermore, CA (United States)] (ORCID:0000000265028659)
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Abstract

We compute nuclear response functions by solving the time-dependent 𝐴-body Schrödinger equation, recording the time-dependent transition moment and extracting spectral information via Fourier transforms. The solution of the time-dependent many-body problem accounts for correlations on top of the mean field by taking advantage of a time-dependent formulation of coupled-cluster theory. As a validation, we focus on electric dipole transitions in 4 He and 16 O and compare moments of the response function distribution to the results of an equivalent static framework, finding negligible discrepancies. We investigate how proton and neutron densities evolve in time, and we see the traditional picture of soft and giant dipole resonances as collective oscillations of protons and neutrons emerging from our calculations in 16 O and 24 O. Furthermore, this method also allows us to investigate the behavior of the nucleus in the presence of a strong electric field. In that regime, the behavior of the system becomes chaotic. Qualitatively, the spectral information obtained in this limit is in line with previous time-dependent mean-field results.

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Ab initio calculationsCluster modelsLinear response theoryNuclear many-body theoryOptical, coupled-channel & distorted wave modelsPhysics - Nuclear physics and radiation physics

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Bonaiti, Francesca [Michigan State University, East Lansing, MI (United States); Oak Ridge National Laboratory (ORNL), Oak Ridge, TN (United States)] (ORCID:0000000239261609), Balos, Cody [Lawrence Livermore National Laboratory (LLNL), Livermore, CA (United States)] (ORCID:0000000191380720), Godbey, Kyle [Michigan State University, East Lansing, MI (United States)] (ORCID:0000000306223646), Hagen, Gaute [Oak Ridge National Laboratory (ORNL), Oak Ridge, TN (United States); University of Tennessee, Knoxville, TN (United States)], Papenbrock, Thomas [Oak Ridge National Laboratory (ORNL), Oak Ridge, TN (United States); University of Tennessee, Knoxville, TN (United States)] (ORCID:0000000187332849), Woodward, Carol S. [Lawrence Livermore National Laboratory (LLNL), Livermore, CA (United States)] (ORCID:0000000265028659). 2026-02-09. Computing nuclear response functions with time-dependent coupled-cluster theory. https://doi.org/10.1103/scn2-dnyg

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