Publications (76)
Approximate Treatment of Lepton Distortion in Charged-Current Neutrino Scattering from Nuclei
J. Engel
The partial-wave expansion used to treat the distortion of scattered electrons by the nuclear Coulomb field is simpler and considerably less time-consuming when applied to the prod…
Coupled-cluster calculations of neutrinoless double-beta decay in Ca
S. J. Novario, P. Gysbers, J. Engel +6
We use coupled-cluster theory and nuclear interactions from chiral effective field theory to compute the nuclear matrix element for the neutrinoless double-beta decay of Ca.…
Proceedings of The Magnificent CENS Workshop 2018
D. Aristizabal Sierra, A. B. Balantekin, D. Caratelli +42
The Magnificent CENS Workshop (2018) was held November 2 & 3 of 2018 on the University of Chicago campus and brought together theorists, phenomenologists, and experimentalists…
Beta decay of r-process waiting-point nuclei in a self-consistent approach
J. Engel, M. Bender, J. Dobaczewski +2
Beta-decay rates for spherical neutron-rich r-process waiting-point nuclei are calculated within a fully self-consistent Quasiparticle Random-Phase Approximation, formulated in the…
Solving Nuclear Structure Problems with the Adaptive Variational Quantum Algorithm
A. M. Romero, J. Engel, Ho Lun Tang +1
We use the Lipkin-Meshkov-Glick (LMG) model and the valence-space nuclear shell model to examine the likely performance of variational quantum eigensolvers in nuclear-structure the…
Capture of Solar and Higher-Energy Neutrinos by Iodine 127
J. Engel, S. Pittel, P. Vogel
We discuss and improve a recent treatment of the absorption of solar neutrinos by I, in connection with a proposed solar neutrino detector. With standard-solar-model flux…
Scatttering of Weakly Interacting Massive Particles from Ge73
V. Dimitrov, J. Engel, S. Pittel
We use a "hybrid" method, mixing variationally-determined triaxial nuclear Slater determinants, to calculate the response of Ge73 to hypothetical dark-matter particles such as neut…
Fundamental Symmetries, Neutrons, and Neutrinos (FSNN): Whitepaper for the 2023 NSAC Long Range Plan
B. Acharya, C. Adams, A. A. Aleksandrova +176
This whitepaper presents the research priorities decided on by attendees of the 2022 Town Meeting for Fundamental Symmetries, Neutrons and Neutrinos, which took place December 13-1…
Time-Reversal Violating Schiff Moment of 225Ra
J. Engel, M. Bender, J. Dobaczewski +2
We use the Skyrme-Hartree-Fock method, allowing all symmetries to be broken, to calculate the time-reversal-violating nuclear Schiff moment (which induces atomic electric dipole mo…
Beta decay of deformed r-process nuclei near A = 80 and A= 160, including odd-A and odd-odd nuclei, with the Skyrme finite-amplitude method
T. Shafer, J. Engel, C. Fröhlich +3
After identifying the nuclei in the regions near A =80 and A = 160 for which beta-decay rates have the greatest effect on weak and main r-process abundance patterns, we apply the f…
Octupole correlations in low-lying states of 150Nd and 150Sm and their impact on neutrinoless double-beta decay
J. M. Yao, J. Engel
We present a generator-coordinate calculation, based on a relativistic energy-density functional, of the low-lying spectra in the isotopes Nd and Sm and of the nucl…
Spectroscopy of Double-Beta and Inverse-Beta Decays from 100Mo for Neutrinos
H. Ejiri, J. Engel, R. Hazama +3
Spectroscopic studies of two beta-rays from 100Mo are shown to be of potential interest for investigating both the Majorana neutrino mass by neutrinoless double beta-decay and low…
Ab initio uncertainty quantification of neutrinoless double-beta decay in Ge
A. Belley, J. M. Yao, B. Bally +9
The observation of neutrinoless double-beta () decay would offer proof of lepton number violation, demonstrating that neutrinos are Majorana particles, while also helping…
Ab-initio coupled-cluster effective interactions for the shell model: Application to neutron-rich oxygen and carbon isotopes
G. R. Jansen, J. Engel, G. Hagen +2
We derive and compute effective valence-space shell-model interactions from ab-initio coupled-cluster theory and apply them to open-shell and neutron-rich oxygen and carbon isotope…
Excited-State Density Distributions of Neutron-Rich Unstable Nuclei
J. Terasaki, J. Engel
We calculate densities of excited states in the quasiparticle random-phase approximation (QRPA)with Skyrme interactions and volume pairing. We focus on low-energy peaks/bumps in th…
R-Process Freezeout, Nuclear Deformation, and the Rare-Earth Element Peak
R. Surman, J. Engel, J. R. Bennett +1
We use network calculations of r-process nucleosynthesis to explore the origin of the peak in the solar r-process abundance distribution near nuclear mass number A = 160. The peak…
Towards Precise and Accurate Calculations of Neutrinoless Double-Beta Decay: Project Scoping Workshop Report
V. Cirigliano, Z. Davoudi, J. Engel +20
We present the results of a National Science Foundation (NSF) Project Scoping Workshop, the purpose of which was to assess the current status of calculations for the nuclear matrix…
Pairing and Isospin Symmetry in Proton-Rich Nuclei
J. Engel, K. Langanke, P. Vogel
Unlike their lighter counterparts, most odd-odd N=Z nuclei with mass A > 40 40 have ground states with isospin T=1, suggesting an increased role for the isovector pairing interacti…
Neutralino Inelastic Scattering with Subsequent Detection of Nuclear Gamma Rays
J. Engel, P. Vogel
We consider the potential benefits of searching for supersymmetric dark-matter through its inelastic excitation, via the "scalar current", of low-lying collective nuclear states in…
Chiral Two-Body Currents and Neutrinoless Double-Beta Decay in the QRPA
J. Engel, F. Simkovic, P. Vogel
We test the effects of an approximate treatment of two-body contributions to the axial-vector current on the QRPA matrix elements for neutrinoless double-beta decay in a range of i…
Gamow-Teller strength in Ca and Ni with the charge-exchange subtracted second random-phase approximation
D. Gambacurta, M. Grasso, J. Engel
We develop a fully self-consistent subtracted second random-phase approximation for charge-exchange processes with Skyrme energy-density functionals. As a first application, we stu…
Large-Scale Calculations of the Double-Beta Decay of 76Ge, 130Te, 136Xe, and 150Nd in the Deformed Self-Consistent Skyrme Quasiparticle Random-Phase Approximation
M. T. Mustonen, J. Engel
We use the axially-deformed Skyrme Quasiparticle Random-Phase Approximation (QRPA) together with the SkM* energy-density functional, both as originally presented and with the time-…
Multi-layer scintillation detector for the MOON double beta decay experiment: Scintillation photon responses studied by a prototype detector MOON-1
H. Nakamura, P. Doe, H. Ejiri +50
An ensemble of multi-layer scintillators is discussed as an option of the high-sensitivity detector Mo Observatory Of Neutrinos (MOON) for spectroscopic measurements of neutrino-le…
Nuclear time-reversal violation and the Schiff moment of 225Ra
J. Dobaczewski, J. Engel
We present a comprehensive mean-field calculation of the Schiff moment of the nucleus 225Ra, the quantity which determines the static electric dipole moment of the corresponding at…
Global description of beta-minus decay in even-even nuclei with the axially-deformed Skyrme finite amplitude method
M. T. Mustonen, J. Engel
We use the finite amplitude method for computing charge-changing Skyrme-QRPA transition strengths in axially-deformed nuclei together with a modern Skyrme energy-density functional…
What Can Be Learned with an Iodine Solar-Neutrino Detector?
J. Engel, P. I. Krastev, K. Lande
We study the potential benefits of an iodine-based solar-neutrino detector for testing hypotheses that involve neutrino oscillations. We argue that such a detector will have a good…
Effects of beyond-mean-field correlations on nuclear Schiff moments
E. F. Zhou, J. M. Yao, J. Engel +1
We compute the nuclear Schiff moments of the diamagnetic atoms Xe, Hg, and Ra in multireference covariant density functional theory. Beyond-mean-field corre…
Neutrinoless double-beta decay matrix elements in large shell-model spaces with the generator-coordinate method
C. F. Jiao, J. Engel, J. D. Holt
We use the generator-coordinate method with realistic shell-model interactions to closely approximate full shell-model calculations of the matrix elements for the neutrinoless doub…
Self-consistent Skyrme QRPA for use in axially-symmetric nuclei of arbitrary mass
J. Terasaki, J. Engel
We describe a new implementation of the quasiparticle random phase approximation (QRPA) in axially-symmetric deformed nuclei with Skyrme and volume-pairing energy-density functiona…
New determination of double-beta-decay properties in 48Ca: high-precision Q-value measurement and improved nuclear matrix element calculations
A. A. Kwiatkowski, T. Brunner, J. D. Holt +16
We report a direct measurement of the Q-value of the neutrinoless double-beta-decay candidate 48Ca at the TITAN Penning-trap mass spectrometer, with the result that Q = 4267.98(32)…
Towards a Microscopic Reaction Description Based on Energy-Density-Functional Structure Models
G. P. A. Nobre, F. S. Dietrich, J. E. Escher +4
A microscopic calculation of reaction cross sections for nucleon-nucleus scattering has been performed by explicitly coupling the elastic channel to all particle-hole excitations i…
The Influence of Beta Decay Rates on r-Process Observables
Kelsey A. Lund, J. Engel, G. C. McLaughlin +3
The rapid neutron capture process (r-process) is one of the main mechanisms whereby elements heavier than iron are synthesized, and is entirely responsible for the natural producti…
Neutrinoless Double Beta Decay
C. Adams, K. Alfonso, C. Andreoiu +229
This White Paper, prepared for the Fundamental Symmetries, Neutrons, and Neutrinos Town Meeting related to the 2023 Nuclear Physics Long Range Plan, makes the case for double beta…
What Can Be Learned with a Lead-Based Supernova-Neutrino Detector?
J. Engel, G. C. McLaughlin, C. Volpe
We examine the prospects for using lead as a supernova-neutrino detector by considering the spectrum of electrons produced, and the number of one- and two-neutron events. We show t…
Testing the importance of collective correlations in neutrinoless decay
J. Menéndez, N. Hinohara, J. Engel +2
We investigate the extent to which theories of collective motion can capture the physics that determines the nuclear matrix elements governing neutrinoless double-beta decay. To th…
Quasielastic neutrino scattering from oxygen and the atmospheric neutrino problem
J. Engel, E. Kolbe, K. Langanke +1
We examine several phenomena beyond the scope of Fermi-gas models that affect the quasielastic scattering (from oxygen) of neutrinos in the 0.1 -- 3.0 GeV range. These include Coul…
A Microscopic T-Violating Optical Potential: Implications for Neutron-Transmission Experiments
J. Engel, C. R. Gould, V. Hnizdo
We derive a T-violating P-conserving optical potential for neutron-nucleus scattering, starting from a uniquely determined two-body -exchange interaction with the same symmetry…
Jastrow functions in double-beta decay
J. Engel, J. Carlson, R. B. Wiringa
We use simple analytic considerations and a Monte Carlo calculation of nucleons in a box to argue that the use of Jastrow functions as short-range correlators in the commonly emplo…
Supernova-Neutrino Studies with Mo
H. Ejiri, J. Engel, N. Kudomi
We show that supernova neutrinos can be studied by observing their charged-current interactions with Mo, which has strong spin-isospin giant resonances. Information about b…
HFODD (v2.40h) User's Guide
J. Dobaczewski, B. G. Carlsson, J. Dudek +11
We describe the input data and installation procedures of the code HFODD (v2.40h). The present write-up contains complete and comprehensive information that has originally been giv…
Limit on T-Violating P-Conserving Interaction from the Decay of Fe
M. T. Ressell, J. Engel, P. Vogel
We use the experimental limit on the interference of M1 and E2 multipoles in the -decay of Fe to bound the time-reversal-violating parity-conserving vertex. Our…
Schiff Screening of Relativistic Nucleon Electric-Dipole Moments by Electrons
C. -P. Liu, J. Engel
We show, at leading-order in the multipole expansion of the electron-nucleus interaction, that nucleon electric-dipole moments are completely shielded by electrons so that they con…
Testing Skyrme energy-density functionals with the QRPA in low-lying vibrational states of rare-earth nuclei
J. Terasaki, J. Engel
Although nuclear energy density functionals are determined primarily by fitting to ground state properties, they are often applied in nuclear astrophysics to excited states, usuall…
Anomalous Behavior of 2+ Excitations around 132Sn
J. Terasaki, J. Engel, W. Nazarewicz +1
In certain neutron-rich Te isotopes, a decrease in the energy of the first excited 2+ state is accompanied by a decrease in the E2 strength to that state from the ground state, con…
Neutrino induced transitions between the ground states of the A=12 triad
J. Engel, E. Kolbe, K. Langanke +1
Neutrino induced reactions on C, an ingredient of liquid scintillators, have been studied in several experiments. We show that for currently available neutrino energies, $E_…
Application of efficient generator-coordinate subspace-selection algorithm to neutrinoless double- decay
A. M Romero, J. M. Yao, B. Bally +2
The generator coordinate method begins with the variational construction of a set of non-orthogonal mean-field states that span a subspace of the full many-body Hilbert space. Thes…
Ab initio calculation of symmetry-breaking observables
A Belley, B. Romeo, J. Engel +8
Symmetry-violating observables such as the nuclear anapole and Schiff moments provide sensitive probes of the fundamental symmetries of nature and physics beyond the Standard Model…
Ab Initio Treatment of Collective Correlations and the Neutrinoless Double Beta Decay of Ca
J. M. Yao, B. Bally, J. Engel +3
Working with Hamiltonians from chiral effective field theory, we develop a novel framework for describing arbitrary deformed medium-mass nuclei by combining the in-medium similarit…
Solution of the Skyrme-Hartree-Fock-Bogolyubov equations in the Cartesian deformed harmonic-oscillator basis. (VI) HFODD (v2.38j): a new version of the program
J. Dobaczewski, W. Satula, B. G. Carlsson +10
We describe the new version (v2.38j) of the code HFODD which solves the nuclear Skyrme-Hartree-Fock or Skyrme-Hartree-Fock-Bogolyubov problem by using the Cartesian deformed harmon…
Response of Mica to Weakly Interacting Massive Particles
J. Engel, M. T. Ressell, I. S. Towner +1
We calculate spin-dependent cross sections for the scattering from mica of hypothetical weakly interacting dark-matter particles such as neutralinos. The most abundant odd-A isotop…
Changes in r-process abundances at late times
R. Surman, J. Engel
We explore changes in abundance patterns that occur late in the r process. As the neutrons available for capture begin to disappear, a quasiequilibrium funnel shifts material into…
Generator-coordinate reference states for spectra and decay in the in-medium similarity renormalization group
J. M. Yao, J. Engel, L. J. Wang +2
We use a reference state based on symmetry-restored states from deformed mean-field or generator-coordinate-method (GCM) calculations in conjunction with the in-medium similarity-r…
Ab initio studies of double Gamow-Teller transition and its correlation with neutrinoless double beta decay
J. M. Yao, I. Ginnett, A. Belley +7
We use chiral interactions and several {\em ab initio} methods to compute the nuclear matrix elements (NMEs) for ground-state to ground-state double Gamow-Teller transitions in a r…
Benchmark neutrinoless double-beta decay matrix elements in a light nucleus
R. A. M. Basili, J. M. Yao, J. Engel +4
We compute nuclear matrix elements of neutrinoless double-beta decay mediated by light Majorana-neutrino exchange in the A = 6 system. The goal is to benchmark two many-body approa…
Intrinsic-Density Functionals
J. Engel
The Hohenberg-Kohn theorem and Kohn-Sham procedure are extended to functionals of the localized intrinsic density of a self-bound system such as a nucleus. After defining the intri…
Elucidating the finite temperature quasiparticle random phase approximation
E. M. Ney, A. RavliÄ, J. Engel +1
In numerous astrophysical scenarios, such as core-collapse supernovae and neutron star mergers, as in well as heavy-ion collision experiments, transitions between thermally populat…
Two-body weak currents in heavy nuclei
E. M. Ney, J. Engel, N. Schunck
In light and medium-mass nuclei, two-body weak currents from chiral effective field theory account for a significant portion of the phenomenological quenching of Gamow-Teller trans…
Symmetry restoration in the axially deformed proton-neutron quasiparticle random phase approximation for nuclear beta decay: The effect of angular-momentum projection
R. N. Chen, Y. N. Zhang, J. M. Yao +1
We examine the effects of symmetry restoration on nuclear beta decay within the axially deformed proton-neutron quasiparticle random phase approximation (QRPA). We employ the proto…
Nuclear Octupole Correlations and the Enhancement of Atomic Time-Reversal Violation
J. Engel, J. L. Friar, A. C. Hayes
We examine the time-reversal-violating nuclear ``Schiff moment'' that induces electric dipole moments in atoms. After presenting a self-contained derivation of the form of the Schi…
Finite Amplitude Method for Charge-Changing Transitions in Axially-Deformed Nuclei
M. T. Mustonen, T. Shafer, Z. Zenginerler +1
We describe and apply a version of the finite amplitude method for obtaining the charge-changing nuclear response in the quasiparticle random phase approximation. The method is sui…
Structure of Pairs in Heavy Weakly-Bound Nuclei
J. R. Bennett, J. Engel, S. Pittel
We study the structure of nucleon pairs within a simple model consisting of a square well in three dimensions and a delta-function residual interaction between two weakly-bound par…
Subtraction method in the second random--phase approximation: first applications with a Skyrme energy functional
D. Gambacurta, M. Grasso, J. Engel
We make use of a subtraction procedure, introduced to overcome double--counting problems in beyond--mean--field theories, in the second random--phase--approximation (SRPA) for the…
Effective Operators for Double-Beta Decay
J. Engel, P. Vogel
We use a solvable model to examine double-beta decay, focusing on the neutrinoless mode. After examining the ways in which the neutrino propagator affects the corresponding matrix…
Global Description of Beta Decay with the Axially-Deformed Skyrme Finite Amplitude Method: Extension to Odd-Mass and Odd-Odd Nuclei
E. M. Ney, J. Engel, N. Schunck
We use the finite amplitude method (FAM), an efficient implementation of the quasiparticle random phase approximation, to compute beta-decay rates with Skyrme energy-density functi…
Neutron-Proton Correlations in an Exactly Solvable Model
J. Engel, S. Pittel, P. Vogel +2
We examine isovector and isoscalar neutron-proton correlations in an exactly solvable model based on the algebra SO(8). We look particularly closely at Gamow-Teller strength and do…
Double Beta Decay
S. R. Elliott, J. Engel
We review recent developments in double-beta decay, focusing on what can be learned about the three light neutrinos in future experiments. We examine the effects of uncertainties i…
Self-Consistent Description of Multipole Strength in Exotic Nuclei I: Method
J. Terasaki, J. Engel, M. Bender +3
We use the canonical Hartree-Fock-Bogoliubov basis to implement a completely self-consistent quasiparticle-random-phase approximation with arbitrary Skyrme energy density functiona…
Experimental Constraint on Stellar Electron-Capture Rates from the reaction at 115 MeV/u
J. C. Zamora, R. G. T. Zegers, Sam M. Austin +22
The Gamow-Teller strength distribution from Sr was extracted from a experiment at 115 MeV/ to constrain estimates for the electron-capture rate…
Coupled-channels calculations of nonelastic cross sections using a density-functional structure model
G. P. A. Nobre, F. S. Dietrich, J. E. Escher +4
A microscopic calculation of the reaction cross-section for nucleon-nucleus scattering has been performed by explicitly coupling the elastic channel to all particle-hole (p-h) exci…
Time-Reversal-Violating Schiff Moment of 199Hg
J. H. de Jesus, J. Engel
We calculate the Schiff moment of the nucleus 199Hg, created by pi-N-N vertices that are odd under parity (P) and time-reversal (T). Our approach, formulated in diagrammatic pertur…
Neutron-proton pairing and double-beta decay in the interacting boson model
P. Van Isacker, J. Engel, K. Nomura
Background: The interacting boson model (IBM) has been used extensively to calculate the matrix elements governing neutrinoless double-beta decay. Studies within other models indic…
Systematics of the first 2+ excitation in spherical nuclei with Skryme-QRPA
J. Terasaki, J. Engel, G. F. Bertsch
We use the Quasiparticle Random Phase Approximation (QRPA) and the Skyrme interactions SLy4 and SkM* to systematically calculate energies and transition strengths for the lowest 2+…
Self-consistent description of multipole strength: systematic calculations
J. Terasaki, J. Engel
We use the quasiparticle random phase approximation with a few Skyrme density functionals to calculate strength functions in the Jpi = 0+, 1-, and 2+ channels for even Ca, Ni, and…
Finite-temperature electron-capture rates for neutron-rich nuclei around N=50 and effects on core-collapse supernovae simulations
S. Giraud, E. M. Ney, A. RavliÄ +7
The temperature dependence of stellar electron-capture (EC) rates is investigated, with a focus on nuclei around , just above , which play an important role during the…
Constraints for stellar electron-capture rates on Kr via the Kr(,He)Br reaction and the implications for core-collapse supernovae
R. Titus, E. M. Ney, R. G. T. Zegers +20
In the late stages of stellar core-collapse, prior to core bounce, electron captures on medium-heavy nuclei drive deleptonization and simulations require the use of accurate reacti…
Gamow-Teller strength and the spin-isospin coupling constants of the Skyrme energy functional
M. Bender, J. Dobaczewski, J. Engel +1
We investigate the effects of the spin-isospin channel of the Skyrme energy functional on predictions for Gamow-Teller distributions and superdeformed rotational bands. We use the…