A5068908155- Nuclear physics research studies
- Atomic and Molecular Physics
- Nuclear Physics and Applications
- Quantum Chromodynamics and Particle Interactions
- Astronomical and nuclear sciences
- Neutrino Physics Research
- Advanced Chemical Physics Studies
- Particle physics theoretical and experimental studies
- Advanced NMR Techniques and Applications
- Atomic and Subatomic Physics Research
- Superconducting Materials and Applications
- Dark Matter and Cosmic Phenomena
- Particle accelerators and beam dynamics
- Quantum, superfluid, helium dynamics
- Rare-earth and actinide compounds
- Nuclear reactor physics and engineering
- Scientific Research and Discoveries
- Quantum chaos and dynamical systems
- High-Energy Particle Collisions Research
- Radiopharmaceutical Chemistry and Applications
- Spectral Theory in Mathematical Physics
- Astro and Planetary Science
- Cold Atom Physics and Bose-Einstein Condensates
- Muon and positron interactions and applications
- Inorganic Fluorides and Related Compounds
McGill University
2020-2025
TRIUMF
2016-2025
University of South Carolina Lancaster
2024
Lawrence Livermore National Laboratory
2023
National Oceanography Centre
2017-2022
Precision BioSciences (United States)
2022
Technical University of Darmstadt
2013-2015
GSI Helmholtz Centre for Heavy Ion Research
2013-2015
Michigan State University
2009-2015
Oak Ridge National Laboratory
2010-2014
The limit of neutron-rich nuclei, the neutron drip line, evolves regularly from light to medium-mass nuclei except for a striking anomaly in oxygen isotopes. This is not reproduced shell-model calculations derived microscopic two-nucleon forces. Here, we present first explanation based on three-nucleon forces that have been established few-body systems. leads repulsive contributions interactions among excess neutrons change location line (28)O experimentally observed (24)O. Since mechanism...
We present a nucleus-dependent valence-space approach for calculating ground and excited states of nuclei, which generalizes the shell-model in-medium similarity renormalization group to an ensemble reference with fractionally filled orbitals. Because is used only as reference, not represent physical states, no symmetry restoration required. This allows us capture 3N forces among valence nucleons Hamiltonian specifically targeted each nucleus interest. Predicted ground-state energies from...
We present the first ab initio construction of valence-space Hamiltonians for medium-mass nuclei based on chiral two- and three-nucleon interactions using in-medium similarity renormalization group. When applied to oxygen isotopes, we find experimental ground-state energies are well reproduced, including flat trend beyond drip line at (24)O. Similarly, natural-parity spectra in (21,22,23,24)O agreement with experiment, predictions excited states (25,26)O. The results exhibit a weak...
We link the structure of nuclei around Sn100, heaviest doubly magic nucleus with equal neutron and proton numbers (N=Z=50), to nucleon-nucleon (NN) three-nucleon (NNN) forces constrained by data few-nucleon systems. Our results indicate that Sn100 is magic, we predict its quadrupole collectivity. present precise computations Sn101 based on three-particle–two-hole excitations find one interaction accurately reproduces small splitting between lowest Jπ=7/2+ 5/2+ states.Received 21 September...
We predict the limits of existence atomic nuclei, proton and neutron drip lines, from light through medium-mass regions. Starting a chiral two- three-nucleon interaction with good saturation properties, we use valence-space in-medium similarity renormalization group to calculate ground-state separation energies helium iron, nearly 700 isotopes in total. available experimental data quantify theoretical uncertainties for our ab initio calculations towards lines. Where lines are known...
Heavy atomic nuclei have an excess of neutrons over protons, which leads to the formation a neutron skin whose thickness is sensitive details nuclear force. This links properties stars, thereby relating objects that differ in size by orders magnitude. The nucleus ${}^{208}$Pb particular interest because it exhibits simple structure and experimentally accessible. However, computing such heavy has been out reach for ab initio theory. By combining advances quantum many-body methods, statistical...
We propose a novel storage scheme for three-nucleon (3N) interaction matrix elements relevant the normal-ordered two-body approximation used extensively in ab initio calculations of atomic nuclei. This reduces required memory by approximately two orders magnitude, which allows generation 3N with standard truncation ${E}_{3\mathrm{max}}=28$, well beyond previous limit 18. demonstrate that this is sufficient to obtain ground-state energy $^{132}\mathrm{Sn}$ converged within few MeV respect...
Abstract Molecules containing short-lived, radioactive nuclei are uniquely positioned to enable a wide range of scientific discoveries in the areas fundamental symmetries, astrophysics, nuclear structure, and chemistry. Recent advances ability create, cool, control complex molecules down quantum level, along with recent upcoming species production at several facilities around world, create compelling opportunity coordinate combine these efforts bring precision measurement extreme nuclei. In...
This paper introduces the neutrinoless double-beta decay (the rarest nuclear weak process) and describes status of research for this transition, both from point view theoretical physics in terms present future experimental scenarios. Implications phenomenon on crucial aspects particle are briefly discussed. The calculations matrix elements case mass mechanisms reviewed, a range these quantities is proposed most appealing candidates. After introducing general concepts—such as choice best...
We explore the impact of nuclear matter saturation on properties and systematics finite nuclei across chart. By using ab initio in-medium similarity renormalization group (IM-SRG), we study ground-state energies charge radii closed-shell from $^{4}\mathrm{He}$ to $^{78}\mathrm{Ni}$ based a set low-resolution two- three-nucleon interactions that predict realistic properties. first investigate in detail convergence these Hamiltonians with respect model-space truncations for both three-body...
Understanding and predicting the formation of shell structure from nuclear forces is a central challenge for physics. While magic numbers N=2,8,20 are generally well understood, N=28 first standard number that not reproduced in microscopic theories with two-nucleon forces. In this Letter, we show three-nucleon give rise to repulsive interactions between two valence neutrons key explain 48Ca as nucleus, high 2+ excitation energy concentrated magnetic dipole transition strength. The mechanism...
$A\phantom{\rule{0}{0ex}}b$ $i\phantom{\rule{0}{0ex}}n\phantom{\rule{0}{0ex}}i\phantom{\rule{0}{0ex}}t\phantom{\rule{0}{0ex}}i\phantom{\rule{0}{0ex}}o$ calculations using elastic scattering data on oxygen are able to accurately reproduce the isotopes' binding energies but fail describe charge and matter radii of most neutron-rich systems.
We present precision Penning trap mass measurements of neutron-rich calcium and potassium isotopes in the vicinity neutron number N=32. Using TITAN system, 51K was measured for first time, (51,52)Ca values were improved significantly. The new show a dramatic increase binding energy compared to those reported atomic evaluation. In particular, 52Ca is more bound by 1.74 MeV, behavior with deviates substantially from tabulated values. An increased predicted recently based on calculations that...
We present ab initio predictions for ground and excited states of doubly open-shell fluorine neon isotopes based on chiral two- three-nucleon interactions. use the in-medium similarity renormalization group to derive mass-dependent $sd$ valence-space Hamiltonians. The experimental ground-state energies are reproduced through neutron number $N=14$, beyond which a new targeted normal-ordering procedure improves agreement with data large-space multireference calculations. For spectroscopy, we...
We review the impact of nuclear forces on matter at neutron-rich extremes. Recent results have shown that nuclei become increasingly sensitive to three-nucleon forces, which are forefront theoretical developments based effective field theories quantum chromodynamics. This includes formation shell structure, spectroscopy exotic nuclei, and location neutron dripline. Nuclear also constrain properties matter, including skin, symmetry energy, structure stars. first our understanding show how...
A precision mass investigation of the neutron-rich titanium isotopes $^{51\ensuremath{-}55}\mathrm{Ti}$ was performed at TRIUMF's Ion Trap for Atomic and Nuclear science (TITAN). The range measurements covers $N=32$ shell closure, overall uncertainties $^{52\ensuremath{-}55}\mathrm{Ti}$ values were significantly reduced. Our results conclusively establish existence weak effect $N=32$, narrowing down abrupt onset this closure. data compared with state-of-the-art ab initio model calculations...
We study ground- and excited-state properties of all sd-shell nuclei with neutron proton numbers 8 <= N,Z 20, based on a set low-resolution two- three-nucleon interactions that predict realistic saturation nuclear matter. focus estimating the theoretical uncertainties due to variation resolution scale, low-energy couplings, as well from many-body method. The experimental two-neutron two-proton separation energies are reasonably reproduced, an uncertainty range about 5 MeV. first excited...
We calculate basis-space converged neutrinoless $\ensuremath{\beta}\ensuremath{\beta}$-decay nuclear matrix elements for the lightest candidates: $^{48}\mathrm{Ca}$, $^{76}\mathrm{Ge}$, and $^{82}\mathrm{Se}$. Starting from initial two- three-nucleon forces, we apply ab initio in-medium similarity renormalization group to construct valence-space Hamiltonians consistently transformed operators. find that tensor component is non-negligible in $^{76}\mathrm{Ge}$ $^{82}\mathrm{Se}$, resulting...
One of the strongest challenges to shell-model concept nuclei are islands inversion, where empirical evidence shows ground states being dominated by intruder configurations, i.e., that would be excitations in normal picture. Whereas phenomenological calculations have previously supported this concept, work Miyagi $e\phantom{\rule{0}{0ex}}t$ $a\phantom{\rule{0}{0ex}}l$. demonstrates how one can arrive at these non-intuitive results from an $a\phantom{\rule{0}{0ex}}b$...
Collinear laser spectroscopy is performed on the nickel isotopes ^{58-68,70}Ni, using a time-resolved photon counting system. From measured isotope shifts, nuclear charge radii R_{c} are extracted and compared to theoretical results. Three ab initio approaches all employ, among others, chiral interaction NNLO_{sat}, which allows an assessment of their accuracy. We find agreement with experiment in differential δ⟨r_{c}^{2}⟩ for employed methods interactions, while absolute consistent data...
Background: Recent developments in ab initio nuclear theory demonstrate promising results medium- to heavy-mass nuclei. A particular challenge for many of the many-body methodologies, however, is an accurate treatment electric-quadrupole, $E2$, strength associated with collectivity.Purpose: The valence-space in-medium similarity renormalization group (VS-IMSRG) a particularly powerful method accessing and high-mass nuclei but has been found underpredict $E2$ strengths. purpose this work...