A5054727335- Neutrino Physics Research
- Gamma-ray bursts and supernovae
- Nuclear physics research studies
- Particle physics theoretical and experimental studies
- Astrophysics and Cosmic Phenomena
- Pulsars and Gravitational Waves Research
- Astrophysical Phenomena and Observations
- Astronomical and nuclear sciences
- Dark Matter and Cosmic Phenomena
- Nuclear Physics and Applications
- Nuclear reactor physics and engineering
- Astro and Planetary Science
- Atomic and Subatomic Physics Research
- Scientific Research and Discoveries
- Particle accelerators and beam dynamics
- Cosmology and Gravitation Theories
- Quantum, superfluid, helium dynamics
- Stellar, planetary, and galactic studies
- Particle Accelerators and Free-Electron Lasers
- Radioactive Decay and Measurement Techniques
- Quantum Chromodynamics and Particle Interactions
- Superconducting Materials and Applications
- Mechanics and Biomechanics Studies
- Solar and Space Plasma Dynamics
- Astronomical Observations and Instrumentation
North Carolina State University
2016-2025
University of California, Berkeley
2024-2025
University of Tennessee at Knoxville
2011-2024
University of New Hampshire
2024
Joint Institute for Nuclear Astrophysics
2018-2023
University of Notre Dame
2014-2019
University of Guelph
2015-2019
Arizona State University
2016
Union College
2008-2015
Oak Ridge National Laboratory
2008-2014
This is an exciting time for the study of r-process nucleosynthesis. Recently, a neutron star merger GW170817 was observed in extraordinary detail with gravitational waves and electromagnetic radiation from radio to γ rays. The very red color associated kilonova suggests that mergers are important site. Astrophysical simulations core collapse supernovae making rapid progress. Detection both electron neutrinos antineutrinos next galactic supernova will constrain composition neutrino-driven...
Providing an accurate modeling of neutrino physics in dense astrophysical environments such as binary neutron star mergers presents a challenge for hydrodynamic simulations. Nevertheless, understanding how flavor transformation can occur and affect the dynamics, mass ejection, nucleosynthesis will need to be achieved future. Computationally expensive, large-scale simulations frequently evolve first classical angular moments distributions. By promoting these quantities matrices space, we...
Abstract Multi-messenger astrophysics has produced a wealth of data with much more to come in the future. This enormous set will reveal new insights into physics core-collapse supernovae, neutron star mergers, and many other objects where it is actually possible, if not probable, that operation. To tease out different possibilities, we need analyze signals from photons, neutrinos, gravitational waves, chemical elements. task made all difficult when necessary evolve neutrino component...
Neutrino-nucleus coherent elastic scattering provides a theoretically appealing way to measure the neutron part of nuclear form factors. Using an expansion factors into moments, we show that neutrinos from stopped pions can probe not only second moment factor (the radius) but also fourth moment. simple Monte Carlo techniques for argon, germanium, and xenon detectors 3.5 tonnes, 1.5 300 kg, respectively, radii be found with uncertainty few percent when near neutrino flux...
Neutron star mergers offer unique conditions for the creation of heavy elements and additionally provide a testbed our understanding this synthesis known as $r$-process. We have performed dynamical nucleosynthesis calculations identified single isotope, $^{254}$Cf, which has particularly high impact on brightness electromagnetic transients associated with order 15 to 250 days. This is due anomalously long half-life isotope efficiency fission thermalization compared other nuclear channels....
We evaluate the impact of using sets fission yields given by GEF code for spontaneous (sf), neutron-induced ((n,f)), and beta-delayed (betadf) processes which take into account approximate initial excitation energy fissioning compound nucleus. further explore energy-dependent dynamics in r process considering sensitivity our results to treatment sharing de-excitation fragments FREYA code. show that asymmetric-to-symmetric yield trends predicted can reproduce high-mass edge second r-process...
Neutrinos play a critical role of transporting energy and changing the lepton density within core-collapse supernovae neutron star mergers. The quantum kinetic equations (QKEs) combine effects neutrino-matter interactions treated in classical Boltzmann transport with neutrino flavor-changing oscillation calculations. We present method for extending existing interaction rates to full QKE source terms use numerical demonstrate absorption emission by nucleons nuclei, electron scattering,...
The mergers of binary neutron stars, as well black hole-neutron star systems, are expected to produce an electromagnetic counterpart that can be analyzed infer the element synthesis occurred in these events. We investigate one source uncertainties pertinent lanthanide-rich outflows: nuclear inputs rapid capture nucleosynthesis calculations. begin by examining thirty-two different combinations inputs: eight mass models, two types spontaneous fission rates, and daughter product distributions....
The flavor evolution of neutrinos in core collapse supernovae and neutron star mergers is a critically important unsolved problem astrophysics. Following the electron neutrino system essential for calculating thermodynamics compact objects as well chemical elements they produce. Accurately accounting transformation these environments challenging number reasons, including large involved, small spatial scale oscillation, nonlinearity system. We take step addressing issues by presenting method...
We present the first calculations with three flavors of collective and shock wave effects for neutrino propagation in core-collapse supernovae using hydrodynamical density profiles S matrix formalism. explore interplay between neutrino-neutrino interaction multiple resonances upon time signal positrons supernova observatories. A specific signature is found inverted hierarchy a large third mixing angle we predict, this case, dearth lower energy Cherenkov detectors midway through simultaneous...
We consider hot accretion disk outflows from black hole - neutron star mergers in the context of nucleosynthesis they produce. begin with a three dimensional numerical model merger and calculate neutrino antineutrino fluxes emitted resulting disk. then follow element synthesis material outflowing along parameterized trajectories. find that at least weak r-process is produced, some cases main as well. The neutron-rich conditions required for this production nuclei stem directly interactions...
Black hole accretion disks can form through the collapse of rotating massive stars. These produce large numbers neutrinos and antineutrinos electron flavor that influence energetics nucleosynthesis. Neutrinos are produced in sufficient that, after they emitted, undergo transformation facilitated by neutrino self interaction. We show some phenomenology for is similar to supernova case, but also, we find disk geometry lends itself different behaviors. transformations strongly nucleosynthetic...
We study the formation and final structure of rare earth peak ($A\sim160$) $r$-process nucleosynthesis. The forms at late times in after neutron exhaustion (neutron-to-seed ratio unity or R=1) as matter decays back to stability. Since does not occur during \nggn \ equilibrium it is sensitive strong interplay between time thermodynamic evolution nuclear physics input. Depending on conditions either because pattern capture rates separation energies. analyze three mass models under different...
The Matter-Neutrino Resonance (MNR) phenomenon has the potential to significantly alter flavor content of neutrinos emitted from compact object mergers. We present first calculations MNR transitions using neutrino self interaction potentials and matter generated selfconsistently a dynamical model three-dimensional neutron star merger. In context single angle approximation, we find that Symmetric Standard occur in both normal inverted hierarchy scenarios. examine spatial regions above merger...
The Canadian Penning Trap mass spectrometer at the Californium Rare Isotope Breeder Upgrade (CARIBU) facility was used to measure masses of eight neutron-rich isotopes Nd and Sm. These measurements are first push into region nuclear relevant formation rare-earth abundance peak $A\ensuremath{\sim}165$ by rapid neutron-capture process. We compare our results with theoretical predictions obtained from ``reverse engineering'' surface that best reproduces observed solar abundances in this through...
Matter-neutrino resonances (MNR) can occur in environments where the flux of electron antineutrinos is greater than neutrinos. These may result dramatic neutrino flavor transformation. Compact object merger disks are an example environment outnumber We study MNR several such disk configurations and find two qualitatively different types matter-neutrino resonances: a standard symmetric MNR. examine transformation that occurs each type resonance explore consequences for nucleosynthesis.
The rapid neutron capture process (r-process) is one of the main mechanisms whereby elements heavier than iron are synthesized, and entirely responsible for natural production actinides. Kilonova emissions modeled as being largely powered by radioactive decay species synthesized via r -process. Given that -process occurs far from nuclear stability, unmeasured beta rates play an essential role in setting time scale In effort to better understand sensitivity kilonova modeling different...
Abstract We simulate a black hole accretion disk system with full-transport general relativistic neutrino radiation magnetohydrodynamics for 1.2 s. This is likely to form after the merger of two compact objects and thought be robust site r -process nucleosynthesis. consider case arising from neutron stars. Our simulation time coincides nucleosynthesis timescale (∼1 s). Because these simulations are time-consuming, it common practice run “short” duration approximately 0.1–0.3 analyze...
We discuss how matter-enhanced active-sterile neutrino transformation in the ${\ensuremath{\nu}}_{e}\ensuremath{\rightleftharpoons}{\ensuremath{\nu}}_{s}$ and ${\overline{\ensuremath{\nu}}}_{e}\ensuremath{\rightleftharpoons}{\overline{\ensuremath{\nu}}}_{s}$ channels could enable production of rapid neutron capture $(r$-process) nuclei neutrino-heated supernova ejecta. In this scheme lightest sterile would be heavier than ${\ensuremath{\nu}}_{e}$ split from it by a vacuum mass-squared...
We explore neutrino capture during $r$-process nucleosynthesis in neutrino-driven ejecta from nascent neutron stars. focus on the interplay between charged-current weak interactions and element synthesis, we delineate important role of equilibrium nuclear dynamics. During period coexistence free nucleons light and/or heavy nuclei, electron inhibits $r$-process. At all stages, neutrons has a larger impact than nuclei. However, nuclei by itself, if it is very strong, also detrimental to until...
We examine the nucleosynthesis products that are produced in outflow from rapidly accreting disks. find type of element synthesis varies dramatically with degree neutrino trapping disk and therefore accretion rate disk. Disks relatively high rates such as 10 M_solar/s can produce very neutron rich nuclei found r process. more moderate copious amounts Nickel well light elements Lithium Boron. lower 0.1 large some unusual Ti-49, Sc-45, Zn-64, Mo-92. This wide array potential is due to varying...
We study the sensitivity of r-process abundance pattern to neutron capture rates along rare earth region (A~150 A~180). introduce concepts large nuclear flow and saturation which determine that are influential in setting abundances. illustrate value two by considering high entropy conditions favorable for peak production identifying important among isotopes. also show how these influence specific sections pattern.
Abstract Binary neutron star mergers produce high-energy emissions from several physically different sources, including a gamma-ray burst (GRB) and its afterglow, kilonova (KN), and, at late times, remnant many parsecs in size. Ionizing radiation these sources can be dangerous for life on Earth-like planets when located too close. Work to date has explored the substantial danger posed by GRB on-axis observers; here we focus instead potential threats nearby off-axis observers. Our analysis is...
Quantum angular moment transport schemes are an important avenue toward describing neutrino flavor mixing phenomena in dense astrophysical environments such as supernovae and merging neutron stars. Successful implementation will require new closure relations that go beyond those used classical transport. In this paper, we derive the first analytic expression for a quantum M1 closure, valid limit of small coherence, based on maximum entropy principle. We verify resulting relation has...