Conveners
Particle and Nuclear Astrophysics: Parallel 2
- James Allmond (ORNL)
Particle and Nuclear Astrophysics: Parallel 4
- Eilens Lopez Saavedra (Argonne National laboratory)
Particle and Nuclear Astrophysics: Parallel 9
- Luke Johns (Los Alamos National Lab)
Particle and Nuclear Astrophysics: Parallel 7
- Sherwood Richers (University of Tennessee Knoxville)
The calorimetric Proton Detector GAseous Detector with GErmanium Tagging (GADGET) detection system has been upgraded to operate as a Time Projection Chamber (TPC) to detect low energy β-delayed single- and multi-particle emission of interest to nuclear astrophysics. The upgrade, known as GADGET II, uses micro pattern gaseous amplifier detector technology and will be surrounded by an array of...
The Laboratory for Experimental Nuclear Astrophysics (LENA) located at Triangle Universities Nuclear Laboratory (TUNL) is a world leading facility for the direct measurement of cross sections relevant to stellar burning and nucleosynthesis. For over a decade, LENA has been using low energy, high intensity ($>$ 1 mA) proton beams to study radiative capture reactions on stable isotopes. With the...
Reliable $(\alpha,n)$, $(\alpha,p)$, and $(p,\alpha)$ cross sections and reaction rates are critical to modeling nucleosynthesis in novae, X-ray bursts, and neutrino-driven winds, yet direct measurements at astrophysically relevant energies remain limited. \par
The Multi-Sampling Ionization Chamber (MUSIC) active-target detector is designed for precise measurements of ionization energy loss...
Neutrino flavor oscillation in compact object mergers will significantly affect the merger dynamics and the electron fraction. In particular, fast flavor instability close to the central object in neutron star merger simulations can change r-process abundance. Over the years, many approaches have been taken to include flavor oscillation during the simulation or post-processing. In this talk, I...
Due to recently observed low-lying isomeric states in $^{136}$Cs, charged-current interactions in liquid xenon (LXe) time projection chambers (TPCs) of the form $\nu + ^{136}$Xe are expected to create time-delayed coincident signals that can be used for background rejection on the order of $10^{-9}$, enabling background-free searches. In this talk we will discuss the capabilities of nEXO, a...
Neutrino self-interactions beyond the standard model have profound implications in astrophysics and cosmology. In this work, we study an uncharted scenario in which one of the three neutrino species has a mass much smaller than the temperature of the cosmic neutrino background. This results in a relativistic component that significantly broadens the absorption feature on the astrophysical...
The IceCube Neutrino Observatory, which instruments one cubic kilometer of clear glacial ice beneath the South Pole, is designed to reconstruct neutrino energies and arrival directions above 1 GeV. However, the detector is also sensitive to the few-second burst of ~10 MeV neutrinos produced in transients such as core-collapse supernovae. A core collapse in the Milky Way will produce...
Gravitational wave observations of binary neutron star mergers ahve the potential to revolutionize our understanding of the nuclear equation of state and the fundamental interactions that determine its properties. A major hurdle in obtaining this nuclear information comes from the computational cost to solve the neutron star structure equations (Tolman-Oppenheimer-Volkoff equations) alongside...
The study of neutron stars, dense remnants of stellar core collapse, provides a unique opportunity to explore the fundamental properties of matter under extreme conditions. In this talk I will review the status of our current understanding of the neutron star equation of state (EOS) through measurements derived from multi-messenger observations of binary neutron star mergers. Then, focusing on...
Magneto-Rotational supernovae (MR-SNe) are rare and energetic supernovae that have exceptionally high magnetic fields. They are relatively uncommon but could be important in enriching galaxies with heavy elements. These explosions have early and fast ejection of matter compared with classic core-collapse supernovae so that rapid neutron capture could take place. We simulated the beta-decay...
The study of Ultra-High-Energy Cosmic Rays (UHECR) has undergone dramatic evolution over the last two decades, driven primarily by the unprecedented capabilities of the Pierre Auger Observatory and the Telescope Array Project. Historically hindered by low statistics and substantial uncertainties, the UHECR field once grappled with basic questions about flux cutoffs, composition, and source...
The Radar Echo Telescope (RET) is a proposed next-generation ultrahigh energy (UHE) neutrino detector. A prototype instrument, recently deployed to the polar regions, uses the in-ice cascade from a UHE cosmic ray as a proxy for a UHE neutrino, to test the detection technique in nature. This prototype, called the Radar Echo Telescope for Cosmic Rays (RET-CR), collected a full season of data in...
The detection of cosmic-ray antinuclei holds the potential
to be a groundbreaking method for identifying signatures of dark
matter. The dominant background for cosmic antinuclei arises from
interactions of cosmic-ray protons with interstellar hydrogen
gas. However, prevalent (anti)nuclei formation models—the thermal and
coalescence models—are based on different underlying physics. A...
The Canadian Penning Trap (CPT) has been at the Argonne National Laboratory's CARIBU facility for over a decade, where it measured the masses of over 300 nuclei produced via the spontaneous fission of CARIBU’s ${}^{252}$Cf source with a typical precision of around 10 keV. In recent years, particular focus was placed on nuclei involved in the formation of the rare-earth peak in the r-process...
Even with only Standard Model interactions, neutrinos play a critical role in core-collapse supernovae, cooling the proto-neutron star, setting the conditions for nucleosynthesis, and likely powering the explosion. Their effects could be immensely more profound in the presence of new physics, often poorly constrained by laboratory experiments alone. In this talk, I will discuss the effects of...
Neutrinos are crucial actors in some of the marquee targets of multimessenger astronomy. In neutron star mergers and core-collapse supernovae in particular, the production, propagation, and interactions of neutrinos are paramount. But even though these sites are two of the most carefully modeled systems in astrophysics, neutrino oscillations are yet to be reliably incorporated into the...
A computationally efficient method for calculating the transport of neutrino flavor in simulations of supernovae or compact-object mergers is to use angular moments of the neutrino one-body reduced density matrix, i.e., 'quantum moments'. To implement this approach in a simulations we need to grapple with two fundamental issues: how to define a `closure' for the moments and how to adapt...
Neutrino-neutrino interactions drive a number of flavor transformation phenomena in core-collapse supernovae and neutron star mergers that have been shown to impact the supernova explosion mechanism, production of heavy elements in the ejecta, and observable neutrino signatures. The most prominent of these is the Fast Flavor Instability, which can occur deep inside of these systems...
Accurately modeling neutrino flavor oscillations in global simulations of core-collapse supernovae or neutron star mergers remains a major challenge, albeit a potentially crucial one for making reliable predictions. Indeed, it is now widely recognized that flavor instabilities—in which classically computed neutrino distributions are dramatically altered when including quantum effects—are...
Our understanding of the origin of elements heavier than iron relies on nucleosynthesis simulations, which in turn require accurate nuclear structure input, as beta-decay strengths and half-lives, especially for nuclei near the neutron dripline. In this talk, I will present preliminary coupled-cluster calculations of beta-decay strengths for neutron-rich nickel isotopes, motivated by future...
