Bulletin of the American Physical Society
6th Joint Meeting of the APS Division of Nuclear Physics and the Physical Society of Japan
Sunday–Friday, November 26–December 1 2023; Hawaii, the Big Island
Session D08: Minisymposium: Solid State Physics in Neutron Stars: Crystallography and Superfluidity |
Hide Abstracts |
Chair: Kei Iida Room: Hilton Waikoloa Village Kohala 1 |
Wednesday, November 29, 2023 9:00AM - 9:30AM |
D08.00001: Nuclear pasta and the deep inner crust Invited Speaker: William G Newton The crust of a neutron star is an exotic condensed matter system, rich in physics and accessible through a host of astrophysical observables. Measurements of individual neutron star cooling and pulsar glitches, of long timescale temperature, magnetic field and rotational evolution evolution by analysis of neutron star populations, and potential observations of oscillations of the solid crust and even crust shattering all probe the thermal, mechanical, and superfluid properties of the crust. |
Wednesday, November 29, 2023 9:30AM - 9:45AM |
D08.00002: Diffusion and Magnetic Fields in Simulations of Neutron Star Crusts Matthew E Caplan Accreted neutron star crusts exhibit rich variety in their crystal structure because of the mixture of elements produced by burning accreted H and He. Diffusion coefficients in these crystals remain uncertain, but could be important for crustal physics including breaking. This talk will discuss some recent work using molecular dynamics simulations to study diffusion in Coulomb crystals and the impacts of diffusion on neutron star crusts. Additionally, highly magnetized crusts remain important for a long list of transient phenomena and we will describe some ongoing and near future work to develop new capabilities in our molecular dynamics formalism to simulate the nuclear pasta layer with magnetic fields. |
Wednesday, November 29, 2023 9:45AM - 10:00AM |
D08.00003: The role of A=33 mass chain in Urca Cooling of Accreting Neutron Star Crusts Rahul Jain, Hendrik Schatz, Wei Jia Ong, Kirby Hermansen, Nabin Rijal, Hannah Berg, Paul A Deyoung, Eric Flynn, Caley M Harris, Sean N Liddick, Stephanie M Lyons, Sara Miskovich, Fernando Montes, Timilehin H Ogunbeku, Alicia R Kyle, Andrea Richard, Mackenzie Smith, Mallory K Smith, Artemis Spyrou Transient Low Mass X-ray Binaries (LMXBs) in their quiescent phase are observed to be cooling over timescales of decades. Studying this cooling behavior reveals a great deal of information about the properties of neutron stars. The β-decay/e- capture cycles lead to an appreciable cooling of the crust but the strength of this Urca cooling depends primarily on the ground-state to ground-state β-decay transition strengths. A = 33 mass chain is supposedly the strongest cooling agent for crusts composed of X-ray burst ashes which relies in part on the strong ground state branch in 33Mg - 33Al decay measured with high resolution β-delayed γ-ray spectroscopy. However, 33Mg has been recently confirmed to have a negative parity ground state making 33Mg - 33Al a first-forbidden decay. This leads to a discrepancy with theoretical predictions and the 33Mg decay experiment results are questioned in the literature, citing Pandemonium effect as a possible reason. I will present the results and ongoing analysis of the re-measurement of the β-decay of 33Mg experiment performed with the Total Absorption Spectroscopy technique at the National Superconducting Cyclotron Laboratory (NSCL) using NERO/BCS/SuN detector systems. |
Wednesday, November 29, 2023 10:00AM - 10:15AM |
D08.00004: Constraint on the mass and radius of GRB 200415A using the high-frequency QPOs Hajime Sotani Torsional oscillations excited in the neutron star crust strongly depend on the crust elasticity. Once one would identify the observed frequencies of a neutron star with crustal torsional oscillations, one might extract the crust or neutron star properties. In practice, it has been suggested that the crust equation of state (or nuclear saturation parameters) could be constrained by identifying the quasi-periodic oscillations (QPOs) observed in the afterglow of the magnetar giant flares with crustal torsional oscillations. On the other hand, recently high-frequency QPOs are discovered in the gamma-ray burst, GRB 200415A. Unlike the previous magnetar QPOs, only high-frequency QPOs could be observed in GRB 200415A because of the short duration of observation. Nevertheless, we can identify this observation in the same framework as in the previous magnetar QPOs by systematically examining the crustal torsional oscillations, through which we can constrain the nuclear saturation parameters. Furthermore, by consistently considering the neutron star mass and radius expected from the resultant nuclear saturation parameters, we can also constrain the neutron star mass and radius, which are more or less consistent with the other constraints from the astronomical observations. |
Wednesday, November 29, 2023 10:15AM - 10:30AM |
D08.00005: Equation of state for spin-polarized asymmetric nuclear matter with the cluster variational method Hajime Togashi, Masatoshi Takano The nuclear equation of state (EOS) is one of the crucial ingredients in numerical simulations of core-collapse supernovae. Recently, we have constructed a new table of the nuclear EOS applicable to the core-collapse simulations by using the cluster variational method with realistic nuclear forces [1], and the resultant EOS table is available on the Web [2] for the use in various astrophysical simulations. |
Wednesday, November 29, 2023 10:30AM - 10:45AM |
D08.00006: Quasiparticle properties of an impurity trapped in a superfluid quantized vortex Kazunari Ochi, Eiji Nakano, Kei Iida, Hiroyuki Tajima, Junichi Takahashi Atomic polarons are a kind of quasiparticles, namely, impurity atoms dressed by elementary excitations of the surrounding medium via the impurity-medium interactions, which have been actively investigated for cold atomic many-body systems. In the present study we develop the polaron physics by considering a system in which an impurity particle is introduced in a superfluid bosonic medium with a quantum vortex. For a repulsive impurity-medium interaction the impurity particle is bound in the vortex core. This situation is similar to the pinning state that is supposed to be a precursor state proposed for glitch phenomena in neutron stars. In this study, we clarify the polaron picture of an impurity trapped in a quantum vortex. By doing so, we address the polaron's dispersion relation for the momentum along the line of the vortex core, the effective mass, and their dependence on the strength of the impurity-medium interaction. |
Wednesday, November 29, 2023 10:45AM - 11:00AM |
D08.00007: Time-Dependent Slef-Consistent Band Theory for the Inner Crust of Neutron Stars: Anti-Entrainment Effects in the Slab Phase Kazuyuki Sekizawa, Kenta Yoshimura, Masayuki Matsuo In the inner crust of neutron stars, a variety of crystalline structures emerge, which are immersed in a sea of dripped neutrons. The dripped neutrons extend spatially, feeling crystalline, periodic nuclear potentials. The situation resembles the one encountered in terrestrial materials, where electrons are under a periodic potential of an ionic Coulomb lattice. Needless to say, one has to work with the band theory of solids to explain diverse properties of materials, e.g., if it is a metal, an insulator, or a semi-conductor. In the same way, to correctly assess properties of conduction neutrons in the inner crust of neutron stars, the use of the band theory of solids is mandatory. |
Wednesday, November 29, 2023 11:00AM - 11:15AM |
D08.00008: Superfluid and Finite-Temperature Extensions of Self-Consistent Band Theory for the Inner Crust of Neutron Stars Kenta Yoshimura, Kazuyuki Sekizawa Neutron star is regarded as a very unique system with various physical properties of nuclear matter. In the inner area of “crust” of neutron stars, a Coulomb lattice of neutron-rich nuclei and uniform dripped neutrons coexist under the β equilibrium condition. At the bottom layer of inner crust, nuclei form diverse non-uniform crystalline structures, and are thought to provoke a very controversal phenomenon, called “entrainment effect”. The entrainment is characterized as the gain of effective masses of dripped neutrons, and it may disrupt the present interpretation of neutron stars’ astronomical phenomena, such as pulsar glitches. |
Follow Us |
Engage
Become an APS Member |
My APS
Renew Membership |
Information for |
About APSThe American Physical Society (APS) is a non-profit membership organization working to advance the knowledge of physics. |
© 2024 American Physical Society
| All rights reserved | Terms of Use
| Contact Us
Headquarters
1 Physics Ellipse, College Park, MD 20740-3844
(301) 209-3200
Editorial Office
100 Motor Pkwy, Suite 110, Hauppauge, NY 11788
(631) 591-4000
Office of Public Affairs
529 14th St NW, Suite 1050, Washington, D.C. 20045-2001
(202) 662-8700