Nuclear Theory·nucl-th

Monday·September 20, 2021

12 papers—3 primary·9 cross-listed

04
[Submitted on 17 Sept 2021] (cross-list from physics.hist-ph)
Chronicle of the discovery of the back-bending phenomenon in atomic nuclei: a personal recollection 50 years on
Hans Ryde
A chronicle describing the historical context and the development of ideas and experiments leading to the discovery of the back-bending phenomenon in rapidly rotating atomic nuclei some 50 years ago is presented. The moment of inertia of some atomic nuclei increases anomalously at a certain rotational frequency, revealing important clues to our understanding of nuclear structure. I highlight the decisive interactions and contacts between experimentalists and theorists, which created the right environment, allowing for the revelation of an undetected phenomenon in Nature. Finally, I reflect on the key points allowing for the discovery and particularly point to the importance of systematic surveys, which in this case investigated the energy levels in heavy nuclei of a large sample of elements, as well as to the accuracy of the measurements of the ground state levels made at the time.
Comments:
Accepted and published in the European Physical Journal H. 5 pages, 1 figure
Subjects:
History and Philosophy of Physics (physics.hist-ph); Nuclear Experiment (nucl-ex); Nuclear Theory (nucl-th)
arXiv:
2109.08144 [pdf]
Eur.Phys.J.H(2021)·0 citations
05
[Submitted on 16 Sept 2021] (cross-list from nucl-ex)
Evaluation of $^{86}$ Kr Cross Sections For Use in Fusion Diagnostics
M. Vorabbi · G.P.A. Nobre · D.A. Brown · A.M. Lewis · E. Rubino · S. Mughabghab
The National Ignition Facility at Lawrence Livermore National Laboratory uses $^{86}$ Kr as a diagnostic tool to measure the neutron flux produced by fusion reactions. As krypton is chemically inert, it can be implanted directly into the fuel capsule, and the reaction products can be measured to determine the flux of fusion neutrons. $^{86}$ Kr cross sections also provide model constraints for the $^{85}$ Kr branching point in the s-process and the neutron flux in stars. In this work, experimental data on the neutron production, radiative capture, inelastic scattering, and total cross sections of $^{86}$ Kr were used in conjunction with the fast region nuclear reaction code EMPIRE and a new resonance-region evaluation to produce a new evaluation of neutron-induced reactions on $^{86}$ Kr. For the EMPIRE calculations, we fitted the optical model potential up to 12 MeV to simultaneously reproduce the experimental data for the total cross section and the main inelastic gamma transition from the $2^{+}$ state to the $0^{+}$ ground state. For energies above 12 MeV, due to large fluctuations and uncertainties in the total cross section data, we preferred to adopt the Koning-Delaroche global spherical optical model potential. With these models and corrections to the structure of $^{86}$ Kr, the evaluated cross sections matched the experimental data. The new evaluation has been submitted for incorporation in the next release of the ENDF/B nuclear reaction library.
Subjects:
Nuclear Experiment (nucl-ex); Nuclear Theory (nucl-th)
arXiv:
2109.08178 [pdf]
0 citations
06
[Submitted on 16 Sept 2021] (cross-list from astro-ph.IM)
SNEWPY: A Data Pipeline from Supernova Simulations to Neutrino Signals
Amanda L. Baxter · Segev BenZvi · Joahan Castaneda Jaimes · Alexis Coleiro · Marta Colomer Molla · Damien Dornic · Tomer Goldhagen · Anne M. Graf · Spencer Griswold · Alec Habig · Remington Hill · Shunsaku Horiuchi James P. Kneller Rafael F. Lang and 8 other authors
Current neutrino detectors will observe hundreds to thousands of neutrinos from a Galactic supernovae, and future detectors will increase this yield by an order of magnitude or more. With such a data set comes the potential for a huge increase in our understanding of the explosions of massive stars, nuclear physics under extreme conditions, and the properties of the neutrino. However, there is currently a large gap between supernova simulations and the corresponding signals in neutrino detectors, which will make any comparison between theory and observation very difficult. SNEWPY is an open-source software package which bridges this gap. The SNEWPY code can interface with supernova simulation data to generate from the model either a time series of neutrino spectral fluences at Earth, or the total time-integrated spectral fluence. Data from several hundred simulations of core-collapse, thermonuclear, and pair-instability supernovae is included in the package. This output may then be used by an event generator such as sntools or an event rate calculator such as SNOwGLoBES. Additional routines in the SNEWPY package automate the processing of the generated data through the SNOwGLoBES software and collate its output into the observable channels of each detector. In this paper we describe the contents of the package, the physics behind SNEWPY, the organization of the code, and provide examples of how to make use of its capabilities.
Comments:
Software available at https://github.com/SNEWS2/snewpy
Subjects:
Instrumentation and Methods for Astrophysics (astro-ph.IM); High Energy Astrophysical Phenomena (astro-ph.HE); Solar and Stellar Astrophysics (astro-ph.SR); High Energy Physics — Phenomenology (hep-ph); Nuclear Theory (nucl-th)
arXiv:
2109.08188 [pdf]
ApJ(2022)·43 citations
07
[Submitted on 16 Sept 2021] (cross-list from hep-ph)
Finite-temperature effects on D-meson properties
Juan M. Torres-Rincon🇩🇪 · Glòria Montaña🇪🇸 · Àngels Ramos🇪🇸 · Laura Tolos🇪🇸
We study the spectroscopy and transport properties of charmed mesons in a thermal medium by applying an effective field theory based on chiral and heavy-quark symmetries in the imaginary time formalism. Relying on unitarity constraints and self-consistency we extract the in-medium properties (masses and widths) of $D$ and $D_{s}$ mesons and their interactions with light hadrons. We report our findings on 1) dynamically generated states, 2) thermal evolution of chiral partners, 3) in-medium scattering amplitudes, and 4) transport coefficients below the chiral restoration temperature.
Comments:
11 pages, 7 figures. Contribution to the 10th International Workshop on Charm Physics (CHARM2020). Accepted for publication in Proceedings of Science
Subjects:
High Energy Physics — Phenomenology (hep-ph); Nuclear Theory (nucl-th)
arXiv:
2109.08204 [pdf]
PoS(2021)·0 citations
08
[Submitted on 17 Sept 2021] (cross-list from astro-ph.HE)
Magnetically supramassive neutron stars
Arthur G Suvorov · Kostas Glampedakis
It is commonly believed that neutron stars exceeding the maximum mass limit for stability could be formed in the aftermath of binary neutron star mergers, enjoying a short life of metastability before losing centrifugal support and collapsing to a black hole. It is suggested here that a similar scenario could take place when the remnant's excess mass is supported by an ultra-strong $(≳ 1 0^{17} \mbox G)$ magnetic field that could be generated during, and shortly after, coalescence. We show that such 'magnetically supramassive' neutron stars could stave off collapse and survive for a few years before their magnetic energy is sufficiently dissipated due to ambipolar diffusion. In addition, we speculate on multi-messenger signatures of such objects and discuss the robustness of our results against limitations placed by neutron superfluidity and magneto-thermal evolution.
Comments:
5 pages, 3 figures. Accepted for publication as a Letter in Phys. Rev. D
Subjects:
High Energy Astrophysical Phenomena (astro-ph.HE); General Relativity and Quantum Cosmology (gr-qc); Nuclear Theory (nucl-th)
arXiv:
2109.08276 [pdf]
PRD(2022)·12 citations
09
[Submitted on 17 Sept 2021] (cross-list from hep-ph)
Quantum Kinetic Theory with Vector and Axial Gauge Fields
Zhou Chen🇨🇳 · Shu Lin🇨🇳
In this paper we introduce the axial gauge field to the framework of the quantum kinetic theory with vector gauge field in the massless limit. Treating axial-gauge field on an equal footing with the vector-gauge field, we construct a consistent solution to the kinetic equations up to the first order in gradient expansion or equivalently the semi-classical expansion. The intuitive extension of quantum kinetic theory presented in this work provides a natural generalization, and turns out to give rise to the covariant anomaly and the covariant currents. The corresponding consistent currents can be obtained from the covariant ones by adding the Chern-Simons current. We use the consistent currents to calculate various correlation functions among currents and energy-momentum tensor in equilibrium state.
Comments:
23 pages
Subjects:
High Energy Physics — Phenomenology (hep-ph); Mesoscale and Nanoscale Physics (cond-mat.mes-hall); Nuclear Theory (nucl-th)
arXiv:
2109.08440 [pdf]
PRD(2022)·12 citations
10
[Submitted on 17 Sept 2021] (cross-list from astro-ph.HE)
The Radioactive Nuclei $^{26}$ Al and $^{60}$ Fe in the Cosmos and in the Solar System
Roland Diehl · Maria Lugaro · Alexander Heger · Andre Sieverding · Xiaodong Tang · KuoAng Li · Ertao Li · Carolyn L. Doherty · Martin G.H. Krause · Anton Wallner · Nikos Prantzos · Hannah E. Brinkman and 6 other authors
The cosmic evolution of the chemical elements from the Big Bang to the present time is driven by nuclear fusion reactions inside stars and stellar explosions. A cycle of matter recurrently re-processes metal-enriched stellar ejecta into the next generation of stars. The study of cosmic nucleosynthesis and of this matter cycle requires the understanding of the physics of nuclear reactions, of the conditions at which the nuclear reactions are activated inside the stars and stellar explosions, of the stellar ejection mechanisms through winds and explosions, and of the transport of the ejecta towards the next cycle, from hot plasma to cold, star-forming gas. Due to the long timescales of stellar evolution, and because of the infrequent occurrence of stellar explosions, observational studies are challenging. Due to their radioactive lifetime of million years, the 26Al and 60Fe isotopes are suitable to characterise simultaneously the processes of nuclear fusion reactions and of interstellar transport. We describe and discuss the nuclear reactions involved in the production and destruction of 26Al and 60Fe, the key characteristics of the stellar sites of their nucleosynthesis and their interstellar journey after ejection from the nucleosynthesis sites. We connect the theoretical astrophysical aspects to the variety of astronomical messengers, from stardust and cosmic-ray composition measurements, through observation of gamma rays produced by radioactivity, to material deposited in deep-sea ocean crusts and to the inferred composition of the first solids that have formed in the Solar System. We show that considering measurements of the isotopic ratio of 26Al to 60Fe eliminate some of the unknowns when interpreting astronomical results, and discuss the lessons learned from these two isotopes on cosmic chemical evolution.
Comments:
51 pages, 44 figures; review from an ISSI workshop series; accepted for publication in PASA
Subjects:
High Energy Astrophysical Phenomena (astro-ph.HE); Instrumentation and Methods for Astrophysics (astro-ph.IM); Solar and Stellar Astrophysics (astro-ph.SR); Nuclear Experiment (nucl-ex); Nuclear Theory (nucl-th)
arXiv:
2109.08558 [pdf]
Publ.Astron.Soc.Austral.(2021)·40 citations
11
[Submitted on 17 Sept 2021] (cross-list from hep-ph)
Conservation laws in a novel hybrid approach
Anna Schäfer🇩🇪 · Iurii Karpenko🇨🇿 · Hannah Elfner🇩🇪
Heavy-ion collisions covering a wide range of collision energies provide a vast amount of observables characterizing the properties of strongly-interacting matter. In particular collisions towards the high baryon-density regime of the QCD phase-diagram have become of interest to study the postulated first order phase transition and to locate a possible critical end point. In this work, the SMASH-vHLLE-hybrid is presented as a novel hybrid model to theoretically describe such heavy-ion collisions. In addition, the SMASH hadron resonance gas equation of state is introduced. The accuracy of the latter is shown to be of fundamental importance in order to conserve energy, baryon number and electric charge throughout the different stages of the hybrid model. Furthermore, the impact of an inaccurate equation of state on final state observables is discussed. This work constitutes a first validation of the SMASH-vHLLE-hybrid in terms of conservation laws and excitation functions. It is expected to be applied to a broader range of observables in the future.
Comments:
Proceedings CPOD 2021
Subjects:
High Energy Physics — Phenomenology (hep-ph); Nuclear Theory (nucl-th)
arXiv:
2109.08578 [pdf]
PoS(2022)·2 citations
12
[Submitted on 17 Sept 2021] (cross-list from hep-ph)
[1]Title: $Υ$ and $η_{b}$ mass shifts in nuclear matter and the $^{12}$ C nucleus bound states, [2]Title: $Υ$ and $η_{b}$ mass shifts in nuclear matter and the nucleus bound states
G. N. Zeminiani🇧🇷 · J. J. Cobos-Martínez🇲🇽 · K. Tsushima🇧🇷
[1]Abstract: This is a contribution for the PANIC 2021 Proceedings based on the articles, Eur. Phys. J. A 57, 259 (2021) and the accompanied article $[$ arXiv:2109.08636 $[$ hep-ph $]]$ (Hadron 2021 contribution). We have estimated for the first time the mass shifts of the $Υ$ and $η_{b}$ mesons in symmetric nuclear matter by an SU(5) flavor symmetric effective Lagrangian approach, as well as the in-medium mass of $B^{*}$ meson by the quark-meson coupling (QMC) model. The attractive potentials for the $Υ$ - and $η_{b}$ -nuclear matter are obtained, and one can expect for these mesons to form nuclear bound states. We have indeed found such nuclear bound states with $^{12}$ C nucleus, where the results for the $^{12}$ C nucleus bound state energies are new, and we report here for the first time. [2]Abstract: We estimate for the first time the mass shifts (scalar potentials) in symmetric nuclear matter of the $Υ$ and $η_{b}$ mesons using an effective Lagrangian approach, as well as the in-medium mass of the $B^{*}$ meson by the quark-meson coupling model. The attractive potentials of both $Υ$ and $η_{b}$ are expected to be strong enough for these mesons to be bound to the $^{4}$ He nucleus, and we have obtained such nuclear bound state energies.
Comments:
[1] 5 pages, 3 figures (5 eps figure files, 1 table), contribution for the PANIC 2021 proceedings (September 5 - September 10, 2021), [2] 4 pages, 3 figures (5 eps figure files, 1 table), contribution for the HADRON 2021 proceedings (July 26 - July 31, 2021)
Subjects:
High Energy Physics — Phenomenology (hep-ph); High Energy Physics — Experiment (hep-ex); Nuclear Experiment (nucl-ex); Nuclear Theory (nucl-th)
arXiv:
2109.08636 [pdf]
PoS(2022)·6 citations

Affiliations

first authorsco-authorsvia INSPIRE