Nuclear Theory·nucl-th

Monday·February 17, 2020

10 papers—6 primary·4 cross-listed

01
[Submitted on 14 Feb 2020]
Description of Four- and Five-Nucleon Systems by Solving Faddeev-Yakubovsky Equations in Configuration Space
Rimantas Lazauskas🇫🇷 · Jaume Carbonell🇫🇷
The Faddeev Yakubovsky equations constitute a rigorous formulation of the quantum mechanical N body problem in the framework of non relativistic dynamics. They allow the exact solutions of the Schrodinger equation for bound and scattering states to be obtained. In this review, we will present the general formalism as well as the numerical tools we use to solve Faddeev Yakubovsky equations in configuration space. We will consider in detail the description of the four and five nucleon systems based on modern realistic nuclear Hamiltonians. Recent achievements in this domain will be summarized. Some of the still controversial issues related with the nuclear Hamiltonians as well as the numerical methods traditionally employed to solve few nucleon problems will be highlighted.
Comments:
Published in Frontiers in Physics 7:251 (2020)
Subjects:
Nuclear Theory (nucl-th); Atomic Physics (physics.atom-ph)
arXiv:
2002.05876 [pdf]
Front.in Phys.(2020)·41 citations
02
[Submitted on 14 Feb 2020]
Ab initio calculation of the electron capture spectrum of 163Ho: Auger-Meitner decay into continuum states
M. Brass🇩🇪 · M.W. Haverkort🇩🇪
Determining the electron neutrino mass by electron capture in $^{163}$ Ho relies on an accurate understanding of the differential electron capture nuclear decay rate as a function of the distribution of the total decay energy between the neutrino and electronic excitations. The resulting spectrum is dominated by resonances due to local atomic multiplet states with core holes. Coulomb scattering between electrons couple the discrete atomic states, via Auger-Meitner decay, to final states with free electrons. The atomic multiplets are above the auto-ionisation energy, such that the delta functions representing these discrete levels turn into a superposition of Lorentzian, Mahan- and Fano-like line-shapes. We present an \textit{ab initio} method to calculate nuclear decay modifications due to such processes. It includes states with multiple correlated holes in local atomic orbitals interacting with unbound Auger-Meitner electrons. A strong energy-dependent, asymmetric broadening of the resonances in good agreement with recent experiments is found. We present a detailed analysis of the mechanisms determining the final spectral line-shape and discuss both the Fano interference between different resonances, as well as the energy dependence of the Auger-Meitner Coulomb matrix elements. The latter mechanism is shown to be the dominant channel responsible for the asymmetric line-shape of the resonances in the electron capture spectrum of $^{163}$ Ho.
Subjects:
Nuclear Theory (nucl-th); Strongly Correlated Electrons (cond-mat.str-el)
arXiv:
2002.05989 [pdf]
New J.Phys.(2020)·26 citations
03
[Submitted on 14 Feb 2020]
Clustering structure effect on Hanbury-Brown-Twiss correlation in $^{12}$ C + $^{197}$ Au collisions at 200 GeV}
Junjie He🇨🇳 · Song Zhang🇨🇳 · Yu-Gang Ma🇨🇳 · Jinhui Chen🇨🇳 · Chen Zhong🇨🇳
Through $^{12}$ C + $^{197}$ Au collisions at $s_{N N} =$ 200 GeV using a multiphase transport (AMPT) model, the azimuthal angle dependences of the Hanbury Brown-Twiss (HBT) radii relative to the second- and third-order participant plane from $π$ - $π$ correlations are discussed. Three initial geometric configurations of $^{12}$ C, namely three- $α$ -cluster triangle, three- $α$ -cluster chain and Woods-Saxon distribution of nucleons, are taken into account, and their effects on the correlations are investigated. The ratio of the third- to the second-order HBT radii $R_{o (s), 3}^{2} / R_{o (s), 2}^{2}$ is shown to be a clear probe for three configurations. In addition, this work presents the hadronic rescattering time evolution of the azimuthally dependent HBT radii. From the present study, one can learn that the HBT correlation from identical particles at freeze-out is able to provide the information of different initial configurations as collective flow proposed before.
Comments:
11 pages, 6 figures, 3 tables
Subjects:
Nuclear Theory (nucl-th); Nuclear Experiment (nucl-ex)
arXiv:
2002.06058 [pdf]
EPJA(2020)·25 citations
04
[Submitted on 14 Feb 2020]
Dispersive optical model description of nucleon scattering on Pb-Bi isotopes
Xiuniao Zhao · Weili Sun · R. Capote · E.Sh. Soukhovitski\~ı · D.S. Martyanov · J.M. Quesada
A recently derived dispersive optical model potential (DOMP) for $^{208}$ Pb is extended to consider the non-locality in the real potential and the shell-gap in the definition of the nuclear imaginary potentials near the Fermi energy. The modified DOMP improves the simultaneous description of nucleon scattering on $^{208}$ Pb and of the $^{208}$ Pb particle-hole bound states. The new potential is shown to give a very good description of nucleon scattering data on near-magic targets $^{206, 207}$ Pb and $^{209}$ Bi.
Comments:
9 pages, 8 figures
Subjects:
Nuclear Theory (nucl-th)
arXiv:
2002.06065 [pdf]
PRC(2020)·10 citations
05
[Submitted on 14 Feb 2020]
Nucleon-number scalings of anisotropic flows and nuclear modification factor for light nuclei in the squeeze-out region
T. T. Wang🇨🇳 · Y. G. Ma🇨🇳
The number of nucleon (NN) scaling of the directed flow $v_{1}$ and elliptic flow ( $v_{2}$ ) as well as the nuclear modification factor ( $R_{c p}$ ) are tested for light nuclei which are produced in 0.4 $A$ GeV $^{197} A u +^{197} A u$ collisions at different impact parameters with two different in-medium nucleon-nucleon cross sections in the framework of an isospin-dependent quantum molecular dynamics (IQMD) model. In that energy domain, the emission of light nuclei can be well described by the squeeze-out phenonomenon. The results show a nice NN scaling behavior for flow parameters $v_{1}$ , $v_{2}$ and $R_{c p}$ . These results demonstrate that the nucleon coalescence mechanism is responsible for nucleon-number scaling of above physical observables in squeeze-out region in heavy-ion collisions at intermediate energy.
Comments:
8 pages, 6 figures
Subjects:
Nuclear Theory (nucl-th); Nuclear Experiment (nucl-ex)
arXiv:
2002.06067 [pdf]
EPJA(2019)·10 citations
06
[Submitted on 14 Feb 2020]
Three-nucleon force effects in inclusive spectra of the neutron-deuteron breakup reaction
H. Witała · J. Golak · R. Skibiński · V. Soloviov · K. Topolnicki
We investigate the sensitivity of the non-exclusive nucleon induced deuteron breakup reaction to the three-nucleon interaction and distributions of three-nucleon force effects in inclusive spectra. To this end we solve the three-nucleon Faddeev equation at a number of incoming nucleon laboratory energies using the CD Bonn nucleon-nucleon interaction alone or combined with the 2{\pi}-exchange Tucson-Melbourne three-nucleon force. Based on these solutions energy spectra of an outgoing nucleon, at a specified detection angle as well as spectra integrated over that angle, are calculated. By integrating the spectra at a given angle over the energy of the outgoing nucleon the angular distributions of three-nucleon force effects in the breakup process are additionally obtained. Contrary to elastic nucleon-deuteron scattering, where at higher energies significant three-nucleon force effects were encountered for scattering angles around the minimum of the cross section, for the breakup process only moderate effects are found and they are restricted to forward angles. Results of the present investigation show that the large three-nucleon force effects found for some specific complete breakup configurations are reduced substantially in the incomplete spectra when averaging over contributing complete geometries is performed.
Subjects:
Nuclear Theory (nucl-th)
arXiv:
2002.06087 [pdf]
PRC(2020)·2 citations
07
[Submitted on 14 Feb 2020] (cross-list from nucl-ex)
A New Heavy Flavor Program for the Future Electron-Ion Collider
Xuan Li🇺🇸 · Ivan Vitev🇺🇸 · Melynda Brooks🇺🇸 · Lukasz Cincio🇺🇸 · J. Matthew Durham🇺🇸 · Michael Graesser🇺🇸 · Ming X. Liu🇺🇸 · Astrid Morreale🇺🇸 · Duff Neill🇺🇸 · Cesar da Silva🇺🇸 · Walter E. Sondheim🇺🇸 · Boram Yoon🇺🇸
The proposed high-energy and high-luminosity Electron-Ion Collider (EIC) will provide one of the cleanest environments to precisely determine the nuclear parton distribution functions (nPDFs) in a wide $x$ - $Q^{2}$ range. Heavy flavor production at the EIC provides access to nPDFs in the poorly constrained high Bjorken- $x$ region, allows us to study the quark and gluon fragmentation processes, and constrains parton energy loss in cold nuclear matter. Scientists at the Los Alamos National Laboratory are developing a new physics program to study heavy flavor production, flavor tagged jets, and heavy flavor hadron-jet correlations in the nucleon/nucleus going direction at the future EIC. The proposed measurements will provide a unique way to explore the flavor dependent fragmentation functions and energy loss in a heavy nucleus. They will constrain the initial-state effects that are critical for the interpretation of previous and ongoing heavy ion measurements at the Relativistic Heavy Ion Collider and the Large Hadron Collider. We show an initial conceptual design of the proposed Forward Silicon Tracking (FST) detector at the EIC, which is essential to carry out the heavy flavor measurements. We further present initial feasibility studies/simulations of heavy flavor hadron reconstruction using the proposed FST.
Comments:
6 pages, 5 figures, proceedings for the XLIX International Symposium on Multiparticle Dynamics (ISMD2019) (9-13 September 2019) conference
Subjects:
Nuclear Experiment (nucl-ex); High Energy Physics — Experiment (hep-ex); High Energy Physics — Phenomenology (hep-ph); Nuclear Theory (nucl-th)
arXiv:
2002.05880 [pdf]
EPJ Web Conf.(2020)·23 citations
08
[Submitted on 14 Feb 2020] (cross-list from hep-ph)
Transport properties in magnetized compact stars
Toshitaka Tatsumi🇯🇵 · Hiroaki Abuki🇯🇵
Transport properties of dense QCD matter is discussed. Using the Kubo formula for conductivity, we discuss some topological aspects of quark matter during chiral transition. The close relation to Weyl semimetal is pointed out and anomalous Hall effect is demonstrated to be possible there. In particular, it is shown that the spectral asymmetry of the quasi-particles plays an important role for the Hall conductivity in the magnetic field.
Comments:
10 pages, submitted to "Symmetry"
Subjects:
High Energy Physics — Phenomenology (hep-ph); Nuclear Theory (nucl-th)
arXiv:
2002.05917 [pdf]
Symmetry(2020)·1 citation
09
[Submitted on 14 Feb 2020] (cross-list from nucl-ex)
The Hoyle Family: The search for alpha-condensate states in light nuclei
R. Smith · J. Bishop · J. Hirst · Tz. Kokalova · C. Wheldon
Our present understanding of the structure of the Hoyle state in $^{12}$ C and other near-threshold states in $α$ -conjugate nuclei is reviewed in the framework of the $α$ -condensate model. The $^{12}$ C Hoyle state, in particular, is a candidate for $α$ -condensation, due to its large radius and $α$ -cluster structure. The predicted features of nuclear $α$ -particle condensates are reviewed along with a discussion of their experimental indicators, with a focus on precision break-up measurements. Two experiments are discussed in detail, firstly concerning the break-up of $^{12}$ C and then the decays of heavier nuclei. With more theoretical input, and increasingly complex detector setups, precision break-up measurements can, in principle, provide insight into the structures of states in $α$ -conjugate nuclei. However, the commonly-held belief that the decay of a condensate state will result in $N$ $α$ -particles is challenged. We further conclude that unambiguously characterising excited states built on $α$ -condensates is difficult, despite improvements in detector technology.
Comments:
Submitted to Few-Body Systems on 9th November 2019
Subjects:
Nuclear Experiment (nucl-ex); Nuclear Theory (nucl-th)
arXiv:
2002.05952 [pdf]
Few Body Syst.(2020)·8 citations
10
[Submitted on 14 Feb 2020] (cross-list from astro-ph.EP)
Xenon Isotopes Identify Large-scale Nucleosynthetic Heterogeneities across the Solar System
Guillaume Avice🇫🇷 · Manuel Moreira🇫🇷 · Jamie D Gilmour🇬🇧
Nucleosynthetic isotopic anomalies in meteorites and planetary objects contribute to our understanding of the formation of the solar system. Isotope systematics of chondrites demonstrate the existence of a physical separation between isotopic reservoirs in the solar system. The isotopic composition of atmospheric xenon (Xe) indicates that its progenitor, U-Xe, is depleted in 134Xe and 136Xe isotopes relative to Solar or Chondritic end-members. This deficit supports the view that nucleosynthetic heterogeneities persisted during the Solar System formation. Measurements of xenon emitted from comet 67P/Churyumov-Gerasimenko (67P) identified a similar, but more extreme, deficit of cometary gas in these isotopes relative to Solar gas. Here we show that the data from 67P demonstrate that two distinct sources contributed xenon isotopes associated with the r-process to the solar system. The h-process contributed at least 29% (2sigmas) of solar system 136Xe. Mixtures of these r-process components and the s-process that match the heavy isotope signature of cometary Xe lead to depletions of the precursor of atmospheric Xe in p-only isotopes. Only the addition of pure p-process Xe to the isotopic mixture brings 124Xe/132Xe and 126Xe/132Xe ratios back to solar-like values. No pure p-process Xe has been detected in solar system material, and variation in p-process Xe isotopes is always correlated with variation in r-process Xe isotopes. In the solar system, p-process incorporation from the interstellar medium happened before incorporation of r-process nuclides or material in the outer edge of the solar system carries a different mixture of presolar sources as have been preserved in parent bodies.
Subjects:
astro-ph.EP (astro-ph.EP); Nuclear Theory (nucl-th)
arXiv:
2002.05957 [pdf]
ApJ(2020)·2 citations

Affiliations

first authorsco-authorsvia INSPIRE