Nuclear Theory·nucl-th

Tuesday·May 28, 2019

17 papers—8 primary·9 cross-listed

01
Rescattering effects in antiproton-induced exclusive $J / ψ$ and $ψ^{'}$ production on the deuteron
A.B. Larionov🇩🇪 · A. Gillitzer🇩🇪 · M. Strikman🇺🇸
On the basis of the generalized eikonal approximation we study the exclusive reactions $p ˉ d \to J / ψ n$ and $p ˉ d \to ψ^{'} n$ in vicinity of the thresholds for charmonium production on a free proton target. It is shown that the rescattering of the incoming antiproton and outgoing charmonium on the spectator neutron leads to a depletion of the charmonium production at low- and to an enhancement at high transverse momenta. This is in qualitative agreement with previous studies of hard proton knockout in proton-deuteron collisions. We analyze different physical sources of uncertainty which may influence the extraction of the total charmonium-neutron cross section. The color transparency effect for the incoming $p ˉ$ largely compensates the influence of charmonium rescattering both at low and high transverse momenta. Different choices of the deuteron wave function lead to significant uncertainties at high transverse momenta. As an outcome of the calculations of charmonium production, we also provide predictions on the production of open charm hadrons due to the dissociation of the charmonium on the neutron. It is shown that the open charm production cross section is proportional to the total charmonium-nucleon cross section and quite stable with respect to the variation of other parameters of the model. We thus suggest that open charm channels are most suited for future studies of charmonium-nucleon interactions at PANDA with a deuteron target.
nucl-thhep-exhep-phnucl-exEPJA(2019)·3 citations
02
Ab initio limits of atomic nuclei
S. R. Stroberg · J. D. Holt · A. Schwenk · J. Simonis
We predict the limits of existence of atomic nuclei, the proton and neutron drip lines, from the light through medium-mass regions. Starting from a chiral two- and three-nucleon interaction with good saturation properties, we use the valence-space in-medium similarity renormalization group to calculate ground-state and separation energies from helium to iron, nearly 700 isotopes in total. We use the available experimental data to quantify the theoretical uncertainties for our ab initio calculations towards the drip lines. Where the drip lines are known experimentally, our predictions are consistent within the estimated uncertainty. For the neutron-rich sodium to chromium isotopes, we provide predictions to be tested at rare-isotope beam facilities.
nucl-thnucl-exPRL(2021)·267 citations
03
A microscopic resolution of the chiral conundrum with crossing twin bands in Ag-106
P. W. Zhao · Y. K. Wang · Q. B. Chen
The nuclear chiral conundrum with crossing twin bands is investigated with three-dimensional tilted axis cranking covariant density functional theory in a fully self-consistent and microscopic way. The energy spectra and electromagnetic transition strengths for bands 1 and 2 in Ag-106 are well reproduced with two distinct configurations with two and four quasiparticles, respectively. For the four-quasiparticle configuration, a chiral vibrational band on top of band 2 is expected due to the soft Routhian curves. Therefore, it provides a microscopic and solid solution for the chiral conundrum in Ag-106. It also paves the way for understanding similar chiral structure in other nuclei in the future..
nucl-thnucl-exPRC(2019)·22 citations
04
Heavy flavor dissociation in the framework of multi-body Dirac equations
Shuzhe Shi🇨🇳 · Jiaxing Zhao🇨🇳 · Pengfei Zhuang🇨🇳
We study heavy flavor properties at finite temperature in the framework of a relativistic potential model. With an improved method to solve the three-body Dirac equation, we determine a universal set of model parameters for both mesons and baryons by fitting heavy flavor masses in vacuum. Taking heavy quark potential from lattice QCD simulations in hot medium, we systematically calculate heavy flavor binding energies and averaged sizes as functions of temperature. The meson and baryons are separately sequentially dissociated in the quark-gluon plasma, and the mesons can survive at higher temperature due to the stronger potential between quark-antiquark pairs than that between quark-quark pairs.
nucl-thhep-phCPC(2020)·23 citations
05
Effects of $ϕ_{0}$ -meson on the EOS of hyperon star in the relativistic mean field model
S. K. Biswal
Nuclear effective interactions are considered as a vital tool to guide into the region of the high degree of isospin asymmetry and density. We take varieties of parameter sets of the RMF model to show the parametric dependence of the hyperon star properties. We add $ϕ_{0}$ -meson to $σ$ - $ω$ - $ρ$ model. The effects of $ϕ_{0}$ -meson on the equation of state and consequently on the maximum mass of the hyperon star are discussed. Due to the inclusion of $ϕ_{0}$ -meson the threshold density of different hyperon production shift to higher density region. The effects of the hyperon-meson coupling constants on the maximum mass and radius of the hyperon stars are discussed.
nucl-thAIP Conf.Proc.(2019)·8 citations
06
Gravitational Wave Signatures of Highly Magnetized Neutron Stars
Cesar V. Flores🇧🇷 · Luiz L. Lopes🇧🇷 · Luis B. Castro🇧🇷 · Débora P. Menezes🇧🇷
Motivated by the recent gravitational wave detection by the LIGO-VIRGO observatories, we study the Love number and dimensionless tidal polarizability of highly magnetized stars. We also investigate the fundamental quasi-normal mode of neutron stars subject to high magnetic fields. To perform our calculations we use the chaotic field approximation and consider both nucleonic and hyperonic stars. As far as the fundamental mode is concerned, we conclude that the role played by the constitution of the stars is far more relevant than the intensity of the magnetic field and if massive stars are considered, the ones constituted by nucleons only present frequencies somewhat lower than the ones with hyperonic cores, a feature that can be used to point out the real internal structure of neutron stars. Moreover, our studies clearly indicate that strong magnetic fields play a crucial role in the deformability of low mass neutron stars, with possible consequences on the interpretation of the detected gravitational waves signatures.
nucl-thastro-ph.HEhep-phEPJC(2020)·27 citations
07
Parallel tale of seniority isomers in 130Cd and 206Hg: Testing the robustness of magic numbers
Bhoomika Maheshwari · Hasan Abu Kassim · Norhasliza Yusof · Ashok Kumar Jain
The neutron-rich nuclei 130Cd and 206Hg, so important in the astrophysical processes, may also be useful in tracking the evolution of nuclear shell gaps as one traverses the neutron-rich region. The high spin 8+ isomer in 130Cd and the 10+ isomer in 206Hg turn out to be the lampposts, which may shed light on the shell gaps and validity of the seniority scheme in the neutron-rich systems. We explore the robustness of the N=82 and N=126 magic numbers in the neutron-rich 130Cd and 206Hg nuclides, respectively. A parallel between the two nuclides in terms of the high-spin isomers allows us to investigate these waiting-point nuclei, which have limited experimental data, by using the concept of seniority as the stepping stone. In this paper, we report large scale shell model calculations by using the available realistic effective interactions derived from the Charge Dependent Bonn potential through the renormalized G matrix. We also explore if any change in the interaction is also required to consistently explain both the level structures as well the B(E2) values. A structural similarity between the 8+ isomer in 130Cd and the 10+ isomer in 206Hg is noticed due to goodness of seniority. They are found to possess a maximally aligned, seniority v = 2 configuration from their respective intruder orbits. No shell quenching seems to be needed for the seniority isomers in these nuclei. Therefore, N=82 and 126 appear to be very robust magic numbers even in the neutron-rich region.
nucl-th0 citations
08
Constraining the properties of dense matter and neutron stars by combining nuclear physics and gravitational waves from GW170817
I. Tews🇺🇸 · J. Margueron🇫🇷 · S. Reddy🇺🇸
Gravitational waves from neutron-star mergers are expected to provide stringent constraints on the structure of neutron stars. At the same time, recent advances in nuclear theory have enabled reliable calculations of the low density equation of state using effective field theory based Hamiltonians and advanced techniques to solve the quantum many-body problem. In this paper, we address how the first observation of gravitational waves from GW170817 can be combined with modern calculations of the equation of state to extract useful insights about the equation of state of matter encountered inside neutron stars. We analyze the impact of various uncertainties and we show that the tidal deformability extracted from GW170817 is compatible, while less constraining, than modern nuclear physics knowledge.
nucl-thastro-ph.HEAIP Conf.Proc.(2019)·9 citations
09
Digitization of Scalar Fields for Quantum Computing
Natalie Klco🇺🇸 · Martin J. Savage🇺🇸
Qubit, operator and gate resources required for the digitization of lattice $λ ϕ^{4}$ scalar field theories onto quantum computers are considered, building upon the foundational work by Jordan, Lee and Preskill, with a focus towards noisy intermediate-scale quantum (NISQ) devices. The Nyquist-Shannon sampling theorem, introduced in this context by Macridin, Spentzouris, Amundson and Harnik building on the work of Somma, provides a guide with which to evaluate the efficacy of two field-space bases, the eigenstates of the field operator, as used by Jordan, Lee and Preskill, and eigenstates of a harmonic oscillator, to describe $0 + 1$ - and $d + 1$ -dimensional scalar field theory. We show how techniques associated with improved actions, which are heavily utilized in Lattice QCD calculations to systematically reduce lattice-spacing artifacts, can be used to reduce the impact of the field digitization in $λ ϕ^{4}$ , but are found to be inferior to a complete digitization-improvement of the Hamiltonian using a Quantum Fourier Transform. When the Nyquist-Shannon sampling theorem is satisfied, digitization errors scale as $∣ lo g ∣ lo g ∣ ϵ_{dig} ∣∣∣ \sim n_{Q}$ (number of qubits describing the field at a given spatial site) for the low-lying states, leaving the familiar power-law lattice-spacing and finite-volume effects that scale as $∣ lo g ∣ ϵ_{latt} ∣∣ \sim N_{Q}$ (total number of qubits in the simulation). For localized(delocalized) field-space wavefunctions, it is found that $n_{Q} \sim 4 (7)$ qubits per spatial lattice site are sufficient to reduce theoretical digitization errors below error contributions associated with approximation of the time-evolution operator and noisy implementation on near-term quantum devices.
↳ quant-phhep-lathep-phnucl-thPRA(2019)·215 citations
10
Close Binary Galaxies: Application to Source of Energy and Expansion in Universe
V. V. Sargsyan · H. Lenske · G. G. Adamian · N. V. Antonenko
Applying the microscopic nuclear physics ideas for fusion reactions to macroscopic galactic systems, we study the evolution of the compact binary galaxy in mass asymmetry (transfer) coordinate. The conditions for the formation of stable symmetric binary galaxy are analyzed. The role of symmetrization of asymmetric binary galaxy in the transformation of gravitational energy into internal energy of galaxies accompanied by the release of a large amount of energy during the symmetrization process is revealed.
↳ astro-ph.GAnucl-thIJMPE(2019)·3 citations
11
A Study of Stress-Tensor Distribution around Flux Tube in Abelian-Higgs Model
Ryosuke Yanagihara🇯🇵 · Masakiyo Kitazawa🇯🇵
We study the stress-tensor distribution around the flux tube in static quark and anti-quark systems based on the momentum conservation and the Abelian-Higgs (AH) model. We first investigate constraints on the stress-tensor distribution from the momentum conservation and show that the effect of boundaries plays a crucial role to describe the structure of the flux tube in SU(3) Yang-Mills theory which has measured recently on the lattice. We then study the distributions of the stress tensor and energy density around the magnetic vortex with and without boundaries in the AH model, and compare them with the distributions in SU(3) Yang-Mills theory based on the dual superconductor picture. It is shown that a wide parameter range of the AH model is excluded by a comparison with the lattice results in terms of the stress tensor.
↳ hep-phhep-latnucl-thPTEP(2019)·22 citations
12
Pion scattering in the isospin I=2 channel from elongated lattices
C. Culver🇺🇸 · M. Mai🇺🇸 · A. Alexandru🇺🇸 · M. Doring🇺🇸 · F. X. Lee🇺🇸
Pion-pion elastic scattering in the isospin I=2 channel is investigated in two-flavor dynamical lattice QCD. Six ensembles are used with lattices elongated in one of the spatial dimensions at two quark masses corresponding to a pion mass of 315 MeV and 226 MeV. The energy of the low-lying states below the inelastic threshold are extracted in each case using the standard variational method.The extracted finite-volume spectrum is fitted by the inverse amplitude method simultaneously for both quark masses and extrapolated thereafter to the physical point. The resulting phase-shifts and scattering length are compared with those from experiment, leading-order chiral perturbation theory and other lattice studies. Our calculations match the experimental results.
↳ hep-lathep-phnucl-thPRD(2019)·47 citations
13
Canonical interpretation of $Y (10750)$ and $Υ (10860)$ in the $Υ$ family
Qi Li🇨🇳 · Ming-Sheng Liu🇨🇳 · Qi-Fang Lü🇨🇳 · Long-Cheng Gui🇨🇳 · Xian-Hui Zhong🇨🇳
Inspired by the new resonance $Y (10750)$ , we calculate the masses and two-body OZI-allowed strong decays of the higher vector bottomonium sates within both screened and linear potential models. We discuss the possibilities of $Υ (10860)$ and $Y (10750)$ as mixed states via the $S - D$ mixing. Our results suggest that $Y (10750)$ and $Υ (10860)$ might be explained as mixed states between $5 S$ - and $4 D$ -wave vector $b b ˉ$ states. The $Y (10750)$ and $Υ (10860)$ resonances may correspond to the mixed states dominated by the $4 D$ - and $5 S$ -wave components, respectively. The mass and the strong decay behaviors of the $Υ (11020)$ resonance are consistent with the assignment of the $Υ (6 S)$ state in the potential models.
↳ hep-phhep-exnucl-thEPJC(2020)·36 citations
14
Electron-capture Rates in $^{20}$ Ne for a Forbidden Transition to the Ground State of $^{20}$ F Relevant to Final Evolution of High-density O-Ne-Mg Cores
Toshio Suzuki · Shuai Zha · Shing-Chi Leung · Ken'ichi Nomoto
Electron capture on $^{20}$ Ne is critically important for the final stage of evolution of stars with the initial masses of 8 - 10 $M_{⊙}$ . In the present paper, we evaluate electron capture rates for a forbidden transition $^{20}$ Ne (0 $_{g . s .}^{+}$ ) $\to$ $^{20}$ F (2 $_{g . s .}^{+}$ ) in stellar environments by the multipole expansion method with the use of shell-model Hamiltonians. These rates have not been accurately determined in theory as well as in experiments. Our newly evaluated rates are compared with those obtained by a prescription that treats the transition as an allowed Gamow-Teller (GT) transition with the strength determined from a recent $β$ -decay experiment for $^{20}$ F (2 $_{g . s .}^{+}$ ) $\to$ $^{20}$ Ne (0 $_{g . s .}^{+}$ ) \citep{Kirsebom}. We find that different electron energy dependence of the transition strengths between the two methods leads to sizable differences in the weak rates of the two methods. We also find that the Coulomb effects, that is, the effects of screening on ions and electrons are non-negligible. We apply our e-capture rates on $^{20}$ Ne to the calculation of the evolution of high-density O-Ne-Mg cores of 8 - 10 $M_{⊙}$ stars. We find that our new rates affect the abundance distribution and the central density at the final stage of evolution.
↳ astro-ph.SRnucl-thApJ(2019)·19 citations
15
Quantum Kinetic Theory of Spin Polarization of Massive Quarks in Perturbative QCD: Leading Log
Shiyong Li🇺🇸 · Ho-Ung Yee🇺🇸
We present the quantum kinetic equation for spin polarization of massive quarks in leading log order of perturbative QCD, which describes time evolution of the spin density matrix in momentum space of a massive quark interacting with a background QCD plasma. We find that the time evolution operator of the spin density matrix, or the quantum kinetic collision terms, are universally of order $α_{s}^{2} lo g (1/ α_{s})$ in terms of the QCD coupling constant $α_{s} = g^{2} / (4 π)$ . Our quantum kinetic equation is valid for an arbitrary quark mass $m ≫ m_{D} \sim g T$ , where $m_{D}$ is the Debye mass, and can be used to study relaxation dynamics of spin polarization of massive quarks in perturbative QCD regime.
↳ hep-phhep-thnucl-thPRD(2019)·88 citations
16
Structure of $^{38}$ Cl and the quest for a comprehensive shell model interaction
R. S. Lubna (1) · K. Kravvaris (1 and 2) · S. L. Tabor (1) · Vandana Tripathi (1) · A. Volya (1) · E. Rubino (1) · J. M. Allmond (3) · B. Abromeit (1) · L. T. Baby (1) · T. C. Hensley (1) ((1) Florida State University, Tallahassee, (2) Lawrence Livermore National Laboratory, Livermore, (3) Physics Division, Oak Ridge National Laboratory)
The higher-spin structure of $^{38}$ Cl ( $N = 21$ ) was investigated following the $^{26}$ Mg( $^{14}$ C, $p n$ ) reaction at 30 and 37 MeV beam energies. The outgoing protons were detected in an $E - Δ E$ Si telescope placed at 0 $^{\circ}$ close to the target with a Ta beam stopper between the target and telescope. Multiple $γ$ rays were detected in time coincidence with the protons using an enhanced version of the FSU $γ$ detection array. The level scheme was extended up to 8420 keV with a likely spin of 10 $ℏ$ . A new multishell interaction was developed guided by the experimental information. This FSU interaction was built by fitting to the energies of 270 experimental states from $^{13}$ C to $^{51}$ Ti. Calculations using the FSU interaction reproduce observed properties of $^{38}$ Cl rather well, including the spectroscopic factors. The interaction has been successfully used to interpret the $1 p 1 h$ and $2 p 2 h$ configurations in some nearby nuclei as well.
↳ nucl-exnucl-thPRC(2019)·35 citations
17
Neutron stars in general relativity and scalar-tensor theory of gravity
F. J. Fattoyev🇺🇸
The masses and radii of neutron stars are discussed in general relativity and scalar-tensor theory of gravity and the differences are compared with the current uncertainties stemming from the nuclear equation of state in the relativistic mean-field framework. It is shown that astrophysical and gravitational waves observations of radii of neutron stars with masses $M ≲ 1.4 M_{⊙}$ constrain only the nuclear equation of state, and in particular the density dependence of the nuclear symmetry energy. Future observations of massive neutron stars may constrain the coupling parameters of the scalar-tensor theory provided that a general consensus on the dense nuclear matter equation of state is reached.
↳ gr-qcastro-ph.HEnucl-thArab.J.Math.(2019)·5 citations

Affiliations

first authorsco-authorsvia INSPIRE