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Nuclear Theory·nucl-th

Thursday·June 8, 2023

8 papers—5 primary·3 cross-listed

All8Primary5Cross-lists3
  1. 01

    [Submitted on 6 Jun 2023]

    Five-body calculation of -wave -He scattering at next-to-leading order pionless effective field theory

    Mirko Bagnarol · Martin Schäfer · Betzalel Bazak · Nir Barnea

    We present the first five-body calculations of -wave -He scattering within leading order and next-to-leading order (NLO) pionless effective field theory. Using an harmonic oscillator trap technique and pionless effective field theory fitted to just six well-established experimental parameters, we predict the -wave -He phase shifts, scattering length , and effective range in agreement with experiment. The apparent cutoff independence of our results is used to estimate the theoretical errors coming as an integral part of our final results.

    Subjects:
    Nuclear Theory (nucl-th)
    arXiv:
    2306.04036 [pdf]
    PLB(2023)·20 citations
  2. 02

    [Submitted on 7 Jun 2023]

    Nuclear mass predictions based on deep neural network and finite-range droplet model (2012)

    To Chung Yiu · Haozhao Liang · Jenny Lee

    A neural network with two hidden layers is developed for nuclear mass prediction, based on the finite-range droplet model (FRDM12). Different hyperparameters, including the number of hidden units, the choice of activation functions, the initializers, and the learning rates, are adjusted explicitly and systematically. The resulting mass predictions are achieved by averaging the predictions given by several different sets of hyperparameters with different regularizers and seed numbers. It can provide us not only the average values of mass predictions but also reliable estimations in the mass prediction uncertainties. The overall root-mean-square deviations of nuclear mass have been reduced from MeV for the FRDM12 model to MeV and MeV for the training set and validation set, respectively.

    Comments:
    12 pages, 12 figures, and 1 table
    Subjects:
    Nuclear Theory (nucl-th); Nuclear Experiment (nucl-ex)
    arXiv:
    2306.04171 [pdf]
    CPC(2024)·5 citations
  3. 03

    [Submitted on 7 Jun 2023]

    Momentum Shell in Quarkyonic Matter from Explicit Duality: A Dual Model for Cold, Dense QCD

    Yuki Fujimoto🇺🇸 · Toru Kojo🇯🇵 · Larry D. McLerran🇺🇸

    We present a model of cold QCD matter that bridges nuclear and quark matter through the duality relation between quarks and baryons. The baryon number and energy densities are expressed as functionals of either the baryon momentum distribution, , or the quark distribution, , which are subject to the constraints on fermions, . The theory is ideal in the sense that the confinement of quarks into baryons is reflected in the duality relation between and , while other possible interactions among quarks and baryons are all neglected. The variational problem with the duality constraints is formulated and we explicitly construct analytic solutions, finding two distinct regimes: A nuclear matter regime at low density and a Quarkyonic regime at high density. In the Quarkyonic regime, baryons underoccupy states at low momenta but form a momentum shell with on top of a quark Fermi sea. Such a theory describes a rapid transition from a soft nuclear equation of state to a stiff Quarkyonic equation of state. At this transition, there is a rapid increase in the pressure.

    Comments:
    6 pages, 3 figures; v2: published version
    Subjects:
    Nuclear Theory (nucl-th); High Energy Astrophysical Phenomena (astro-ph.HE); High Energy Physics — Phenomenology (hep-ph)
    arXiv:
    2306.04304 [pdf]
    PRL(2024)·63 citations
  4. 04

    [Submitted on 7 Jun 2023]

    The magnetic dual chiral density wave phase in a rotating cold quark matter

    H. Mortazavi Ghalati🇮🇷 · N. Sadooghi🇮🇷

    The effect of rotation on the formation of the magnetic dual chiral density wave (\MD) in a dense and magnetized cold quark matter is studied. This phase is supposed to exist in the extreme conditions prevailing, e.g., in a neutron star. These conditions are, apart from high densities and strong magnetic fields, a relatively large angular velocity. To answer the question of whether the rotation enhances or suppresses the formation of this phase, we first determine the effect of rotation on the energy dispersion relation of a fermionic system in the presence of a constant magnetic field and then focus on the thermodynamic potential of the model at low temperature and finite chemical potential . The thermodynamic potential consists, in particular, of an anomalous part leading to certain topological effects. We show that in comparison with the nonrotating case, a term proportional to the angular velocity appears in this anomalous potential. We then solve the corresponding gap equations to the chiral and spatial modulation condensates, and study the dependence of these dynamical variables on the chemical potential (), magnetic field (), and angular velocity (). It turns out that the interplay between these parameters suppresses the formation of the \MD~phase in relevant regimes for cold neutron stars. This is interpreted as the manifestation of the inverse magnetorotational catalysis, which is also reflected in the phase portraits -, -, and -, explored in this work.

    Comments:
    V1: 19 pages, 7 figures, 2 tables; V2: Discussions improved, accepted for publication in PRD
    Subjects:
    Nuclear Theory (nucl-th); High Energy Physics — Phenomenology (hep-ph)
    arXiv:
    2306.04472 [pdf]
    PRD(2023)·12 citations
  5. 05

    [Submitted on 7 Jun 2023]

    Structure Factors for Hot Neutron Matter from Ab Initio Lattice Simulations with High-Fidelity Chiral Interactions

    Yuan-Zhuo Ma · Zidu Lin · Bing-Nan Lu · Serdar Elhatisari · Dean Lee · Ning Li · Ulf-G. Meißner · Andrew W. Steiner · Qian Wang

    We present the first ab initio lattice calculations of spin and density correlations in hot neutron matter using high-fidelity interactions at next-to-next-to-next-to-leading order (N3LO) in chiral effective field theory. These correlations have a large impact on neutrino heating and shock revival in core-collapse supernovae and are encapsulated in functions called structure factors. Unfortunately, calculations of structure factors using high-fidelity chiral interactions were well out of reach using existing computational methods. In this work, we solve the problem using a computational approach called the rank-one operator (RO) method. The RO method is a general technique with broad applications to simulations of fermionic many-body systems. It solves the problem of exponential scaling of computational effort when using perturbation theory for higher-body operators and higher-order corrections. Using the RO method, we compute the vector and axial static structure factors for hot neutron matter as a function of temperature and density. The ab initio lattice results are in good agreement with virial expansion calculations at low densities but are more reliable at higher densities. Random phase approximation codes used to estimate neutrino opacity in core-collapse supernovae simulations can now be calibrated with ab initio lattice calculations.

    Subjects:
    Nuclear Theory (nucl-th)
    arXiv:
    2306.04500 [pdf]
    PRL(2024)·32 citations

Affiliations

first authorsco-authorsvia INSPIRE