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Nuclear Theory·nucl-th

Monday·August 16, 2021

5 papers—2 primary·3 cross-listed

All5Primary2Cross-lists3
  1. 01

    [Submitted on 13 Aug 2021]

    High-precision nuclear chronometer for the cosmos

    X. H. Wu · P. W. Zhao · S. Q. Zhang · J. Meng

    Nuclear chronometer, which predicts the ages of the oldest stars by comparing the present and initial abundances of long-lived radioactive nuclides, provides an independent dating technique for the cosmos. A new nuclear chronometer called Th-U-X chronometer is proposed, which imposes stringent constraints on the astrophysical conditions in the -process simulation by synchronizing the previous Th/X, U/X and Th/U chronometers. The astrophysical uncertainties of nuclear chronometer are significantly reduced from more than billion years to within 0:3 billion years by the Th-U-X chronometer. The proposed chronometer is then applied to estimate the ages of the six metal-poor stars with observed uranium abundances, and the predicted ages are compatible with the cosmic age 13.8 billion years predicted from the cosmic microwave background radiation, but in contradictory with the new cosmic age 11.4 billion years from the gravitational lenses measurement.

    Comments:
    5 pages, 4 figures
    Subjects:
    Nuclear Theory (nucl-th); Cosmology and Nongalactic Astrophysics (astro-ph.CO); Instrumentation and Methods for Astrophysics (astro-ph.IM); Nuclear Experiment (nucl-ex)
    arXiv:
    2108.06104 [pdf]
    ApJ(2022)·13 citations
  2. 02

    [Submitted on 12 Aug 2021]

    The impact of transverse Slavnov-Taylor identities on dynamical chiral symmetry breaking

    Luis Albino🇧🇷 · Adnan Bashir🇲🇽 · Bruno El-Bennich🇧🇷 · Eduardo Rojas🇨🇴 · Fernando E. Serna🇧🇷 · Roberto Correa da Silveira🇧🇷

    We extend earlier studies of transverse Ward-Fradkin-Green-Takahashi identities in QED, their usefulness to constrain the transverse fermion-boson vertex and their importance for multiplicative renormalizability, to the equivalent gauge identities in QCD. To this end, we consider transverse Slavnov-Taylor identities that constrain the transverse quark-gluon vertex and derive its eight associated scalar form factors. The complete vertex can be expressed in terms of the quark's mass and wave-renormalization functions, the ghost-dressing function, the quark-ghost scattering amplitude and a set of eight form factors. The latter parametrize the hitherto unknown nonlocal tensor structure in the transverse Slavnov-Taylor identity which arises from the Fourier transform of a four-point function involving a Wilson line in coordinate space. We determine the functional form of these eight form factors with the constraints provided by the Bashir-Bermudez vertex and study the effects of this novel vertex on the quark in the Dyson-Schwinger equation using lattice QCD input for the gluon and ghost propagators. We observe significant dynamical chiral symmetry breaking and a mass gap that leads to a constituent mass of the order of 500 MeV for the light quarks. The flavor dependence of the mass and wave-renormalization functions as well as their analytic behavior on the complex momentum plane is studied and as an application we calculate the quark condensate and the pion's weak decay constant in the chiral limit. Both are in very good agreement with their reference values.

    Comments:
    Published version in JHEP which includes the chiral limit case in figure 6, typos corrected, improved discussion about transverse form factor ( and ) contributions on pages 21-22; 36 pages, 8 figures, 1 table
    Subjects:
    Nuclear Theory (nucl-th); High Energy Physics — Lattice (hep-lat); High Energy Physics — Phenomenology (hep-ph)
    arXiv:
    2108.06204 [pdf]
    JHEP(2021)·24 citations

Affiliations

first authorsco-authorsvia INSPIRE