PaperPanorama

Nuclear Theory·nucl-th

Wednesday·October 23, 2019

5 papers3 primary·2 cross-listed

  1. 04

    [Submitted on 22 Oct 2019] (cross-list from astro-ph.SR)

    LRP2020: The cosmic origin and evolution of the elements

    Rodrigo Fernández · Falk Herwig · Samar Safi-Harb · Iris Dillmann · Kim A. Venn · Benoit Côté · Craig O. Heinke · Erik Rosolowsky · Tyrone E. Woods · Daryl Haggard · Luis Lehner · John J. Ruan and 7 other authors

    The origin of many elements of the periodic table remains an unsolved problem. While many nucleosynthetic channels are broadly understood, significant uncertainties remain regarding certain groups of elements such as the intermediate and rapid neutron-capture processes, the p-process, or the origin of odd-Z elements in the most metal-poor stars. Canada has a long tradition of leadership in nuclear astrophysics, dating back to the work of Alastair Cameron in the 1950s. Recent faculty hires have further boosted activity in the field, including transient observation and theory, survey science on galactic nucleosynthesis, and nuclear experiments. This white paper contains a brief overview of recent activity in the community, highlighting strengths in each sub-field, and provides recommendations to improve interdisciplinary collaboration. Sustaining Canadian leadership in the next decade will require, on the observational side, access to transient and non-transient surveys like LSST, SKA, or MSE, support for target-of-opportunity observing in current and future Canadian telescopes, and participation in next-generation X-ray telescopes such as ATHENA. State-of-the-art theoretical predictions will require an ambitious succession plan for the Niagara supercomputer to support large parallel jobs. We propose a funding instrument for postdoctoral training that reflects the interdisciplinary nature of nuclear astrophysics research, and the creation of a national collaborative funding program that allows for joint projects and workshop organization.

    Comments:
    White paper submitted to the Canadian Long Range Plan 2020. Minor formatting changes relative to submitted version
    Subjects:
    Solar and Stellar Astrophysics (astro-ph.SR); Astrophysics of Galaxies (astro-ph.GA); High Energy Astrophysical Phenomena (astro-ph.HE); General Relativity and Quantum Cosmology (gr-qc); Nuclear Theory (nucl-th)
    arXiv:
    1910.09712 [pdf]
    0 citations
  2. 05

    [Submitted on 22 Oct 2019] (cross-list from hep-ph)

    Extraction of gluon distributions from structure functions at small x in holographic QCD

    Akira Watanabe🇨🇳 · Takahiro Sawada🇯🇵 · Mei Huang🇨🇳

    We investigate the nucleon and pion gluon distribution functions in the framework of holographic QCD, focusing on the small Bjorken x region. Based on an approximate relation, the gluon distributions are extracted from structure functions of the unpolarized deep inelastic scattering which can be calculated with a holographic QCD model, assuming the Pomeron exchange. All the adjustable parameters of the model are determined with the HERA data of the proton structure functions. We explicitly show that the extracted proton gluon distribution is consistent with results of the recent global QCD analysis. The structure functions of the pion can be computed without any additional parameter, which enables us to predict its gluon distribution also. We find that the resulting pion gluon density is smaller than the proton's, and agrees with the recent global QCD analysis result within the uncertainties.

    Comments:
    6 pages, 4 figures; v2: version accepted for publication in Phys. Lett. B
    Subjects:
    High Energy Physics — Phenomenology (hep-ph); High Energy Physics — Experiment (hep-ex); Nuclear Experiment (nucl-ex); Nuclear Theory (nucl-th)
    arXiv:
    1910.10008 [pdf]
    PLB(2020)·29 citations

Affiliations

first authorsco-authorsvia INSPIRE