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Nuclear Theory·nucl-th

Wednesday·August 4, 2021

9 papers—5 primary·4 cross-listed

All9Primary5Cross-lists4
  1. 06

    [Submitted on 3 Aug 2021] (cross-list from quant-ph)

    Exposing minimal composition of Kohn-Sham theory and its extendability

    H. Nakada

    Reducing the many-fermion problem to a set of single-particle (s.p.) equations, the Kohn-Sham (KS) theory has provided a practical tool to implement \textit{ab initio} calculations of ground-state energies and densities in many-electron systems. There have been attempts to extend the KS theory so that it could describe other physical quantities, or it could be applied to other many-fermion systems. By generalizing and reformulating the KS theory in terms of the 1-body density matrix, we expose the minimal composition of the theory that enables the reduction of the many-fermion problem to the s.p. equations. Based on the reformulation, several basic issues are reconsidered. The - and -representabilities for the KS theory are distinguished from those for the Hohenberg-Kohn theorem. Criteria for the extendability of the KS theory are addressed.

    Comments:
    33 pages including 2 figures; to appear in Phys. Scr. (Several typos have been corrected from the previous version.)
    Subjects:
    Quantum Physics (quant-ph); Nuclear Theory (nucl-th)
    arXiv:
    2108.01232 [pdf]
    Phys.Scripta(2023)·4 citations
  2. 07

    [Submitted on 3 Aug 2021] (cross-list from hep-ph)

    Transverse-momentum-dependent parton distribution functions for spin-1 hadrons

    S. Kumano🇯🇵 · Qin-Tao Song🇨🇳

    We show transverse-momentum-dependent parton distribution functions (TMDs) for spin-1 hadrons including twist-3 and 4 functions by taking the decomposition of a quark correlation function in the Lorentz-invariant way with the conditions of Hermiticity and parity invariance. We found 30 new TMDs in the tensor-polarized spin-1 hadron at twists 3 and 4 in addition to 10 TMDs at twist 2. Since time-reversal-odd terms of the collinear correlation function should vanish after integrals over the partonic transverse momentum, we obtained new sum rules for the time-reversal-odd structure functions, , at twists 3 and 4. We also indicated that transverse-momentum-dependent fragmentation functions exist in tensor-polarized spin-1 hadrons. The TMDs can probe color degrees of freedom, so that they are valuable in providing unique opportunities for creating interdisciplinary physics fields such as gluon condensate, color Aharonov-Bohm effect, and color entanglement. We also found three new collinear PDFs at twists 3 and 4, and a twist-2 relation and a sum rule were derived in analogy to the Wandzura-Wilczek relation and the Burkhardt-Cottingham sum rule on the structure function .

    Comments:
    SciPost Physics Proceedings, 28th International workshop on Deep-Inelastic Scattering and Related Subjects (DIS2021), (Online) Stony Brook, New York, USA, April 12-16, 2021
    Subjects:
    High Energy Physics — Phenomenology (hep-ph); High Energy Physics — Experiment (hep-ex); High Energy Physics — Lattice (hep-lat); Nuclear Theory (nucl-th)
    arXiv:
    2108.01381 [pdf]
    SciPost Phys.Proc.(2022)·0 citations
  3. 08

    [Submitted on 3 Aug 2021] (cross-list from nucl-ex)

    Impact of Be breakup on Li(p,n) Neutron Spectrum

    Midhun C.V · M.M Musthafa · S.V Suryanarayana · T. Santhosh · A. Baishya · P. Patil · A Pal · P.C Rout · S Santra · R. Kujur · Antony Joseph · Shaima A and 8 other authors

    The formation of continuum neutron distribution in Li(p,n) has been identified as due to the coupling of the Be breakup levels to the final state of the reaction. The continuum neutron spectra produced by Li(p,n) reaction has been estimated by measuring the double differential cross sections for continuum and resonant breakup of Be, through Li(p,n)Be reaction at 21 MeV of proton energy. The breakup contributions from continuum and , states of Be have been identified. The measured double differential cross sections have been reproduced through CDCC-CRC calculations. The cross sections were projected to neutron spectrum using Monte-Carlo approach and validated using experimentally measured He gated neutron spectra. Li(p,n) neutron spectrum at 20 MeV incident proton energy measured by McNaughton. et al. has been reproduced by adapting estimated model parameters for the reaction.

    Subjects:
    Nuclear Experiment (nucl-ex); Nuclear Theory (nucl-th)
    arXiv:
    2108.01382 [pdf]
    PRC(2021)·10 citations
  4. 09

    [Submitted on 3 Aug 2021] (cross-list from hep-ph)

    Nonlinear diffusion of gluons

    Georg Wolschin🇩🇪

    It is proposed to consider the fast thermalization of gluons in relativistic heavy-ion collisions as a diffusion process in momentum space. Closed-form analytical solutions of a nonlinear boson diffusion equation (NBDE) with constant drift and diffusion coefficients v, D and boundary conditions at the singularity are derived. The time evolution towards local central temperatures T< 600 MeV through inelastic gluon scatterings in heavy-ion collisions is calculated for under- and overoccupied systems in the full momentum range. The results are consistent with QCD-based numerical calculations for gluon thermalization via inelastic gluon collisions.

    Comments:
    14 pages, 6 figures; as published in PHYSICA A
    Subjects:
    High Energy Physics — Phenomenology (hep-ph); Nuclear Theory (nucl-th)
    arXiv:
    2108.01607 [pdf]
    Physica A: Statistical Mechanics and its Applications(2022)·2 citations

Affiliations

first authorsco-authorsvia INSPIRE