English

Distribution Functions of $\Lambda$ and $\Sigma^0$ Baryons

High Energy Physics - Phenomenology 2025-09-09 v2 High Energy Physics - Experiment High Energy Physics - Lattice Nuclear Experiment Nuclear Theory

Abstract

Treating baryons as quark + interacting-diquark bound states, a symmetry-preserving formulation of a vector×\,\times\,vector contact interaction (SCI) is used to deliver an extensive, coherent set of predictions for Λ,Σ0\Lambda, \Sigma^0 baryon unpolarised and polarised distribution functions (DFs) -- valence, glue, and four-flavour separated sea -- and compare them with those of a like-structured nucleon. Λ,Σ0\Lambda, \Sigma^0 baryons are strangeness negative-one isospin partners within the SU(3)(3)-flavour baryon octet. This makes such structural comparisons significant. The study reveals impacts of diquark correlations and SU(3)(3)-flavour symmetry breaking on Λ\Lambda, Σ0\Sigma^0 structure functions, some of which are significant. For instance, were it not for the presence of axialvector diquarks in the Σ0\Sigma^0 at the hadron scale, the ss quark could carry none of the Σ0\Sigma^0 spin. The discussion canvasses issues that include helicity retention in hard scattering processes; the sign and size of polarised gluon DFs; and the origin and decomposition of baryon spins. Interpreted judiciously, the SCI analysis delivers an insightful explanation of baryon structure as expressed in DFs.

Keywords

Cite

@article{arxiv.2505.10663,
  title  = {Distribution Functions of $\Lambda$ and $\Sigma^0$ Baryons},
  author = {Yang Yu and Peng Cheng and Hui-Yu Xing and Daniele Binosi and Craig D. Roberts},
  journal= {arXiv preprint arXiv:2505.10663},
  year   = {2025}
}

Comments

24 pages, 10 figures, 6 tables. To appear in Eur. Phys. J. A

R2 v1 2026-06-28T23:35:02.170Z