K. -I. Kubo | Searcharxiv

arXiv2005

Spin Polarization of Hyperons in the Hadron-Hadron Inclusive Collisions - Mechanisms and Dynamics -

We discuss interplay of the scalar and vector diquarks which decide the characteristics of the spin polarization as functions of $p_T$ and $x_F$ in the wide kinematical range. We demonstrate a significant effect of quark masses on the pair-creation probabilities from vacuum in $pp \to Σ^- X$ and $γp \to ΛX$ collisions, and also a remarkable correction induced by the diquark form factor in $ Σ^- p \to ΛX $ collision.

hep-ph↗

arXiv1999

Analyzing powers in inclusive pion production at high energy and the nucleon spin structure

Analyzing powers in inclusive pion production in high energy transversely polarized proton-proton collisions are studied theoretically in the framework of the quark recombination model. Calculations by assuming the SU(6) spin-flavor symmetry for the nucleon structure disagree with the experiments. We solve this difficulty by taking into account the %We overcome this difficulty by taking into account the realistic spin distribution functions of the nucleon, which differs from the SU(6) expectation at large $x$, %but coincides with a perturbative QCD constraint on the ratio of the unpolarized valence distributions, $u/d \to 5$ as $x \to 1$. We also discuss the kaon spin asymmetry and find $A_N(K^+) = -A_N(K^0)$ in the polarized proton-proton collisions at large $x_F$.

hep-ph↗