Potential linear and angular momentum in the scalar diquark model

We present an analytic two-loop calculation within the scalar diquark model of the potential linear and angular momenta, defined as the difference between the Jaffe-Manohar and Ji notions of linear and angular momenta. As expected by parity and time-reversal symmetries, a direct calculation confirms that the potential transverse momentum coincides with the Jaffe-Manohar (or canonical) definition of average quark transverse momentum, also known as the quark Sivers shift. We examine whether initial/final-state interactions at the origin of the Sivers asymmetry can also generate a potential angular momentum in the scalar diquark model.

Analysis of the Pcs(4459) as the hidden-charm pentaquark state with QCD sum rules

In this paper, we study the scalar-diquark–scalar-diquark–antiquark-type [Formula: see text] pentaquark state with the QCD sum rules, the predicted mass [Formula: see text] is in excellent agreement with the experimental data [Formula: see text] from the LHCb collaboration, and supports assigning the [Formula: see text] to be the hidden-charm pentaquark state with the spin-parity [Formula: see text]. We take into account the flavor [Formula: see text] mass-breaking effect, and estimate the mass spectrum of the diquark–diquark–antiquark-type [Formula: see text] pentaquark states with the strangeness [Formula: see text].

Analysis of the X0(2900) as the scalar tetraquark state via the QCD sum rules

In this article, we study the axialvector-diquark–axialvector-antidiquark (AA)-type and scalar-diquark–scalar-antidiquark (SS) type fully open flavor [Formula: see text] tetraquark states with the spin-parity [Formula: see text] via the QCD sum rules. The predicted masses [Formula: see text] GeV and [Formula: see text] GeV support assigning the [Formula: see text] to be the AA-type scalar [Formula: see text] tetraquark state.