Tensor form factors of decuplet hyperons in QCD

TL;DR

This paper addresses the tensor form factors of spin-3/2 decuplet hyperons (Ω^-, Σ^{*+}, Ξ^{*-}) using QCD sum rules. It constructs a three-point correlation function with a tensor current, analyzes both the physical hadronic side and the QCD operator-product expansion side, applies a double Borel transform, and matches Lorentz structures to extract the complete set of tensor form factors for both isosinglet and isovector currents in the range $0<Q^2<10$ GeV^2. The results are fitted with a generalized $p$-pole form, and forward tensor charges are extracted, revealing flavor-dependent spin dynamics across the hyperon states. These nonperturbative inputs enhance our understanding of transverse spin structure in baryons and provide valuable benchmarks for phenomenology, lattice QCD, and future experiments exploring tensor currents and transversity in hadrons.

Abstract

Tensor form factors encode essential information about the internal spin structure and tensor dynamics of baryons. In this work, we investigate the tensor form factors of the baryon hyperons $Ω^-$, $Σ^{*+}$, and $Ξ^{*-}$ within the framework of QCD sum rules. For the $Σ^{*+}$ and $Ξ^{*-}$ baryons, both isosinglet and isovector tensor currents are considered, allowing us to disentangle flavor-dependent tensor contributions. The complete set of tensor form factors is numerically evaluated in the momentum transfer region $0<Q^2<10~\text{GeV}^2$. In addition, the quark tensor charges of the considered hyperons are extracted in the forward limit. The results provide new non-perturbative insight into the tensor structure and spin content of spin-$3/2$ baryons and offer valuable theoretical input for future phenomenological analyses and experimental studies.

Figures (10)

• Figure 1: Dependence of the $\Omega^-$ TFFs on the Borel mass parameter $M^2$ at $Q^2 = 1.0~\text{GeV}^2$ for three different values of the continuum threshold $s_0$.
• Figure 2: Variation of the $\Omega^-$ TFFs with $Q^2$ at a fixed Borel parameter $M^2 = 7.5~\text{GeV}^2$, shown for three choices of the continuum threshold $s_0$.
• Figure 3: Dependence of the isosinglet TFFs of the $\Sigma^{*+}$ baryon on the Borel parameter $M^2$, evaluated at $Q^2 = 1.0~\text{GeV}^2$ for three different continuum thresholds $s_0$.
• Figure 4: Variation of the $\Sigma^{*+}$ isosinglet TFFs with $Q^2$ at $M^2 = 5.5~\text{GeV}^2$ for three choices of the continuum threshold $s_0$.
• Figure 5: Dependence of the isovector TFFs of the $\Sigma^{*+}$ baryon on the Borel mass $M^2$, evaluated at $Q^2 = 1.0~\text{GeV}^2$ for three different continuum threshold values $s_0$.