2025/06/03 by Arifi, Ahmad Jafar, Choi, Ho-Meoyng, Ji, Chueng-Ryong · 2 citations
#FOS: Physical sciences #High Energy Physics - Phenomenology (hep-ph)
paper · doi:10.48550/arxiv.2506.02844
In this study, we present a comprehensive analysis of decay constants and chiral-even and chiral-odd distribution amplitudes (DAs) up to twist 4 for the ρ meson in the standard light-front quark model (LFQM) based on the Bakamjian-Thomas (BT) construction. For the ρ meson, which possesses both longitudinal (h=0) and transverse (h=± 1) polarizations, two types of decay constants, fρ∥ and fρ⊥, arises accordingly. We demonstrate that these decay constants can be self-consistently extracted from both local (zμ=0) and nonlocal (zμ≠ 0) matrix elements ⟨ 0 | q(z) Γ q(-z) | ρ(P,h) ⟩, with Γ= (γμ, σμν, γμγ5, 1), in a manner independent of current components, polarizations, and reference frames. In particular, we emphasize the role of nonlocal matrix elements involving axial-vector and scalar currents, where mixing between fρ∥ and fρ⊥ occurs. We show that this mixing is consistently resolved through the BT construction, ensuring the proper extraction of these decay constants. Additionally, we investigate the structure of chiral-even DAs (ϕ2;V^∥, ϕ3;V^∥, ψ3;A^⊥, ϕ4;V^∥) and chiral-odd DAs (ϕ2;T^⊥, ϕ3;T^⊥, ψ3;S^∥, ϕ4;T^⊥) beyond leading twists, and present their corresponding ξ-moments and Gegenbauer moments. These results provide deeper insight into the nonperturbative structure of vector mesons and demonstrate the robustness and self-consistency of the LFQM based on the BT framework.