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Davier, M., Diaz-Calderon, D., Malaescu, B., Pich, A., Rodriguez-Sanchez, A., & Zhang, Z. (2023). The Euclidean Adler function and its interplay with Delta alpha(had)(QED) and alpha(s). J. High Energy Phys., 04(4), 067–57pp.
Abstract: Three different approaches to precisely describe the Adler function in the Euclidean regime at around 2 GeVs are available: dispersion relations based on the hadronic production data in e(+)e(-) annihilation, lattice simulations and perturbative QCD (pQCD). We make a comprehensive study of the perturbative approach, supplemented with the leading power corrections in the operator product expansion. All known contributions are included, with a careful assessment of uncertainties. The pQCD predictions are compared with the Adler functions extracted from ?a( QED)(had)(Q(2)), using both the DHMZ compilation of e(+)e(-) data and published lattice results. Taking as input the FLAG value of a(s), the pQCD Adler function turns out to be in good agreement with the lattice data, while the dispersive results lie systematically below them. Finally, we explore the sensitivity to a(s) of the direct comparison between the data-driven, lattice and QCD Euclidean Adler functions. The precision with which the renormalisation group equation can be tested is also evaluated.
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Lin, J. X., Encarnacion, P., Feijoo, A., & Albaladejo, M. (2026). Signatures of the Ω(2012)- state in Ξ*(K)over-bar correlation functions. Phys. Lett. B, 880, 140789–9pp.
Abstract: We investigate the Omega(2012) resonance in the strangeness S = -3 sector within a coupled-channel chiral unitary approach and present the first quantitative predictions for femtoscopic correlation functions directly sensitive to its dynamics. The Omega(2012) is dynamically generated as a quasi-bound Xi*(K) over bar-Omega eta 2 molecular state, with its coupling to the Xi(K) over bar channel driven by d-wave transitions. Model parameters are constrained by the measured mass, width, and the Belle determination of the branching fraction R-Xi K(Xi(K) over bar pi), yielding M (Omega(2012)) = (2012.53 +/- 0.73) MeV and Gamma(Omega(2012)) = (4.05 +/- 0.13) MeV.Within this framework, we compute the femtoscopic correlation functions of the Xi K-*0(-), Xi*(-)(K) over bar (0) and Omega(-) eta systems. The Xi*(K) over bar correlation functions exhibit pronounced near-threshold structures that arise from the proximity of the Omega(2012) pole, demonstrating an exceptional sensitivity to its position and coupled-channel composition. In particular, the Xi*K-0(-) correlation function is identified as a clean and highly selective probe of the Omega(2012) resonance. These results establish femtoscopic correlation measurements as powerful tools for extracting resonance properties beyond conventional invariant-mass analyses and provide concrete theoretical benchmarks for upcoming experimental studies aimed at elucidating the molecular nature of the Omega(2012).
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