Radiative decays with light scalar mesons and singlet-octet mixing in ChPT

Abstract

We study different types of radiative decays involving f0(980) and a0(980) mesons within a unified ChPT-based approach at one-loop level. Light scalar resonances which are seen in pi pi, pi eta, K K-bar channels of phi(1020) radiative decays and in J/psi decays are responsible for key questions of low-energy dynamics in the strong interaction sector, and decays phi(1020) -> gamma a0(980), phi(1020) -> gamma f0(980), a0(980) -> gamma gamma, f0(980) -> gamma gamma are of interest for current experimental programs in Juelich, Frascati and Novosibirsk. From theoretical point of view it is important to verify whether light scalar mesons are members of some flavor octet or nonet. We find a value of mixing angle dictated by consistency with experiment and coupling structures of ChPT Lagrangian. Decay widths f0(980)/a0(980) -> gamma rho(770)/omega(782), which are not studied experimentally yet, are predicted. We also obtain several relations between widths, which hold independently of coupling constants and represent a fingerprint of the model.

18 pages, 8 figures; misprints in text and tables corrected, discussion extended, references added; version accepted for publication in Eur.Phys.J. C

References in corpus (7)

• High statistics study of f_0(980) resonance in gamma gamma --> pi^+ pi^- production
• Two-photon decays of hadronic molecules
• Ordinary and Extraordinary Hadrons
• Prospects for e+e- physics at Frascati between the phi and the psi
• Electromagnetic form factors of charged and neutral kaons in an extended vector-meson-dominance model
• Investigation of light scalar resonances at COSY
• Calculation of the two-photon decay width of the f_0(980) scalar meson

Cited by in corpus (7)

• Meson loops in the $f_0(980)$ and $a_0(980)$ radiative decays into $\rho$, $\omega$
• Pi pi scattering lengths at O(p^6) revisited
• On the role of meson loops in the $f_0(1710)$ decay into $V\gamma$
• e+e- annihilation to (pi0 pi0 gamma) and (pi0 eta gamma) as a source of information on scalar and vector mesons
• Refining the scalar and tensor contributions in $\tau \to \pi \pi \pi {\nu }_{\tau }$ decays
• Linear Sigma Model predictions for V->Sgamma and S->Vgamma decays
• Polarization effects in radiative decay of polarized $\tau$ lepton