Calculation of the two-photon decay width of the f_0(980) scalar meson

Abstract

The applicability of the quasi-static approximation for calculating the two-photon annihilation rate of the scalar f_0(980) meson envisaged as a K\bar K molecule is critically re-examined. It is shown that the validity of this approximation depends on the detailed interplay between the momentum dependence of the annihilation amplitude and the momentum transform of the bound state wave function of the annihilating pair. The approximation becomes invalid when these two scales of variation are similar. An improved method of calculation based on the inclusion of electromagnetic corrections to the kernel of the Bethe-Salpeter equation for the interacting K\bar K pair is outlined to cover this case and applied to re-evaluate the two-photon decay width for f_0(980) in a one boson exchange model for the interkaon interaction. The corrections are significant and result in a much better agreement with experiment.

arXiv comment14 pages, 3 figures. Fig.3 replaced. Additional remarks with references

References in corpus (7)

• Big-Bang nucleosynthesis (Particle Data Group mini-review)
• The Cosmological Parameters 2006
• Low-energy Universality and the New Charmonium Resonance at 3870 MeV
• Interference and binding effects in decays of possible molecular component of X(3872)
• Study of the $D_s^{+}\to {\pi }^{-}{\pi }^{+}{\pi }^{+}$ decay and measurement of $f_0$ masses and widths
• Lifetime of Kaonium
• Dynamical Generation of Linear $\sigma$ model SU(3) Lagrangian and Meson Nonet Mixing

Cited by in corpus (4)

• Two-photon decays of hadronic molecules
• f0(980) meson as a K bar K molecule in a phenomenological Lagrangian approach
• Radiative decays with light scalar mesons and singlet-octet mixing in ChPT
• KKbar molecules with momentum-dependent interactions