Comment on "Two-photon decay of the sigma meson"

Abstract

We comment on a recent paper by Giacosa, Gutsche, and Lyobovitskij, in which it is argued that a quarkonium interpretation of the $\sigma$ meson should give rise to a much smaller two-photon decay width than commonly assumed. The reason for this claimed discrepancy is a term in the transition amplitude, necessary for gauge invariance, which allegedly is often omitted in the literature, including the work of the present authors. Here we show their claims to be incorrect by demonstrating, in the context of the Quark-Level Linear $\sigma$ Model, that the recently extracted experimental value ${\Gamma }_{\sigma \to 2\gamma }=(4.1\pm 0.3)$ keV is compatible with a $q\bar{q}$ assignment for the $\sigma$, provided that meson loops are taken into account as well.

RevTeX, 4 pages, Comment on Phys. Rev. D 77 (2008) 034007 [0710.3403 [hep-ph]]

References in corpus (14)

• The Cosmological Parameters 2006
• Big-Bang nucleosynthesis (Particle Data Group mini-review)
• Mass and width of the lowest resonance in QCD
• Dynamical generation of the gauged SU(2) linear sigma model
• Amplitude Analysis of High Statistics Results on $\gamma \gamma \to {\pi }^{+}{\pi }^{-}$ and the Two Photon Width of Isoscalar States
• Dynamical Generation of Linear $\sigma$ model SU(3) Lagrangian and Meson Nonet Mixing
• Remarks on the f_0(400-1200) scalar meson as the dynamically generated chiral partner of the pion
• Ground-State Scalar $\bar{q}q$ Nonet: SU(3) Mass Splittings and Strong, Electromagnetic, and Weak Decay Rates
• Identifying the quark content of the isoscalar scalar mesons f_0(980), f_0(1370), and f_0(1500) from weak and electromagnetic processes
• $s\bar{s}$ dominance of the $f_0$(980) meson
• On the two-photon decay width of the sigma meson
• a_0(980) -> gamma gamma and f_0(980) -> gamma gamma: a consistent description
• Comments on compositeness in the SU(2) linear sigma model
• Chiral Shielding

Cited by in corpus (14)

• From controversy to precision on the sigma meson: a review on the status of the non-ordinary $f_0(500)$ resonance
• Study of measured pulsar masses and their possible conclusions
• Discovering Technicolor
• The Technicolor Higgs in the Light of LHC Data
• Decay of light scalar mesons into vector-photon and into pseudoscalar mesons
• The Quark-Level Linear σ Model
• Dispersion theory of nucleon Compton scattering and polarizabilities
• Structure of scalar mesons and the Higgs sector of strong interaction
• Observation of the Higgs Boson of strong interaction via Compton scattering by the nucleon
• Composite Higgs to two Photons and Gluons
• Reply to comment on "Two-photon decay of the sigma meson"
• Hadron physics with KLOE-2
• Hadronic structure from two photon collisions
• The $Y(4260)$ and $Y(4360)$ enhancements within coupled-channels