Electromagnetic trace anomaly in a generalized linear sigma model

Abstract

We build the electromagnetic trace anomaly effective term for a generalized linear sigma model with two chiral nonets, one with a quark-antiquark structure, the other one with a four quark content. In the leading order of this framework, we study the decays into two photons of the lowest isosinglet scalar mesons. We find that the direct inclusion of underlying mixing among two- and four-quark components in the trace anomaly term is essential in order for the model prediction to agree with the available experimental data on decay width of $f_0(980)$ to two photons. Consequently, this sets a lower bound of 0.5 KeV on the decay with of $f_0(500)$ to two photons.

7 pages, 2 figures, version accepted for publication in Phys. Rev. D. arXiv admin note: text overlap with arXiv:1407.3870

References in corpus (15)

• A low-lying scalar meson nonet in a unitarized meson model
• A Theory of Scalar Mesons
• Nature of the f_0(600) from its N_c dependence at two loops in unitarized Chiral Perturbation Theory
• Comprehensive Amplitude Analysis of $\gamma \gamma \to {\pi }^{+}{\pi }^{-},{\pi }^0{\pi }^0$ and $\overline{K}K$ below 1.5 GeV
• Mixing of scalar tetraquark and quarkonia states in a chiral approach
• Note on a sigma model connection with instanton dynamics
• Mass Uncertainties of f0(600) and f0(1370) and their Effects on Determination of the Quark and Glueball Admixtures of the I=0 Scalar Mesons
• Amplitude Analysis of High Statistics Results on $\gamma \gamma \to {\pi }^{+}{\pi }^{-}$ and the Two Photon Width of Isoscalar States
• Improved dispersion relations for γγ\to π^0π^0
• Lightest scalar and tensor resonances in $\gamma \gamma \to \pi \pi$ after the Belle experiment
• Two chiral nonet model with massless quarks
• The sigma -> gamma gamma Width from Nucleon Electromagnetic Polarizabilities
• On the two-photon decay width of the sigma meson
• Low energy scattering with a nontrivial pion
• Chiral Nonet Mixing in ${\eta }^{\prime }\to \eta \pi \pi$ Decay