Obtaining sigma --> gamma gamma Width from Nucleon Polarizabilities

Abstract

We propose a new method that fixes the coupling to two photons of the recently found lightest QCD resonance, the sigma. This coupling provides crucial information for discriminating the yet unknown nature of this special state. Our method uses available data on the nucleon polarizabilities together with analyticity and unitarity. Taking into account all the uncertainties, our result is Gamma_{pole}= 1.2 +- 0.4 keV.

7 pages, 1 figure, Invited Talk given by J.P. at 14th International Conference on QCD (QCD' 08), 7-12 July 2008, Montpellier, France

References in corpus (15)

• Big Bang Nucleosynthesis (in "The Review of Particle Properties" 2004)
• Mass and width of the lowest resonance in QCD
• Photon-Photon Scattering, Pion Polarizability and Chiral Symmetry
• Experimental status of the $\pi \pi$ isoscalar S wave at low energy: $f_0(600)$ pole and scattering length
• Polarizability of the Nucleon and Compton Scattering
• 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
• Two photons into π^0π^0
• Dispersion Relations and the Nucleon Polarizability
• Location, correlation, radiation: where is the $\sigma$, what is its structure and what is its coupling to photons?
• The sigma -> gamma gamma Width from Nucleon Electromagnetic Polarizabilities
• Electromagnetic polarizabilities of the nucleon and properties of the $\sigma$-meson pole contribution
• Electromagnetic polarizabilities and the excited states of the nucleon
• Properties of the ${\pi }^0$, $\eta$, ${\eta }^{\prime }$, $\sigma$, $f_0(980)$ and $a_0(980)$ mesons and their relevance for the polarizabilities of the nucleon
• Structure of the $\sigma$-meson and diamagnetism of the nucleon

Cited by in corpus (3)

• On the size of the sigma meson and its nature
• Gluonium nature of the sigma/f_0(600) from its coupling to KK
• Observation of the Higgs Boson of strong interaction via Compton scattering by the nucleon