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 (6)

• Experimental status of the $\pi \pi$ isoscalar S wave at low energy: $f_0(600)$ pole and scattering length
• 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
• 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

Cited by in corpus (1)

• Gluonium nature of the sigma/f_0(600) from its coupling to KK