arXiv 0809.24752008-09-15hep-ph

Obtaining sigma --> gamma gamma Width from Nucleon Polarizabilities

Joaquim Prades, Jose Bernabeu

备注：: 7 pages, 1 figure, Invited Talk given by J.P. at 14th International Conference on QCD (QCD' 08), 7-12 July 2008, Montpellier, France
发表信息：: Nucl.Phys.Proc.Suppl.186:279-282,2009
DOI：: 10.1016/j.nuclphysbps.2008.12.062

英文摘要：

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.

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