--------------------
- Two-photon width and gluonic component of sigma/f_0(600) doi link

Auteur(s): Mennessier Gerard(Corresp.), Narison S.(Corresp.), Ochs W.(Corresp.)

(Article) Publié: Nuclear Physics B, vol. 181-182 p.238-242 (2008)
Texte intégral en Openaccess : arxiv


Ref HAL: hal-00378070_v1
Ref Arxiv: 0806.4092
DOI: 10.1016/j.nuclphysbps.2008.09.043
Ref. & Cit.: NASA ADS
Exporter : BibTex | endNote
10 citations
Résumé:

We analyse data on pi pi and gamma gamma scattering below 700 MeV within animproved analytic K-matrix model. This model is based on an effective theorywith couplings between resonances, hadrons and photons. The two-photon decay ofa resonance can proceed through intermediate transition into charged hadrons(here: pi^+ pi^-) and their subsequent annihilation or through a ``direct''transition into photons. Our analysis confirms the rather large total radiativewidth of the sigma/f_0(600) resonance which we find as (3.9 \pm 0.6) keV butsuggests its dominance by the pi pi rescattering process. This process is notsensitive to the internal structure of the resonance contrary to the directcomponent which we find small, (0.13 \pm 0.05) keV, and well consistent withthe expectations for an unmixed glueball according to the QCD sum rulecalculations.



Commentaires: Talk (W.O.) at the International Workshop on e+e- collisions from phi to psi, Frascati, April 2008.