Light scalar mesons in QCD

Stéphan Narison (1)

1 LPTA - Laboratoire de Physique Théorique et Astroparticules

I present a mini-review of the masses and couplings of the bare (unmixed)light scalar mesons : $\bar qq, (\overline{qq})(qq), (\bar qq)(\bar qq), gg$from QCD spectral sum rules (QSSR) and low-energy theorems (LET) which wecompare with recent lattice calculations when available. Some unbiased commentson the different scenarios are given. The possiblity for the $\sigma (0.6)$ tobe mostly a gluonium/glueball with a huge violation of the OZI rule in itsdecay is discussed. This review complements and updates the ones presentedearlier [1]. Despite some progresses, the internal structure of the lightscalar mesons remain puzzling, and some further efforts are required. It willbe more fun at LHC if the Higgs of the Standard Model is a $\sigma$-likeresonance.

Domaines: Physique des Hautes Energies - Phénoménologie [hep-ph]; Physique des Hautes Energies - Expérience [hep-ex]; Physique des Hautes Energies - Réseau [hep-lat]; Physique Nucléaire Théorique [nucl-th]

Stéphan Narison. Light scalar mesons in QCD. 14th International Conference QCD 08, Jul 2008, Montpellier, France. pp.306-311, ⟨10.1016/j.nuclphysbps.2008.12.069⟩. ⟨hal-00378089⟩