Eur. Phys. J. C (2007) 50: 609-616
https://doi.org/10.1140/epjc/s10052-007-0219-5

Regular Article - Theoretical Physics

Positive parity scalar mesons in the 1–2 GeV mass range

¹ Dip. Fisica, Università di Roma “La Sapienza” and INFN, Roma, Italy
² I.N.F.N. Sezione di Pavia and Dipartimento di Fisica Nucleare e Teorica, via A. Bassi 6, 27100, Pavia, Italy
³ INFN, Sezione di Roma 1, Roma, Italy

^* e-mail: antonio.polosa@cern.ch

Received: 25 September 2006
Revised: 27 November 2006
Published online: 7 February 2007

Abstract

Based on the observation that K₀ ^*(1430) is lighter than its SU₃ counterpart, a₀(1450), we examine the possibility that these particles, together with f₀(1370), f₀(1500) and f₀(1710), fill a tetraquark recurrence of the sub-GeV 0⁺⁺ nonet mixed with a glueball state. We find the picture to be consistent with the known data about the three f₀ resonances, more than the qq̄ hypothesis. Conventional spin–orbit coupling suggests the qq̄, P-wave, nonet to lie around 1200 MeV. We review possible experimental indications of a scalar isovector resonance at 1.29 GeV, first observed by OBELIX in pp̄ annihilation.