Decays of the f₀(1370) scalar glueball candidate in pp Central Exclusive Production (CEP) and in antiproton annihilations at rest

INFN-Ferrara, Via Saragat 1, 44122 Ferrara, Italy

Published online: 14 November 2018

Abstract

Decays into π⁺π^- of the f₀(1370) are the main source of an isolated structure localized between 1.2 and 1.5 GeV in the π⁺π^- mass spectrum measured in pp Central Exclusive Production (CEP) at √s=200 GeV at very low four momentum transfer ltl by the STAR experiment. These data confirm in the π⁺π^- decay channel the existence of the f₀(1370) as an isolated well identified structure previously observed in K⁺K^-, K_sK_s, π⁺π^-π⁺π^-, 2π⁰π⁺π^- and 4π⁰ decays measured in pbar annihilations at rest. The ensemble of these data point at a high gg content of the f₀(1370). CEP interactions at higher energies favour production of 0⁺⁺ and 2⁺⁺ mesons. Selection of events with lower ltl at both proton vertices suppresses 2⁺⁺ structures. LHC runs dedicated to pp CEP measurements at low ltl could then provide a unique source of all the low energy scalars. This would make it clear if and where scalar gluonium is resident and the nature (composition in terms of qqbar, qqqbarqbar, qqbar-qqbar and gg) of f₀(500), f₀(980), f₀(1370), f₀(1500) and f₀(1710).