Elliptic anisotropy measurement of the f₀(980) hadron in proton-lead collisions and evidence for its quark-antiquark composition.

ABSTRACT: Despite the f₀(980) hadron having been discovered half a century ago, the question about its quark content has not been settled: it might be an ordinary quark-antiquark ( qq¯ ) meson, a tetraquark ( qq¯qq¯ ) exotic state, a kaon-antikaon ( KK¯ ) molecule, or a quark-antiquark-gluon ( qq¯g ) hybrid. This paper reports strong evidence that the f₀(980) state is an ordinary qq¯ meson, inferred from the scaling of elliptic anisotropies (v₂) with the number of constituent quarks (n_q), as empirically established using conventional hadrons in relativistic heavy ion collisions. The f₀(980) state is reconstructed via its dominant decay channel f₀(980) → π⁺π^-, in proton-lead collisions recorded by the CMS experime

SUBMITTER: CMS Collaboration 

PROVIDER: S-EPMC12391314 | biostudies-literature | 2025 Aug

REPOSITORIES: biostudies-literature