Aaij, RoelAlfonso Albero, AlejandroGarcia Moreno, PaulaGarrido Beltrán, LluísGironella Gironell, PereGomez Fernandez, SergioGraugés Pous, EugeniLobo Salvia, AniolLópez Huertas, AlbertMarin Benito, CarlaMauricio Ferre, JoanVazquez Gomez, RicardoManera Escalero, Rafel2025-06-032025-06-0320230031-9007https://hdl.handle.net/2445/221341An amplitude analysis of 0→ / 0S decays is performed using proton-proton collision data, corresponding to an integrated luminosity of 9 fb−1, collected with the LHCb detector at center-of-mass energies of 7, 8, and 13 TeV. Evidence with a significance of 4.0 standard deviations of a structure in the / 0S system, named 1(4000)0, is seen, with its mass and width measured to be 3991+12−10 +9−17 MeV/c2 and 105+29−25 +17−23 MeV, respectively, where the first uncertainty is statistical and the second systematic. The 1(4000)0 state is likely to be the isospin partner of the 1(4000)+ state, previously observed in the / + system of the +→ / + decay. When isospin symmetry for the charged and neutral 1(4000) states is assumed, the signal significance increases to 5.4 standard deviations.11 p.application/pdfeng(c) American Physical Society, 2023Física de partículesFusió nuclearParticle physicsNuclear fusionEvidence of a J/ψ KS0 Structure in B0 →j/ψφ KS0 Decaysinfo:eu-repo/semantics/article7547842025-06-03info:eu-repo/semantics/openAccess