%0 Journal Article
%T Evidence of a J / ψK0S Structure in B0 → J / ψφK0S Decays
%A LHCb Collaboration (Aaij, R. et al
%A Jaimes Elles, S. J.
%A Jashal, B. K.
%A Martinez-Vidal, F.
%A Oyanguren, A.
%A Rebollo De Miguel, M.
%A Remon Alepuz, C.
%A Ruiz Vidal, J.
%A Sanderswood, I.
%J Physical Review Letters
%D 2023
%V 131
%N 13
%I Amer Physical Soc
%@ 0031-9007
%G English
%F LHCbCollaborationAaij_etal2023
%O WOS:001102953400002
%O exported from refbase (https://references.ific.uv.es/refbase/show.php?record=5951), last updated on Wed, 10 Apr 2024 12:45:24 +0000
%X An amplitude analysis of B0 -> J=psi phi K0S 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 J=psi K0S system, named T theta psi s1o4000 thorn 0, is seen, with its mass and width measured to be 3991 thorn 12 thorn 9 -10 -17 MeV=c2 and 105 thorn 29 thorn 17 -25 -23 MeV, respectively, where the first uncertainty is statistical and the second systematic. The T theta psi s1 o4000 thorn 0 state is likely to be the isospin partner of the T theta psi s1 o4000 thorn thorn state, previously observed in the J=psi K thorn system of the B thorn -> J=psi phi K thorn decay. When isospin symmetry for the charged and neutral T theta psi s1 o4000 thorn states is assumed, the signal significance increases to 5.4 standard deviations.
%R 10.1103/PhysRevLett.131.131901
%U https://arxiv.org/abs/2301.04899
%U https://doi.org/10.1103/PhysRevLett.131.131901
%P 131901 - 11pp