# Observation of the Y (4140) structure in the J/psi phi mass spectrum in B-+/- -> J/psi phi K-+/- decays

Aaltonen, T, Alvarez Gonzalez, B, Amerio, S, Amidei, D, Anastassov, A, Annovi, A, Antos, J, Apollinari, G, Appel, JA, Apresyan, A
et al (show 494 more authors) (2017) Observation of the Y (4140) structure in the J/psi phi mass spectrum in B-+/- -> J/psi phi K-+/- decays. MODERN PHYSICS LETTERS A, 32 (26). 26-.

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## Abstract

The observation of the $Y(4140)$ structure in $B^\pm\rightarrow J/\psi\,\phi K^\pm$ decays produced in $\bar{p} p$ collisions at $\sqrt{s}=1.96~\TeV$ is reported with a statistical significance greater than 5 standard deviations. A fit to the $J/\psi\,\phi$ mass spectrum is performed assuming the presence of a Breit-Wigner resonance. The fit yields a signal of $19^{+6}_{-5}$ resonance events, and resonance mass and width of $4143.4^{+2.9}_{-3.0}(\mathrm{stat})\pm0.6(\mathrm{syst})~\MeVcc$ and $15.3^{+10.4}_{-6.1}(\mathrm{stat})\pm2.5(\mathrm{syst})~\MeVcc$ respectively. The parameters of this resonance-like structure are consistent with values reported from an earlier CDF analysis.

Item Type: Article 7 pages, 2 figures, submited to Phys. Rev. Lett hep-ex, hep-ex Symplectic Admin 14 Sep 2017 13:39 19 Jan 2023 06:54 10.1142/S0217732317501395 https://arxiv.org/abs/1101.6058 https://livrepository.liverpool.ac.uk/id/eprint/3009402