Evidence for a [?] State

Authors

V. Abazov, Joint Institute for Nuclear Research, Dubna, Russia
Kenneth A. Bloom, University of Nebraska-LincolnFollow
Daniel R. Claes, University of Nebraska-LincolnFollow
Kayle DeVaughan, University of Nebraska-Lincoln
Aaron Dominguez, University of Nebraska-LincolnFollow
M. Eads, University of Nebraska-Lincoln, Lincoln,Follow
Ioannis Katsanos, University of Nebraska-LincolnFollow
Sudhir Malik, University of Nebraska-LincolnFollow
Gregory Snow, University of Nebraska-LincolnFollow
M. Voutilainen, University of Nebraska-Lincoln
D0 Collaboration

Date of this Version

2016

Citation

PRL 117, 022003 (2016)

Comments

© 2016 American Physical Society

DOI: 10.1103/PhysRevLett.117.022003

Abstract

We report evidence for a narrow structure, X(5568), in the decay sequence X(5568) → [?], [?] → J/ψϕ, J/ψ → μ⁺μ⁻, ϕ → K⁺K⁻. This is evidence for the first instance of a hadronic state with valence quarks of four different flavors. The mass and natural width of this state are measured to be m = 5567.8 ± 2.9(stat)[?](syst) MeV/c² and Γ = 21.9 ± 6.4(stat)[?](syst) MeV/c² . if the decay is X(5568) → [?] → [?] with an unseen y, m(X(5568)) will be shifted up by m([?]) - m([?]) ~ 49 MeV/c². This measurement is based on 10.4 fb^-1 of pp collision data at [?] = 1.96 TeV collected by the D0 experiment at the Fermilab Tevatron collider.