Observation of Five New Narrow Ωc0 States Decaying to Ξc+K−

Abstract

The Ξ_{c}^{+}K^{-} mass spectrum is studied with a sample of pp collision data corresponding to an integrated luminosity of 3.3 fb^{-1}, collected by the LHCb experiment. The Ξ_{c}^{+} is reconstructed in the decay mode pK^{-}π^{+}. Five new, narrow excited Ω_{c}^{0} states are observed: the Ω_{c}(3000)^{0}, Ω_{c}(3050)^{0}, Ω_{c}(3066)^{0}, Ω_{c}(3090)^{0}, and Ω_{c}(3119)^{0}. Measurements of their masses and widths are reported.

DΞ and D*Ξ molecular states from one boson exchange

“…Recently, the LHCb Collaboration observed five narrow states, Ω c ð3000Þ 0 , Ω c ð3050Þ 0 , Ω c ð3066Þ 0 , Ω c ð3090Þ 0 , and Ω c ð3119Þ 0 [29], four of which have also been recently confirmed from an analysis of the Belle data [30]. These states can be accommodated as excited Ω c baryons [31,32], as compact baryons in which the ss strange quark pair forms a diquark [33], or as molecular states [34][35][36][37][38].…”

Very narrow excited Ωc baryons

“…If that were the case, at least some of the states we predict would not correspond to the five observed by LHCb, but would lie below Ξ + c K − threshold. There is, in fact, some hint in the LHCb data just near threshold, of some activity exceeding phase space [1]. ¶ A value of ∆E P S (Ω c ) larger than 240 MeV is estimated by comparison with the observed S-P splitting in the Ξ c states.…”

“…Very recently LHCb reported the discovery of five extremely narrow excited Ω c baryons decaying into Ξ + c K − [1], with masses and widths shown in Table I. We quote also our favored spin-parity assignment for these states, which we shall choose among the 5!…”

Investigating the excited Ωc0 states through ΞcK<

“…0 [9]. Moreover, the decay widths of these states were also observed by the experiment, which are only a few MeV.…”