Invariant-mass spectrum of Λ(Λ)over-bar pair in the process e+ e- → φΛ(Λ)over-bar

We show that the final-state interaction perfectly explains the recent experimental data of the BESIII Collaboration on the near-threshold invariant-mass spectrum of Lambda(Lambda) over bar in the process e(+) e(-) -> phi Lambda(Lambda) over bar. The position of the peak in the invariant-mass spectrum is above the threshold, though the interaction of Lambda and (Lambda) over bar is due to an attractive potential. This potential has a simple form and depends only on two parameters. We show that the invariant-mass spectrum is consistent with the quantum numbers J(PC) = 1(++) and 2(++) of Lambda(Lambda) over bar pair but the quantum numbers J(PC) = 2(++) are less likely.

Automated summary

The study demonstrates that the final-state interaction can perfectly explain the experimental data on the invariant-mass spectrum of phi Lambda(Lambda) over bar in the process e(+) e(-) -> phi Lambda(Lambda) over bar by the BESIII Collaboration. The peak position in the spectrum is above the threshold, despite the attractive potential between Lambda and (Lambda) over bar. The study also suggests that the invariant-mass spectrum is consistent with the quantum numbers J(PC) = 1(++) and 2(++) of Lambda(Lambda) over bar pair, but less likely with J(PC) = 2(++).