Detecting the pure triangle singularity effect through the ψ(2S) → p(p)over-barη/p(p)over-barπ0 process

In this work, the triangle singularity mechanism is investigated in the psi(2S)-> p (p) over bar eta/p (p) over bar pi(0) process. The triangle loop composed by J/psi, eta, and p has a singularity in the physical kinematic range for the psi(2S) -> p (p) over bar eta/p (p) over bar pi(0) process, and it would generate a very narrow peak in the invariant mass spectrum of p eta(pi) around 1.56387 GeV, which is far away from both the threshold and relative resonances. In these processes, all the involved vertices are constrained by the experimental data. Thus, we can make a precise model independent prediction here. It turns out that the peak in the p eta invariant mass spectrum is visible, while it is very small in the p pi(0) invariant mass spectrum. We expect this effect shown in p (p) over bar eta final state can be observed by the Beijing Spectrometer and Super Tau-Charm Facility in the future.

Automated summary

This study investigates the triangle singularity mechanism in a specific process, predicting a narrow peak in the p eta invariant mass spectrum, while it is very small in the p pi(0) invariant mass spectrum.