Production of $J/ψp \bar p$ in electron-positron collisions

Abstract

The discoveries of the hidden-charm $P_c$ pentaquarks by the LHCb Collaboration have been not confirmed by other experiments yet. It is desirable to investigate the feasibility of observing them in other experiments. We present an order-of-magnitude estimate of the cross section of the $e^+e^-\to J/ψp \bar p$ process, where the hidden-charm pentaquarks may be searched for, and find it to be of $\mathcal{O}(4~\text{fb})$ when the $e^+e^-$ c.m. energy is around 6 GeV. The cross section for $e^+e^-\to P_c \bar p$ is then estimated to be $\lesssim \mathcal{O}(0.1~\text{pb})$. Thus, it is promising to search for $P_c$ at the future high-luminosity super tau-charm facilities with annual integrated luminosity about $1~ab^{-1}$. We also predict the branching fraction of $Υ\to J/ψp\bar p$ to be of $\mathcal{O}(2\times 10^{-6})$, which can be tested at $B$ factories.

Figures (3)

• Figure 1: Two-gluon exchange mechanisms for the $e^+e^-\to J/\psi p \bar{p}$ and $J/\psi \to \gamma p \bar{p}$. The recangles stand for the hadronization of the gluons into the proton-antiproton pair.
• Figure 2: Cross section estimate of $e^+e^-\to J/\psi gg$ using the LO NRQCD.
• Figure 3: Feynman diagrams for the $J/\psi gg$ production in $e^-e^+$ collisions.