Production of the spin partner of the X(3872) in e^+e^- collisions

TL;DR

This paper investigates the production of the X_2(4012), a spin partner of X(3872), in electron-positron collisions, identifying optimal energy regions and challenges for experimental observation.

Contribution

It predicts the production conditions of the X_2(4012) in e^+e^- collisions and highlights the energy range suitable for its detection.

Findings

Optimal energy range for observing X_2(4012) is 4.4-4.5 GeV.

Production is linked to ^{*}_1(2420) and ^{*}_2(2460) thresholds.

Detection around 4.26 GeV is challenging.

Abstract

We study the production of the spin partner of the X(3872), which is a D^{*}\bar D^{*} bound state with quantum numbers J^{PC}=2^{++} and named X_2(4012) here, with the associated emission of a photon in electron--positron collisions. The results show that the ideal energy region to observe the X_2(4012) in e^+e^- annihilations is from 4.4~GeV to 4.5~GeV, due to the presence of the S-wave \bar D^{*} D_1(2420) and \bar D^{*} D_2(2460) thresholds, respectively. We also point out that it will be difficult to observe the \gamma X(4012) at the e^+e^- center-of-mass energy around 4.26~GeV.