Evidence of the low-lying baryon ^* (1/2^-) in the process c^+ ^+

Motivated by the Belle measurements of the process c^+ ^+, we investigate this process by considering the contributions from the (1670), a₀ (980), and (1385). In addition, we also consider the predicted low-lying baryon ^* (1/2^-). Our results involving the ^* (1/2^-) are favored by fitting to the Belle data of the and ^+ invariant mass distributions. Furthermore, we predict the ^+ invariant mass distribution and the angular distribution d/d cos, which are significantly different depending on whether or not the contribution from the ^* (1/2^-) is considered. Finally, we show that, with the contribution from the ^* (1/2^-), the calculated Dalizt plot agrees with the Belle measurements. Future precise measurements of the process c^+ ^+ could shed further light on the existence of the low-lying ^* (1/2^-).