Sequential single pion production explaining the dibaryon "d*(2380)" peak*

Abstract

Abstract In this study, we investigate the two step sequential one pion production mechanism, that is, followed by the fusion reaction , to describe the reaction with in state . In this reaction, a narrow peak identified with a " " dibaryon has been previously observed. We discover that the second reaction step is driven by a triangle singularity that determines the position of the peak of the reaction and the high strength of the cross section. The combined cross section of these two mechanisms produces a narrow peak with a position, width, and strength, that are compatible with experimental observations within the applied approximations made. This novel interpretation of the peak accomplished without invoking a dibaryon explains why this peak has remained undetected in other reactions.