We have derived a general formula for the coalescence model that expresses the formation cross sections for various kinds of composite particles consisting of an arbitrary number of particles with different interaction ranges and masses. We have studied the formation of light nuclei to confirm the validity of this model. We have also studied the formation of a double-lambda hypernucleus ${(}_{\mathrm{\Lambda }\mathrm{\Lambda }}^{6\mathrm{H}\mathrm{e}}$) and a pineut (${\mathrm{\pi }}^{\mathrm{-}}$${\mathit{n}}^2$) as examples. This formula is extremely useful for studying the formation cross sections of composite particles.

• Received 20 November 1992

DOI:https://doi.org/10.1103/PhysRevC.48.2403