First measurement of ΛN inelastic scattering with Λ from e+e-→J/ψ→ Λ Λ¯

Abstract

Using an e+e- collision data sample of (10087±44)×106 J/ψ events taken at the center-of-mass energy of 3.097 GeV by the BESIII detector at the BEPCII collider, the process Λ+N→ς++X is studied for the first time employing a novel method. The ς+ hyperons are produced by the collisions of Λ hyperons from J/ψ decays with nuclei in the material of the BESIII detector. The total cross section of Λ+Be9→ς++X is measured to be σ=(37.3±4.7±3.5) mb with Λ momenta within [1.057,1.091] GeV/c, where the uncertainties are statistical and systematic, respectively. This analysis is the first study of Λ-nucleon interactions at an e+e- collider, providing information and constraints relevant for the strong-interaction potential, the origin of color confinement, the unified model for baryon-baryon interactions, and the internal structure of neutron stars.