Observations of double J/ψ in pPb collisions and triple J/ψ in pp collisions

Abstract

Multi parton scattering (MPI) research has great importance in the field of high energy physics. Two recent outcomes of MPI studies conducted by the CMS collaboration at the LHC are presents. The first observation of double J/ψ production in proton-lead (pPb) collisions is reported, as well as the first observation of the concurrent production of triple J/ψ in proton-proton (pp) collisions. Both studies provide calculations of the effective cross section.