Measurements of the Charged­ Particle distributions with the ATLAS detector

Inclusive charged ­particle measurements at hadron colliders probe the low­ energy non­perturbative region of QCD. The ATLAS collaboration has measured the charged­ particle multiplicity and its dependence on transverse momentum and pseudorapidity in special data sets with low LHC beam currents, recorded at center­-of­-mass energies of 8 TeV and 13 TeV. The new precise measurements at 8 TeV cover a wide spectrum using charged­ particle selections with minimum transverse momentum of both 100 MeV and 500 MeV and in various phase space regions of low and high charged particle multiplicities. The measurements at 13 TeV present the first detailed studies with a minimum transverse momentum of both 100 MeV and 500 MeV. The measurements are compared with predictions of various MC generators and are found to provide strong constraints on these.