Jet and particle correlations with ATLAS experiment

Two new ATLAS measurements are discussed. The jet energy-energy correlations was measured using 8TeV data and the observables were used to extract the strong coupling constant. The observables are constructed in such a way to reduce both experimental and theoretical uncertainties. The second measurement deals with the study of two-particle correlations using three-hadron particle chains. It is observed that particle pairs with small momentum difference are entirely produced by low mass chain. This observation is compatible with helix-light fragmentation and is not described by the existing MC generators.