Experimental HEP seminar

Measurement of pionium (π⁺π^- hydrogen-like state) lifetime to test low energy QCD predictons

Cibrán Santamarina Ríos

McGill University

The scattering lengths of a two pion system are the golden magnitudes to test the QCD predictions in the low energy sector. The DIRAC(PS-212) experiment at CERN has obtained a particular combination of the S-wave isospin 0 and 2 scattering lengths by measuring the lifetime of pionium, the hydrogen-like π⁺π^- atom. The results of the collaboration will be presented as well as an explanation of the experimental method followed to determine the pionium lifetime. A brief introduction of the collaboration plans to extend their research to the s-quark sector measuring the lifetime of π-K atoms will be presented.