Measurement of the pionium lifetime

Abstract

We report the progress in the measurement of the pionium lifetime by the DIRAC Collaboration at CERN (PS212). Based on data collected in 2001-2003 on Ni targets we have achieved the precision of 11% in the measurement of the pionium lifetime, which corresponds to the measurement of S-wave pion-pion scattering lengths difference |a0-a2| with the accuracy of 6%.

arXiv commentParallel talk at ICHEP08, Philadelphia, USA, July 2008. 4 pages, LaTeX, 3 eps figures. v2: Term with pion mass squared was introduced into formula (1) to be consistent with scattering lengths normalization. v3: template update by the ICHEP08 organizing committee