NA48

NA48 is a series of particle physics experiments in the field of kaon physics being carried out at the North Area of the SPS accelerator at CERN. The collaboration involves over 100 physicists mostly from Western Europe and Russia.

Historical overview

The series were launched in the early 1990s. Its primary physics goal – the search for direct CP violation – was inherited from the predecessor experiment NA31. The setup was launched in 1997, and physics data taking runs took place in the next 5 years. Finally, in 1999 the discovery of the phenomenon of direct CP violation was announced by the collaboration, one of the most important experimental results ever obtained at CERN. (The final publication of the result was made in 2001). A number of other results were published as well.

The second stage (NA48/1) was carried out in 2002 and was devoted to high precision study of rare decays of kaons and neutral hyperons. The next stage (NA48/2) was carried out in 2003–2004 and was dedicated to a large programme of studies of properties of charged kaons, including the search of direct CP violation, calculation of rare decays branching ratio and form-factors. A new stage (referred early as NA48/3 and now as NA62, also known as P326) is foreseen in 2007–2010 to study several hot topics of modern kaon physics: search for the very rare decay of the charged kaon into a pion and a pair of neutrinos, precise measurement of Ke2/Kμ2 decays ratio, and a possible a rare decay program. The first data acquisition process of kaon decays started spring 2007 and lasted till the middle of November 2007.