DIRAC experiment at CERN

Abstract

Abstract. The precise measurements of π + π − and πK atom lifetime allow to check the predictions of Chiral Perturbation Theory for the pion-pion s-wave scattering lengths with isospin 0 and 2 and for the pion-kaon scattering lengths with isospin 1/2 and 3/2. The DIRAC experiment with the latest results is presented together with the proposal for future investigations.

Scouring meson decays for true muonium

“…Currently, the HPS [39] experiment is searching for true muonium [40] via e − Z → (µ + µ − )X. Another fixed-target experiment, DIRAC [41] could look for (µ + µ − ) in an upgraded run [42]. The existing KOTO experiment [43] and proposed NA62-KLEVER [44] hope to achieve sensitivities to K L decays with BR ∼ 10 −13 , which would also present an opportunity to detect true muonium [37].…”

Upgraded DIRAC spectrometer at CERN PS for the investigation of ππ and πK atoms

“…Since then, two of the upstream detectors have been modified, SFD X and Y planes. The latest results [BEN12] show that the multiple scattering angle due to the SFD X plane is 10% smaller than in the SFD detector, which was installed up to 2003, while the SFD Y plane is unchanged.…”

Applying Bayesian inference to Galileon solutions of the muon problem

“…2, we see that the largest energy corrections in true muonium are in a different region of parameter space, and therefore are a strong complement to the muonic helium measurements. Near-future experiments to detect and measure true muonium have been proposed [61][62][63][64][65].…”