Light meson decays from photon-induced reactions with CLAS

Abstract

Abstract. Photoproduction experiments with the CEBAF Large Acceptance Spectrometer CLAS at the Thomas Jefferson National Facility produce data sets with competitive statistics of light mesons. With these data sets, measurements of transition form factors for η, ω, and η mesons via conversion decays can be performed using the invariant mass distribution of the final state dileptons. Tests of fundamental symmetries and information on the light quark mass difference can be performed using a Dalitz plot analysis of the meson decay. An overview of preliminary results, from existing CLAS data, and future prospects within the newly upgraded CLAS12 apparatus are given.

The hadronic light-by-light contribution to the muon’s anomalous magnetic moment

“…The respective values are determined as Λ η = 0.79 ± 0.04 stat ± 0.02 syst and γ η = 0.13 ± 0.06 stat ± 0.03 syst , which improves on the values previously determined in the Dalitz decay into muon pairs [62]. Further measurements of Dalitz decays of the η meson have been announced by the A2 [63] and CLAS [64] Collaborations.…”

The branching ratio $$\omega \rightarrow \pi ^+\pi ^-$$ ω → π + π - revisited

“…Final data for this decay can be expected in the very near future from both the CLAS [50] and the BESIII [15] collaborations.…”