PhD start seminar: Light Meson Decays with BESIII

  • Date: –16:30
  • Location: Ångströmlaboratoriet, Lägerhyddsvägen 1 Å12167
  • Lecturer: Viktor Thorén (Uppsala University), Andrzej Kupsc (Uppsala University)
  • Website
  • Contact person: Elin Bergeås Kuutmann
  • Phone: 018-471 3828
  • Seminarium

The start seminar of Viktor Thorén. His subject is hadron physics, with Andrzej Kupsc as supervisor.


The BESIII experiment in Beijing, China has collected a sample of 5 billion J/psi events, the world's largest of its kind. Through primarily the radiative decay of J/psi, roughly 25 million eta' are produced. This has opened up for many first measurements of its decays and high precision studies of branching ratios and decay dynamics.

One such decay, eta' -> pi+ pi- e+ e-, offers several interesting avenues of research. A measurement of its branching ratio provides a test of predictions from low energy effective field theories such as Chiral Perturbation Theory, or Vector Meson Dominance. In addition, this decay probes an unconventional, beyond standard model CP-violation which is not constrained by measurements of the nEDM. If it exists, such a CP-violation will be manifested as an asymmetry in the angle between the decay planes of pi+pi- and e+e-.

In this seminar, I will present my ongoing analysis of eta' -> pi+pi-e+e- using data from BESIII, with the goal of measuring the branching ratio and CP-violating asymmetry.