PRISMA+ Colloquium

June 7, 2017 at 1 p.m. in Lorentz-Raum 05-127, Staudingerweg 7

Prof. Dr. Tobias Hurth
Institut für Physik, THEP

Search of New Physics with Pion Decays
Dr. Luca Doria (TRIUMPH, Vancouver, Canada)

In the Standard Model, leptons have identical electroweak gauge interactions, a hypothesis known as lepton universality.
PIENU is a high precision experiment designed to test lepton universality measuring the ratio of the rate of the pion decay to electron plus neutrino compared to pion decay to muon plus neutrino, including radiative processes.
The Standard Model theoretical prediction of this ratio is one of the most accurately calculated weak interaction observables involving quarks with uncertainty of <0.01%, while the present experimental value is an order of magnitude less precise.
Testing lepton universality can constrain many non-Standard Model scenarios and a measured deviation can point towards the presence of new physics with sensitivity up to 1000 TeV.
In this talk we present the latest results from the PIENU experiment at TRIUMF which provide the most stringent test of lepton universality as well as limits on the presence of massive neutrino states coupled to electrons.