# 55. International Winter Meeting on Nuclear Physics

23-27 January 2017
Bormio, Italy
Europe/Berlin timezone

## Looking for new Physics with Pion Decays

24 Jan 2017, 18:00
20m
Bormio, Italy

#### Bormio, Italy

Short Contribution

### Speaker

Dr Luca Doria (TRIUMF)

### Description

In the Standard Model, electrons, muons, and tau leptons have identical electroweak gauge interactions, a hypothesis known as lepton universality. PIENU is a high precision measurement of 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 SM theoretical prediction of this ratio is one of the most accurately calculated weak interaction observables involving quarks with uncertainty of <0.01%. The experimental value is an order of magnitude less precise. Testing lepton universality can constrain many non-Standard Model scenarios. However, pseudoscalar or scalar interactions induced by leptoquarks, supersymmetric particles, extra dimensions etc. can cause measurable deviations from the theoretical prediction. Experimental observation of such a deviation would be clear evidence of new physics sensitive to mass scales up to 1000 TeV. In this talk we present the latest results from the PIENU experiment which provide the most stringent test of lepton universality as well as limits on the presence of massive neutrino states coupled to electrons.

### Primary author

Dr Luca Doria (TRIUMF)

 Slides