Date:  Wednesday 23 January 2019
Speaker:  Thomas Koffas (Carleton University)
Title:  "Searches for the neutrinoless double-beta with the EXO detector"


Neutrinos have been termed the “mystery” particles in physics. Perhaps this is a well-earned characterization 
considering how little we know about their properties. For example, we don’t even know their absolute mass, 
which despite of the Standard Model assumption of it being zero, we now have unambiguous experimental evidence 
that this is absolutely not so. 

So how much do neutrinos weigh? To answer this, a major experimental program has been on-going for several decades. 
One of the most promising approaches to measure the neutrino mass, is through the search for Majorana neutrinos via 
the observation of the so-called neutrinoless double beta decay. This is an extremely rare process, allowed in a 
very small number of isotopes. Its observation will signal the presence of new physics beyond the Standard Model, 
such as the Majorana nature of the neutrinos, lepton number violation and constrain the absolute scale of the neutrino 
mass spectrum.

In this presentation, the most recent results from the EXO-200 detector which is looking for this rare process in the 
136Xe isotope, will be presented and interpreted in terms of neutrino mass limits. An overview of the EXO program and 
the current work towards a ton-scale, monolithic, liquid Xe detector that will dramatically enhance the sensitivity to 
search for Mjorana neutrinos, will then follow. The physics prospects of such a detector will also be discussed. 

One thing is certain; the experimental neutrino physics effort is entering a new exciting era and the coming decade is 
promising important results and a real glimpse of new physics beyond the Standard Model.