My primary research interests are on experimental particle physics as a member of the ATLAS collaboration. ATLAS is a multi-purpose detector operating at the Large Hadron Collider at CERN in Europe. It has been designed to search for signals that will enable physicists to understand the fundamental laws of nature and in particular the acquisition of mass through the so-called Higgs mechanism. Thus, data from the ATLAS experiment are probing the basic forces that have shaped our Universe since the beginning of time and that will eventually determine its fate.
I made substantial contributions to the direct discovery of the Higgs boson announced in July 2012 by the ATLAS and CMS collaborations. This discovery led to the award of the 2013 Nobel Prize to Peter Higgs and François Englert “for the theoretical discovery of a mechanism that contributes to our understanding of the origin of mass of subatomic particles”. Over time I have also worked on the reconstruction of electrons in ATLAS by combining the information from the ATLAS tracker and electromagnetic calorimeter. This constituted the ground-work for the discovery of the Higgs boson via its decays to four leptons which I was involved in.
The discovery of the Higgs boson opens the way to a new phase of particle physics in which the study of its properties will allow an examination of the nature of the Higgs in detail and perhaps will also provide the means for new discoveries. We know that the particle we have discovered is a brand new boson. Even though it fulfils the basic requirements of a Higgs boson, it is not clear that its properties correspond exactly to those predicted for the Higgs boson by the standard model of particle physics, which is currently the best theory we have for describing the fundamental particles and their interactions.
The ongoing LHC RUN II is expected to produce four times more Higgs boson candidates that will allow us to further study the new particle properties. The most promising way to study the properties of the Higgs boson is via its decays to into two Z bosons which in turn each decay into an oppositely charged pair of electrons or muons, as they have the lower level of background noise.
In the standard model the Higgs and its associated field are predicted to have a spin of 0. This means that, unlike electomagnetism, they lack directionality. Further Higgs production will allow us to confirm this hypothesis. A more powerful LHC could also reveal whether the Higgs has siblings. For example one popular way to extend the standard model is a theory called supersymmetry, which specifies a minimum of five types of Higgs boson. Another open question is the determination of the rate with which the Higgs boson is produced via different mechanisms, and its comparison with the standard model predictions.
We currently stand at the cross roads of either achieving a more thorough understanding of the SM Higgs mechanism, or the perhaps more exciting prospect of discovering new physics phenomena, and is to this questions that my research will be addressed. As such it will have a profound and lasting impact on our understanding of the fundamental nature of matter and expand humanity’s understanding of the fundamental laws of nature.