Fabiola Gianotti: «Progress evolves smoothly based on the development and improvement of known technology»

Translation: Teresa Galarza

(Versión en castellano aquí)

If we had to describe Fabiola Gianotti in a single word that would be vocation. If we had two, we could add: magnetism. If we were granted a third, it would be, undoubtedly: flair. The first woman to hold the position of coordinator of one of the two major experiments of the LHC (Atlas) and also the first woman to be appointed General Director of CERN lifts her hand of pianist-like long fingers when the interviewer compares her with her great model, Marie Curie. «Do not exaggerate!», she protests, “I am a simple researcher doing what I can”. One imagines exactly the same reaction from Madame Curie herself. An unfeigned modesty that emanates from the soul of a scientist who is passionate about her work.

The discovery of the Higgs boson has been one of the landmarks of modern science and you played a major role in it, as spokesperson of the ATLAS collaboration, one of the two LHC experiments that has found the signal of the Higgs particle. How did you live that crucial moment?

It turns out that today is the 5th anniversary of the announcement of the discovery, which was announced on the 4th of July of 2012. It was one of the most wonderful moments of my life. There is nothing more rewarding and exciting for a scientist than a discovery and the period (full of emotion, hopes and suspense) that leads to it. For months we were seeing the signal of the new particle developing, but for a long time it was inconclusive. We were searching mainly in two channels (Higgs decaying two a pair of photons and Higgs decaying to four charged leptons). At the end of 2011 we had a suggestive but not conclusive signal, then, all along 2012 we developed our blind analysis (a technique in which the physicists analyzing the data blind the region where the signal is expected, to avoid being biased by background or statistical fluctuations). One month before the announcement, the two-photon channel started to develop into a signal, but the four lepton channel was kind of stale, so for a while we were really biting our finger nails in ATLAS, watching the significance of the signal grow so very slowly. Our mood and hopes were changing with the statistical fluctuations. But a couple of weeks before the announcement, the four-lepton channel also started to be populated, thus removing the doubts of even the most conservative of us.  And on the 4^th of July, ATLAS and CMS announced the discovery of a new Higgs-like particle. And what a particle! The Higgs particle is one of the most essential ingredients of the Standard Model, the proof that we understand something about how the masses of elementary particles are generated. Think about it! The Brout-Englert-Higgs (BEH) mechanism was proposed as a purely mathematical theory, and then this theory predicts the existence of a very special particle, which has been searched for more than 50 years. And we found it.  It was a truly magical moment.