The first time I came to CERN was during my university studies. I had studied economics and languages in the school in Italy, and everything about math and physics was mostly new to me. I loved it all. 
I came with my class mates and I did not really know what CERN was. A lab. But which lab? And what do they do? Mystery. 

After the tour at the so-called CMS experiment (“Compact Muon.. what”?) I was so excited and so enthusiastic about everything I heard that I knew exactly what I wanted to specialise in: particle physics. The idea of studying the very small to understand the universe was something that completely blew my mind. 

With many hours of studying, wonderful supervisors and strong determination I finished my Master’s degree in particle physics with a thesis on the Higgs boson. I was very happy and felt motivated to continue with a PhD. 

I moved to Vienna in Austria to start working on a topic that to me sounded like one of the most interesting challenges on Earth: particle track reconstruction. In the very innermost part of our huge detectors, we have sub-detectors that produce an electric signal when a particle passes though them. These signals are saved as a collection of 3D-points, which then must be analysed to reconstruct not only the path of the particle but also some of its most important characteristics, such as the charge and the momentum. 

It is like looking at a snow field where animals have left their traces: which animal went in which direction? You are the one that has to reconstruct the history. Maybe with a couple of different animals the problem is not so difficult, but what about thousands of them? It is one of the most captivating problem of the High-Luminosity LHC. Still today, after many years of working and researching on this topic, I find it incredibly fascinating.

Since 2018 I am a Fellow at CERN. I continue writing code to reconstruct tracks in the CMS detector (my first encounter!) and I have also added a ‘hardware’ topic. With my colleagues and my equipment (mask, gloves and a white lab coat), we test silicon detectors which will then be used in the CMS High Granularity Calorimeter several years from now. It is exciting every single time we receive new sensors and every day there is some new interesting challenge to solve. Because this is what an experimental physicist does: You build your skills doing the job, continuously adapting to new situations and new projects while injecting the expertise you collected during your journey. 

And for this CERN is the perfect place to be. It represents for me a huge playground for particle physicists – but not only that. People coming from all over the world overcome technological and cultural barriers to understand how nature works. Meeting after meeting, coffee after coffee, day after day. The secret to make this miracle work? Passion for what you are doing.. a gigatonne of that!

If you're inspired by Erica's story and want to take part, apply now for a CERN Fellowship!