Meet the ESRs: Diego Fernandez

Hi everyone!

My name is Diego, and I am the ESR at the INFN Napoli section. It has been just 4 months since I started, and even though the pandemic situation makes it difficult to visit beautiful places in the city or travel around the country, I am enjoying a lot my experience here and I am very happy for being selected for this position!

I was born in one of the smallest cities in Spain, Soria, but soon I moved to Pamplona, in the north, where I studied elementary and high school. Maybe this city sounds more familiar to you because of its major feast, the “Sanfermines” (if someone wonders no, I haven’t run in front of the bulls yet!)

San Fermin feast bullrunning in Pamplona. [Retrieved from:]

Since I was young, I’ve always had a very strong passion for physics – I wanted to know the answer for the more fundamental questions. Therefore, it was very easy for me to choose which Bachelor degree I wanted. I started the degree in Physics at the University of Zaragoza, where I discovered and enjoyed the student life, but also learnt what hard-work means! Since the first year, I was impatiently waiting  for the higher years where the more fundamental/theoretical subjects are teached (quantum mechanics, QFT, nuclear physics…) It was there when I discovered my particular interest in particle physics, and started to put everything that I had in hand in order to be a researcher in that field.

In my last year of the degree I had the opportunity to study abroad at San Diego State University (California, US). It was definitely one of the best years of my life, where I had the opportunity to meet a lot of international people, mix with different cultures, and also be part of a different educational system with very good professors, which also helped to broaden my knowledge.

After my experience abroad and thanks to my Bachelor’s thesis supervisor, I started my Master’s in Nuclear Physics at the UCM in Madrid. In the beginning, it was difficult for me to find a suitable thesis, since it was quite a tough decision to make because it can mark the starting point for the next couple of years of research, but I had the luck of being selected for a thesis in Higgs boson measurements within the CMS project at the CIEMAT. I learned a lot of things regarding high energy experimental particle physics, but one of the best parts was the opportunity to familiarize with Machine Learning techniques and how to apply them to particle physics experiments.

I knew that I wanted to contribute to future discoveries in the field of particle physics, so the next step would be to do a PhD in that topic. It was at that moment when I saw the INSIGHTS position at the INFN Naples, and I had no doubt that I needed to apply for it! For the people that wonder what my project is about, I’m working under the supervision of Drs. Orso Iorio and Luca Lista on the Search for Vector-Like Quark T (a particle predicted by some Beyond Standard Model theories)  in the semileptonic decay mode with data from the LHC Run 2. This VLQ T decays into a top quark and a Z or H boson. We are studying the case where the W form the top quark decays leptonically, and the Z/H boson decays hadronically. The biggest effort is centered in the reconstruction of the leptonically decaying top quark, for which various Machine Learning techniques are used, such as Boosted Decision Trees or Deep Neural Networks.

Although my fellowship is shortened and is not leading yet to a PhD, I am extracting the maximum out of it and I am very grateful for receiving it. Stay tuned because (hopefully!) sooner or later I will be able to announce my enrollment in a PhD program!

Panoramic view of the city of Naples with the Vesubius at the back. 
[Retrieved from:]