At the beginning of this year, the entire rectoral team went on a multi-day work retreat at CERN. This marked the Rector’s second visit to CERN since the start of her mandate in September 2024.
 
In line with UCLouvain’s commitment to sustainability, the team chose to travel by train, thereby reducing the environmental impact of the visit.

During their stay, the council had the opportunity to visit two experiments in which UCLouvain plays a major role: NA62 and CMS. They were welcomed by CERN’s Director for Research and Computing, Gautier Hamel de Monchenault, who presented the organisation’s current missions and strategic objectives, as well as Belgium’s contribution to them.

The NA62 spokesperson,  Giuseppe Ruggiero, then guided the group through the NA62 hall, detailing the goals of the experiment and the technical feats of the detector.

The subsequent visit to the CMS cavern - likely one of the last before the experiment’s decommissioning later this year - was guided by the CMS spokesperson, Anadi Canepa. She highlighted and praised UCLouvain’s long-standing involvement and scientific achievements within the collaboration.

In light of the societal and institutional challenges universities are currently facing, an exchange was also organised with CERN’s Equal Opportunities team.

Anna’s research lies at the heart of particle physics. She explores the data collected by the Compact Muon Solenoid (CMS), a flagship detector of the Large Hadron Collider at CERN, the world’s most powerful particle accelerator. Through her work, she seeks to uncover phenomena that lie beyond the Standard Model, including the elusive nature of dark matter. Within the CMS Collaboration, she is currently serving as coordinator of the Physics Performance and Datasets (PPD) group, one of the five coordination areas of the experiment. This role reflects both her scientific leadership and her deep commitment to the community.

Links:

- https://www.frs-fnrs.be/docs/Lettre/lettre135.pdf#page=38
- https://www.youtube.com/watch?v=rA0uKY7Smi0

The culmination of this effort was the MadGraph5_aMC@NLO paper, published in the Journal of High Energy Physics in 2014. This 158-page paper introduced a tool that enabled researchers worldwide to simulate any SM or BSM model at QCD NLO accuracy, making precision predictions accessible to the entire community. Building on the flexibility of MadGraph5 (released three years earlier), the new framework integrated automated NLO computations with parton shower matching, setting a new standard for collider phenomenology.

The evolution didn’t stop there. In 2018, MadGraph5_aMC@NLO expanded its capabilities to include fixed-order electroweak corrections, further enhancing its precision for processes at the energy frontier.

Over the years, MadGraph5_aMC@NLO has become a cornerstone of theoretical and experimental studies. It serves as the main event generator for the CMS experiment at CERN and is widely used across all LHC experiments and beyond. Its versatility also inspired the development of numerous tools that rely on it as a matrix-element provider, including Herwig, MadDM, MadSpin, and many others.

Today, the MadGraph5_aMC@NLO paper has reached an extraordinary milestone: 10,000 citations. This achievement reflects its profound impact on particle physics research and its role in shaping the future of collider phenomenology.

How did the universe come into being ? Since the idea of a Big Bang was first proposed by George Lemaitre, there multitude of theories on this subject have been proposed. Many of these explain the overall homogeneity and isotropy of the observable universe by postulating a brief period of accelerated cosmic expansion during the first split-seconds of its existence, known as cosmic inflation. Many theoretical ideas have been proposed to explain this acceleration. However, almost all of these require the existence of new elementary particles that cannot be detected in any near future experiments, making a direct test of the underlying theory in the laboratory impossible.

It is usually assumed that the rapid dilution of particles rendered space cold and empty during this phase, raising the question how it was subsequently populated with the hot plasma that we see in the Cosmic Microwave Background (CMB). A new model proposed by scientists from Caltech, UCLouvain and the Max Planck Institute for Physics aims to rewrite cosmic history: In this scenario, the accelerated expansion is driven by a so-called axion field. The axion interacts with gluons, the particles that mediate the well-known strong nuclear force which holds protons and neutrons together. This interaction leads to a kind of friction and populates the cosmos with a hot plasma of elementary particles during inflation.

While the idea of a “warm inflation” has been proposed before, the new model is the first one that can explain the observed CMB by one of the established forces of nature, i.e., without requiring a sizeable number of hypothetical new elementary particles. Moreover, the only new particle needed – the axion – could be found in experimental searches on Earth. Axions have been proposed for other reasons, e.g. in the context of Dark Matter, and there are many experiments looking for them. This opens up a unique opportunity to probe the connection between the Big Bang and fundamental physics in the laboratory.

Read more about this:

• https://www.uclouvain.be/fr/news/et-si-le-big-bang-n-etait-pas-aussi-froid-qu-on-ne-le-pensait
• https://www.nature.com/articles/d41586-025-03414-9  
• https://www.scientificamerican.com/article/did-dark-matter-help-supersize-the-universe/  
• https://phys.org/news/2025-10-universe-cosmic-inflation-standard-particle.html  
• https://www.spektrum.de/news/warme-inflation-lief-der-urknall-voellig-anders-ab-als-gedacht/2293397

UCLouvain organises du for September 6 to September 9, a summer camp for high school girls intereted in science.  This camp aims at breaking gender bias and raise awareness of the young women's legitimacy in STEM university courses. The program consists of research work in small groups, team building, Q&A sessions with experienced female researchers. It's a new week met Anna, the young researcher who initiated the ces "Physics project days" in UCLouvain. 

I have a postdoctoral fellowship of the UCLouvain and work in the CP3 IRMP department where I am mainly working with Andrea Giammanco, who is a Research Director of FNRS. I have just received the FNRS CR fellowship which will start in October and allows me to stay another 3 years at UCLouvain to do my research. I am a particle physicist, working on the CMS experiment, one out of four experiments at the Large Hadron Collider at CERN (Conseil européen pour la recherche nucléaire) in Geneva, Switzerland.

The Large Hadron Collider is the world’s most powerful particle accelerator and it collides two highly energetic particle beams. The outcome of these collisions is detected with a huge detector (the CMS experiment), which works similar to an everyday camera, but much faster and with many more channels. There is still a lot we don’t know about matter and the very existence of the universe and we are looking for some answers by studying the dynamics of elementary particles that are created in high energy collisions. These give us insight in the creation of the universe, the building blocks of matter and the natural forces. One project I lead is the development of pileup mitigation techniques in CMS which is explained nicely in this physics briefing.

When I started my studies in physics in Kiel, Germany, among the 40-50 students, there were only 4 women. And during my whole Bachelor degree I was never taught by a female professor. There is a long but disproved rumor that physics or scientific-technical subjects in general have a gender-specific requirement profile. In addition, many female high school students have the opinion that despite having the best possible grades in physics they are not suited for a university physics degree. With the Physics Project Days we aim to change this mindset, show the girls that they are good enough to study physics and that it is a lot of fun! The decision of what subject to study at the university is often influenced by the parents, friends and teachers. Therefore, another important part of this project is the research presentation at the end of the workshop, where the girls present their results to the general public, especially their parents. I have seen many parents realising that their daughters can explain complicated physics, which the parents might not even understand, but they realise that their daughter is suitable to study physics.

I always knew that I wanted to study physics and my parents were very supportive. However, I also experience the imposter syndrome, which means that people feel like a fraud and fear that tomorrow people will find out that you don’t deserve the position/reputation you have. This is often felt especially by highly successful women. Therefore, it is very important to encourage and support women on all career levels, whether they have not yet started studying or at high career levels, because together we can make a difference.

Despite all the achievements that we made in terms of overcoming stereotypes, there are still things to do. Most of us don’t discriminate on purpose. However, society and stereotypes change slowly and we should fight them to create a better future for our kids. There are great exercises about understanding the unconscious bias. If we are aware of our own biases it is already one step in the right direction. We should try to go through the world with open eyes. If I could give an advice I would say that they should support their kids with whatever they want to study and encourage them to try subjects where they don’t fit the stereotype! It is more likely they will succeed if they are allowed to do what they like. It’s not a problem that she wants to be a princess, it’s a problem that she thinks she can’t be a knight!

Physics project days : a 4 days dive into the research labs of physics at UCLouvain.
Read more