RIP 20/08/2020 ✞

Témoignage philosophique en video

Ne manquez pas les vidéos de la Corneille Ebouriffée !

Experimental particle physics

How can we investigate the particles and forces of the Universe at their most fundamental level? One possibility is to collide particles at very high energies in a laboratory. During the past 50 years, this has been a very successful way to both discover new particles (as well as their possible substructure) and quantify their interactions. We have a machine able to accelerate protons to unprecedented energies: the Large Hadron Collider (LHC). I am a member of the ATLAS collaboration, a large experiment aiming at discovering and studying fundamental physics phenomena in high-energy proton-proton collisions. I significantly contributed to the analysis and coordination of various searches for new massive long-lived particles in ATLAS, presently leading the ATLAS searches for magnetic monopoles and launching a new direct search for right-handed neutrinos. Besides ATLAS, I am playing a major role in the MoEDAL experiment, a small-scale LHC detector whose aim is also to discover new physics, but focusing especially on magnetic monopoles.

"Don't put all your eggs in one basket." Who first told me that? It must have been my grand-mother... Anyway, it is important to complement the big projects by following other strategies and coming up with original ideas outside of the mainstream. That kind of thinking motivated my search for monopoles in polar volcanic rocks and my review article on stable massive particles in the cosmos.

The LHC has now been running at the highest energies for several years and the Higgs boson is the only new particle discovered so far. This motivates my shift in focus from strongly-coupled to weakly-coupled particles -- still within the same broad topic of new long-lived particle searches. Assuming no surprise discovery during the next few years, as the LHC experiments collect increasing amounts of data, one expects only marginal increases in sensitivity to new physics at high mass scales (high-energy frontier), while the search for new physics with weak couplings to the SM appears to be a more promising approach (high-intensity frontier). With these considerations in mind, I initiated a novel search for right-handed neutrinos using a displaced-vertex signature in ATLAS (using the LHC as a W factory!), and I started the development of a timing detector as a contribution to the design of the SHiP experiment at the CERN SPS. This new search programme will allow to probe for the existence of right-handed neutrinos with masses of the order of the GeV with couplings that could explain at once the puzzles of neutrino masses, dark matter, and matter-antimatter asymmetry.

Other interests

My fascination with natural phenomena is not limited to the understanding of its underlying physics principles, but also the origins of life, human nature, and culture.

Life is an amazing structure which, by definition, perpetuates itself. By doing so, it evolves. Features seen within a given species are adaptations, they can be understood as being solutions to an evolutionary problem. This applies to traits which develop universally in all humans - physical and psychological alike. Evolutionary psychology, which studies what all humans have in common, is a fascinating emerging field of science. Understanding our nature is about understanding in which conditions our genes evolved to give us the specific configuration of body and brain shared by all humans today.

But nature is not everything. The conditions in which our brains have been growing since infancy determine a very large part of our personalities and behaviours. The values and customs which have been vehiculed by human society through the generations form what we call our culture. Scientific and technological advances have been so fast during the past few centuries that our culture didn't have time to properly adjust to the changing conditions. In fact, given today's technological possibilities, the market system currently ruling the world is outdated, reaching a point where the nuisances far outweight the benefits. The time has come to start seriously revising societal values and rethinking the way we organise our society. Participation in a global free sharing network might be a good training to facilitate the transition.

As a hobby, I like to write stories in which my thoughts about life, humans and society are expressed with as much imagination and humour as I can muster. Science fiction does not need to be about new science: to me, it is about staging a new situation in an artfully elaborated thought experiment.

I am also a prolific game designer. I created board games as well as games following the new concept of "parlour games 2.0", i.e., turn-based video games played on the same screen in the same room and designed to encourage interactions between players.

I got a rare and aggressive form of leukemia in 2019. When hospitalised for chemotherapy treatments I made a few videos on my "ruffled crow" youtube channel.