PhD-student Lex Greeven wins public poster award at Veldhoven conference

28 January 2022

PhD student Lex Greeven of Nikhef and Maastricht University has won the audience award for the best poster at the annual physics conference in Veldhoven, the Netherlands. This year due to corona the conference was entirely online.

Greeven works for the LHCb experiment at CERN. His prize-winning poster highlights one of the recent results of the Geneva experiment, which found possible deviations from the standard model of particle physics. He collaborated on the analyses of the particle collisions where this can be seen.

At the Physics Connects 2022 conference, the poster sessions were held online in a virtual environment. Visitors moved as avatars along the rooms with digital posters and could interact with the creator there. For the audience prize, they could give likes to their three favorite posters.

Not ideal, says Greeven. “You’d rather have people opposite you who you can tell your story to based on the poster. But apparently it worked now anyway.”

In the poster “Hints of new physics in weird beauty-hadron decays” Greeven leads the viewer with crisp text past the remarkable results of measurements with the LHCb detector at CERN. When protons from the LHC accelerator collide, lambda-b particles containing a beauty quark are very occasionally created.

These lambda particles quickly disintegrate in a process that gives a pair of an electron-antielectron, or a pair of a muon-antimuon. According to the standard model, this happens equally often; in the measurements, there appears to be a difference. Greeven worked with former Nikhef PhD student Mick Mulder and Nikhef researcher Niels Tuning on the analyses of the process.

The poster includes as little text as possible, quite a few images and is divided into numbered colored blocks, which give the different parts of the work. “And yet a viewer should be able to read the poster even without explanations,” says Greeven. The winning poster is the first he made as a PhD student.

Greeven won a small amount of money with the audience prize, which was spent with the group Thursday afternoon at the Polder cafe at Amsterdam SciencePark. He is now working on two other processes in the LHCb measurements and hopes to receive a PhD on his work in a year and a half. “We’re just not saying anything about that at conferences for a while until the results are approved by the collaboration,” he said.