Max Planck Institute for Physics

A familiar particle - newly explored

Hawking radiation could put humanity on the trail of extraterrestrial life

Dark matter particles could leave traces in gamma spectrum

Various factors determine, how much energy a surfing particle can gain

Detailed insights into the nature of the Higgs boson could help answer big open questions in physics

Lea Heckmann from the Max Planck Institute for Physics is spending two months working on the MAGIC telescopes on La Palma in the Canary Islands. She talks about unforgettable sunsets and explains what La Palma has in common with Ireland.

The detection of the Higgs boson represented a huge success for the particle accelerator known as the Large Hadron Collider. But other expected or unexpected discoveries, which physicists hoped would explain the appearance of the world we live in, have failed to materialize. Now, Hermann Nicolai, Director at the Max Planck Institute for Gravitational Physics in Potsdam, and Siegfried Bethke, Director at the Max Planck Institute for Physics in Munich, are on a quest for new prospects in particle physics.

When, on a clear night, you gaze at twinkling stars, glimmering planets or the cloudy band of the Milky Way, you are actually seeing only half the story – or, to be more precise, a tiny fraction of it. With the telescopes available to us, using all of the possible ranges of the electromagnetic spectrum, we can observe only a mere one percent of the universe. The rest remains hidden, spread between dark energy and dark matter.

Gravitational waves are some of the most spectacular predictions of the 1915 general theory of relativity. However, it wasn’t until half a century later that physicist Joseph Weber attempted to track them down. In the early 1970s, Max Planck scientists also began working in this research field, and developed second-generation detectors. The groundwork laid by these pioneers meant the waves in space-time ceased to be just figments of the imagination: in September 2015 they were finally detected.

Science without computers? Unthinkable, nowadays! Yet over half a century ago, that was commonplace. Then, in the early 1950s, mathematician and physicist Heinz Billing entered the scene - and introduced the Max Planck Society to electronic computing. It all started with the "Göttingen 1."

The neutrino: Hardly any other particle provides physics with more exciting questions. Why is it so much lighter than its siblings in the particle zoo - and what exactly is its mass? Is it identical to its own antiparticle? Are there other neutrino species besides the known three? Accordingly, many experiments are trying to decipher the nature of this particle. My group is involved in the KATRIN experiment at the Karlsruhe Institute of Technology (KIT). There, about 150 researchers are trying to find out the mass of the neutrino.   

The Standard Model of particle physics describes the elementary particles and their interactions. Since the discovery of the Higgs boson it has been considered complete. However, some characteristics of Higgs boson itself raise new questions. This also goes for many other phenomena we are unable to explain by the means of the Standard Model. Collider experiments as the Large Hadron Collider (LHC) are expected to deliver answers. For these projects to succeed, physicists need to rely on precisely calculated predictions.

Using the ground-based Cherenkov telescopes, the sky can be scanned for high-energy gamma radiation. In January 2019, the two MAGIC telescopes on the Canary island of La Palma targeted a gamma-ray burst and measured the highest-energy radiation from such an object to date. It was thus possible to gain new insights into the processes in gamma-ray bursts. Scientists hope to find many more celestial bodies in the highest energy range. For this purpose, the Cherenkov Telescope Array (CTA) – with over one hundred individual telescopes – is currently being built on La Palma and in Chile.

So far gravity is hard to integrate in established theories in particle physics. This is why phyisicists try to find new ways to bring this fundamental force into accordance with other models.

Are neutrinos responsible for the matter-antimatter asymmetry in the universe? Are neutrinos identical to their own antiparticles? The GERDA experiment for the search of the neutrinoless double beta decay was built to find answers to these questions.