NA62: Search for a rare decay and exotic particles

The Standard Model of particle physics describes how the matter of the universe is structured in the subatomic regime and which forces act between the elementary particles. However, the Standard Model is not “finished” in the sense of complete. Experiments provide ever more precise measurement results, which can be used to verify theoretical predictions.

One of these experiments is NA62. In this experiment, proton beams from the SPS accelerator at CERN are fired at a beryllium target. Scientists use it to study the very rare decay of the K meson (kaon for short), a particle consisting of two quarks. During decay, the kaon can transform into two neutrinos and a pion, another, lighter type of meson. According to theoretical predictions, only about one in 10 billion kaons decays in this way. The theory's prediction for this decay is very accurate, so even the smallest deviations would show up clearly in experiment. This, in turn, would be an indication of "new physics" beyond the Standard Model.

The beam dump project

In addition to the decay of K mesons, the NA62 experiment can be used to address other questions that cannot be explained by the Standard Model, such as what dark matter is made of. The group at MPP is involved in a project that uses the SPS proton beam to search for new, exotic particles. In the NA62 experiment, most of the protons end up as "particle junk" in the so-called beam dump.

However, these protons are valuable material for particle decays. These could also produce previously unknown, long-lived particles that interact very weakly with matter – a property that is typical of dark matter. These particles would succeed in passing through a three-meter-thick wall at the beginning of the experiment. Their tracks could then be measured in the 130-meter detector area of NA62.

The focus of our group is on the theoretical predictions, computer models and on the measurements. The NA62 experiment has about 200 active participants from 14 nations. The first measurement data were collected in 2015, and current measurements will continue until 2025. After the upgrade of the CERN accelerator facilities, operations will continue with the successor experiment HIKE (High Intensity Kaon Experiments).

More information on the group

On the right: The calorimeter of the NA62 experiment, with which the particle energy is measured. On the left is the green Ring Imaging Cherenkov (RICH) detector, which is used to identify the positively charged pions (Photo: CERN)

Discovery of a rare decay – a possible hint for new physics?

The NA62 experiment at CERN has detected a very rare decay for the first time. The particle process was predicted theoretically, is now statistically confirmed and thus experimentally proven. The scientists involved presented their results today at…

Read more
 Prof. Dr. Johannes Henn and Dr. Babette Döbrich (Photos: A. Griesch/MPP; privat))

Funding in the millions for two projects in particle physics

The Max Planck Institute for Physics is pleased to announce two successful applications to the European Research Council (ERC): 10 million euros will go to the project "UNIVERSE+: Positive Geometry in Particle Physics and Cosmology", coordinated by…

Read more
Dr. Babette Döbrich (Photo: private)

Search for Dark Matter: Babette Döbrich leads new research team at MPP

The Max Planck Institute for Physics (MPP) welcomes Babette Döbrich, who has begun research at the institute on November 1. She prevailed in the challenging application process of the Lise-Meitner Excellence Program and will immediately head an…

Read more

E-mail address: e-mail@mpp.mpg.de
Phone number: +49 89 32354-extension
name function e-mail extension office
Ayyagari, Sri Vrushank Student ayyagari 583 A.3.68
Döbrich, Babette, Dr. Senior Scientist dobrich 205 A.3.95
Jerhot, Jan, Dr. Postdoc jerhot 546 A.3.68
Lezki, Samet, Dr. Postdoc lezki 583 A.3.93
Lo Chiatto, Prisco, Dr. Postdoc lochiatt 546 A.3.68
Lombardi, Luca Student lombalu 546 A.3.68
Schubert, Jonathan PhD Student jschuber 546 A.3.68

Measurement of the very rare K++→π+νν‾π+νν decay
NA62 Collaboration (Eduardo Cortina Gil)
JHEP 06 (2021) 093
DOI: 10.1007/JHEP06(2021)093

New Physics Searches at Kaon and Hyperon Factories
Evgueni Goudzovski, Diego Redigolo, Kohsaku Tobioka, Jure Zupan, Gonzalo Alonso-Álvarez
Rept.Prog.Phys. (2022)
DOI: 10.1088/1361-6633/ac9cee

ALPtraum: ALP production in proton beam dump experiments
Babette Döbrich, Joerg Jaeckel,  Felix Kahlhoefer, Andreas Ringwald, Kai Schmidt-Hoberg, DESY
JHEP 02 (2016) 018, JHEP 02 (2016) 018
https://inspirehep.net/literature/1409104 

The Beam and detector of the NA62 experiment at CERN
NA62 Collaboration (Eduardo Cortina)
JINST 12 (2017) 05, P05025
DOI: 10.1088/1748-0221/12/05/P05025