Contributions of MPIK to the Max Planck Yearbook
Yearbook 2020: A breath of eternity: The slowest particle reaction ever observed
Is there anything older than our Universe? Surely not, but billions of years appear as a blink of an eye compared to some extremely slow processes. Physicists of the XENON1T collaboration detected such a process. It is the radioactive decay of the xenon-124 atomic nucleus, the slowest decay process ever measured! The half-life of this extremely rare nuclear transformation is for unimaginably long 1.8 × 1022 years. This corresponds to about a trillion times the age of the Universe!
