Speaker
Description
The decay of the free neutron offers many opportunities to determine fundamental parameters in the Standard Model of particle physics, and also plays an important role in cosmology. The lifetime of the neutron is of particular importance, especially since it should be easy to measure in principle.
Even though we discovered the neutron almost a hundred years ago, experimental physicists face an embarrassing dilemma; the result of the measurements seems to depend on the measurement method. More precise measurements in the past 30 years have revealed an increasing, unexplained tension of nearly 10 seconds between the two main neutron lifetime experiment types!
For more than two decades, we have been developing a new instrument at TUM: PENeLOPE combines both measurement methods and should also make it possible to reduce the statistically and systematically limited measurement uncertainties by an order of magnitude. A key installation is a powerful source of ultra-cold neutrons, such as the one currently under construction at FRMII. However, in order to obtain initial measurements more quickly, the instrument, whose basic components have been completed, was relocated to TRIUMF, Vancouver, where it was set up and subjected to initial tests this year. This presentation will reveal details of both the physical motivation and the measurement method, as well as the current status of PENeLOPE.
