Garchinger Maier-Leibnitz-Kolloquium: Indications for a bound tetraneutron

by Dr Thomas Faestermann (Physik-Department, TUM)

Thursday 3 Feb 2022, 16:15 → 17:15 Europe/Berlin

Online via ZOOM

The existence of a resonance or a bound state in the three- or four-neutron system could help to constrain e.g. the three-body interaction of the nuclear force. It would also have consequences for the composition of neutron stars. I will report on experimental indications for a bound tetraneutron. Using the reaction 7Li(7Li,10C) we tried to populate states in the tetraneutron. A peak in the energy spectrum of identified 10C, which we cannot attribute to a reaction with any other of the target components, corresponds to an excitation of the 10C+4n system of 2.93 ±0.16 MeV. Under different kinematic conditions an equivalent peak was observed. For a binding energy of the tetraneutron of −2.93 MeV a much larger width than the observed upper limit of  <0.24 MeV (mainly due to experimental spread) is expected. Therefore, we favour the interpretation that this peak corresponds to 10C in the first excited state at 3.354 MeV and a tetraneutron with a binding energy of +0.42 ±0.16 MeV. This result will be discussed in the context of older experiments and of recent theoretical work.

Online via ZOOM:
               
 https://lmu-munich.zoom.us/j/98457332925?pwd=TWc3V1JkSHpyOTBPQVlMelhuNnZ1dz09

Meeting ID: 984 5733 2925
Passcode: 979953

kolloquium-03-02-22.pdf