The spectrometer and target systems for hypernuclear physics at the Mainz Microtron

At the Mainz Microtron MAMI, the technique of high-resolution spectroscopy of decay-pions in strangeness electroproduction has been established to extract Lambda ground state binding energies of light hyperfragments. In a first series of measurements, using a momentum setting covering 133MeV/c. and a Be-9 target, the H-4(Lambda) binding energy was determined with unprecedented precision. The current measurement employs a novel lithium target of 50 mm length and only 0.75 mm thickness to precisely determine the hypertriton binding energy in a setting covering its two-body decay momentum of 114MeV/c. The experiment aims for statistical and systematic errors of approximately 20 keV and is running during the summer of 2022.

Automated summary

The technique of high-resolution spectroscopy of decay-pions has been established at the Mainz Microtron MAMI to extract Lambda ground state binding energies of light hyperfragments. With different target materials and momentum settings, the binding energy of H-4(Lambda) has been determined with unprecedented precision. A current experiment is aiming for precise determination of the hypertriton binding energy using a novel lithium target.