Speaker
Description
A recent ab-initio calculation of the monopole transition form factor of $^4$He (Phys. Rev. Lett. 110, 042503 (2013)) pointed to a strong dependence on the different realistic potentials used. The inconsistencies met between the recent ab-initio form factor calculation and the existing data from $^4$He(e,e‘)$^4$He call for further investigation. In order to shed some light on this challenging subject, an exclusive measurement of the $^4$He + $^4$He $\rightarrow$ $^4$He + $^4$He $\rightarrow$ $^4$He + $^3$H + $^1$H reaction in the region of the first 0+ excited state of $^4$He was performed at the MAGNEX facility of INFN – Laboratori Nazionali del Sud. The $^4$He ions were momentum analyzed by the MAGNEX spectrometer, while the $^3$H ions were detected by the OSCAR telescope. The $^4$He + $^4$He $\rightarrow$ $^4$He + $^4$He* $\rightarrow$ $^4$He + $^3$He + n reaction was also measured simultaneously thanks to the large momentum acceptance of the MAGNEX spectrometer. The data analysis, including the relevant Monte Carlo simulations will be presented and discussed.
