The Two-Body Photodisintegration Reaction $^{4}$He($\gamma $,p)$^{3}$H between 22 and 30 MeV

The $^{4}$nucleus is often considered as the link between the classical few-body systems and more complex nuclei. Only recently it became possible to calculate the photoabsorption cross section of $^{4}$with realistic nucleon-nucleon potential models. However, the experimental situation is still as controversial as it was a quarter century ago. Using TUNL's HIGS facility, the two-body photodisintegration cross section of $^{4}$He into a proton and triton was measured between 22 and 30 MeV in 0.5 MeV energy steps. High-pressure $^{4}$He/Xe gas scintillators of various compositions served as targets and detectors. Pure Xe gas scintillators were used for background measurements. A NaI detector was employed for the incident photon flux determination. Our data are in fairly good agreement with recent theoretical calculations of the Trento group [1], but differ significantly from the majority of the previous data, including the recent data of Shima \textit{et al}. [2] obtained with mono-energetic photon beams and a time-projection chamber. \\[4pt] [1] S. Quaglioni \textit{et al}., Phys. Rev. C \textbf{69}, 044002 (2004). \\[0pt] [2] T. Shima \textit{et al., }Phys. Rev. C \textbf{72}, 044004 (2005).