Resonances in Unbound Systems from ⁷Be reacting on Deuterium Gas in Inverse Kinematics

The inverse kinematic reactions of ⁷Be on a D₂ gas target have advantages in measuring exotic reactions relevant to nuclear structure and nuclear astrophysics. For example, from a nuclear astrophysics’ perspective, the reaction ⁷Be(d,t)⁶Be provides access to resonances in the unbound nucleus ⁶Be, which are connected to the solar p-p chain. These could explain the overabundance predicted by the Big Bang Nucleosynthesis (BBN) model in the reaction ³He(³He,2p)⁴He, which competes with ³He(⁴He,γ)⁷Be in the p-p chain. In the nuclear structure aspect, unbound resonances in nuclei can decay sequentially or democratically and the angular correlation between emitted particles can inform us about the cluster structure of unbound systems. Using the Active Target Time Projection Chamber (AT-TPC), we can study the decay mechanisms of several channels: (d,p), (d,d), (d,t), and (d,³He). Among these, three lead to unbound systems: ⁶Be, ⁷Be*, and ⁸Be. These reactions allow simultaneous investigation of both the reaction dynamics and decay properties, which are captured and analyzed using clustering algorithms in the AT-TPC data analysis framework.