Toward correction-free ⁸Li(α, n)¹¹B data at the Gamow energy of explosive nucleosynthesis

The ⁸Li+⁴He → ¹¹B+n reaction inside the center-of-mass energy region E_cm = 0.5–2.5 MeV, corresponding to the temperature range T₉ = 1–5, is of relevant interest in the fields of nuclear cosmology and nuclear astrophysics. In the context of Big Bang nucleosynthesis, it has been invoked to overcome the A = 8 mass gap; in r-process nucleosynthesis, it is considered a candidate precursor of seed nuclei. In this experimental work, the cross section, summed over all ¹¹B final bound states, at the energy of 1.05 MeV in the center-of-mass system, is investigated by a correction-free projectile-correlated inclusive neutron measurement. The radioactive ⁸Li beam delivered by the EXCYT facility at LNS-Catania is used to induce the inverse-kinematics reaction process. A zero-energy-threshold 4π detection system is used. Thanks to the improved experimental and analysis procedures, the result obtained in this work represents a strong argument to reopen the debate on the magnitude of the ⁸Li(α, n)¹¹B reaction rate in explosive astrophysical environments.