Nuclear astrophysics

Nuclear physics experiments give reaction rates that, via modelling and comparison with primordial abundances, constrain cosmological parameters. The error bars of a key reaction, D(p,γ)³He, were tightened in 2020, revealing discrepancies between different analyses and calling for more accurate measurements of other reactions.

Understanding the first few minutes of the Universe has been hampered by uncertainty in the cross section of the so-called deuterium burning process. A paper in Nature reports a much-improved cross section, putting models of the early Universe on firmer footing.

The cosmic origin of the heaviest elements in the periodic table remains a mystery. Estimates of the physical locations of element-producing events within small galaxies that formed in the early Universe are now providing new clues.

One of the fundamental radioactive decay modes of nuclei is β decay. Now, nuclear theorists have used first-principles simulations to explain nuclear β decay properties across a range of light- to medium-mass isotopes, up to ¹⁰⁰Sn.

Deep-sea sediments reveal the production sites of the heaviest chemical elements in the Universe to be neutron star mergers — rare events that eject large amounts of mass — and not core-collapse supernovae.

By swapping the roles of the target and beam in an experiment that is otherwise impossible to implement, researchers have confirmed the doubly magic nature of the neutron-rich radioactive tin isotope ¹³²Sn.