A look back at Physical Review C’s first half century, and a salute to the talented authors and diligent referees who have made the journal a success.

New analysis of nuclear reaction data finds holes in a theory about the first stars.

Synopsis on:
R. J. deBoer et al.
Phys. Rev. C 103, 055815 (2021)

This Low Energy Nuclear Physics International Collaboration (LENPIC) paper provides an example of $ab$-$initio$ nuclear structure calculations worth noting. Using chiral effective field theory starting from two-body and three-body nuclear data, the authors work up through $p$-shell nuclei, with careful attention paid to quantifying the theoretical uncertainties. The remaining discrepancies with experiment, particularly overbinding in the upper $p$ shell, point to next steps to be taken. As a caveat, known excited states that cannot be well described within current computational limitations are missing.

Precise measurements, in proton-${}^3$He elastic scattering near 65 MeV, of cross sections, proton and ${}^3$He analyzing powers, and the spin correlation coefficient $C_{y,y}$ are compared with rigorous neutron-${}^3$H scattering calculations based upon realistic two-nucleon potentials. Proton-${}^3$He scattering at intermediate energies is found to be an excellent tool with which to test nuclear interaction models. Moreover, outstanding features that differ from those seen in nucleon-${}^2$H elastic scattering suggest the possibility of exploring $T=3/2$ three-nucleon forces, which are not accessible in three-nucleon scattering.

At the beginning of 2021, eight Physical Review journals began publishing Letters which are intended for the accelerated publication of important new results targeted to the specific readership of each journal.

A new analysis of heavy-ion collision experiments uncovers evidence that two colliding nuclei behave like a Josephson junction—a device in which Cooper pairs tunnel through a barrier between two superfluids.

Viewpoint on:
G. Potel, F. Barranco, E. Vigezzi, and R. A. Broglia
Phys. Rev. C 103, L021601 (2021)

Neutron star merger ejecta are currently the most viable astrophysical site for $r$-process nucleosynthesis. Fission plays a fundamental role. The manuscript presents an updated scission-point model for fission fragment distributions, which improves agreement with experimental fission yields. Two astrophysical scenarios, based on alternative weak-interaction hypotheses, are employed to reanalyze the role of fission. Regions of the nuclear chart where fission is important are identified, and the impact of fission yields on the final $r$-process abundance distribution is elaborated.

APS Editor in Chief, Michael Thoennessen, discusses a new opportunity for communicating authors to include their pronouns together with their contact email in order to promote a more respectful, inclusive, and equitable environment.

Researchers look back at key contributions to the field of nuclear physics.

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