# Discovery of $^{68}$Br in secondary reactions of radioactive beams

## TL;DR

This paper reports the discovery of the proton-rich isotope 68Br through secondary fragmentation reactions of radioactive beams, demonstrating an effective method for identifying new isotopes in nuclear physics.

## Contribution

It introduces secondary fragmentation reactions of radioactive beams as a novel approach to discover new isotopes like 68Br.

## Key findings

- Discovered 68Br in secondary reactions of radioactive beams.
- Estimated the lifetime of 68Br's isomeric state.
- Showed secondary fragmentation populates low-lying nuclear states.

## Abstract

The proton-rich isotope 68Br was discovered in secondary fragmentation reactions of fast radioactive beams. Proton-rich secondary beams of 70,71,72Kr and 70Br, produced at the RIKEN Nishina Center and identified by the BigRIPS fragment separator, impinged on a secondary 9Be target. Unambiguous particle identification behind the secondary target was achieved with the ZeroDegree spectrometer. Based on the expected direct production cross sections from neighboring isotopes, the lifetime of the ground or long-lived isomeric state of 68Br was estimated. The results suggest that secondary fragmentation reactions, where relatively few nucleons are removed from the projectile, offer an alternative way to search for new isotopes, as these reactions populate preferentially low-lying states.