Parity-transfer $({}^{16}{\rm O},{}^{16}{\rm F}(0^-,{\rm g.s.}))$ reaction as a selective probe of isovector $0^-$ states in nuclei

TL;DR

The paper demonstrates that the parity-transfer reaction $({}^{16}{ m O},{}^{16}{ m F}(0^-,{ m g.s.}))$ is an effective and selective method for probing isovector $0^-$ excitations in nuclei, revealing specific nuclear states with enhanced clarity.

Contribution

It introduces and validates the parity-transfer reaction as a new, selective probe for isovector $0^-$ states, enabling detailed studies of spin-isospin nuclear modes.

Findings

Successfully observed the $0^-$ state at 9.3 MeV with enhanced cross section.

Identified structures at 6.6 and 14.8 MeV with forward-peaked angular distributions.

Demonstrated the reaction's potential for systematic studies of spin-isospin modes in nuclei.

Abstract

We demonstrate that the parity-transfer $({}^{16}{\rm O},{}^{16}{\rm F}(0^-,{\rm g.s.}))$ reaction provides a selective probe of isovector $0^-$ excitations in nuclei. This reaction selectively populates unnatural-parity states through a $0^+ \to 0^-$ transition in the projectile. The excitation-energy spectrum of $^{12}\mathrm{B}$ was reconstructed via the ${}^{12}{\rm C}({}^{16}{\rm O},{}^{16}{\rm F}(0^-,{\rm g.s.}))$ reaction at 247~MeV/u from the coincident detection of the ${}^{15}\mathrm{O}+p$ decay products of ${}^{16}\mathrm{F}$. The known $0^{-}$ state at $E_x = 9.3~{\rm MeV}$ was clearly observed with a strongly enhanced forward cross section, establishing the selectivity of the reaction. Structures observed at $E_x = 6.6 \pm 0.4$ and $14.8 \pm 0.3~{\rm MeV}$ exhibit forward-peaked angular distributions and are suggested to contain significant $0^-$ strength. These results demonstrate that the parity-transfer reaction provides a powerful probe of $0^-$ excitations and highlight its potential for systematic studies of spin-isospin modes, including pion-related dynamics, in nuclei.