Isospin quartets ($T=3/2$) and quintets ($T=2$) have been investigated for $A=15$ and $A=16$ nuclei, respectively. Data from an invariant-mass experiment, with a ${}^{17}\mathrm{Ne}$ beam, were reanalyzed and the $T=3/2$ and $T=2$ states in ${}^{15}\mathrm{O}$ and ${}^{16}\mathrm{F}$, associated with $p+{}^{14}\mathrm{N}$ and $2p+{}^{14}\mathrm{N}$ exit channels, respectively, were found. In some cases, $\gamma$-ray gating was used to tag on events that decay to the excited $0^{+}$, $T=1$ state in ${}^{14}\mathrm{N}$ rather than the ground state. With the new states, the lowest-energy $1/2^{+}$ and $5/2^{+}$ quartets for $A=15$ and the $0^{+}$ and $2^{+}$ quintets for $A=16$ are completed. In addition, members of these multiplets in ${}^{15}\mathrm{F}$ and ${}^{16}\mathrm{Ne}$ decaying to the $p+{}^{14}\mathrm{O}$ and $2p+{}^{14}\mathrm{O}$ channels are reevaluated by gating on events where the ${}^{14}\mathrm{O}$ fragment recoils perpendicular to beam axis in the parent reference frame. Such transverse-decay events have the best invariant-mass resolution. No evidence for deviations from a quadratic dependence of the mass on the isospin projection was found for the $A=15$ quartets. However for the $A=160^{+}$ and $2^{+}$ quintets, evidence for deviations were found.

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• Coulomb energies & analogue states
• Energy levels
• Nuclear structure & decays
• Proton emission
• Rare & new isotopes
• 6 ≤ A ≤ 19
• Radioactive beams