Background: The nuclear structure in the region southwest of the doubly magic ${}^{208}\mathrm{Pb}$ is important to benchmark theoretical models relevant for neutron-rich heavy element formation and for the origin of the $A\approx 195$ peak in the mass abundance distribution. Although neutron-rich Pb, Tl, and Hg ($Z=80\text{–}82$) isotopes are relatively well studied, experimental data for neutron-rich Au isotopes ($Z=79$) remain largely limited due to experimental challenges.

Purpose: The purpose of this work is to investigate the evolution of the high-spin structure in neutron-rich Au isotopes near the $N=126$ shell closure and to characterize the underlying shell-model configurations, with a particular focus on the roles of the high-$j$ unique-parity $\pi h_{11/2}$ and $\nu i_{13/2}$ orbitals.

Methods: Neutron-rich ${}^{195\text{–}202}\mathrm{Au}$ isotopes were produced using multinucleon transfer reactions of ${}^{198}\mathrm{Pt}({}^{136}\mathrm{Xe}, {}^x\mathrm{I}){}^y\mathrm{Au}$ at a beam energy of 7 MeV/nucleon. Prompt and delayed $\gamma$-ray spectroscopy of isotopically identified reaction products was performed with a unique experimental setup combining the $\mathrm{VAMOS}++$ large acceptance magnetic spectrometer, the AGATA high-purity germanium $\gamma$-ray tracking array, and the CATLIFE detection system.

Results: In even-$A {}^{196,198,200,202}\mathrm{Au}$ isotopes, prompt $\gamma$-ray transitions built on the ${12}^{-}$ isomer have been observed for the first time. The odd-$J$ band built on the ${11}^{-}$ state vanishes for $A\ge 196$. In odd-$A {}^{195,197,199,201}\mathrm{Au}$ isotopes, new prompt and delayed $\gamma$-ray transitions above the $11/2^{-}$ isomer were identified, confirming and extending the known level schemes. New isomeric states assigned to ($25/2^{+}$) have been established in ${}^{199}\mathrm{Au}$ and ${}^{201}\mathrm{Au}$. The minima in the excitation energies of the bands as a function of $N$ built on the $11/2^{-}$ and ${12}^{-}$ isomers occur at ${}^{198}\mathrm{Au}$ ($N=119$), showing a dip against an otherwise smooth evolution.

Conclusions: Large-scale shell-model calculations based on the Kuo-Herling hole effective interaction show an overall good agreement with experimental level schemes. However, the present calculations do not reproduce the minima in excitation energies at $N=119$ observed in both Au and Hg isotopes. A systematic analysis of $\pi h_{11/2}$ and $\nu i_{13/2}$ hole occupancies, together with spin contributions of protons and neutrons, sheds light on the role of these high-$j$ unique-parity orbitals in the generation of high-spin states. Part of the results of this work have been reported in another publication [Y. Cho et al., Phys. Lett. B 878, 140558 (2026)].

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• Energy levels
• High spin states
• Isomer decays
• Nuclear reactions
• Nuclear spin & parity
• Nuclear structure & decays
• Nucleon-nucleon interactions
• 190 ≤ A ≤ 219
• Shell model