Detailed spectroscopy of Bi195

An experiment focused on the study of shape coexistence and new high-spin structures in $^{195}\mathrm{Bi}$ has been performed. The nucleus is in a transitional region of the bismuth isotope chain. A large number of new states have been found, resulting in a significant extension of the previously known level scheme. Several new collective structures have been identified. A strongly coupled rotational band built upon the $13/{2}^{+}$ isomeric state was extended up to ${I}^{\ensuremath{\pi}}=(49/{2}^{+})$ and an energy of 5706 keV. The ${I}^{\ensuremath{\pi}}=31/{2}^{+}$ member of the $\ensuremath{\pi}{i}_{13/2}$ band was also found to feed a new long-lived isomeric state with an excitation energy of 2616 keV and a spin and parity of ${I}^{\ensuremath{\pi}}=29/{2}^{+}$. The half-life of the $29/{2}^{+}$ isomeric state was determined to be $1.49(1)\phantom{\rule{0.28em}{0ex}}\ensuremath{\mu}\mathrm{s}$. It decays via the emission of 457-keV $E2$ and 236-keV $E1$ transitions, respectively. A low-energy 46-keV $E2$ transition has been identified to depopulate the ($29/{2}^{\ensuremath{-}}$) isomeric state, with a measured half-life of ${T}_{1/2}=614(5)\phantom{\rule{0.28em}{0ex}}\mathrm{ns}$. This transition allows the excitation energy of the isomeric state to be determined as 2381 keV. The feeding patterns of both $29/{2}^{+}$ and ($29/{2}^{\ensuremath{-}}$) isomeric states have also been described. This is the first time collective structures have also been observed up to high spins and excitation energies in the neutron-deficient $^{195}\mathrm{Bi}$ nucleus. Evidence for the manifestation of shape coexistence in $^{195}\mathrm{Bi}$ is also discussed.