Excited states in 195 Au have been studied experimentally via the 192 Os( 7 Li, 4n) reaction at a beam energy of 44 MeV. Based on the γ -γ -t coincidence measurement, a level scheme consisting of 15 new transitions and 10 new levels is established for 195 Au. The triaxial shape-polarizing effect of the high-j h 11/2 proton hole was studied by total Routhian surface calculations. By comparing with the level structures in the odd-A Au isotopes and the even-even core Hg nuclei, configurations are proposed to the rotational bands and three-quasiparticle states observed in 195 Au.

Background: According to standard stellar evolution, lithium abundance is believed to be a useful indicator of the stellar age. However, many evolved stars like red giants show huge fluctuations around expected theoretical abundances that are not yet fully understood. The better knowledge of nuclear reactions that contribute to the creation and destruction of lithium can help to solve this puzzle. Purpose: In this work we apply the Gamow shell model (GSM) formulated in the coupled-channel representation (GSM-CC) to investigate the mirror radiative capture reactions 6 Li(p, γ) 7 Be and 6 Li(n, γ) 7 Li. Method: GSM offers the most general treatment of couplings between discrete resonant states and the non-resonant continuum. The cross-sections are calculated using a translationally invariant Hamiltonian with the finite-range interaction which is adjusted to reproduce spectra, binding energies and one-nucleon separation energies in 6−7 Li, 7 Be. The reaction channels are built by coupling the wave functions of ground state 1 + 1 and excited states 3 + 1 , 0 + 1 , 2 + 1 of 6 Li with the projectile wave function in different partial waves. Results: We include all relevant E1, M 1, and E2 transitions from the initial continuum states to the final bound states J = 3 2 − 1 and J = 1 2 − of 7 Li and 7 Be. Our microscopic astrophysical factor for the 6 Li(p,γ) 7 Be reaction follows the average trend of the experimental value as a function of the center of mass energy. For 6 Li(n, γ) 7 Li, the calculated cross section agrees well with the data from the direct measurement of this reaction at stellar energies. Conclusion: We demonstrate that the s-wave radiative capture of proton (neutron) to the first excited state J π = 1 2 + 1 of 7 Be (7 Li) is crucial and increases the total astrophysical S-factor by about 40 %.