Towards a better understanding of 16O nuclear structure: Muon capture and radiative pion capture reactions

Radiative pion capture in nuclei: a continuum shell-model approach

“…Shell-model (SM) calculations do not present this deficiency. This was observed in the pioneering work of Vergados [1] and Eramzhyam et al [8] and in the results obtained by Ohtsuka and Ohtsubo [9] and Wünsch [10] within the continuum SM approach. Much of this work has been devoted to the analysis of the role played by the resonances in the reaction and the main conclusion is that the RPC can be described assuming a dominant resonance character for the process.…”

Muon capture, continuum random phase approximation, and in-medium renormalization of the axial-vector coupling constant

“…We would like to point out that most of the capture rate goes to particle-unbound states. In 12 C capture to particle-bound levels (mainly the 12 B ground state) contributes about 16% of the total rate, while in 16 O the bound-state contributions are roughly 10%. As is obvious from In accordance with our discussion above, we find an average excitation energy which in all cases corresponds to the regime of the giant dipole and spin-dipole resonances in these nuclei.…”

“…Noting that the residual interaction is repulsive in the isovector channel and pushes the T = 1 strength to higher excitation energies, a weakening of the force results in the T = 1 states, which are the only states populated in muon capture on T = 0 targets like 12 C, 16 O, and 40 Ca, residing at lower excitation energies. Consequently, the energy of the neutrinos E ν , which are released after the capture to these states, are slightly higher.…”

“…The method combines the usual RPA treatment with the correct description of the continuum nucleon decay channel. We have used this method for calculations of the muon capture processes on 12 C, 16 O, and 40 Ca. As residual interactions we adopted the finite-range force [8] based on the Bonn potential [9] and the zero-range Landau-Migdal force with the parametrizations for 12 C and 16 O taken from Refs.…”

Muon capture by3Henuclei followed by proton and deuteron production

“…It is not yet clear why the charged particle yield at muon capture increases as one goes from 1p−shell nuclei to (2s − 1d)−shell nuclei. Structure peculiarities of the giant resonance in (2s − 1d)−shell nuclei [20,21,22,23] may play an important role, though.…”