Core-Excited Molecules by Resonant Intense X-Ray Pulses Involving Electron-Rotation Coupling

It has been reported that electron-rotation coupling plays a significant role in diatomic nuclear dynamics induced by intense VUV pulses [Phys. Rev. A 102(2020) 033114;Phys. Rev. Res. 2(2020) 043348]. As a further step, we present here investigations of the electron-rotation coupling effect in the presence of Auger decay channel for core-excited molecules, based on theoretical modeling of the total electron yield(TEY), resonant Auger scattering(RAS) and x-ray absorption spectra(XAS) for two showcases of CO and CH^(+) molecules excited by resonant intense x-ray pulses. The Wigner D-functions and the universal transition dipole operators are introduced to include the electron-rotation coupling for the core-excitation process. It is shown that with the pulse intensity up to 10^(16) W/cm^(2), no sufficient influence of the electron-rotation coupling on the TEY and RAS spectra can be observed. This can be explained by a suppression of the induced electron-rotation dynamics due to the fast Auger decay channel, which does not allow for effective Rabi cycling even at extreme field intensities,contrary to transitions in optical or VUV range. For the case of XAS, however, relative errors of about 10% and 30% are observed for the case of CO and CH^(+), respectively, when the electron-rotation coupling is neglected.It is concluded that conventional treatment of the photoexcitation, neglecting the electron-rotation coupling,can be safely and efficiently employed to study dynamics at the x-ray transitions by means of electron emission spectroscopy, yet the approximation breaks down for nonlinear processes as stimulated emission, especially for systems with light atoms.

Large-Scale Shell Model for Nuclear Structure and Nuclear Astrophysics Studies

The study of neutron-rich nuclei near132 Sn is interesting and important for both nuclear structure and nuclear astrophysics. For a considerably large model space allowing cross-shell excitations,a new effective Hamiltonian is determined by employing the extended pairing-plus-quadrupole model with monopole corrections. Calculations for two mass regions, for the north-east quadrant of132 Sn with Z > 50 and N > 82 and for the south-west quadrant with Z < 50 and N < 82, have been performed recently. The structure of these nuclei is analyzed in detail, and the role of the monopole corrections can be clearly seen.

Monopole effects, core excitations, and β decay in the A = 130 hole nuclei near ^(132)Sn

The proton and neutron cross-shell excitations across the Z = 50 shell are investigated in the southwest quadrant of ^(132) Sn by large-scale shell-model calculations with extended pairing and multipole-multipole force. The model space allows proton(neutron) core excitations, and both the low-and high-energy states for ^(130) In are well described, as found by comparison with the experimental data. The monopole effects between the proton orbit and neutron orbit are studied as the new monopole correction that perfectly reproduces the first 1^+ level in ^(130) In. The energy interval of proton(neutron) core excitations in ^(130) In lies in the range of 4.5-6.5(2.0-4.1) MeV, and the high energy yrast states are predicted as neutron core excitations. The decays are calculated among the A=130 nuclei of ^(130) In, ^(130) Sn and ^(130) Cd.