Intense X-ray laser-induced proton emission from halo nuclei

TL;DR

This paper explores how intense X-ray lasers induce proton emission from halo nuclei, revealing angular distribution patterns, the influence of Coulomb repulsion, and polarization effects, advancing understanding of laser-nuclear interactions.

Contribution

It provides a nonperturbative quantum S-matrix analysis of proton emission, including angular distributions, multi-photon rates, and polarization effects, with detailed insights into laser frequency dependence.

Findings

Angular distributions depend on laser frequency and show petal structures.

Coulomb potential hinders proton emission rates and causes blue shifts.

Polarization affects total emission rates and transitions from perturbative to nonperturbative regimes.

Abstract

We investigate the intense X-ray laser-induced proton emission from halo nuclei within the framework of a nonperturbative quantum $S$-matrix approach. We have analytically deduced the angular differential as well as the total multi-photon rates of the proton emissions. For a linearly polarized X-ray laser field, we find that the angular distributions of proton emission sensitively depend on the laser frequency and show an interesting petal structure with increasing the laser frequency as well as the number of absorbed photons. Meanwhile, we find the Coulomb repulsion potential between the proton and the remainder nucleus has a strong hindering effect on the total multi-photon rates of the proton emissions and leads to the blue shifts of the multi-photon transition frequency. Moreover, the polarization effects of laser fields on total rates of proton emission have also been addressed. We find that the polarized ellipticity corresponding to the maximum of the total rates depend on the laser frequency showing a transition from perturbative to nonperturbative proton emission. The underlying mechanism of the above findings is uncovered, and some implications are discussed.