Four-body Coulomb explosion of HCl dimers in strong laser fields

We performed a four-body coincidence measurement involving ${\mathrm{H}}^{+}, {\mathrm{H}}^{+}, {\mathrm{Cl}}^{+}$, and ${\mathrm{Cl}}^{+}$ fragments generated by strong field ionization of the HCl dimer. The energy correlation maps reveal the rapid explosion of two protons and the slow repulsion between two ${\mathrm{Cl}}^{+}$ ions during the four-body fragmentation. Moreover, the kinetic energy of the fragments relative to the emission angles provides valuable insights into how the motion of the proton affects the energy distribution between ions. We also performed ab initio calculations to track the real-time movements of the four fragments. The simulations reveal the influence of fast-moving protons on the comparatively slow fragmentation process of ${\mathrm{Cl}}^{+}$ ions. This comprehensive approach sheds light on the dynamics and offers valuable insights into the ultrafast fragmentation of molecular clusters.