Spin polarization dynamics in the non-boost-invariant background

Space-time evolution of spin polarization within the framework of hydrodynamics with spin based on de Groot-van Leeuwen-van Weert forms of energy-momentum and spin tensors is studied. Due to the nonboost invariant flow in the system the spin polarization components couple to each other implying some effects on the spin polarization observables. We study transverse-momentum and rapidity dependence of mean spin polarization vector for ? hyperons. Our results show qualitative agreement for rapidity dependence of the global spin polarization with the experiments and other models. The quadrupole structure of the longitudinal component at midrapidity is not found; however, as compared to the results for Bjorken expansion, some nontrivial signal at forward rapidities is observed.

Automated summary

The evolution of spin polarization in the framework of hydrodynamics reveals that the nonboost invariant flow in the system leads to coupling between spin polarization components, impacting observables. The study of mean spin polarization vector for ? hyperons shows qualitative agreement with experiments and other models in terms of rapidity dependence of global spin polarization, with the absence of quadrupole structure in the longitudinal component at midrapidity. However, some nontrivial signals at forward rapidities are observed in comparison to results for Bjorken expansion.