Hydrodynamic simulations predict lambda polarization in p+Ar collisions that is six times larger for strong early longitudinal flow than for Bjorken flow, with an anti-lambda sign flip at weak flow, testable at LHCb SMOG.
$\Lambda$ polarization from vortex ring as medium response for jet thermalization
1 Pith paper cite this work. Polarity classification is still indexing.
abstract
We performed a systematic study on the formation of vorticity rings as the process for jet thermalization in the medium created in high-energy nuclear collisions. In this work, we expanded our previous analysis to a more realistic framework by considering non-central events and fluctuations in the initial condition. We simulate the formation and evolution of the flow vortex structure in a relativistic viscous hydrodynamic model and study the sensitivity of the proposed ``ring observable'' ($\mathcal{R}^{t}_{\Lambda}$) that can be measured experimentally through the polarization of $\Lambda$ hyperons. We show that this observable is robust with respect to fluctuating initial conditions to capture the jet-induce vortex flow signal and further study its dependence on different model parameters, such as the jet's velocity, position, the fluid's shear viscosity, and the collision's centrality. The proposed observable is associated to the formation of vorticity in a quark-gluon plasma, showing that the measurement of particle polarization can be a powerful tool to probe different properties of jet-medium interactions and to understand better the polarization induced by the transverse and longitudinal expansions of the medium.
citation-role summary
citation-polarity summary
fields
nucl-th 1years
2025 1verdicts
CONDITIONAL 1roles
background 1polarities
unclear 1representative citing papers
citing papers explorer
-
Event-by-event vortex rings in fixed-target p+Ar collisions
Hydrodynamic simulations predict lambda polarization in p+Ar collisions that is six times larger for strong early longitudinal flow than for Bjorken flow, with an anti-lambda sign flip at weak flow, testable at LHCb SMOG.