Polarization transfer in hyperon decays and its effect in relativistic nuclear collisions

4 Nov 2019, 17:40
Wanda Han Show Theatre & Wanda Reign Wuhan Hotel

Wanda Han Show Theatre & Wanda Reign Wuhan Hotel

Poster Presentation Chirality, vorticity and spin polarization Poster Session


Gaoqing Cao (Sun Yat-sen University)


We study the contribution to the polarization of $\Lambda$ hyperons in relativistic nuclear collisions at high energy from the decays of $\Sigma^*(1385)$ and $\Sigma^0$, which are the predominant sources of $\Lambda$ production besides the primary component, as a function of the $\Lambda$ momentum. Particularly, we determine the longitudinal component of the mean spin vector as a function of the azimuthal angle and show that it has a very similar pattern to the primary one, if primary $\Sigma^*$ and $\Sigma^0$ polarization follow the predictions of local thermodynamic equilibrium in a relativistic fluid. Therefore, we conclude that the secondary decays cannot account for the discrepancy between experimental data and hydrodynamic model predictions of the longitudinal polarization of $\Lambda$ hyperons recently measured by the STAR experiment at RHIC.

Primary authors

Gaoqing Cao (Sun Yat-sen University) Francesco Becattini (Unversity of Florence) Enrico Speranza (Frankfurt University)

Presentation Materials

There are no materials yet.