Published: 12 April 2017

[Credit: Long-Gang Pang]

The third appointment of the ALICE Journal Club is about to come. On Thursday 20 of April, Isaac Upsal, Ph.D. student at Ohio State University and member of the STAR Collaboration, will talk about global lambda hyperion polarization in Au-Au collisions.

The latest results on this topic, explained in a recent pre-print paper, have been submitted to Nature for publication.


Non-central heavy-ion collisions are expected to give rise to a system with strong global angular momentum that, expanding hydrodynamically, also develops a strong localised angular momentum, usually quantified in terms of vorticity. This phenomenon may provide important constrains to the models describing the collective dynamics of the QGP and may lead to novel physical phenomena within a chirally restored system. In a recent publication, STAR reported the first experimental evidence of such phenomenon: they measured the global polarisation of (anti-)Lambda, i.e. the polarisation with respect to the reaction plane, due to the alignment of their spin with the angular momentum of the system.