Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Vorticity in the QGP liquid and $\Lambda$ polarization at the RHIC Beam
  Energy Scan   Polarization of $\Lambda$ hyperons and their antiparticles is calculated in a
3+1 dimensional viscous hydrodynamic model with initial state from UrQMD
hadron/string cascade. We find that, along with recent results from STAR, the
mean polarization at fixed centrality decreases as a function of collision
energy from 1.5% at $\sqrt{s_{\rm NN}}=7.7$ GeV to 0.2% at $\sqrt{s_{\rm
NN}}=200$ GeV. We explore the effects which lead to such collision energy
dependence, feed-down corrections and a difference between $\Lambda$ and
$\bar\Lambda$.

34
The categories of this paper are: chem-ph
4
The categories of this paper are: cond-mat
26
The categories of this paper are: bayes-an
14
The categories of this paper are: math-ph
22
The categories of this paper are: chao-dyn
17
The categories of this paper are: q-fin
36
The categories of this paper are: cmp-lg
23
The categories of this paper are: solv-int
37
The categories of this paper are: supr-con
30
The categories of this paper are: q-alg
32
The categories of this paper are: atom-ph
6
The categories of this paper are: astro-ph
18
The categories of this paper are: econ
5
The categories of this paper are: gr-qc
35
The categories of this paper are: mtrl-th
19
The categories of this paper are: eess