Pith. sign in

REVIEW 3 cited by

Measurement of global polarization of {Λ} hyperons in few-GeV heavy-ion collisions

Not yet reviewed by Pith; the record is open.

This paper has not been read by Pith yet. Machine review is queued; the pith claim, tier, and objections will appear here once it completes.

SPECIMEN: schema-true, not a live event

T0 review · schema-true

One-sentence machine reading of the paper's core claim.

pith:XXXXXXXX · record.json · timestamp

arxiv 2207.05160 v2 pith:7MP3BG4T submitted 2022-07-11 nucl-ex

Measurement of global polarization of {Λ} hyperons in few-GeV heavy-ion collisions

classification nucl-ex
keywords collisionspolarizationlambdacentralitycollisionobservedfunctionglobal
verification ladder T0 review T1 audit T2 compute T3 formal T4 reserved
0 comments
read the original abstract

The global polarization of {\Lambda} hyperons along the total orbital angular momentum of a relativistic heavy-ion collision is presented based on the high statistics data samples collected in Au+Au collisions at \sqrt{s_{NN}} = 2.4 GeV and Ag+Ag at 2.55 GeV with the High-Acceptance Di-Electron Spectrometer (HADES) at GSI, Darmstadt. This is the first measurement below the strangeness production threshold in nucleon-nucleon collisions. Results are reported as a function of the collision centrality as well as a function of the hyperon transverse momentum (p_T) and rapidity (y_{CM}) for the range of centrality 0--40%. We observe a strong centrality dependence of the polarization with an increasing signal towards peripheral collisions. For mid-central (20--40%) collisions the polarization magnitudes are <P_{\Lambda}>(%) = 6.8 \pm 1.3 (stat.) \pm 2.1 (syst.) for Au+Au and <P_{\Lambda}>(%) = 6.2 \pm 0.4 (stat.) \pm 0.6 (syst.) for Ag+Ag, which are the largest values observed so far. This observation thus provides a continuation of the increasing trend previously observed by STAR and contrasts expectations from recent theoretical calculations predicting a maximum in the region of collision energies about 3 GeV. The observed polarization is of a similar magnitude as predicted by 3D fluid dynamics and the UrQMD plus thermal vorticity model and significantly above results from the AMPT model.

discussion (0)

Sign in with ORCID, Apple, or X to comment. Anyone can read and Pith papers without signing in.

Forward citations

Cited by 3 Pith papers

Reviewed papers in the Pith corpus that reference this work. Sorted by Pith novelty score.

  1. Boost-invariant and cylindrically symmetric perfect spin hydrodynamics

    hep-ph 2026-05 unverdicted novelty 5.0

    In boost-invariant cylindrical spin hydrodynamics, azimuthal-longitudinal coupling in the spin tensor produces nonzero total polarization only via the longitudinal magnetic component coupled to the azimuthal electric ...

  2. Excitation function for global \Lambda polarization in relativistic heavy ion collisions with the Core Corona model

    hep-ph 2026-04 unverdicted novelty 5.0

    A Core-Corona model with field-theoretic vortical polarization computes the excitation function of global Lambda polarization in heavy-ion collisions and predicts a robust maximum near 3 GeV.

  3. Global polarization of $\Lambda$, $\Xi^{-}$, and $\Omega^{-}$ hyperons in Au+Au collisions at RHIC BES-II energies

    nucl-th 2026-06 unverdicted novelty 4.0

    Hydrodynamic calculations show Omega hyperon polarization exceeds that of Lambda and Xi due to spin but falls below STAR data, with particle-antiparticle splitting growing at lower energies and driven by chemical pote...