Core meets corona: a two-component source to explain Lambda and anti-Lambda global polarization in semi-central heavy-ion collisions

Abstract

We compute the Lambda and anti-Lambda global polarization in semi-central heavy-ion collisions modeling the source as consisting of a high-density core and a less dense corona. We show that when more Lambdas than anti-Lambdas are produced in the corona, and this is combined with a smaller number of Lambdas coming from the core, as compared to those coming from the corona, an amplification effect for the anti-Lambda with respect to that of Lambda polarization can occur. This amplification becomes more important for lower collision energies and quantitatively accounts for the Lambda and anti-Lambda polarizations measured by the STAR beam energy scan.

arXiv comment6 pages, 5 figures. Version to appear in Phys. Lett. B

References in corpus (48)

• Global $\Lambda$ hyperon polarization in nuclear collisions: evidence for the most vortical fluid
• Centrality determination of Pb-Pb collisions at $\sqrt{s_{\mathrm{NN}}}$ = 2.76 TeV with ALICE
• Angular momentum conservation in heavy ion collisions at very high energy
• Measurements of Strange Particle Production in $p+p$ Collisions at $\sqrt{s}$= 200 GeV
• Global polarization of $\Lambda$ hyperons in Au+Au collisions at $\sqrt{s_{{}_{NN}}}$ = 200 GeV
• Global hyperon polarization at local thermodynamic equilibrium with vorticity, magnetic field and feed-down
• Rotating quark-gluon plasma in relativistic heavy ion collisions
• Study of Lambda polarization in relativistic nuclear collisions at sqrt{s}_NN = 7.7-200 GeV
• Global $\Lambda$ polarization in heavy-ion collisions from a transport model
• QCD Analysis of Unpolarized and Polarized Lambda - Baryon Production in Leading and Next-to-Leading Order
• Lambda Polarization in Peripheral Heavy Ion Collisions
• Probing vorticity structure in heavy-ion collisions by local $\Lambda$ polarization
• J/Psi Suppression in Pb-Pb Collisions: A Hint of Quark-Gluon Plasma Production?
• Lambda hyperon polarization in relativistic heavy ion collisions from the chiral kinetic approach
• Magnetic Field Induced Polarization Difference between Hyperons and Anti-hyperons
• Parameterization of Deformed Nuclei for Glauber Modeling in Relativistic Heavy Ion Collisions
• Polarized Lambdas in the Current Fragmentation Region
• Lambda polarization from unpolarized quark fragmentation
• Polarized Lambda-Baryon Production in pp Collisions
• Observation of Transverse $\Lambda /\bar{\Lambda }$ Hyperon Polarization in $e^{+}{e}^{-}$ Annihilation at Belle
• Lambda and Lambda-bar Polarization in Lepton Induced Processes
• Spin content of Lambda and its longitudinal polarization in $e^{+}{e}^{-}$ annihilation at high energies
• Different space-time freeze-out picture -- an explanation of different $\Lambda$ and $\bar{\Lambda }$ polarization?
• Strangeness in Nuclear Collisions
• The Proton Spin Puzzle and $\Lambda$ Polarization in Deep--Inelastic Scattering
• Lambda and Antilambda polarization from deep inelastic muon scattering
• Mid-rapidity anti-baryon to baryon ratios in pp collisions at $\sqrt{s}$ = 0.9, 2.76 and 7 TeV measured by ALICE
• $\Lambda$ polarization in peripheral collisions at moderate relativistic energies
• Spin Hydrodynamic Generation in the Charged Subatomic Swirl
• $\Lambda$, $\bar{\Lambda }$ Polarization and Spin Transfer in Lepton Deep-Inelastic Scattering
• Measurement of the Antilambda Polarization in nu_mu Charged Current Interactions in the NOMAD Experiment
• Lambda hyperon production and polarization in collisions of p(3.5 GeV) + Nb
• Measurement of the transverse polarization of $\Lambda$ and $\bar{\Lambda }$ hyperons produced in proton-proton collisions at $\sqrt{s}=7$ TeV using the ATLAS detector
• Polarization of Lambda and Anti-Lambda in 920 GeV Fixed-Target Proton-Nucleus Collisions
• Relaxation time for quark spin and thermal vorticity alignment in heavy-ion collisions
• Investigating different $\Lambda$ and $\bar{\Lambda }$ polarizations in relativistic heavy-ion collisions
• Longitudinal Spin Transfer to $\Lambda$ and $\bar{\Lambda }$ Hyperons in Polarized Proton-Proton Collisions at $\sqrt{s}$ = 200 GeV
• Transverse Polarization of Lambda and Lambda-bar Hyperons in Quasireal Photoproduction
• Lambda^0 polarization as a probe for production of deconfined matter in ultra-relativistic heavy-ion collisions
• Longitudinal Polarization of Lambda and anti-Lambda Hyperons in Lepton-Nucleon Deep-Inelastic Scattering
• Lambda and Lambda-bar polarization in polarized DIS
• Lambda Polarization in an Exact Rotating and Expanding fluid dynamical model for peripheral heavy ion reactions
• Lambda and Antilambda polarization in Au-Au collisions at RHIC
• Vorticity in the QGP liquid and $\Lambda$ polarization at the RHIC Beam Energy Scan
• Transverse polarization of the $\Lambda$ hyperon from unpolarized quark fragmentation in the diquark model
• Polarization difference between hyperons and anti-hyperons induced by external magnetic field
• Polarization of Lambda^0 hyperons in nucleus-nucleus collisions at high energies
• Transverse ${\Lambda }^0$ polarization in inclusive quasi-real photoproduction at the current fragmentation

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• Rise and fall of $\Lambda$ and $\bar{\Lambda }$ global polarization in semi-central heavy-ion collisions at HADES, NICA and RHIC energies from the core-corona model
• Fermion propagator in a rotating environment
• Impact of strong magnetic field, baryon chemical potential, and medium anisotropy on polarization and spin alignment of hadrons
• Hyperon global polarization in heavy-ion collisions at NICA energies. Feed-down effects and the role of ${\Sigma }^0$ hyperons
• Investigate the $\Lambda$ and $\bar{\Lambda }$ polarization splitting effect with combined mechanisms
• Two-component source to explain $\Lambda$ and $\bar{\Lambda }$ global polarization in non-central heavy-ion collisions