Polarization of Lambda ((Lambda)over-bar) Hyperons along the Beam Direction in Au plus Au Collisions at root S-NN=200 GeV

Kód výsledku v IS VaVaI

<a href="https://www.isvavai.cz/riv?ss=detail&h=RIV%2F61389005%3A_____%2F19%3A00509894" target="_blank" >RIV/61389005:_____/19:00509894 - isvavai.cz</a>

Nalezeny alternativní kódy

RIV/68407700:21340/19:00337234

Výsledek na webu

<a href="https://doi.org/10.1103/PhysRevLett.123.132301" target="_blank" >https://doi.org/10.1103/PhysRevLett.123.132301</a>

DOI - Digital Object Identifier

<a href="http://dx.doi.org/10.1103/PhysRevLett.123.132301" target="_blank" >10.1103/PhysRevLett.123.132301</a>

Jazyk výsledku

angličtina

Název v původním jazyce

Polarization of Lambda ((Lambda)over-bar) Hyperons along the Beam Direction in Au plus Au Collisions at root S-NN=200 GeV

Popis výsledku v původním jazyce

The Lambda ((Lambda) over bar) hyperon polarization along the beam direction has been measured in Au + Au collisions at root S-NN = 200 GeV, for the first time in heavy-ion collisions. The polarization dependence on the hyperons' emission angle relative to the elliptic flow plane exhibits a second harmonic sine modulation, indicating a quadrupole pattern of the vorticity component along the beam direction, expected due to elliptic flow. The polarization is found to increase in more peripheral collisions, and shows no strong transverse momentum (p(T)) dependence at p(T) greater than 1 GeV/c. The magnitude of the signal is about 5 times smaller than those predicted by hydrodynamic and multiphase transport models. The observed phase of the emission angle dependence is also opposite to these model predictions. In contrast, the kinematic vorticity calculations in the blast-wave model tuned to reproduce particle spectra, elliptic flow, and the azimuthal dependence of the Gaussian source radii measured with the Hanbury Brown-Twiss intensity interfemmetry technique reproduce well the modulation phase measured in the data and capture the centrality and transverse momentum dependence of the polarization signal.

Název v anglickém jazyce

Polarization of Lambda ((Lambda)over-bar) Hyperons along the Beam Direction in Au plus Au Collisions at root S-NN=200 GeV

Popis výsledku anglicky

The Lambda ((Lambda) over bar) hyperon polarization along the beam direction has been measured in Au + Au collisions at root S-NN = 200 GeV, for the first time in heavy-ion collisions. The polarization dependence on the hyperons' emission angle relative to the elliptic flow plane exhibits a second harmonic sine modulation, indicating a quadrupole pattern of the vorticity component along the beam direction, expected due to elliptic flow. The polarization is found to increase in more peripheral collisions, and shows no strong transverse momentum (p(T)) dependence at p(T) greater than 1 GeV/c. The magnitude of the signal is about 5 times smaller than those predicted by hydrodynamic and multiphase transport models. The observed phase of the emission angle dependence is also opposite to these model predictions. In contrast, the kinematic vorticity calculations in the blast-wave model tuned to reproduce particle spectra, elliptic flow, and the azimuthal dependence of the Gaussian source radii measured with the Hanbury Brown-Twiss intensity interfemmetry technique reproduce well the modulation phase measured in the data and capture the centrality and transverse momentum dependence of the polarization signal.

Druh

J_imp - Článek v periodiku v databázi Web of Science

CEP obor

—

OECD FORD obor

10303 - Particles and field physics

Projekt

Výsledek vznikl pri realizaci vícero projektů. Více informací v záložce Projekty.

Návaznosti

P - Projekt vyzkumu a vyvoje financovany z verejnych zdroju (s odkazem do CEP)

Rok uplatnění

2019

Kód důvěrnosti údajů

S - Úplné a pravdivé údaje o projektu nepodléhají ochraně podle zvláštních právních předpisů

Název periodika

Physical Review Letters

ISSN

0031-9007

e-ISSN

—

Svazek periodika

123

Číslo periodika v rámci svazku

13

Stát vydavatele periodika

US - Spojené státy americké

Počet stran výsledku

8

Strana od-do

132301

Kód UT WoS článku

000488270200019

EID výsledku v databázi Scopus

2-s2.0-85072781702