Transport Model Approach to Λ and <inline-formula><math display="inline"><semantics><mover accent="true"><mi mathvariant="normal">Λ</mi><mo>¯</mo></mover></semantics></math></inline-formula> Polarization in Heavy-Ion Collisions
This paper investigates the symmetry breaking between the polarizations of <inline-formula><math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><semantics><mi mathvariant="normal">Λ</mi></semantics></math></inlin...
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| Format: | Article |
| Language: | English |
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MDPI AG
2021-10-01
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| Series: | Symmetry |
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| Online Access: | https://www.mdpi.com/2073-8994/13/10/1852 |
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| author | Larissa V. Bravina Kyrill A. Bugaev Oleksandr Vitiuk Evgeny E. Zabrodin |
| author_facet | Larissa V. Bravina Kyrill A. Bugaev Oleksandr Vitiuk Evgeny E. Zabrodin |
| author_sort | Larissa V. Bravina |
| collection | DOAJ |
| description | This paper investigates the symmetry breaking between the polarizations of <inline-formula><math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><semantics><mi mathvariant="normal">Λ</mi></semantics></math></inline-formula> and <inline-formula><math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><semantics><mover accent="true"><mi mathvariant="normal">Λ</mi><mo>¯</mo></mover></semantics></math></inline-formula> hyperons in relativistic collisions of heavy ions at intermediate and low energies. The microscopic transport model UrQMD is employed to study the thermal vorticity of hot and dense nuclear matter formed in non-central Au + Au collisions at center-of-mass energies <inline-formula><math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><semantics><mrow><mn>7.7</mn><mo>≤</mo><msqrt><msub><mi>s</mi><mrow><mi>N</mi><mi>N</mi></mrow></msub></msqrt><mo>≤</mo><mn>62.4</mn></mrow></semantics></math></inline-formula> GeV. The whole volume of an expanding fireball is subdivided into small cubic cells. Then, we trace the final <inline-formula><math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><semantics><mi mathvariant="normal">Λ</mi></semantics></math></inline-formula> and <inline-formula><math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><semantics><mover accent="true"><mi mathvariant="normal">Λ</mi><mo>¯</mo></mover></semantics></math></inline-formula> hyperons back to their last interaction point within a certain cell. Extracting the bulk parameters, such as energy density, net baryon density, and net strangeness of the hot and dense medium in the cell, one can obtain the cell temperature and the chemical potentials at the time of the hyperon emission. To do this, the extracted characteristics have to be fitted to the statistical model (SM) of ideal hadron gas. After that, the vorticity of nuclear matter and polarization of both hyperons are calculated. We found that the polarization of both <inline-formula><math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><semantics><mi mathvariant="normal">Λ</mi></semantics></math></inline-formula> and <inline-formula><math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><semantics><mover accent="true"><mi mathvariant="normal">Λ</mi><mo>¯</mo></mover></semantics></math></inline-formula> increases with decreasing energy of heavy-ion collisions. The stronger polarization of <inline-formula><math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><semantics><mover accent="true"><mi mathvariant="normal">Λ</mi><mo>¯</mo></mover></semantics></math></inline-formula> is explained by (i) the slightly different freeze-out conditions of both hyperons and (ii) the different space–time distributions of <inline-formula><math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><semantics><mi mathvariant="normal">Λ</mi></semantics></math></inline-formula> and <inline-formula><math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><semantics><mover accent="true"><mi mathvariant="normal">Λ</mi><mo>¯</mo></mover></semantics></math></inline-formula>. |
| first_indexed | 2024-03-10T06:10:30Z |
| format | Article |
| id | doaj.art-7e2043e7bf2f46f38c86a4e6fdca1b6f |
| institution | Directory Open Access Journal |
| issn | 2073-8994 |
| language | English |
| last_indexed | 2024-03-10T06:10:30Z |
| publishDate | 2021-10-01 |
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| series | Symmetry |
| spelling | doaj.art-7e2043e7bf2f46f38c86a4e6fdca1b6f2023-11-22T20:10:04ZengMDPI AGSymmetry2073-89942021-10-011310185210.3390/sym13101852Transport Model Approach to Λ and <inline-formula><math display="inline"><semantics><mover accent="true"><mi mathvariant="normal">Λ</mi><mo>¯</mo></mover></semantics></math></inline-formula> Polarization in Heavy-Ion CollisionsLarissa V. Bravina0Kyrill A. Bugaev1Oleksandr Vitiuk2Evgeny E. Zabrodin3Department of Physics, University of Oslo, PB 1048 Blindern, N-0316 Oslo, NorwayBogolyubov Institute for Theoretical Physics, Metrologichna str. 14-B, UA-03680 Kiev, UkraineInstitute for Nuclear Research, National Academy of Sciences of Ukraine, Prospekt Nauki av. 47, UA-03680 Kiev, UkraineDepartment of Physics, University of Oslo, PB 1048 Blindern, N-0316 Oslo, NorwayThis paper investigates the symmetry breaking between the polarizations of <inline-formula><math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><semantics><mi mathvariant="normal">Λ</mi></semantics></math></inline-formula> and <inline-formula><math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><semantics><mover accent="true"><mi mathvariant="normal">Λ</mi><mo>¯</mo></mover></semantics></math></inline-formula> hyperons in relativistic collisions of heavy ions at intermediate and low energies. The microscopic transport model UrQMD is employed to study the thermal vorticity of hot and dense nuclear matter formed in non-central Au + Au collisions at center-of-mass energies <inline-formula><math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><semantics><mrow><mn>7.7</mn><mo>≤</mo><msqrt><msub><mi>s</mi><mrow><mi>N</mi><mi>N</mi></mrow></msub></msqrt><mo>≤</mo><mn>62.4</mn></mrow></semantics></math></inline-formula> GeV. The whole volume of an expanding fireball is subdivided into small cubic cells. Then, we trace the final <inline-formula><math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><semantics><mi mathvariant="normal">Λ</mi></semantics></math></inline-formula> and <inline-formula><math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><semantics><mover accent="true"><mi mathvariant="normal">Λ</mi><mo>¯</mo></mover></semantics></math></inline-formula> hyperons back to their last interaction point within a certain cell. Extracting the bulk parameters, such as energy density, net baryon density, and net strangeness of the hot and dense medium in the cell, one can obtain the cell temperature and the chemical potentials at the time of the hyperon emission. To do this, the extracted characteristics have to be fitted to the statistical model (SM) of ideal hadron gas. After that, the vorticity of nuclear matter and polarization of both hyperons are calculated. We found that the polarization of both <inline-formula><math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><semantics><mi mathvariant="normal">Λ</mi></semantics></math></inline-formula> and <inline-formula><math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><semantics><mover accent="true"><mi mathvariant="normal">Λ</mi><mo>¯</mo></mover></semantics></math></inline-formula> increases with decreasing energy of heavy-ion collisions. The stronger polarization of <inline-formula><math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><semantics><mover accent="true"><mi mathvariant="normal">Λ</mi><mo>¯</mo></mover></semantics></math></inline-formula> is explained by (i) the slightly different freeze-out conditions of both hyperons and (ii) the different space–time distributions of <inline-formula><math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><semantics><mi mathvariant="normal">Λ</mi></semantics></math></inline-formula> and <inline-formula><math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><semantics><mover accent="true"><mi mathvariant="normal">Λ</mi><mo>¯</mo></mover></semantics></math></inline-formula>.https://www.mdpi.com/2073-8994/13/10/1852relativistic heavy-ion collisionstransport modelsthermal vorticitypolarization of hyperons |
| spellingShingle | Larissa V. Bravina Kyrill A. Bugaev Oleksandr Vitiuk Evgeny E. Zabrodin Transport Model Approach to Λ and <inline-formula><math display="inline"><semantics><mover accent="true"><mi mathvariant="normal">Λ</mi><mo>¯</mo></mover></semantics></math></inline-formula> Polarization in Heavy-Ion Collisions Symmetry relativistic heavy-ion collisions transport models thermal vorticity polarization of hyperons |
| title | Transport Model Approach to Λ and <inline-formula><math display="inline"><semantics><mover accent="true"><mi mathvariant="normal">Λ</mi><mo>¯</mo></mover></semantics></math></inline-formula> Polarization in Heavy-Ion Collisions |
| title_full | Transport Model Approach to Λ and <inline-formula><math display="inline"><semantics><mover accent="true"><mi mathvariant="normal">Λ</mi><mo>¯</mo></mover></semantics></math></inline-formula> Polarization in Heavy-Ion Collisions |
| title_fullStr | Transport Model Approach to Λ and <inline-formula><math display="inline"><semantics><mover accent="true"><mi mathvariant="normal">Λ</mi><mo>¯</mo></mover></semantics></math></inline-formula> Polarization in Heavy-Ion Collisions |
| title_full_unstemmed | Transport Model Approach to Λ and <inline-formula><math display="inline"><semantics><mover accent="true"><mi mathvariant="normal">Λ</mi><mo>¯</mo></mover></semantics></math></inline-formula> Polarization in Heavy-Ion Collisions |
| title_short | Transport Model Approach to Λ and <inline-formula><math display="inline"><semantics><mover accent="true"><mi mathvariant="normal">Λ</mi><mo>¯</mo></mover></semantics></math></inline-formula> Polarization in Heavy-Ion Collisions |
| title_sort | transport model approach to λ and inline formula math display inline semantics mover accent true mi mathvariant normal λ mi mo ¯ mo mover semantics math inline formula polarization in heavy ion collisions |
| topic | relativistic heavy-ion collisions transport models thermal vorticity polarization of hyperons |
| url | https://www.mdpi.com/2073-8994/13/10/1852 |
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