Evidence of spin-orbital angular momentum interactions in relativistic heavy-ion collisions
Autor(a) principal: | |
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Data de Publicação: | 2020 |
Outros Autores: | , , , |
Tipo de documento: | Artigo |
Idioma: | eng |
Título da fonte: | Repositório Institucional da UFRGS |
Texto Completo: | http://hdl.handle.net/10183/212742 |
Resumo: | The first evidence of spin alignment of vector mesons ( K * 0 and ϕ ) in heavy-ion collisions at the Large Hadron Collider (LHC) is reported. The spin density matrix element ρ 00 is measured at midrapidity ( | y | < 0.5 ) in Pb-Pb collisions at a center-of-mass energy ( √ s NN ) of 2.76 TeV with the ALICE detector. ρ 00 values are found to be less than 1 / 3 ( 1 / 3 implies no spin alignment) at low transverse momentum ( p T < 2 GeV / c ) for K * 0 and ϕ at a level of 3 σ and 2 σ , respectively. No significant spin alignment is observed for the K 0 S meson ( spin = 0 ) in Pb-Pb collisions and for the vector mesons in p p collisions. The measured spin alignment is unexpectedly large but qualitatively consistent with the expectation from models which attribute it to a polarization of quarks in the presence of angular momentum in heavy-ion collisions and a subsequent hadronization by the process of recombination. |
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Acharya, ShreyasiGay Ducati, Maria BeatrizPereira, Luis GustavoPezzi, Rafael PerettiALICE Collaboration2020-08-08T03:46:05Z20200031-9007http://hdl.handle.net/10183/212742001116391The first evidence of spin alignment of vector mesons ( K * 0 and ϕ ) in heavy-ion collisions at the Large Hadron Collider (LHC) is reported. The spin density matrix element ρ 00 is measured at midrapidity ( | y | < 0.5 ) in Pb-Pb collisions at a center-of-mass energy ( √ s NN ) of 2.76 TeV with the ALICE detector. ρ 00 values are found to be less than 1 / 3 ( 1 / 3 implies no spin alignment) at low transverse momentum ( p T < 2 GeV / c ) for K * 0 and ϕ at a level of 3 σ and 2 σ , respectively. No significant spin alignment is observed for the K 0 S meson ( spin = 0 ) in Pb-Pb collisions and for the vector mesons in p p collisions. The measured spin alignment is unexpectedly large but qualitatively consistent with the expectation from models which attribute it to a polarization of quarks in the presence of angular momentum in heavy-ion collisions and a subsequent hadronization by the process of recombination.application/pdfengPhysical review letters. Melville. Vol. 125, no. 1 (July 2020), 012301, 12 p.Colisao de ions pesadosAceleradores de partículasEvidence of spin-orbital angular momentum interactions in relativistic heavy-ion collisionsEstrangeiroinfo:eu-repo/semantics/articleinfo:eu-repo/semantics/publishedVersioninfo:eu-repo/semantics/openAccessreponame:Repositório Institucional da UFRGSinstname:Universidade Federal do Rio Grande do Sul (UFRGS)instacron:UFRGSTEXT001116391.pdf.txt001116391.pdf.txtExtracted Texttext/plain60843http://www.lume.ufrgs.br/bitstream/10183/212742/2/001116391.pdf.txte83c57aa35aa2a925e5ca4e64aea0e12MD52ORIGINAL001116391.pdfTexto completo (inglês)application/pdf471627http://www.lume.ufrgs.br/bitstream/10183/212742/1/001116391.pdf0495cd923932cd3b9cdd2e8566ebcc88MD5110183/2127422023-11-15 04:25:32.445373oai:www.lume.ufrgs.br:10183/212742Repositório de PublicaçõesPUBhttps://lume.ufrgs.br/oai/requestopendoar:2023-11-15T06:25:32Repositório Institucional da UFRGS - Universidade Federal do Rio Grande do Sul (UFRGS)false |
dc.title.pt_BR.fl_str_mv |
Evidence of spin-orbital angular momentum interactions in relativistic heavy-ion collisions |
title |
Evidence of spin-orbital angular momentum interactions in relativistic heavy-ion collisions |
spellingShingle |
Evidence of spin-orbital angular momentum interactions in relativistic heavy-ion collisions Acharya, Shreyasi Colisao de ions pesados Aceleradores de partículas |
title_short |
Evidence of spin-orbital angular momentum interactions in relativistic heavy-ion collisions |
title_full |
Evidence of spin-orbital angular momentum interactions in relativistic heavy-ion collisions |
title_fullStr |
Evidence of spin-orbital angular momentum interactions in relativistic heavy-ion collisions |
title_full_unstemmed |
Evidence of spin-orbital angular momentum interactions in relativistic heavy-ion collisions |
title_sort |
Evidence of spin-orbital angular momentum interactions in relativistic heavy-ion collisions |
author |
Acharya, Shreyasi |
author_facet |
Acharya, Shreyasi Gay Ducati, Maria Beatriz Pereira, Luis Gustavo Pezzi, Rafael Peretti ALICE Collaboration |
author_role |
author |
author2 |
Gay Ducati, Maria Beatriz Pereira, Luis Gustavo Pezzi, Rafael Peretti ALICE Collaboration |
author2_role |
author author author author |
dc.contributor.author.fl_str_mv |
Acharya, Shreyasi Gay Ducati, Maria Beatriz Pereira, Luis Gustavo Pezzi, Rafael Peretti ALICE Collaboration |
dc.subject.por.fl_str_mv |
Colisao de ions pesados Aceleradores de partículas |
topic |
Colisao de ions pesados Aceleradores de partículas |
description |
The first evidence of spin alignment of vector mesons ( K * 0 and ϕ ) in heavy-ion collisions at the Large Hadron Collider (LHC) is reported. The spin density matrix element ρ 00 is measured at midrapidity ( | y | < 0.5 ) in Pb-Pb collisions at a center-of-mass energy ( √ s NN ) of 2.76 TeV with the ALICE detector. ρ 00 values are found to be less than 1 / 3 ( 1 / 3 implies no spin alignment) at low transverse momentum ( p T < 2 GeV / c ) for K * 0 and ϕ at a level of 3 σ and 2 σ , respectively. No significant spin alignment is observed for the K 0 S meson ( spin = 0 ) in Pb-Pb collisions and for the vector mesons in p p collisions. The measured spin alignment is unexpectedly large but qualitatively consistent with the expectation from models which attribute it to a polarization of quarks in the presence of angular momentum in heavy-ion collisions and a subsequent hadronization by the process of recombination. |
publishDate |
2020 |
dc.date.accessioned.fl_str_mv |
2020-08-08T03:46:05Z |
dc.date.issued.fl_str_mv |
2020 |
dc.type.driver.fl_str_mv |
Estrangeiro info:eu-repo/semantics/article |
dc.type.status.fl_str_mv |
info:eu-repo/semantics/publishedVersion |
format |
article |
status_str |
publishedVersion |
dc.identifier.uri.fl_str_mv |
http://hdl.handle.net/10183/212742 |
dc.identifier.issn.pt_BR.fl_str_mv |
0031-9007 |
dc.identifier.nrb.pt_BR.fl_str_mv |
001116391 |
identifier_str_mv |
0031-9007 001116391 |
url |
http://hdl.handle.net/10183/212742 |
dc.language.iso.fl_str_mv |
eng |
language |
eng |
dc.relation.ispartof.pt_BR.fl_str_mv |
Physical review letters. Melville. Vol. 125, no. 1 (July 2020), 012301, 12 p. |
dc.rights.driver.fl_str_mv |
info:eu-repo/semantics/openAccess |
eu_rights_str_mv |
openAccess |
dc.format.none.fl_str_mv |
application/pdf |
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reponame:Repositório Institucional da UFRGS instname:Universidade Federal do Rio Grande do Sul (UFRGS) instacron:UFRGS |
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Repositório Institucional da UFRGS |
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Repositório Institucional da UFRGS |
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