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

被引：19

作者：

Abou Yassine, R. ^{[6
,17
]}

Adamczewski-Musch, J. ^{[5
]}

Asal, C. ^{[8
]}

Becker, M. ^{[11
]}

Belounnas, A. ^{[12
]}

Blanco, A. ^{[1
]}

Blume, C. ^{[8
]}

Chlad, L. ^{[13
,17
]}

Chudoba, P. ^{[13
]}

Ciepal, I ^{[3
]}

Cordts, M. ^{[6
]}

Dreyer, J. ^{[7
]}

Esmail, W. A. ^{[5
]}

Fabbietti, L. ^{[9
,10
]}

Floersheimer, H. ^{[6
]}

Fonte, P. ^{[1
,18
]}

Friese, J. ^{[10
]}

Froehlich, I ^{[8
]}

Foertsch, J. ^{[16
]}

Galatyuk, T. ^{[5
,6
]}

Gniazdowski, T. ^{[15
]}

Greifenhagen, R. ^{[7
,19
]}

Grunwald, M. ^{[15
]}

Gumberidze, M. ^{[5
]}

Harabasz, S. ^{[6
]}

Heinz, T. ^{[5
]}

Hoehne, C. ^{[5
,11
]}

Hojeij, F. ^{[12
]}

Holzmann, R. ^{[5
]}

Huck, H. ^{[8
]}

Idzik, M. ^{[2
]}

Kaempfer, B. ^{[7
,19
]}

Kampert, K-H ^{[16
]}

Kardan, B. ^{[8
]}

Kedych, V ^{[6
]}

Koenig, I ^{[5
]}

Koenig, W. ^{[5
]}

Kohls, M. ^{[8
]}

Kolas, J. ^{[15
]}

Kornakov, G. ^{[15
]}

Kotte, R. ^{[7
]}

Kres, I ^{[16
]}

Krueger, W. ^{[6
]}

Kugler, A. ^{[13
]}

Lalik, R. ^{[4
]}

Lebedev, S. ^{[11
]}

Linev, S. ^{[5
]}

Linz, F. ^{[5
,6
]}

Lopes, L. ^{[1
]}

Lorenz, M. ^{[8
]}

机构：

[1] LIP Lab Instrumentacao & Fis Expt Particulas, P-3004516 Coimbra, Portugal

[2] AGH Univ Sci & Technol, Fac Phys & Appl Comp Sci, PL-30059 Krakow, Poland

[3] Polish Acad Sci, Inst Nucl Phys, PL-31342 Krakow, Poland

[4] Jagiellonian Univ Cracow, Smoluchowski Inst Phys, PL-30059 Krakow, Poland

[5] GSI Helmholtzzentrum Schwerionenforsch GmbH, D-64291 Darmstadt, Germany

[6] Tech Univ Darmstadt, D-64289 Darmstadt, Germany

[7] Helmholtz Zentrum Dresden Rossendorf, Inst Strahlenphys, D-01314 Dresden, Germany

[8] Goethe Univ, Inst Kernphys, D-60438 Frankfurt, Germany

[9] Excellence Cluster Origin & Struct Universe, D-85748 Garching, Germany

[10] Tech Univ Munich, Phys Dept E62, D-85748 Garching, Germany

[11] Justus Liebig Univ Giessen, Phys Inst 2, D-35392 Giessen, Germany

[12] Univ Paris Saclay, Lab Phys Infinis Irene Joliot Curie 2, CNRS IN2P3, F-91405 Orsay, France

[13] Czech Acad Sci, Nucl Phys Inst, Rez 25068, Czech Republic

[14] Uniwersytet Warszawski, Inst Fizyki Wiadczalnej, PL-02093 Warsaw, Poland

[15] Warsaw Univ Technol, PL-00662 Warsaw, Poland

[16] Berg Univ Wuppertal, D-42119 Wuppertal, Germany

[17] Charles Univ Prague, Fac Math & Phys, Prague 12116, Czech Republic

[18] Coimbra Polytech ISEC, Coimbra, Portugal

[19] Tech Univ Dresden, D-01062 Dresden, Germany

[20] Czech Tech Univ, Prague 16000, Czech Republic

[21] Univ Wroclaw, PL-50204 Wroclaw, Poland

来源：

PHYSICS LETTERS B | 2022年 / 835卷

关键词：

PLUS AU COLLISIONS; MESONS; FLOW; SPIN;

D O I：

10.1016/j.physletb.2022.137506

中图分类号：

P1 [天文学];

学科分类号：

0704 ;

摘要：

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 root s(NN)= 2.4GeV 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's 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 +/- 1.3 (stat.) +/- 2.1 (syst.) for Au+Au and < P-Lambda >(%) = 6.2 +/- 0.4 (stat.) +/- 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 3GeV. 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. (c) 2022 The Author(s). Published by Elsevier B.V. This is an open access article under the CC BY license (http://creativecommons.org/licenses/by/4.0/).

引用

页数：6

共 45 条

[21]

Becattini F, 2020, ANNU REV NUCL PART S, V70, P395, DOI [10.1146/annurev-nucl-021920095245, 10.1146/annurev-nucl-021920-095245]

[22] Polarization probes of vorticity in heavy ion collisions [J].

Betz, Barbara ;

Gyulassy, Miklos ;

Torrieri, Giorgio .

PHYSICAL REVIEW C, 2007, 76 (04)

[23] Relativistic dissipative spin dynamics in the relaxation time approximation [J].

Bhadury, Samapan ;

Florkowski, Wojciech ;

Jaiswal, Amaresh ;

Kumar, Avdhesh ;

Ryblewski, Radoslaw .

PHYSICS LETTERS B, 2021, 814

[24] Relativistic hadron-hadron collisions in the ultra-relativistic quantum molecular dynamics model [J].

Bleicher, M ;

Zabrodin, E ;

Spieles, C ;

Bass, SA ;

Ernst, C ;

Soff, S ;

Bravina, L ;

Belkacem, M ;

Weber, H ;

Stöcker, H ;

Greiner, W .

JOURNAL OF PHYSICS G-NUCLEAR AND PARTICLE PHYSICS, 1999, 25 (09) :1859-1896

[25] Azimuthally sensitive correlations in nucleus-nucleus collisions [J].

Borghini, N ;

Ollitrault, JY .

PHYSICAL REVIEW C, 2004, 70 (06) :064905-1

[26] Vorticity in low-energy heavy-ion collisions [J].

Deng, Xian-Gai ;

Huang, Xu-Guang ;

Ma, Yu-Gang ;

Zhang, Song .

PHYSICAL REVIEW C, 2020, 101 (06)

[27]

Fu B., 2021, ARXIV

[28] Hyperon polarization from the vortical fluid in low-energy nuclear collisions [J].

Guo, Yu ;

Liao, Jinfeng ;

Wang, Enke ;

Xing, Hongxi ;

Zhang, Hui .

PHYSICAL REVIEW C, 2021, 104 (04)

[29] Global Λ polarization in moderately relativistic nuclear collisions [J].

Ivanov, Yu B. .

PHYSICAL REVIEW C, 2021, 103 (03)

[30]

Kornas Frederic Julian, 2022, EPJ Web of Conferences, V259, DOI 10.1051/epjconf/202225911016

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