Event shape selection method in search of the chiral magnetic effect in heavy-ion collisions
The search for the chiral magnetic effect (CME) in heavy-ion collisions has been impeded by the significant background arising from the anisotropic particle emission pattern, particularly elliptic flow. To alleviate this background, the event shape selection (ESS) technique categorizes collision eve...
| Main Authors: | , , , , |
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| Format: | Article |
| Language: | English |
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Elsevier
2024-01-01
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| Series: | Physics Letters B |
| Subjects: | |
| Online Access: | http://www.sciencedirect.com/science/article/pii/S0370269323007013 |
| _version_ | 1797363805076848640 |
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| author | Zhiwan Xu Brian Chan Gang Wang Aihong Tang Huan Zhong Huang |
| author_facet | Zhiwan Xu Brian Chan Gang Wang Aihong Tang Huan Zhong Huang |
| author_sort | Zhiwan Xu |
| collection | DOAJ |
| description | The search for the chiral magnetic effect (CME) in heavy-ion collisions has been impeded by the significant background arising from the anisotropic particle emission pattern, particularly elliptic flow. To alleviate this background, the event shape selection (ESS) technique categorizes collision events according to their shapes and projects the CME observables to a class of events with minimal flow. In this study, we explore two event shape variables to classify events and two elliptic flow variables to regulate the background. Each type of variable can be calculated from either single particles or particle pairs, resulting in four combinations of event shape and elliptic flow variables. By employing a toy model and the realistic event generator, event-by-event anomalous-viscous fluid dynamics (EBE-AVFD), we discover that the elliptic flow of resonances exhibits correlations with both the background and the potential CME signal, making the resonance flow unsuitable for background control. Through the EBE-AVFD simulations of Au+Au collisions at sNN=200 GeV with various input scenarios, we ascertain that the optimal ESS strategy for background control entails utilizing the single-particle elliptic flow in conjunction with the event shape variable based on particle pairs. |
| first_indexed | 2024-03-08T16:26:12Z |
| format | Article |
| id | doaj.art-58f0dabb0fa54a2d9a073f3874ff0c07 |
| institution | Directory Open Access Journal |
| issn | 0370-2693 |
| language | English |
| last_indexed | 2024-03-08T16:26:12Z |
| publishDate | 2024-01-01 |
| publisher | Elsevier |
| record_format | Article |
| series | Physics Letters B |
| spelling | doaj.art-58f0dabb0fa54a2d9a073f3874ff0c072024-01-07T04:28:28ZengElsevierPhysics Letters B0370-26932024-01-01848138367Event shape selection method in search of the chiral magnetic effect in heavy-ion collisionsZhiwan Xu0Brian Chan1Gang Wang2Aihong Tang3Huan Zhong Huang4Department of Physics and Astronomy, University of California, Los Angeles, CA 90095, United States of AmericaDepartment of Physics and Astronomy, University of California, Los Angeles, CA 90095, United States of AmericaDepartment of Physics and Astronomy, University of California, Los Angeles, CA 90095, United States of America; Corresponding author.Brookhaven National Laboratory, Upton, NY 11973, United States of AmericaDepartment of Physics and Astronomy, University of California, Los Angeles, CA 90095, United States of America; Key Laboratory of Nuclear Physics and Ion-beam Application (MOE), and Institute of Modern Physics, Fudan University, Shanghai-200433, People's Republic of ChinaThe search for the chiral magnetic effect (CME) in heavy-ion collisions has been impeded by the significant background arising from the anisotropic particle emission pattern, particularly elliptic flow. To alleviate this background, the event shape selection (ESS) technique categorizes collision events according to their shapes and projects the CME observables to a class of events with minimal flow. In this study, we explore two event shape variables to classify events and two elliptic flow variables to regulate the background. Each type of variable can be calculated from either single particles or particle pairs, resulting in four combinations of event shape and elliptic flow variables. By employing a toy model and the realistic event generator, event-by-event anomalous-viscous fluid dynamics (EBE-AVFD), we discover that the elliptic flow of resonances exhibits correlations with both the background and the potential CME signal, making the resonance flow unsuitable for background control. Through the EBE-AVFD simulations of Au+Au collisions at sNN=200 GeV with various input scenarios, we ascertain that the optimal ESS strategy for background control entails utilizing the single-particle elliptic flow in conjunction with the event shape variable based on particle pairs.http://www.sciencedirect.com/science/article/pii/S0370269323007013Event shapeHeavy-ion collisionChiral magnetic effect |
| spellingShingle | Zhiwan Xu Brian Chan Gang Wang Aihong Tang Huan Zhong Huang Event shape selection method in search of the chiral magnetic effect in heavy-ion collisions Physics Letters B Event shape Heavy-ion collision Chiral magnetic effect |
| title | Event shape selection method in search of the chiral magnetic effect in heavy-ion collisions |
| title_full | Event shape selection method in search of the chiral magnetic effect in heavy-ion collisions |
| title_fullStr | Event shape selection method in search of the chiral magnetic effect in heavy-ion collisions |
| title_full_unstemmed | Event shape selection method in search of the chiral magnetic effect in heavy-ion collisions |
| title_short | Event shape selection method in search of the chiral magnetic effect in heavy-ion collisions |
| title_sort | event shape selection method in search of the chiral magnetic effect in heavy ion collisions |
| topic | Event shape Heavy-ion collision Chiral magnetic effect |
| url | http://www.sciencedirect.com/science/article/pii/S0370269323007013 |
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