Abstract
New measurements of directed flow for charged hadrons, characterized by the Fourier coefficient v1, are presented for transverse momenta pT, and centrality intervals in Au+Au collisions recorded by the STAR experiment for the center-of-mass energy range sNN=7.7–200 GeV. The measurements underscore the importance of momentum conservation, and the characteristic dependencies on sNN, centrality and pT are consistent with the expectations of geometric fluctuations generated in the initial stages of the collision, acting in concert with a hydrodynamic-like expansion. The centrality and pT dependencies of v1 even, as well as an observed similarity between its excitation function and that for v3, could serve as constraints for initial-state models. The v1 even excitation function could also provide an important supplement to the flow measurements employed for precision extraction of the temperature dependence of the specific shear viscosity.
Original language | English |
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Pages (from-to) | 26-32 |
Number of pages | 7 |
Journal | Physics Letters, Section B: Nuclear, Elementary Particle and High-Energy Physics |
Volume | 784 |
DOIs | |
State | Published - Sep 10 2018 |
Bibliographical note
Funding Information:We thank the RHIC Operations Group and RCF at BNL, the NERSC Center at LBNL, and the Open Science Grid consortium for providing resources and support. This work was supported in part by the Office of Nuclear Physics within the U.S. DOE Office of Science , the U.S. National Science Foundation , the Ministry of Education and Science of the Russian Federation , National Natural Science Foundation of China , Chinese Academy of Science , the Ministry of Science and Technology of China and the Chinese Ministry of Education , the National Research Foundation of Korea , GA and MSMT of the Czech Republic , Department of Atomic Energy and Department of Science and Technology of the Government of India ; the National Science Centre of Poland , National Research Foundation , the Ministry of Science, Education and Sports of the Republic of Croatia, RosAtom of Russia and German Bundesministerium fur Bildung, Wissenschaft, Forschung and Technologie ( BMBF ) and the Helmholtz Association .
Funding Information:
We thank the RHIC Operations Group and RCF at BNL, the NERSC Center at LBNL, and the Open Science Grid consortium for providing resources and support. This work was supported in part by the Office of Nuclear Physics within the U.S. DOE Office of Science, the U.S. National Science Foundation, the Ministry of Education and Science of the Russian Federation, National Natural Science Foundation of China, Chinese Academy of Science, the Ministry of Science and Technology of China and the Chinese Ministry of Education, the National Research Foundation of Korea, GA and MSMT of the Czech Republic, Department of Atomic Energy and Department of Science and Technology of the Government of India; the National Science Centre of Poland, National Research Foundation, the Ministry of Science, Education and Sports of the Republic of Croatia, RosAtom of Russia and German Bundesministerium fur Bildung, Wissenschaft, Forschung and Technologie (BMBF) and the Helmholtz Association.
Publisher Copyright:
© 2018
ASJC Scopus subject areas
- Nuclear and High Energy Physics