Measurements of midrapidity charged-particle multiplicity distributions, dNch/dη, and midrapidity transverse-energy distributions, dET/dη, are presented for a variety of collision systems and energies. Included are distributions for Au+Au collisions at sNN=200, 130, 62.4, 39, 27, 19.6, 14.5, and 7.7 GeV, Cu+Cu collisions at sNN=200 and 62.4 GeV, Cu+Au collisions at sNN=200 GeV, U+U collisions at sNN=193 GeV, d+Au collisions at sNN=200 GeV, He3+Au collisions at sNN=200 GeV, and p+p collisions at sNN=200 GeV. Centrality-dependent distributions at midrapidity are presented in terms of the number of nucleon participants, Npart, and the number of constituent quark participants, Nqp. For all A+A collisions down to sNN=7.7 GeV, it is observed that the midrapidity data are better described by scaling with Nqp than scaling with Npart. Also presented are estimates of the Bjorken energy density, BJ, and the ratio of dET/dη to dNch/dη, the latter of which is seen to be constant as a function of centrality for all systems.
Bibliographical noteFunding Information:
We acknowledge support from the Office of Nuclear Physics in the Office of Science of the Department of Energy, the National Science Foundation, Abilene Christian University Research Council, Research Foundation of SUNY, and Dean of the College of Arts and Sciences, Vanderbilt University (USA); Ministry of Education, Culture, Sports, Science, and Technology and the Japan Society for the Promotion of Science (Japan); Conselho Nacional de Desenvolvimento Cientifico e Tecnologico and Fundacao de Amparo Pesquisa do Estado de Sa o Paulo (Brazil); Natural Science Foundation of China (People's Republic of China); Croatian Science Foundation and Ministry of Science, Education, and Sports (Croatia); Ministry of Education, Youth and Sports (Czech Republic); Centre National de la Recherche Scientifique, Commissariat l'nergie Atomique, and Institut National de Physique Nuclaire et de Physique des Particules (France); Bundesministerium fur Bildung und Forschung, Deutscher Akademischer Austausch Dienst, and Alexander von Humboldt Stiftung (Germany); National Science Fund, OTKA, Kroly Robert University College, and the Ch. Simonyi Fund (Hungary); Department of Atomic Energy and Department of Science and Technology (India); Israel Science Foundation (Israel); Basic Science Research Program through NRF of the Ministry of Education (Korea); Physics Department, Lahore University of Management Sciences (Pakistan); Ministry of Education and Science, Russian Academy of Sciences, Federal Agency of Atomic Energy (Russia); VR and Wallenberg Foundation (Sweden); the U.S. Civilian Research and Development Foundation for the Independent States of the Former Soviet Union, the Hungarian American Enterprise Scholarship Fund, and the US-Israel Binational Science Foundation.
© 2016 American Physical Society.
ASJC Scopus subject areas
- Nuclear and High Energy Physics