We report a measurement of e+e- pairs from semileptonic heavy-flavor decays in p+p collisions at sNN=200 GeV. The e+e- pair yield from bb and cc is separated by exploiting a double differential fit done simultaneously in dielectron invariant mass and pT. We used three different event generators, pythia, mc@nlo, and powheg, to simulate the e+e- spectra from cc and bb production. The data can be well described by all three generators within the detector acceptance. However, when using the generators to extrapolate to 4π, significant differences are observed for the total cross section. These difference are less pronounced for bb than for cc. The same model dependence was observed in already published d+A data. The p+p data are also directly compared with d+A data in mass and pT, and within the statistical accuracy no nuclear modification is seen.
Bibliographical noteFunding Information:
We thank the staff of the Collider-Accelerator and Physics Departments at Brookhaven National Laboratory and the staff of the other PHENIX participating institutions for their vital contributions. We acknowledge support from the Office of Nuclear Physics in the Office of Science of the Department of Energy, the National Science Foundation, a sponsored research grant from Renaissance Technologies LLC, 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 Científico e Tecnológico and Fundação de Amparo à Pesquisa do Estado de São Paulo (Brazil), Natural Science Foundation of China (People's Republic of China), Croatian Science Foundation and Ministry of Science and Education (Croatia), Ministry of Education, Youth and Sports (Czech Republic), Centre National de la Recherche Scientifique, Commissariat à l'Énergie Atomique, and Institut National de Physique Nucléaire et de Physique des Particules (France), Bundesministerium für Bildung und Forschung, Deutscher Akademischer Austausch Dienst, and Alexander von Humboldt Stiftung (Germany), National Science Fund, OTKA, EFOP, 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 US 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.
All Science Journal Classification (ASJC) codes
- Nuclear and High Energy Physics