Di-electron spectrum at mid-rapidity in p+p collisions at root s=200 GeV

0385117 - ÚJF 2013 RIV US eng J - Journal Article
Adamczyk, M. - Agakishiev, G. - Aggarwal, M. M. - Ahammed, Z. - Alakhverdyants, A. V. - Alekseev, I. - Alford, J. - Anderson, B. D. - Barnovská, Zuzana - Bielčík, J. - Bielčíková, Jana - Chaloupka, Petr - Chung, Paul - Hajková, O. - Kapitán, Jan - Pachr, M. - Rusňák, Jan - Šumbera, Michal - Tlustý, David … Total 369 authors
Di-electron spectrum at mid-rapidity in p+p collisions at root s=200 GeV.
Physical Review. C. Roč. 86, č. 2 (2012), s. 024906. ISSN 0556-2813
R&D Projects: GA MŠMT LA09013
Institutional support: RVO:61389005
Keywords : di-electron production * relativistic collision
Subject RIV: BG - Nuclear, Atomic and Molecular Physics, Colliders
Impact factor: 3.715, year: 2012

We report on the mid-rapidity mass spectrum of di-electrons and cross sections of pseudoscalar and vector mesons via e(+) e(-) decays, from root s = 200 GeV p + p collisions, measured by the large-acceptance experiment STAR at the Relativistic Heavy Ion Collider. The ratio of the di-electron continuum to the combinatorial background is larger than 10% over the entire mass range. Simulations of di-electrons from light-meson decays and heavy-flavor decays (charmonium and open charm correlation) are found to describe the data. The extracted omega -> e(+) e(-) invariant yields are consistent with previous measurements. The mid-rapidity yields (dN/dy) of phi and J/psi are extracted through their di-electron decay channels and are consistent with the previous measurements of phi -> K+ K- and J/psi -> e(+) e(-). Our results suggest a new upper limit of the branching ratio of the eta -> e(+) e(-) of 1.7 x 10(-5) at the 90% confidence level.
Permanent Link: http://hdl.handle.net/11104/0216921