Di-electron spectrum at mid-rapidity in $p+p$ collisions at $\sqrt{s}=200$ GeV

Abstract

We report on mid-rapidity mass spectrum of di-electrons and cross sections of pseudoscalar and vector mesons via $e^{+}{e}^{-}$ decays, from $\sqrt{s}=200$ GeV $p+p$ collisions, measured by the large acceptance experiment STAR at RHIC. 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 $\omega \to e^{+}{e}^{-}$ invariant yields are consistent with previous measurements. The mid-rapidity yields ($dN/dy$) of $\varphi$ and $J/\psi$ are extracted through their di-electron decay channels and are consistent with the previous measurements of $\varphi \to K^{+}{K}^{-}$ and $J/\psi \to e^{+}{e}^{-}$. Our results suggest a new upper limit of the branching ratio of the $\eta \to e^{+}{e}^{-}$ of $1.7\times 10^{-5}$ at 90% confidence level.

15 pages, 17 figures, 4 tables. Published

References in corpus (13)

• Systematic Measurements of Identified Particle Spectra in pp, d+Au and Au+Au Collisions from STAR
• New Fixed-Target Experiments to Search for Dark Gauge Forces
• Color Screening Melts Quarkonium
• Measurement of high-p_T Single Electrons from Heavy-Flavor Decays in p+p Collisions at sqrt(s) = 200 GeV
• J/psi Production vs Transverse Momentum and Rapidity in p+p Collisions at sqrt(s) = 200 GeV
• Study of the electromagnetic transition form-factors in η-> μ^+μ^-γand ω-> μ^+μ^-π^0 decays with NA60
• Heavy quarkonium in any channel in resummed hot QCD
• Nuclear modification factors of phi mesons in d+Au, Cu+Cu and Au+Au collisions at sqrt(S_NN)=200 GeV
• J/psi production at high transverse momentum in p+p and Cu+Cu collisions at \sNN=200GeV
• High transverse momentum eta meson production in p+p, d+Au and Au+Au collisions at sqrt(s_NN) = 200 GeV
• High $p_T$ non-photonic electron production in $p$+$p$ collisions at $\sqrt{s}$ = 200 GeV
• Electromagnetic Probes at RHIC-II
• Production of omega mesons at Large Transverse Momenta in p+p and d+Au Collisions at sqrt(s_NN) = 200 GeV

Cited by in corpus (3)

• The low and intermediate mass dilepton and photon results
• Flavor dependence of the thermal dissociations of vector and axial-vector mesons
• Measurement of inclusive electrons from open heavy-flavor hadron decays in $p$+$p$ collisions at $\sqrt{s}=200$ GeV with the STAR detector