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.

arXiv comment15 pages, 17 figures, 4 tables. Published

References in corpus (49)

• Experimental and Theoretical Challenges in the Search for the Quark Gluon Plasma: The STAR Collaboration's Critical Assessment of the Evidence from RHIC Collisions
• Formation of dense partonic matter in relativistic nucleus-nucleus collisions at RHIC: Experimental evaluation by the PHENIX collaboration
• Quark Gluon Plasma an Color Glass Condensate at RHIC? The perspective from the BRAHMS experiment
• The PHOBOS Perspective on Discoveries at RHIC
• High-Energy-Physics Event Generation with PYTHIA 6.1
• Systematic Measurements of Identified Particle Spectra in pp, d+Au and Au+Au Collisions from STAR
• Transverse momentum and collision energy dependence of high $p_T$ hadron suppression in Au+Au collisions at ultrarelativistic energies
• The STAR Time Projection Chamber: A Unique Tool for Studying High Multiplicity Events at RHIC
• New Fixed-Target Experiments to Search for Dark Gauge Forces
• Identified particle distributions in pp and Au+Au collisions at sqrt{s_NN}=200 GeV
• Enhanced production of direct photons in Au+Au collisions at sqrt(s_NN)=200 GeV and implications for the initial temperature
• First Measurement of the rho Spectral Function in High-Energy Nuclear Collisions
• Detailed measurement of the e+e- pair continuum in p+p and Au+Au collisions at sqrt(s_NN)=200 GeV and implications for direct photon production
• Colour Deconfinement and Quarkonium Binding
• Chiral Restoration in Hot and/or Dense Matter
• Identified hadron spectra at large transverse momentum in p+p and d+Au collisions at \sqrts_NN = 200 GeV
• Color Screening Melts Quarkonium
• Spectra and radial flow at RHIC with Tsallis statistics in a Blast-Wave description
• Measurement of neutral mesons in p+p collisions at sqrt(s) = 200 GeV and scaling properties of hadron production
• Measurement of high-p_T Single Electrons from Heavy-Flavor Decays in p+p Collisions at sqrt(s) = 200 GeV
• Open charm yields in d+Au collisions at $\sqrt{s_{{}_{NN}}}=200$ GeV
• Low-Mass Dileptons at the CERN-SpS: Evidence for Chiral Restoration?
• J/psi Production vs Transverse Momentum and Rapidity in p+p Collisions at sqrt(s) = 200 GeV
• Phi meson production in Au+Au and p+p collisions at sqrt (s)=200 GeV
• Dilepton Radiation at the CERN Super Proton Synchrotron
• rho^0 Production and Possible Modification in Au+Au and p+p Collisions at sqrt(s_NN) = 200 GeV
• Study of the electromagnetic transition form-factors in η-> μ^+μ^-γand ω-> μ^+μ^-π^0 decays with NA60
• Pion, kaon, proton and anti-proton transverse momentum distributions from p+p and d+Au collisions at $\sqrt{s_{NN}}=200$ GeV
• e+e--pair production in Pb-Au collisions at 158 GeV per nucleon
• Heavy quarkonium in any channel in resummed hot QCD
• Extensive Particle Identification with TPC and TOF at the STAR Experiment
• 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
• Examine the species and beam-energy dependence of particle spectra using Tsallis Statistics
• High transverse momentum eta meson production in p+p, d+Au and Au+Au collisions at sqrt(s_NN) = 200 GeV
• The TOFp/pVPD Time of Flight System for STAR
• Measurement of inclusive antiprotons from Au+Au collisions at 130 GeV
• Matter-induced modification of resonances at RHIC freezeout
• The Rare Decays $\piee$, $\etaee$ and \etamumu$ in Chiral Perturbation Theory
• High $p_T$ non-photonic electron production in $p$+$p$ collisions at $\sqrt{s}$ = 200 GeV
• Pi+ Pi- Emission in High-Energy Nuclear Collisions
• Rare decay π^0 \to e^+e^- as a Test of Standard Model
• Measurement of eta meson decays into lepton-antilepton pairs
• 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
• Improving the dE/dx calibration of the STAR TPC for the high-pT hadron identification
• Spectroscopy of resonance decays in high-energy heavy-ion collisions
• Di-lepton production in p+p collisions at $\sqrt{s_{{}_{NN}}}=200$ GeV from STAR
• A New Upper Limit on the Decay $\eta \to e^{+}{e}^{-}$

Cited by in corpus (22)

• Measurements of Dielectron Production in Au$+$Au Collisions at $\sqrt{s_{\mathrm{NN}}}$ = 200 GeV from the STAR Experiment
• Dielectron Mass Spectra from Au+Au Collisions at $\sqrt{s_{\mathrm{NN}}}$ = 200 GeV
• Energy dependence of acceptance-corrected dielectron excess mass spectrum at mid-rapidity in Au+Au collisions at $\sqrt{s_{NN}}=19.6$ and 200 GeV
• Upsilon (1S+2S+3S) production in d+Au and p+p collisions at sqrt(s_NN)=200 GeV and cold-nuclear matter effects
• Dilepton Radiation from Strongly Interacting Systems
• The STAR Dilepton Physics Program
• Beam Energy Dependence of Dielectron Production in Au+Au Collisions from STAR at RHIC
• Dielectron production in proton-proton collisions at $\sqrt{s}$ = 7 TeV
• The low and intermediate mass dilepton and photon results
• Dielectron Azimuthal Anisotropy at mid-rapidity in Au+Au collisions at $\sqrt{s_{{}_{NN}}}=200$ GeV
• Direct photon production in Au+Au collisions at $\sqrt{s_{NN}}=200$ GeV at STAR
• Soft-dielectron excess in proton-proton collisions at $\sqrt{s}$ = 13 TeV
• Dilepton Measurements at STAR
• Dielectron production in 200 GeV p+p and Au+Au collisions at STAR
• 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
• Heavy Flavor, Quarkonia, and Electroweak Probes at Quark Matter 2012
• The di-lepton physics program at STAR
• Measurability of phi, omega and rho mesons via di-electron decays in high-temperature states produced in heavy-ion collisions
• Overview of electromagnetic probes in ultra-relativistic heavy-ion collisions
• The elliptic flow of di-electrons in $\sqrt{s_{NN}}$=200 GeV Au+Au collisions at STAR
• Dielectron production from $\sqrt{s_{NN}}$ = 200 GeV Au + Au collisions at STAR