U.S. Department of EnergyOffice of Scientific and Technical Information
Electron-positron production in ultra-peripheral heavy-ion collisions with the STAR experiment
Abstract
This thesis presents a measurement of the cross-section of the purely electromagnetic production of e+e- pairs accompanied by mutual nuclear Coulomb excitation AuAu → Au*Au* + e+e-, in ultra-peripheral gold-gold collisions at RHIC at the center-of-mass collision energy of √SNN = 200 GeV per nucleon. These reactions were selected by detecting neutron emission by the excited gold ions in the Zero Degree Calorimeters. The charged tracks in the e+e- events were reconstructed with the STAR Time Projection Chamber. The detector acceptance limits the kinematical range of the observed e+e- pairs; therefore the measured cross-section is extrapolated to 4π with the use of Monte Carlo simulations. We have developed a Monte Carlo simulation for ultra-peripheral e+e- production at RHIC based on the Equivalent Photon Approximation, the lowest-order QED e+e- production cross-section by two real photons and the assumption that the mutual nuclear excitations and the e+e- production are independent (EPA model). We compare our experimental results to two models: the EPA model and a model based on full QED calculation of the e+e- production, taking the photon virtuality into account. The measured differential cross-section dσ/dMinv (Minv - e+e- invariant mass) agrees well with both theoretical models. The measured differential cross-section dσ/dpmore »
- Authors:
-
- Univ. of California, Berkeley, CA (United States)
- Publication Date:
- Research Org.:
- Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States)
- Sponsoring Org.:
- USDOE Office of Science (SC), Nuclear Physics (NP)
- OSTI Identifier:
- 817249
- Report Number(s):
- LBNL-53583
R&D Project: NRNC; TRN: US0305181
- DOE Contract Number:
- AC03-76SF00098
- Resource Type:
- Thesis/Dissertation
- Resource Relation:
- Other Information: TH: Thesis (Ph.D.); Submitted to the University of California, Berkeley, CA (US); PBD: 1 Aug 2003
- Country of Publication:
- United States
- Language:
- English
- Subject:
- 72 PHYSICS OF ELEMENTARY PARTICLES AND FIELDS; 73 NUCLEAR PHYSICS AND RADIATION PHYSICS; 74 ATOMIC AND MOLECULAR PHYSICS; CALORIMETERS; COULOMB EXCITATION; DIFFERENTIAL CROSS SECTIONS; EQUIVALENT-PHOTON APPROXIMATION; GOLD IONS; NEUTRON EMISSION; PHOTONS; PRODUCTION; SIMULATION; TIME PROJECTION CHAMBERS; TRANSVERSE MOMENTUM; US EPA
Citation Formats
Morozov, Vladimir Borisovitch. Electron-positron production in ultra-peripheral heavy-ion collisions with the STAR experiment. United States: N. p., 2003.
Web. doi:10.2172/817249.
Morozov, Vladimir Borisovitch. Electron-positron production in ultra-peripheral heavy-ion collisions with the STAR experiment. United States. https://doi.org/10.2172/817249
Morozov, Vladimir Borisovitch. 2003.
"Electron-positron production in ultra-peripheral heavy-ion collisions with the STAR experiment". United States. https://doi.org/10.2172/817249. https://www.osti.gov/servlets/purl/817249.
@article{osti_817249,
title = {Electron-positron production in ultra-peripheral heavy-ion collisions with the STAR experiment},
author = {Morozov, Vladimir Borisovitch},
abstractNote = {This thesis presents a measurement of the cross-section of the purely electromagnetic production of e+e- pairs accompanied by mutual nuclear Coulomb excitation AuAu → Au*Au* + e+e-, in ultra-peripheral gold-gold collisions at RHIC at the center-of-mass collision energy of √SNN = 200 GeV per nucleon. These reactions were selected by detecting neutron emission by the excited gold ions in the Zero Degree Calorimeters. The charged tracks in the e+e- events were reconstructed with the STAR Time Projection Chamber. The detector acceptance limits the kinematical range of the observed e+e- pairs; therefore the measured cross-section is extrapolated to 4π with the use of Monte Carlo simulations. We have developed a Monte Carlo simulation for ultra-peripheral e+e- production at RHIC based on the Equivalent Photon Approximation, the lowest-order QED e+e- production cross-section by two real photons and the assumption that the mutual nuclear excitations and the e+e- production are independent (EPA model). We compare our experimental results to two models: the EPA model and a model based on full QED calculation of the e+e- production, taking the photon virtuality into account. The measured differential cross-section dσ/dMinv (Minv - e+e- invariant mass) agrees well with both theoretical models. The measured differential cross-section dσ/dp $tot\atop{\perp}$ (p$tot\atop{\perp}$- e+e- total transverse momentum) favors the full QED calculation over the EPA model.},
doi = {10.2172/817249},
url = {https://www.osti.gov/biblio/817249},
journal = {},
number = ,
volume = ,
place = {United States},
year = {Wed Jan 01 00:00:00 EST 2003},
month = {Wed Jan 01 00:00:00 EST 2003}
}