Related papers: Positron spectra from internal pair conversion obs…
We present the results of a Doppler-shift correction to the measured e+e- sum-energy spectra obtained from e+e- coincidence measurements in 238U + 206Pb and 238U + 181Ta collisions at beam energies close to the Coulomb barrier, using an…
We present the results from e+e- coincidence measurements in 238U + 206Pb collisions at a beam energy of 5.93 MeV/u, using an improved experimental setup at the double-Orange spectrometer of GSI. The capability of our device to detect…
A multi-detector array has been constructed for the simultaneous measurement of energy- and angular correlation of electron-positron pairs produced in internal pair conversion (IPC) of nuclear transitions up to 18 MeV. The response…
This work presents measurements of electron-positron pairs from p+p collisions at sqrt(s) = 200 GeV collected during the 2005 RHIC run and compares them to results from Au+Au collisions at sqrt(s_NN) = 200 GeV taken in 2004 with the PHENIX…
Excitation spectra of $^{11}$C were measured in the $^{12}$C$(p,d)$ reaction near the $\eta'$ emission threshold. A proton beam extracted from the synchrotron SIS-18 at GSI with an incident energy of 2.5 GeV impinged on a carbon target. The…
We present new results obtained from a series of follow-up e+e- coincidence measurements in heavy-ion collisions, utilizing an improved experimental set-up at the double-Orange beta-spectrometer of GSI. The collision system U+Ta was…
The direct measurements of electrons and positrons over the last 30 years, corrected for the solar effect in the force-field approximation, are considered. The resulting overall electron spectrum may be fitted with a single power law above…
In slow collisions of two bare nuclei with the total charge number larger than the critical value, $Z_{\rm cr} \approx 173$, the initially neutral vacuum can spontaneously decay into the charged vacuum and two positrons. Detection of the…
We present the first energy and angle resolved measurements of e+e- pairs emitted from heavy nuclei (Z>=40) at rest by internal pair conversion (IPC) of transitions with energies of less than 2MeV as well as recent theoretical results using…
The B(E2; Ii -> If) values for transitions in 71Ga and 73Ga were deduced from a Coulomb excitation experiment at the safe energy of 2.95 MeV/nucleon using post-accelerated beams of 71,73Ga at the REX-ISOLDE on-line isotope mass separator…
The first measurements of the cross sections for neutral and charged current deep inelastic scattering in e+p collisions with longitudinally polarised positron beams are presented. The total cross section for e+p charged current deep…
Electron-positron pair production in low-energy collisions of heavy nuclei is considered beyond the monopole approximation. The calculation method is based on the numerical solving of the time-dependent Dirac equation with the full…
Interaction cross sections and charged pion spectra in p+C interactions at 31 GeV/c were measured with the large acceptance NA61/SHINE spectrometer at the CERN SPS. These data are required to improve predictions of the neutrino flux for the…
The cross sections for charged and neutral current deep inelastic scattering in e^+p collisions with a longitudinally polarised positron beam have been measured using the ZEUS detector at HERA. The results, based on data corresponding to an…
Measurements of dielectron production in p+p and p+d collisions with beam kinetic energies from 1.04 to 4.88 GeV are presented. The differential cross section is presented as a function of invariant pair mass, transverse momentum, and…
Measurements of neutral current cross sections for deep inelastic scattering in e+p collisions at HERA with a longitudinally polarised positron beam are presented. The single-differential cross-sections d(sigma)/dQ2, d(sigma)/dx and…
We report measurements of electron pair production in elementary p+p and d+p reactions at 1.25 GeV/u with the HADES spectrometer. For the first time, the electron pairs were reconstructed for n+p reactions by detecting the proton spectator…
New kind of positron sources for future linear colliders, where the converter is a tungsten crystal oriented on the <111> axis, has been studied at CERN in the WA103 experiment. In such sources the photons which create the $e^+ e^-$ pairs…
We calculate the spatial correlation of electrons and positrons emitted by internal pair conversion of Coulomb excited nuclei in heavy ion collisions. The alignment or polarization of the nucleus results in an anisotropic emission of the…
A multi-detector array has been designed and constructed for the simultaneous measurement of energy- and angular correlations of electron-positron pairs. Experimental results are obtained over a wide angular range for high-energy…