arXiv subjects

T. Hallman

Publications and source records attributed to T. Hallman.

4 recordsLinked to original sources

arXiv2003

Conference on the Intersections of Particle and Nuclear Physics 2003: Relativistic Heavy Ion Parallel Session Summary

The Relativistic Heavy Ion Collider (RHIC) came online in 2000, and the last three years have provided a wealth of new experimental data and theoretical work in this new energy frontier for nuclear physics. The transition from quarks and gluons bound into hadrons to a deconfined quark-gluon plasma is expected to occur at these energies, and the effort to understand the time evolution of these complex systems has been significantly advanced. The heavy ion parallel session talks from the Conference on the Intersections of Particle and Nuclear Physics (CIPANP) 2003 are posted at: http://www.phenix.bnl.gov/WWW/publish/nagle/CIPANP/. We provide a brief summary of these sessions here.

nucl-ex↗

arXiv1997

Inclusive Dielectron Cross Sections in p+p and p+d Interactions at Beam Energies from 1.04 to 4.88 GeV

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 rapidity. The shapes of the mass spectra and their evolution with beam energy provide information about the relative importance of the various dielectron production mechanisms in this energy regime. The p+d to p+p ratio of the dielectron yield is also presented as a function of invariant pair mass, transverse momentum, and rapidity. The shapes of the transverse momentum and rapidity spectra from the p+d and p+p systems are found to be similar to one another for each of the beam energies studied. The beam energy dependence of the integrated cross sections is also presented.

nucl-ex↗

arXiv1997

Dielectron Cross Section Measurements in Nucleus-Nucleus Reactions at 1.0 A GeV

We present measured dielectron production cross sections for Ca+Ca, C+C, He+Ca, and d+Ca reactions at 1.0 A GeV. Statistical uncertainties and systematic effects are smaller than in previous DLS nucleus-nucleus data. For pair mass < 0.35 GeV/c2 : 1) the Ca+Ca cross section is larger than the previous DLS measurement and current model results, 2) the mass spectra suggest large contributions from pi0 and eta Dalitz decays, and 3) dsigma/dM is proportional to ApAt. For M > 0.5 GeV/c2 the Ca+Ca to C+C cross section ratio is significantly larger than the ratio of ApAt values.

nucl-ex↗

arXiv1994

Dilepton production from p-p to Ca-Ca at the Bevalac

The DLS collaboration has recently completed a high statistics study of dilepton production at the Bevalac. In particular, we have measured dielectrons (e+e-) from p-p and p-d collisions to understand the basic dilepton production mechanisms in the energy range from 1.05 - 4.9 GeV. These data can be used to determine the basic processes which contribute to nucleon-nucleon dilepton production such as hadronic bremsstrahlung, vector meson processes, and hadronic Dalitz decay. The data show that a simple elastic bremsstrahlung calculation is insufficient to explain the data. Theoretical models are compared with the data. A new high statistics study of Ca-Ca at 1.05 A GeV has been made to study the collectivity of A-A collisions.

nucl-ex↗