Alexei Chikanian

Electron identification in the PHENIX experiment using a tracking TRD

Abstract Measuring dielectron physics signals at RHIC will require the ability to separate electrons from pions to a level of better than 2 × 10−4 over momenta ranging from 0.1 GeV c to 5.0 GeV c . Particle identification over this momentum range is realized in the PHENIX detector at RHIC by a combination of detector subsystems, one of which is a tracking TRD. The PHENIX tracking TRD allows electron-pion separation utilizing both TR and dE/dx information, while simultaneously tracking charged particles with good position accuracy. The electron-pion separation of this device is better than 3 × 10−3 for particles with momenta ranging from 250 MeV c to over 10 GeV c .

Nucleus-nucleus bremsstrahlung from ultrarelativistic collisions

The bremsstrahlung produced when heavy nuclei collide is estimated for central collisions at the Relativistic Heavy Ion Collider. Soft photons can be used to infer the rapidity distribution of the outgoing charge. An experimental design is outlined. {copyright} {ital 1998} {ital The American Physical Society}

Identified Baryon and Meson Distributions at Large Transverse Momenta from Au+Au Collisions at {radical}(s{sub NN})=200 GeV

Transverse momentum spectra of pi+/-, p, and p up to 12 GeV/c at midrapidity in centrality selected Au + Au collisions at square root sNN=200 GeV are presented. In central Au + Au collisions, both pi +/- and p(p) show significant suppression with respect to binary scaling at pT approximately >4 GeV/c. Protons and antiprotons are less suppressed than pi+/-, in the range 1.5 approximately < pT approximately < 6 GeV/c. The pi-/pi+ and p/p ratios show at most a weak pT dependence and no significant centrality dependence. The p/pi ratios in central Au + Au collisions approach the values in p + p and d + Au collisions at pT approximately >5 GeV/c. The results at high pT indicate that the partonic sources of pi+/-, p, and p have similar energy loss when traversing the nuclear medium.