Pseudorapidity Distributions Of Charged Particles In D+Au And P+P Collisions At Root S(Nn)=200 Gev

The measured pseudorapidity distributions of primary charged particles are presented for d+Au and p+p collisions at rootS(NN) = 200 GeV over a wide pseudorapidity range of \eta\ less than or equal to 5.4. The results for d+Au collisions are presented for minimum-bias events and as a function of collision centrality. The measurements for p+p collisions are shown for minimum-bias events. The ratio of the charged particle multiplicity in d+Au and p+A collisions relative to that for inelastic p+p collisions is found to depend only on , and it is remarkably independent of collision energy and system mass. The deuteron and gold fragmentation regions in d+Au collisions are in good agreement with proton nucleus data at lower energies.