DOUBLE PION PRODUCTION IN NN AND $\bar NN$ COLLISIONS

Charm Production in Nn and Γn Collisions

The processes of open and hidden charm production in NN collisions and of open charm production in γN collisions are studied. The near-threshold cross section is predicted and polarization phenomena are calculated in frame of an effective Lagrangian approach.

Pion Interferometry in Auau Collisions at √ S Nn =200 Gev

We present preliminary results from a two-pion intensity interferometry analysis from Au+Au collisions at √ s NN =200 GeV measured in the STAR detector at RHIC. The dependence of the apparent pion source on multiplicity and transverse momentum are discussed and compared with preliminary results from d+Au and p+p collisions at the same beam energy.

Photon and neutral pion production in Au plus Au collisions at root s(NN)=130 GeV

Neutral pion production in Au plus Au collisions at root s(NN)=200 GeV

On the treatment of NN interaction effects in meson production in NN collisions

We clarify under what circumstances the nucleon–nucleon final state interaction fixes the energy dependence of the total cross–section for the reaction NN → NNx close to production threshold, where x can be any meson whose interaction with the nucleon is not too strong. We strongly criticize the procedure used recently by several authors to include the final state interaction in the reactions u...