Simultaneous multiplicity and forward energy characterization of particle spectra in Au+Au collisions at [Formula Presented] GeV/c

In this paper Au+Au collisions at [Formula Presented] are characterized by two global observables: the energy measured near zero degrees [Formula Presented] and the total event multiplicity. Particle spectra are measured for different event classes that are defined in a two-dimensional grid of both global observables. For moderately central events [Formula Presented] the proton [Formula Presented] distributions do not depend on [Formula Presented] but only on the event multiplicity. In contrast the shape of the proton transverse spectra shows little dependence on the event multiplicity. The change in the proton [Formula Presented] distributions suggests that different conditions are formed in the collision for different event classes. These event classes are studied for signals of new physics by measuring pion and kaon spectra and yields. In the event classes doubly selected on [Formula Presented] and multiplicity there is no indication of any unusual pion or kaon yields, spectra, or [Formula Presented] ratio even in the events with extreme multiplicity.