Momentum spectra of π\sp−, K\sp−, p and d have been measured from central collisions of 14.6 × A GeV/c Si beam on Si and W targets at rapidity 1.9 < y < 2.1. The inverse slope parameters T\sb0 obtained by an exponential fit with the transverse mass spectra in transverse kinetic energy are found to be T\sb0(π\sp−)<T\sb0(K\sp−)<T\sb0(p)<T\sb0(d). This result is predicted by a radially expanding flow model. From integrated results, the K\sp−/π\sp− ratios, (2.7 ± 0.3) % from Si and (2.4 ± 0.2) % from W, are consistent with pp collision results. The deuteron production rates can be explained by a relativistic coalescence model.