Measuring coalescence radii and flow using identified protons and deuterons from NA44

Abstract

Transverse mass spectra of protons and deuterons in rapidity windowy=1.9–2.3 are presented for 158 A GeV Pb+Pb and 200 A GeV S+S and S+Pb collisions. The inverse slope parameter increases with system size and with particle mass. In the framework of a coalescence model a radius parameterRG can be extracted. Transverse mass dependence ofRG is consistent with the\({1 \mathord{\left/ {\vphantom {1 {\sqrt {m_T } }}} \right. \kern-\nulldelimiterspace} {\sqrt {m_T } }}\) decrease of the radius parameter as measured by HBT and thus provides an evidence for the radial flow.