Eur. Phys. J. C 23, 225-236 (2002)
https://doi.org/10.1007/s100520100886

Transverse mass distributions of neutral pions from ²⁰⁸Pb-induced reactions at 158 · A GeV

Received: 3 August 2001
Revised: 19 November 2001
Published online: 8 February 2002

Abstract

Results on transverse mass spectra of neutral pions measured at central rapidity are presented for impact parameter selected 158 · A GeV Pb + Pb, and Pb + Nb collisions. The distributions cover the range 0.5 GeV/c² ≤ m_T - m₀ ≤ 4 GeV/c². The change of the spectral shape and the multiplicity with centrality is studied in detail. In going from p+p to semi-peripheral Pb+Pb collisions there is a nuclear enhancement increasing with transverse mass similar to the well known Cronin effect, while for very central collisions this enhancement appears to be weaker than expected.