The invariant spectra of π- mesons produced in (π+/Κ+)p interactions at 250 GeV / c are analysed in the framework of the hydrodynamical model of three-dimensionally expanding cylindrically symmetric finite systems. A satisfactory description of experimental data is achieved. The data favour the pattern according to which the hadron matter undergoes predominantly longitudinal expansion and non-relativistic transverse expansion with mean transverse velocity 〈ut〉 = 0.20 ± 0.07, and is characterized by a large temperature inhomogeneity in the transverse direction: the extracted freeze-out temperature at the center of the tube and at the transverse rms radius are 140 ± 3 MeV and 82 ± 7 MeV, respectively. The width of the (longitudinal) space-time rapidity distribution of the pion source is found to be Δn = 1.36 ± 0.02. Combining this estimate with results of the Bose-Einstein correlation analysis in the same experiment, one extracts a mean freeze-out time of the source of (τf) = 1.4 ± 0.1 fm/c and its transverse geometrical rms radius, RG(rms) = 1.2 ± 0.2 fm.
|Number of pages||10|
|Journal||Physics Letters, Section B: Nuclear, Elementary Particle and High-Energy Physics|
|Publication status||Published - Mar 12 1998|
ASJC Scopus subject areas
- Nuclear and High Energy Physics