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  • <h>Multi</h>-<h>strange bar...
    Anon

    Physics letters. B, 07/2016, Letnik: 758, Številka: C
    Journal Article

    The multi-strange baryon yields in Pbsingle bond Pb collisions have been shown to exhibit an enhancement relative to pp reactions. In this work, Xi and Omega production rates have been measured with the ALICE experiment as a function of transverse momentum, p sub(T)pT, in psingle bond Pb collisions at a centre-of-mass energy of View the MathML source sNN=5.02 TeV. The results cover the kinematic ranges 0.6 GeV/c<p sub(T)<7.2 GeV/c0.6 GeV/c<pT<7.2 GeV/c and 0.8 GeV/c<p sub(T)<5 GeV/c0.8 GeV/c<pT<5 GeV/c, for Xi and Omega respectively, in the common rapidity interval -0.5<y sub(CMS)<0-0.5<yCMS<0. Multi-strange baryons have been identified by reconstructing their weak decays into charged particles. The p sub(T)pT spectra are analysed as a function of event charged-particle multiplicity, which in psingle bond Pb collisions ranges over one order of magnitude and lies between those observed in pp and Pbsingle bond Pb collisions. The measured p sub(T)pT distributions are compared to the expectations from a Blast-Wave model. The parameters which describe the production of lighter hadron species also describe the hyperon spectra in high multiplicity psingle bond Pb collisions. The yield of hyperons relative to charged pions is studied and compared with results from pp and Pbsingle bond Pb collisions. A continuous increase in the yield ratios as a function of multiplicity is observed in psingle bond Pb data, the values of which range from those measured in minimum bias pp to the ones in Pbsingle bond Pb collisions. A statistical model qualitatively describes this multiplicity dependence using a canonical suppression mechanism, in which the small volume causes a relative reduction of hadron production dependent on the strangeness content of the hyperon.