J. H. Chen

Searching for onset of deconfinement via hypernuclei and baryon-strangeness correlations

Abstract We argue that the ratio S 3 = H Λ 3 / ( He 3 × Λ p ) is a good representation of the local correlation between baryon number and strangeness, and therefore is a valuable tool to probe the nature of the dense matter created in high energy heavy-ion collisions: quark gluon plasma or hadron gas. A multiphase transport model (AMPT) plus a dynamical coalescence model is used to elucidate our arguments. We find that AMPT with string melting predicts an increase of S 3 with increasing beam energy, and is consistent with experimental data, while AMPT with only hadronic scattering results in a low S 3 throughout the energy range from AGS to RHIC, and fails to describe the experimental data.

Observation of hypertritons in Au+Au collisions at sNN=200GeV

We report preliminary results of hypertriton observation in heavy-ion collisions at RHIC. We have identified 157 +- 30 candidates in the current sample containing ~10^8 Au+Au events at sqrt{s_{NN}} = 200 GeV. The production rate of hypertriton is close to that of helium 3. No extra penalty factor is observed for hypertriton, in contrast to results observed at the AGS.