Midrapidity Lambda and anti-Lambda production in Au + Au collisions at s(NN)**(1/2) = 130-GeV

The collaboration
Phys.Rev.Lett. 89 (2002) 092301, 2002.

Abstract
We report the first measurement of strange ($\Lambda$) and anti-strange ($\bar{\Lambda}$) baryon production from $\sqrt{s_{_{NN}}}=130$ GeV Au+Au collisions at the Relativistic Heavy Ion Collider (RHIC). Rapidity density and transverse mass distributions at mid-rapidity are presented as a function of centrality. The yield of $\Lambda$ and $\bar{\Lambda}$ hyperons is found to be approximately proportional to the number of negative hadrons. The production of $\bar{\Lambda}$ hyperons relative to negative hadrons increases very rapidly with transverse momentum. The magnitude of the increase cannot be described by existing hadronic string fragmentation models.

• #### Figure 2 left panel

10.17182/hepdata.99050.v1/t1

Transverse mass distributions of $\Lambda$ at mid-rapidity ($|y|<0.5$) for selected centrality bins. Only statistical errors are listed. Combined systematic errors...

• #### Figure 2 right panel

10.17182/hepdata.99050.v1/t2

Transverse mass distributions of $\bar\Lambda$ at mid-rapidity ($|y|<0.5$) for selected centrality bins. Only statistical errors are listed. Combined systematic errors...

• #### Figure 3

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The mid-rapidity $\bar\Lambda$ ($|y|<0.5$) transverse momentum distribution from the top $5\%$ most central collisions. For comparison the distributions for negative...

• #### Figure 4

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$\Lambda$ and $\bar\Lambda$ rapidity density as a function of negative hadron multiplicity at mid-rapidity. The open symbols in the figure...

• #### TABLE I

10.17182/hepdata.99050.v1/t5

Fit parameters from Boltzmann and exponential fits of the $m_{T}$ spectra for $\Lambda$ and $\bar\Lambda$ at mid-rapidity ($|y|<0.5$). Only statistical...