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arXiv · 1012.1970

Longitudinal spin transfer of Lambda and anti-Lambda in polarized pp collisions at \sqrt s=200 GeV at STAR

Qing-hua Xu
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Abstract

We report our measurement on longitudinal spin transfer, D_LL, from high energy polarized protons to $Λ$ and $\barΛ$ hyperons in proton-proton collisions at $\sqrt{s} = 200 GeV$ with the STAR detector at RHIC. The current measurements cover $Λ$, $\barΛ$ pseudorapidity $|η| < 1.2$ and transverse momenta $p_T$ up to $4GeV/c$ using the data taken in 2005. The longitudinal spin transfer is found to be D_LL= -0.03\pm 0.13 (stat) \pm 0.04(syst)$ for inclusive $Λ$ and $D_{LL} = -0.12 \pm 0.08(stat) \pm 0.03(syst)$ for inclusive $\barΛ$ hyperons with $ = 0.5$ and $ = 3.7 GeV/c$. The prospects with 2009 data and the future measurements are also given.

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Qing-hua Xu. 2010-12-09. Longitudinal spin transfer of Lambda and anti-Lambda in polarized pp collisions at \sqrt s=200 GeV at STAR. https://doi.org/10.1088/1742-6596%2F295%2F1%2F012081

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