Measurements of transverse spin effects in the forward region with the STAR detector

2009/11/23 by L. V. Nogach, Nogach, L.
Physics and Astronomy · #FOS: Physical sciences #High Energy Physics - Experiment (hep-ex) #High-Energy Particle Collisions Research #Particle physics theoretical and experimental studies #Quantum Chromodynamics and Particle Interactions

paper · pdf · doi:10.48550/arxiv.0911.4388

openalex publication_date 2009/11/23 · openalex created_date 2025/10/10 · openalex updated_date 2026/07/28

Abstract

Measurements by the STAR collaboration of the cross section and transverse single spin asymmetry (SSA) of neutral pion production at large Feynman x (x_F) in pp-collisions at √(s)=200 GeV were reported previously. The x_F dependence of the asymmetry can be described by phenomenological models that include the Sivers effect, Collins effect or higher twist contributions in the initial and final states. Discriminating between the Sivers and Collins effects requires one to go beyond inclusive π⁰ measurements. For the 2008 run, forward calorimetry at STAR was significantly extended. The large acceptance of the Forward Meson Spectrometer (FMS) allows us to look at heavier meson states and π⁰-π⁰ correlations. Recent results, the status of current analyses and near-term plans will be discussed.

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