Longitudinal double spin asymmetries in single hadron quasi-real photoproduction at high p_T

2015/09/11 by C. Adolph, COMPASS Collaboration, R. Akhunzyanov +435 · 1 citation
Physics and Astronomy · #FOS: Physical sciences #High Energy Physics - Experiment (hep-ex) #High Energy Physics - Phenomenology (hep-ph) #High-Energy Particle Collisions Research #Particle physics theoretical and experimental studies #Quantum Chromodynamics and Particle Interactions #hep-ex #hep-ph

paper · pdf · doi:10.48550/arxiv.1509.03526

openalex publication_date 2015/09/11 · arxiv created 2015/12/14 · arxiv updated 2015/12/15 · openalex created_date 2025/10/10 · openalex updated_date 2026/07/28

Abstract

We measured the longitudinal double spin asymmetries A_LL for single hadron muo-production off protons and deuterons at photon virtuality Q² < 1(GeV/\it c)² for transverse hadron momenta p_T in the range 0.7 GeV/\it c to 4 GeV/\it c . They were determined using COMPASS data taken with a polarised muon beam of 160 GeV/\it c or 200 GeV/\it c impinging on polarised \mathrm⁶LiD or NH₃ targets. The experimental asymmetries are compared to next-to-leading order pQCD calculations, and are sensitive to the gluon polarisation ΔG inside the nucleon in the range of the nucleon momentum fraction carried by gluons 0.05 < x_g < 0.2.

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• Direct- and resolved-photon threshold resummation for polarized high-pT hadron production at COMPASS

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