Abstract
The two-spin parameter ALL in inclusive π0 productionby longitudinally-polarized protons and antiprotons on a longitudinally-polarized proton target has been measured at the 200 GeV Fermilab spin physics facility, for π0's at xF=0 with 1≤pt≤3 GeV/c. The results exclude, at the 95% confidence level, values of ALL (pp) > 0.1 and < - 0.1 for π0's produced by protons, and values of ALL (pp) > 0.1 and < -0.2 for incident antiprotons. The relevance of ALL (pp) for the gluon spin density is discussed. The data are in good agreement with "conventional", small or zero, gluon polarization.
Original language | English |
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Pages (from-to) | 197-200 |
Number of pages | 4 |
Journal | Physics Letters B |
Volume | 261 |
Issue number | 1-2 |
DOIs | |
State | Published - May 23 1991 |