Abstract
Evidence for a positive longitudinal double-spin asymmetry (A1)ρ= 0.24 ± 0.11stat±0.02syst in the cross section for exclusive diffractive ρ0(770) vector-meson production in polarised lepton-proton scattering was observed by the HERMES experiment. The longitudinally polarised 27.56 GeV HERA positron beam was scattered off a longitudinally polarised pare hydrogen gas target. The average invariant mass of the photon-proton system has a value of (W) = 4.9 GeV, while the average negative squared four-momentum of the virtual photon is (Q2) = 1.7 GeV2. The ratio of the present result to the corresponding spin asymmetry in inclusive deep-inelastic scattering is in agreement with an early theoretical prediction based on the generalised vector-meson dominance model.
Original language | English |
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Pages (from-to) | 301-310 |
Number of pages | 10 |
Journal | Physics Letters, Section B: Nuclear, Elementary Particle and High-Energy Physics |
Volume | 513 |
Issue number | 3-4 |
DOIs | |
Publication status | Published - 2001 Aug 2 |
Externally published | Yes |
Keywords
- Asymmetries
- Lepton-nucleon scattering
- Photoabsorbtion
- Rho production
ASJC Scopus subject areas
- Nuclear and High Energy Physics