A single-spin asymmetry in the distribution of exclusively produced π + mesons azimuthally around the virtual photon direction relative to the lepton scattering plane has been measured for the first time in deep-inelastic scattering of positrons off longitudinally polarized protons. Integrated over the experimental acceptance, the sin moment of the polarization asymmetry of the cross section is measured to be -0.18 ± 0.05(stat.) ± 0.02(syst.). The asymmetry is also studied as a function of the relevant kinematic variables, and its magnitude is found to grow with decreasing x and increasing -t and vanish at t → t min (where x is the Bjorken scaling variable and t is the squared four-momentum transferred to the nucleon).
|Number of pages||8|
|Journal||Physics Letters, Section B: Nuclear, Elementary Particle and High-Energy Physics|
|Publication status||Published - 23 May 2002|
ASJC Scopus subject areas
- Nuclear and High Energy Physics