Experimental determination of the π meson structure functions by the Drell-Yan mechanism.

We have studied high statistics samples of dimuon events (∼35,000) produced from π on platinum target in the mass interval 4.2≦ M≦8.5 GeV at 150, 200 and 280 GeV/c. The π structure function is obtained by a fit of dσ/ dx dx to π and π data. At 200 GeV, the simultaneous use of π and π data allows a separate determination of the valence and sea structure functions of the π. Furthermore, the 150 and 280 GeV data allow an accurate determination of the shape of the valence structure function and give an estimate of its evolution between Q=25 and 50 GeV. [ABSTRACT FROM AUTHOR]