Measurement of the nucleon structure functions

Abstract

Measurements have been made of the inclusive scattering of 96, 147, and 219 GeV muons from hydrogen, and of 147 GeV muons from deuterium. Results are presented for the nucleon structure function ${F}_{2}(x,{Q}^{2})$ [$\ensuremath{\equiv}\ensuremath{\nu}{W}_{2}(x,{Q}^{2})$] for $10<\ensuremath{\nu}<200$ GeV and $0.2<{Q}^{2}<80$ ${\mathrm{GeV}}^{2}$. The value of ${F}_{2}$ rises with ${Q}^{2}$ at small $x$, and falls with ${Q}^{2}$ at large $x$, in agreement with the ideas of quantum chromodynamics. An average value of the ratio $\frac{{\ensuremath{\sigma}}_{L}}{{\ensuremath{\sigma}}_{T}}\ensuremath{\equiv}R=0.52\ifmmode\pm\else\textpm\fi{}0.35$ has been obtained for the region $0.003<x<0.10$ and $0.4<{Q}^{2}<30$ ${\mathrm{GeV}}^{2}$. The values of ${F}_{2}$ from this experiment have been combined with those from other charged-lepton scattering experiments to determine moments of the structure functions. The variation with ${Q}^{2}$ of these moments is used to derive values for $\ensuremath{\Lambda}$, taking into account corrections up to second order in ${\ensuremath{\alpha}}_{s}$. The fit to the data is very good.