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%                         P H O T O N 9 9
%                          Freiburg
%                       May  23 - 27, 1999
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Abstract \#000, \today
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{\large \bf
Measurement of the charged and neutral current cross sections at HERA
\\ }
\vspace{5mm}
M.~Erdmann$^1$
(for the H1 Collaboration)
\\
\vspace{5mm}
{\small\it
(1) University Karlsruhe / DESY, Notkestr. 85, D-22607 Hamburg, Germany
\\
}
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Measurements are presented of the cross sections for charged and
neutral current processes with 4-momentum transfer $Q^2$ between 150
and 30000 GeV$^2$. The cross sections for $e^+p$ scattering are
compared with those for $e^-p$, extracted from the ongoing 1998-1999
HERA run.  Evidence for the effect of $Z^0$ exchange in the neutral
current processes is presented. The dependence of the charged current cross
section on the incident quark flavour is examined. The measurements
are used to extract the proton structure function $F_2(x,Q^2)$ for
values of $x$ Bjorken between 0.0032 and 0.65. Using the charged and
neutral current measurements for both lepton charges the valance quark
distributions of the proton are extracted at very high $Q^2$.

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