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\begin{document}

\pagestyle{empty}
\begin{titlepage}

\noindent
\begin{center}
  \begin{small}
  \begin{tabular}{llrr}
  Submitted to & & &
  \epsfig{file=H1logo.epsi
  ,width=1.5cm} \\[.2em] \hline
  \multicolumn{4}{l}{\bf 23rd International Symposium on Lepton-Photon Interactions at High Energy, LP2007}\\
  \multicolumn{4}{l}{August 13-18, 2007, Daegu, Republic of Korea} \\
        \hline
    \multicolumn{4}{l}{\footnotesize {\it Electronic Access:
        www-h1.desy.de/h1/www/publications/conf/conf\_list.html}} \\[.2em]
  \end{tabular}
  \end{small}
  \end{center}

\vspace*{2cm}

\begin{center}
  \Large
  {\bf \boldmath
High $Q^2$ Neutral Currents using the Complete HERA Data}

  \vspace*{1cm}
    {\Large H1 Collaboration} 
\end{center}

\begin{abstract}

\noindent
Neutral Current $e^{\pm}p\rightarrow e^{\pm} X$ single differential cross sections
${\rm d}\sigma/{\rm d}Q^2$ are presented using the full HERA dataset recorded with the 
H1 detector.
%
The cross sections are measured in the region
of large negative four-momentum transfer squared $Q^2 \geq 200\,{\rm GeV}^2$ and inelasticity $y<0.9$. 
%
The total integrated luminosity amounts to $270\,{\rm pb}^{-1}$ of
$e^+p$ and $165\,{\rm pb}^{-1}$ of $e^-p$ data.
%
The measurements are compared to predictions of the
Standard Model.
%
A form factor analysis is
performed and an upper limit is obtained 
on the quark radius of $0.74\cdot 10^{-18}\,{\rm m}$ at $95\%$ CL.

\noindent
\end{abstract}








\end{titlepage}

\pagestyle{plain}

%\section{Introduction} % 
%
Neutral current interactions at high four momentum transfer $Q^2$ at
HERA provide an important test of the Standard Model (SM) at the high
energy frontier.
%
This paper presents a new measurement using the full HERA dataset
recorded with the H1 detector.
%
%high four momentum transfers $Q^2$ at HERA 
%
% provide a test of the SM at the high energy fronteer.
%
The single differential cross section ${\rm d}\sigma/{\rm d}Q^2$ is
analysed over a wide $Q^2$ range from $200\,{\rm GeV}^2$ to
$30000\,{\rm GeV}^2$.
%
The measurement combines the previously
published~\cite{97ep,99em,00ep} HERA I data and preliminary HERA II
data with longitudinally polarised lepton beams.
%
Part of the HERA II data has been already analysed~\cite{ichep06} and
the remaining data from the years 2006 and 2007 is now included.
%
Table~\ref{tab:dataset} summaries the different data sets used in the
cross section measurements.
%
The longitudinal polarisation of the electron\footnote{Unless stated
explicitly, 'electron' refers to both electron and positron in the
following.}  beam $P_e$ is defined as $P_e=(N_R-N_L)/(N_R+N_L)$, where
$N_R (N_L)$ is the number of right (left) handed leptons in the beam.
%
\begin{table}[h]
\vspace{0.4cm}
\begin{center}
\begin{tabular}{|c|c|rl|c|r|c|}
\hline
Beam & $\sqrt{s}\;{\rm (GeV)}$ &  \multicolumn{2}{c|}{Dataset} & ${\cal L} ({\rm pb}^{-1})$ & $P_e (\%)$ & Reference \\ \hline \hline
$e^+$ & $301$ & $94-97$ &     & $35.6$ & $0$     & \cite{97ep} \\ \hline
$e^+$ & $319$ & $99-00$ &     & $65.2$ & $0$     & \cite{00ep} \\ \hline
$e^+$ & $319$ & $03-04$ & $R$ & $26.9$ & $33.6$  & \cite{ichep06} \\
      &       & $03-04$ & $L$ & $20.7$ & $-40.2$ & \\ \hline 
$e^+$ & $319$ & $06-07$ &  & $121.3$ & $2.5$  & this analysis \\ \hline \hline
%$e^+$ & $319$ & $06-07$ & $R$ & \Huge ? & $30.6$  & this analysis \\
%      &       & $06-07$ & $L$ & \Huge ? &  $-35.5$ & \\ \hline \hline
%All $e^+$  & $319$ & $94-07$ &     & $270$   &         &  \\ \hline \hline 
$e^-$ & $319$ & $98-99$ &     & $16.4$ & $0$     & \cite{99em} \\ \hline
$e^-$ & $319$ & $04-05$ & $R$ &  $29.6$ & $37.0$  & \cite{ichep06} \\
      &       & $04-05$ & $L$ &  $68.6$ & $-27.0$ & \\ \hline
$e^-$ & $319$ & $06$    & & $50.2$  & $-5.3$  & this analysis \\ \hline \hline 
%$e^-$ & $319$ & $06$    & $R$ &  & $30.8$  & this analysis \\ 
%   &       & $06$    & $L$ &  & $-24.6$ & \\ \hline \hline
%All $e^-$  & $319$ & $98-06$ &     & $165$   &         &  \\ \hline 
All   & $319$ & $94-07$ &     & $434.5$   &         &  \\ \hline 
\end{tabular}
\caption{The integrated luminosity $({\cal L})$ and the luminosity 
weighted average polarisation $(P_e)$ of all data sets used
in the combination. All data are corrected to  $P_e=0$ and
$\sqrt{s} = 319\;\mbox{GeV}$.
%
%including the new periods from HERA-II 
%presented here. 
%
\label{tab:dataset}}
\end{center}
\end{table}
%

The data analysis and the cross section measurement of the new periods
follow the same procedure as used in previous
publications~\cite{97ep,99em,00ep}.
%
The cross sections are determined separately for $e^-p$ and $e^+p$
data.
%
%running periods and for $L$ and $R$ datasets. 
%
The data from different running periods are averaged by taking a
simple weighted mean using the total errors of the measurements.
%
Correlated errors are treated as being correlated across the data sets
as well as point-to-point within a data set.
%
Prior to the combination with the unpolarised HERA I data, the
combined HERA II datasets are corrected for their small residual
polarisations to $P_e=0$.
%
The $94-97$ data are corrected to a centre-of-mass energy  
of $319\,{\rm GeV}$ before combining with the other data sets.
%
A normalisation uncertainty due to the luminosity measurement is
determined to be $\pm 4.0\%$ for all \mbox{HERA II} data, which
results in an average uncertainty of 3.3\% for all data periods.
%
In the figures this uncertainty is not included in the error bars but
shown separately as dashed lines.
%

The combined cross sections for the $e^-p$, $e^+p$ and $e^\pm p$ data are
shown in figures~\ref{dsdq2ele}-\ref{dsdq2all}, compared to the
corresponding SM expectations determined from the H1 2000 PDF
fit~\cite{00ep}.
%
By combining the individual cross section measurements the precision
of data for $Q^2\ge 1000$~GeV$^2$ is improved dramatically and a total
uncertainty of below $10$\% is achieved up to $Q^2=20\,000$~GeV$^2$.
%

The entire NC sample, corresponding to an integrated luminosity of
$435\,{\rm pb}^{-1}$, is used to perform a form factor analysis to
search for quark substructure.
%
The strategy of the analysis closely follows the previous HERA I
publication [5].
%
Cross section calculations in the SM
are performed in the DIS scheme in next-to-leading order QCD using the
CTEQ6D parton density functions [6]. 
%
The PDF uncertainty of the SM prediction is taken into account.
%
An upper limit of 
 $0.74\cdot 10^{-18}\,{\rm m}$ at $95\%$ CL is derived
on the quark radius.
%
The effect of such a quark radius is illustrated in
figure~\ref{dsdq2fit}.
% 
\begin{thebibliography}{99}

%\cite{Adloff:1999ah}
\bibitem{97ep}
  C.~Adloff {\it et al.}  [H1 Collaboration],
  % ``Measurement of neutral and charged current cross-sections in positron
  % proton collisions at large momentum transfer,''
  Eur.\ Phys.\ J.\ C {\bf 13} 609 (2000)
  [hep-ex/9908059].
  %%CITATION = HEP-EX 9908059;%%

%\cite{Adloff:2000qj}
\bibitem{99em}
  C.~Adloff {\it et al.}  [H1 Collaboration],
  % ``Measurement of neutral and charged current cross sections in electron
  % proton collisions at high Q**2,''
  Eur.\ Phys.\ J.\ C {\bf 19} 269 (2001)
  [hep-ex/0012052].
  %%CITATION = HEP-EX 0012052;%%

\bibitem{00ep}
C.~Adloff {\it et al.}  [H1 Collaboration],
%``Measurement and QCD Analysis of Neutral and Charged Current Cross Sections 
% at HERA''
Eur.\ Phys.\ J.\ C {\bf 30} 1 (2003) 
[hep-ex/0304003].
%%CITATION = HEP-EX 0304003;%%

\bibitem{ichep06}
A.~Aktas {\it et al.}  [H1 Collaboration],
  Contributed paper to the 33rd International Conference on High Energy Physics, ICHEP06, July 26 -  August 2, 2006, Moscow.
\vspace{-2mm}

%\cite{Adloff:2003jm}
\bibitem{bsm03}
  C.~Adloff {\it et al.}  [H1 Collaboration],
  %``Search for new physics in e+- q contact interactions at HERA,''
  Phys.\ Lett.\  B {\bf 568} 35 (2003)
  [hep-ex/0305015].
  %%CITATION = PHLTA,B568,35;%%

%\cite{Pumplin:2002vw}
\bibitem{cteq6}
  J.~Pumplin, D.~R.~Stump, J.~Huston, H.~L.~Lai, P.~Nadolsky and W.~K.~Tung,
  %``New generation of parton distributions with uncertainties from global  QCD
  %analysis,''
  JHEP {\bf 0207} 012 (2002)
  [hep-ph/0201195].
  %%CITATION = JHEPA,0207,012;%%


\end{thebibliography}

%%%%%%%%%%%%%%%%%%%% Fig.2: cross sections vs.Q2 e-  %%%%%%%%%%%%%%%%%%%%%%%%
\begin{figure}[htb]
\begin{center}
\begin{picture}(90,195)(0,0)
\setlength{\unitlength}{1 mm}
\put(-35,55){\epsfig{file=H1prelim-07-141.fig1a.eps,width=0.9\textwidth}}
\put(-35, -10){\epsfig{file=H1prelim-07-141.fig1b.eps,width=0.9\textwidth}}
\put( 0,150){\bf (a)}
\put( 0, 40){\bf (b)}
\end{picture}
\end{center}
\caption{
(a) The $Q^2$ dependence of the NC cross section ${\rm d}\sigma/{\rm
d}Q^2$ for $e^-p$ scattering. 
The total integrated luminosity amounts to  $165\,{\rm pb}^{-1}$.
The full curve represents the Standard
Model expectation determined from the H1 2000 PDF fit~\cite{00ep}.
(b) The ratio of the cross section to the Standard Model expectation. 
%
In (a) and (b)
the inner and outer error bars represent the 
statistical and total measurement errors, respectively.
%
An additional normalisation uncertainty of the data
is not included in the error bars but indicated in (b) separately
by the dashed lines.
%
The shaded error band in (b) shows the PDF uncertainty 
of the Standard Model prediction.
}
\label{dsdq2ele}
\end{figure}
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%

%%%%%%%%%%%%%%%%%%%% Fig.3: cross sections vs.Q2 e+  %%%%%%%%%%%%%%%%%%%%%%%%
\begin{figure}[htb]
\begin{center}
\begin{picture}(90,195)(0,0)
\setlength{\unitlength}{1 mm}
\put(-35,55){\epsfig{file=H1prelim-07-141.fig2a.eps,width=0.9\textwidth}}
\put(-35, -10){\epsfig{file=H1prelim-07-141.fig2b.eps,width=0.9\textwidth}}
\put( 0,150){\bf (a)}
\put( 0, 40){\bf (b)}
\end{picture}
\end{center}
\caption{
(a) The $Q^2$ dependence of the NC cross section ${\rm d}\sigma/{\rm
d}Q^2$ for $e^+p$ scattering. 
The total integrated luminosity amounts to  $270\,{\rm pb}^{-1}$.
The full curve represents the Standard
Model expectation determined from the H1 2000 PDF fit~\cite{00ep}.
(b) The ratio of the cross section to the Standard Model expectation. 
The error bars and bands are defined as for figure~\ref{dsdq2ele}.
}
\label{dsdq2pos}
\end{figure}
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%

%%%%%%%%%%%%%%%%%%%% Fig.4: cross sections vs.Q2 e- & e+  %%%%%%%%%%%%%%%%%%%
\begin{figure}[htb]
\begin{center}
\begin{picture}(90,195)(0,0)
\setlength{\unitlength}{1 mm}
\put(-35,55){\epsfig{file=H1prelim-07-141.fig3a.eps,width=0.9\textwidth}}
\put(-35, -10){\epsfig{file=H1prelim-07-141.fig3b.eps,width=0.9\textwidth}}
\put( 0,150){\bf (a)}
\put( 0, 40){\bf (b)}
\end{picture}
\end{center}
\caption{
(a) The $Q^2$ dependence of the NC cross sections ${\rm d}\sigma/{\rm
d}Q^2$ for $e^\pm p$ scattering. The full curved represents the Standard
Model expectations determined from the H1 2000 PDF fit~\cite{00ep}.
(b) The ratio of the cross sections to the Standard Model expectation. 
The error bars and bands are defined as for figure~\ref{dsdq2ele}.
}
\label{dsdq2all}
\end{figure}
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%

%%%%%%%%%%%%%%%%%%%% Fig.5: quark radius fit %%%%%%%%%%%%%%%%%%%
\begin{figure}[htb]
\begin{center}
\begin{picture}(90,150)(0,0)
\setlength{\unitlength}{1 mm}
\put(-40,0){\epsfig{file=H1prelim-07-141.fig4.eps,width=\textwidth}}
\put( 50,105){\bf (a)}
\put( 50,55){\bf (b)}
\end{picture}
\end{center}
\caption{
The NC cross section ${\rm d}\sigma/{\rm d}Q^2$ 
%at $\sqrt{s}=319\,{\rm GeV}$ 
normalised to the Standard Model expectation determined from 
CTEQ6D~\cite{cteq6} for $e^+p$ (a) and $e^-p$ (b) scattering. 
The curves represent the corrections to the SM prediction 
due to a hypothetical finite quark radius of $0.74\cdot 10^{-18}\,{\rm m}$, 
the $95\%$ CL exclusion limit obtained from a combined form factor analysis of the data shown in (a) and (b).
The error bands are defined as for figure~\ref{dsdq2ele} and the error bars
represent the statistical and uncorrelated errors of the measurements added in quadrature.
An additional normalisation uncertainty of the data
is not included in the error bars but indicated separately
by the dashed lines.
}
\label{dsdq2fit}
\end{figure}
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%

\end{document}
