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%===============================title page=============================

% Some useful tex commands
%
\newcommand{\GeV}{\rm GeV}
\newcommand{\TeV}{\rm TeV}
\newcommand{\pb}{\rm pb}
\newcommand{\cm}{\rm cm}
\newcommand{\hdick}{\noalign{\hrule height1.4pt}}
\newcommand{\rpv}{\slash\hspace{-2.5mm}{R}_{p}}
\newcommand{\m}{\mathrm{m}}
\begin{document}

\pagestyle{empty}
\begin{titlepage}


\noindent
\begin{flushleft}
{{\today}} \hspace*{14cm}\vspace*{-2cm}\epsfig
{file=/h1/www/images/H1logo_bw_small.epsi,width=2.cm}
\end{flushleft}
\vspace*{2cm}
\begin{center}
  \begin{Large}                   
  {\bf Search for new physics phenomena in  
    {\boldmath $e q$} contact interactions at HERA}

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



\begin{abstract} \noindent
Deep-inelastic $e^\pm p$ scattering at high momentum transfer $Q^2$  
is used to search for $eq$ contact interactions associated to scales 
not directly accessible at {\sc Hera}.
The cross section measurements $\rm d \sigma / \rm d Q^2$,
corresponding to integrated luminosities of $16.4~\pb^{-1}$ of $e^-p$ data
and $98.6~\pb^{-1}$ of $e^+p$ data,
are well described by the Standard Model and 
are analysed to set constraints on new phenomena.
For conventional contact interactions lower limits can be set on
compositeness scales $\Lambda$ at $1.8 - 5.4~\TeV$ and
on couplings to leptoquarks and $R$-parity violating squarks
of $M/\lambda > 0.3 - 1.4~\TeV$.
A search for low scale quantum gravity effects in models with large extra 
dimensions gives limits on the effective Planck scale of $M_S > 0.8~\TeV$.
A form factor analysis yields a radius of 
$R_q < 0.8\cdot 10^{-18}$~m for the light quarks.
\end{abstract}


\end{titlepage}





\pagenumbering{arabic}
%\mpara{hier ist eine Randnotiz}


\clearpage

% compositeness scales
\begin{table}[htb]
\begin{center}
{\large\bf H1 preliminary} \\[0.2em] 
\begin{tabular}{l c c}
   \hdick \\[-1.5ex]
 coupling & \ $\Lambda^+~[\TeV]$  &  $\Lambda^-~[\TeV]$ \ \\[1ex]
   \hdick \\[-1.5ex]
 $LL$    &   2.8  & 2.3  \\[.2em] 
 $RR$    &   2.8  & 2.3  \\[.2em] 
 $LR$    &   3.2  & 1.8  \\[.2em]
 $RL$    &   3.2  & 1.9  \\[0.6ex]
 $VV$    &   5.1  & 5.4  \\[.2em]
 $AA$    &   2.5  & 3.9  \\[.2em]
 $VA$    &   2.9  & 2.9  \\[0.6ex]
 $LL+RR$ &   3.8  & 3.7  \\[.2em] 
 $RL+LR$ &   4.3  & 4.1  \\[.2em]
 \hline
\end{tabular}
\end{center}
\caption{
  Compositeness scale parameters 
  $\Lambda^\pm$ (95\%~CL lower limits) for various chiral structures. 
  Results are given %for the present analysis of $e^-p$ and $e^+p$ data 
  for a combined analysis including all HERA I data.}
\label{etafits}
\end{table}

% leptoquarks
\begin{table}[htb]
\begin{minipage}{8cm}
\begin{center}
{\large\bf H1 preliminary}

\begin{tabular}{l c c  }
  \hdick \\[-1.5ex]
    &         &    all $e^+ p$ \& $e^-p$ \\[.5ex]
   LQ & $F$ & $M_{LQ}/\lambda$  $\,[ \GeV ]$ \\[.5ex]
  \hdick \\[-1.5ex]
   $S_0^L$ & 2 & 720 \\[.2em]
   $S_0^R$ & 2 & 670 \\[.2em]
   $\tilde{S}_0^R$ & 2 & 330 \\[.2em]
   $S_{1/2}^L$ & 0 & 870 \\[.2em]
   $S_{1/2}^R$ & 0 & 370 \\[.2em]
   $\tilde{S}_{1/2}^L$ & 0 & 430 \\[.2em]
   $S_1^L$ & 2 & 480 \\[1ex]
  \hline
\end{tabular}
\end{center}\end{minipage}\begin{minipage}{8cm}
\begin{center}
{\large\bf H1 preliminary}

\begin{tabular}{l c c  }
  \hdick \\[-1.5ex]
    &         &    all $e^+ p$ \& $e^-p$ \\[.5ex]
   LQ & $F$ & $M_{LQ}/\lambda$  $\,[ \GeV ]$ \\[.5ex]
  \hdick \\[-1.5ex]
   $V_0^L$ & 0 & 770 \\[.2em]
   $V_0^R$ & 0 & 640 \\[.2em]
   $\tilde{V}_0^R$ & 0 & 1000 \\[.2em]
   $V_{1/2}^L$ & 2 & 420 \\[.2em]
   $V_{1/2}^R$ & 2 & 940 \\[.2em]
   $\tilde{V}_{1/2}^L$ & 2 & 1020 \\[.2em]
   $V_1^L$ & 0 & 1380 \\[1ex]
  \hline
\end{tabular}
\end{center}\end{minipage}
\caption{Fermion number $F$ 
  and 95\%~CL lower limits on $M_{LQ}/\lambda$ for scalar (S) and vector (V) 
  leptoquarks.
  Results are given for a combined analysis including all HERA I data.
  Notation:  {\em L, R} is the lepton chirality,
  subscript $I = 0,\ 1/2,\ 1$ is the weak isospin,
  $\tilde{S}$ and $\tilde{V}$ differ by two units of hypercharge from $S$ and $V$.
  Quantum numbers and helicities are given for $e^-q$ and $e^-\bar{q}$ states.}
\label{lqfits}
\end{table}



% squarks
\begin{table}[htb]
\begin{center}
{\large\bf H1 preliminary}

\begin{tabular}{l c c }
  \hdick \\[-1.5ex]
    &         & all $e^+ p$ \& $e^-p$ \\[.5ex]
   $\rpv$ \ coupling & $\eta^q$ 
    & $M_{\tilde q}/\lambda'$\\[.5ex]
    & $[\lambda'^{\,2}/M_{\tilde q}^2]$ 
    & $[ \GeV ]$\\[1ex]
  \hdick \\[-1.5ex]
   %$S_0^L$  
   $\lambda'_{11k}$ \ \ \ $e^+ \bar u \to \bar{\tilde d}^{\,(k)}$ &
    \ $\eta^u_{LL} = +\frac{1}{2}$ \ & 720 \\[.2em]
   %$\tilde{S}_{1/2}^L$  
   $\lambda'_{1j1}$ \ \ \ $e^+ d \to \tilde{u}^{\,(j)}$ &
    \ $\eta^d_{LR} = -\frac{1}{2}$ \   & 430 \\[1ex]
  \hline
\end{tabular}
\end{center}
\caption{Coefficients $\eta^q_{ab}$
  and 95\%~CL lower limits on $M_{\tilde q}/\lambda'$ for 
  $R_p$ violating couplings to squarks.
  Results are given for a combined analysis 
  including all HERA I data. }
\label{sqfits}
\end{table}
 

% large extra dimensions
\begin{table}[htb]

\begin{center}
{\large\bf H1 preliminary}

\begin{tabular}{l c c c}
   \hdick \\[-1.5ex]
          & \ $e^- p$ $(318~\GeV)$ \ & \ $e^+ p$ $(318~\GeV)$ \
          & \ all $e^+ p$  \& $e^- p$   \\
 coupling \ \ & \ $M_S~[\TeV]$ \ & \ $M_S~[\TeV]$ \  & \ $M_S~[\TeV]$ \ \\[1ex]
  \hline \\[-1.5ex]
 $\lambda = +1$ & 0.58 & 0.77 & 0.83 \\[.2em]
 $\lambda = -1$ & 0.61 & 0.73 & 0.79 \\[.2em]
 \hline
\end{tabular}
\end{center}
\caption{
     Lower limits (95\%~CL) on the gravitational scale $M_S$ assuming
     positive ($\lambda = +1$) and negative ($\lambda = -1$) coupling from
     the present analysis of $e^-p$ and $e^+p$ data 
     and from a combined analysis including all HERA I data.}
\label{ledfits}
\end{table}


% quark radius
\begin{table}[htb]

\begin{center}
{\large\bf H1 preliminary}

\begin{tabular}{l c }
   \hdick \\[-1.5ex]
          & \ all $e^+ p$  \& $e^- p$   \\
 form factor \ \ & \ $R~[10^{-18}~\m]$ \ \\[1ex]
  \hline \\[-1.5ex]
 $f_e \equiv 1$ & 0.82 \\[.2em]
 $f_e = f_q$    & 0.57 \\[.2em]
 \hline
\end{tabular}
\end{center}

\caption{
     Lower limits (95\%~CL) on the quark radius
     assuming point-like leptons ($f_e \equiv 1$) 
     or common form factors ($f_e = f_q$)
     for the analysis including all HERA I data.}
\label{rqfits}
\end{table}



\vfill
\clearpage

% Data Analysis cross sections
%
\begin{figure}[p] 
  \begin{center} \vspace*{-.5cm}
    \mbox{
      \epsfig{file=H1prelim-02-062.fig1a.eps,width=.49\textwidth,
        bbllx=0,bblly=0,bbury=570,bburx=420,clip}  \hfill
      \epsfig{file=H1prelim-02-062.fig1b.eps,width=.49\textwidth,
        bbllx=0,bblly=0,bbury=570,bburx=420,clip}
      }\\[1em]
    \mbox{
      \epsfig{file=H1prelim-02-062.fig1c.eps,width=.49\textwidth,
        bbllx=0,bblly=0,bbury=570,bburx=420,clip}  \hfill
      \epsfig{file=H1prelim-02-062.fig1d.eps,width=.49\textwidth,
        bbllx=0,bblly=0,bbury=570,bburx=420,clip}
      }
  \end{center} \vspace*{-.3cm}
  \caption{Differential cross sections
    ${\rm d}\sigma / {\rm d}Q^2$ at $\sqrt{s} = 318~\GeV$
    for $e^-p \rightarrow e^-X$ scattering (top) and 
    $e^+p \rightarrow e^+X$ scattering (bottom).
    H1 data are compared with Standard Model expectations 
    using CTEQ5D parton distributions.
    The errors include statistics and uncorrelated experimental systematics. 
    The normalisation uncertainties are 3\% ($e^-p$ data) 
    and 1.5\% ($e^+p$ data). }
  \label{cismxsec}
\end{figure} 


\begin{figure}[htb]
  \begin{center}
     \epsfig{file=H1prelim-02-062.fig2.eps,%
      bbllx=0,bblly=0,bbury=311,bburx=400,clip,%
      width=\textwidth}
  \end{center}
  \caption{Lower limits on compositeness scale parameters
    $\Lambda^\pm$ (95\% CL)
    from fits to the combined $e^+ p$ and $e^- p$ data.}
  \label{cilambda}
\end{figure} 

% illustration of VV model sensitivity
%
\begin{figure}[htb]
  \begin{center} 
    \mbox{
      \epsfig{file=H1prelim-02-062.fig3a.eps,%
        bbllx=0,bblly=0,bbury=420,bburx=360,clip,%
        width=.5\textwidth}
      \epsfig{file=H1prelim-02-062.fig3b.eps,%
        bbllx=0,bblly=0,bbury=420,bburx=360,clip,%
        width=.5\textwidth} }
  \end{center} %\vspace*{-.3cm}
  \caption{NC cross section ${\rm d}\sigma/{\rm d}Q^2$ at $\sqrt{s} = 318~\GeV$
    normalised to the Standard Model expectation.
    H1 data of  $e^-p$ and  $e^+p$ scattering
    are compared with VV compositeness models corresponding
    to 95\%~CL exclusion limits of $\Lambda^+$ and $\Lambda^-$. 
    The errors represent statistics and uncorrelated experimental systematics.}
  \label{civvxsec}
\end{figure} 


% Leptoquarks
%
\begin{figure}[htb]
  \begin{center} 
    \mbox{
      \epsfig{file=H1prelim-02-062.fig4a.eps,%
        bbllx=0,bblly=0,bbury=420,bburx=360,clip,%
        width=.5\textwidth}
      \epsfig{file=H1prelim-02-062.fig4b.eps,%
        bbllx=0,bblly=0,bbury=420,bburx=360,clip,%
        width=.5\textwidth} } \\[3ex]
    \mbox{
      \epsfig{file=H1prelim-02-062.fig4c.eps,%
        bbllx=0,bblly=0,bbury=420,bburx=360,clip,%
        width=.5\textwidth}
      \epsfig{file=H1prelim-02-062.fig4d.eps,%
        bbllx=0,bblly=0,bbury=420,bburx=360,clip,%
        width=.5\textwidth} }
  \end{center} %\vspace*{-.3cm}
  \caption{NC cross section ${\rm d}\sigma/{\rm d}Q^2$ at $\sqrt{s} = 318~\GeV$
    normalised to the Standard Model expectation. 
    H1 data of $e^-p$ and $e^+p$ scattering
    are compared with 95\%~CL exclusion limits of leptoquarks
    $S^L_{1}$ and $V^L_{1}$  (top), respectively
    $S^R_{1/2}$ and $V^R_{1/2}$ (bottom).
    The errors represent statistics and uncorrelated experimental systematics.}
  \label{cilqxsec}
\end{figure} 


% Large Extra Dimensions
%
\begin{figure}[t]
  \begin{center} 
    \mbox{
      \epsfig{file=H1prelim-02-062.fig5a.eps,%
        bbllx=0,bblly=0,bbury=420,bburx=360,clip,%
        width=.5\textwidth}
      \epsfig{file=H1prelim-02-062.fig5b.eps,%
        bbllx=0,bblly=0,bbury=420,bburx=360,clip,%
        width=.5\textwidth} }
  \end{center} %\vspace*{-.3cm}
  \caption{NC cross section ${\rm d}\sigma/{\rm d}Q^2$ at $\sqrt{s} = 318~\GeV$
    normalised to the Standard Model expectation.
    H1 data of $e^-p$ and $e^+p$ scattering
    are compared to gravitational effects of large extra dimensions 
    at scales $M_S$ (95\%~CL lower limits)
    with positive ($\lambda = +1$) and negative ($\lambda = -1$) coupling.
    The errors represent statistics and uncorrelated experimental systematics.}
  \label{ledeffect}
\end{figure}

\end{document}

