%================================================================
% LaTeX file with preferred layout for the contributed papers to
% the ICHEP Conference 98 in Vancouver
% process with:  latex hep98.tex
%                dvips -D600 hep98
%================================================================
\documentclass[12pt]{article}
\usepackage{epsfig}
\usepackage{amsmath}
\usepackage{hhline}
\usepackage{amssymb}
\usepackage{times}
\usepackage{cite}

\renewcommand{\topfraction}{1.0}
\renewcommand{\bottomfraction}{1.0}
\renewcommand{\textfraction}{0.0}
\newlength{\dinwidth}
\newlength{\dinmargin}
\setlength{\dinwidth}{21.0cm}
\textheight23.5cm \textwidth16.0cm
\setlength{\dinmargin}{\dinwidth}
\setlength{\unitlength}{1mm}
\addtolength{\dinmargin}{-\textwidth}
\setlength{\dinmargin}{0.5\dinmargin}
\oddsidemargin -1.0in
\addtolength{\oddsidemargin}{\dinmargin}
\setlength{\evensidemargin}{\oddsidemargin}
\setlength{\marginparwidth}{0.9\dinmargin}
\marginparsep 8pt \marginparpush 5pt
\topmargin -42pt
\headheight 12pt
\headsep 30pt \footskip 24pt
\parskip 3mm plus 2mm minus 2mm

%===============================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}}

% Some other macros used in the sample text
\def\mco{\multicolumn}
\def\epp{\epsilon^{\prime}}
\def\vep{\varepsilon}
\def\ra{\rightarrow}
\def\ppg{\pi^+\pi^-\gamma}
\def\vp{{\bf p}}
\def\ko{K^0}
\def\kb{\bar{K^0}}
\def\al{\alpha}
\def\ab{\bar{\alpha}}
\def\be{\begin{equation}}
\def\ee{\end{equation}}
\def\bea{\begin{eqnarray}}
\def\eea{\end{eqnarray}}
\def\CPbar{\hbox{{\rm CP}\hskip-1.80em{/}}}%temp replacemt due to no font
\def\etal{{\it et~al.}}
\def\black{\special{ps: 0 0 0 setrgbcolor}}
\def\white{\special{ps: 1 1 1 setrgbcolor}}

\begin{document}

\pagestyle{empty}
\begin{titlepage}

\noindent
\begin{center}
\begin{small}
\begin{tabular}{llrr}
Submitted to & & &
\epsfig{file=/h1/www/images/H1logo_bw_small.epsi
,width=2.cm} \\[.2em] \hline
\multicolumn{4}{l}{{\bf
                32nd International Conference 
                on High Energy Physics, ICHEP04},
                August~16,~2004,~Beijing} \\
                 & Abstract:        & {\bf 5-0163}    &\\
                 & Parallel Session & {\bf 5}   &\\ \hline
 & \multicolumn{3}{r}{\footnotesize {\it
    www-h1.desy.de/h1/www/publications/conf/conf\_list.html}} \\[.2em]
\end{tabular}
\end{small}
\end{center}
\vspace*{2cm}

\begin{center}
  \Large
    {\bf Inclusive {\boldmath $D^{* {\bold \pm}}$} Meson 
and Associated Dijet Production in
            Deep-Inelastic Scattering}

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

\begin{abstract}

\noindent
The inclusive production of $D^{*\pm}$ mesons in deep inelastic
scattering is studied with the H1 detector at HERA using an
integrated luminosity of 47.0$\ \mbox{pb}^{-1}$. In the kinematic
region $2 \le Q^2 \le 100 \ \mbox{GeV}^2$ and $0.05 \le y
\le 0.7$ an $e^+ p$ cross section for inclusive $D^{*\pm}$ meson
production of $7.72 \pm 0.23\ (\rm{stat.}) \pm 1.09 \, (\rm{syst.})\ \rm{nb}$
is measured in the visible range $1.5
\le p_{t,D^\ast} \le 15\ \mbox{GeV}$ and $|\eta_{D^\ast}| \le 1.5$.
Single and double differential inclusive $D^{*\pm}$ meson cross
sections are compared to perturbative calculations in the 
framework of the DGLAP and CCFM evolution schemes. The
additional requirement is then made that there are
at least two jets with $E_{t,\ \text{jet 1}}
\ge 4\ \mbox{GeV}$, $E_{t,\ \text{jet 2}} \ge 3\ \mbox{GeV}$ 
in the Breit frame of reference and $-1 \le
\eta_{\text{lab,}\ \text{jet 1,2}} \le 2.5$.
In this kinematic range the inclusive cross section for 
dijet production associated with a $D^{*\pm}$ meson is
found to be
$1.63\pm 0.10\ (\rm{stat.}) \pm 0.25\, (\rm{syst.})\ \rm{nb}$.
Differential cross sections for dijet events with $D^{*\pm}$ mesons
 are also presented and compared to QCD model predictions.
Models which provide a good description of inclusive $D^{*\pm}$ production
are found to provide a poorer description of jet production with
$D^{*\pm}$ mesons.
\end{abstract}


\end{titlepage}

\pagestyle{plain}

\section{Introduction}

Results on $D^{*\pm}$ meson production in deep inelastic scattering
(DIS) have been published by the H1 and ZEUS collaborations
\cite{DESY01100,DESY99101,h1gluon,h1f2c,zeusf2c}. The analysis described in
this paper
uses the data collected during the 1999 and 2000 running periods
with positrons at HERA, yielding a significantly larger integrated
luminosity of 47.0 $\mbox{pb}^{-1}$ than used in the previous
publications \cite{DESY01100,h1gluon,h1f2c}. 
As a result, the $D^{*\pm}$ production
cross section is measured with increased precision, and the
measurement of two jet production in events with at least one
tagged $D^{*\pm}$ meson becomes possible in DIS.


\medskip
The description of open heavy flavour production in deep-inelastic $ep$
collisions is based on perturbative QCD with the assumption that
$Q^2$ and the heavy quark mass provide the necessary hard scale. To
leading order (LO), photon gluon fusion $(\gamma g
\rightarrow Q \bar Q)$ is the dominant production process. The
experimental results on inclusive $D^{*\pm}$ meson production are
compared with predictions made using two different pQCD
approaches with the charm quarks considered to be massive:
a next-to-leading order (NLO) calculation
\cite{riemersma,riemersma2,harris}
based on collinear factorisation and the DGLAP evolution 
equations \cite{dglapref} and another 
calculation based on $k_t$ factorisation and parton evolution 
according to the
CCFM equations \cite{ccfm}. In both approaches, gluons and
light quarks are assumed to be the only active flavours in the proton
and therefore charm is produced perturbatively only via photon gluon
fusion. The CCFM approach is expected to provide a better
description of gluon evolution at very 
low values of Bjorken-$x$.
% In this approach, in the parton cascade, gluons are emitted 
%in an angular ordered manner to account for
%taking coherence effects into account.

Following the same line as in a previous publication
\cite{DESY01100} the HVQDIS program by Harris and Smith
\cite{hvqdis} has been used to perform comparisons of the data with the NLO
DGLAP scheme and with the hadron level Monte Carlo generator CASCADE
 \cite{hannes} which implements the CCFM scheme.


\section{Detector and Data Sample}

The data presented were collected with the H1 detector
at HERA during the running periods of 1999 and 2000. In that
period HERA operated with 27.5 GeV positrons and 920 GeV protons
colliding at a center-of-mass energy of $\sqrt{s} = 318\ \mbox{GeV}$. 
The data amount to an integrated luminosity of
 ${\cal L} = 47.0\ \mbox{pb}^{-1}$. A
detailed description of the H1 detector
\cite{Detector1},\cite{Detector2} and the components that are
most relevant for this analysis is given in \cite{DESY01100}.




\section{Event Selection and Kinematics}

The identification and selection of the scattered positron is
performed as described in \cite{DESY01100}.

The geometrical acceptance cuts for the backward calorimeter
(SpaCal) and the backward drift chamber (BDC) impose a limitation
on the measured positron scattering angle of $\theta_e < 178^\circ$.
In order to ensure high acceptance for the entire kinematic
region, the square of the four momentum transfer is restricted to
$2 \le Q^2 \le 100 \ \mbox{GeV}^2$ and the
inelasticity to $0.05 \le y \le 0.7$.


\medskip
At fixed center-of-mass energy $\sqrt{s}$, the kinematics of the
inclusive scattering process $ep \rightarrow eX$ can be completely
determined by using any two of the independent Lorentz variables:
the Bjorken scaling variables $x$ and $y$, the four momentum
squared of the virtual photon and the invariant mass squared $W^2$
of the hadronic final state. In this analysis, these variables are
determined from the measurement of the energy $E^\prime_e$ and the
polar angle $\theta_e$ of the scattered positron according to
\begin{equation}
\begin{array}{ccc}\displaystyle
Q^2=4E_eE^\prime_e\cos^2\left(
\frac{\theta_e}{2}\right)&\quad\quad&\displaystyle y=1-\frac{
E^\prime_e}{ E_e} \sin^2\left(\frac{ \theta_e}{2}\right)
\cr\cr\displaystyle x=\frac{ Q^2}{ ys}&\quad\quad&\displaystyle
W^2=Q^2\left(\frac{ 1-x}{ x}\right)\cr
\end{array}
\end{equation}
where $E_e$, is the electron beam energy.


\medskip
First a fully reconstructed $D^{*\pm}$ meson in the visible range of
the detector is required. $D^{*+}$ mesons are reconstructed using
the decay chain $D^{*+}\longrightarrow
D^0\pi^+_s\longrightarrow K^-\pi^+\pi^+_s$. The method
applied is described in detail in \cite{DESY01100,h1f2c}.

The range of the transverse momentum and the pseudorapidity of the
$D^{*\pm}$ meson is restricted to
 $1.5 \le p_{t,D^\ast} \le 15\ \mbox{GeV}$ and 
$|\eta_{D^\ast}| \le 1.5$ where $\eta$ is defined as $\eta=-\ln
\tan \left(\frac{\theta}{2}\right)\mbox{.}$ These cuts are applied
in order to ensure that the events lie in a region of the detector
where the acceptance is high and well understood. The distribution
of the mass difference $\Delta m = m_{K \pi \pi} - m_{K \pi}$ is
shown in figure \ref{fig1}. A total of $2604\pm 77$ $D^{*\pm}$
mesons is obtained.

\medskip
Figure 2 shows the energy and polar angle distributions of the
scattered positron for events with an identified $D^{*\pm}$ meson.
The data are compared to the prediction of the RAPGAP Monte Carlo.
The RAPGAP \cite{rapgap} Monte Carlo allows the non-diffractive
 as well as the diffractive DIS events to be simulated. Here it is used
to simulate the production of charm via the BGF process.  
Good agreement is observed between the data and the simulation.


\medskip
In order to define the jet sample within the events containing 
a $D^{*\pm}$ meson candidate, the $k_t$-cluster algorithm 
\cite{ktcluster_alg} in its inclusive mode is used in the Breit frame.
The hadronic final state is reconstructed from all energy
depositions in  the SpaCal and the liquid argon calorimeter as well
as from the track momenta measured in the tracking system.
When applying the jet algorithm the momenta of the three particles
originating from the reconstructed  $D^{*\pm}$ meson are treated
as one particle with the four-vector of the tagged $D^{*\pm}$
meson. The $E$ recombination scheme (in which the four-vectors
of the objects are added) is used.

The transverse energy of the leading jet in the Breit frame is
required to be $E_{t,\ \text{jet 1}} \ge 4\ \mbox{GeV}$, the
transverse energy of the second jet $E_{t,\ \text{jet 2}} \ge 3
\ \mbox{GeV}$ and the pseudorapidities of the two leading jets in
the laboratory frame $-1 \le \eta_{\text{jets}} \le 2.5$. 
A total of
$836\pm 51$ events fulfill the jet requirements.


\section{Inclusive {\boldmath $D^{* {\bold \pm}}$} Meson Cross Sections}

The cross section for $D^{*\pm}$ meson production in deep inelastic 
$ep$ scattering is calculated from the observed number of 
$D^{*\pm}$ candidates, $N_{D^{*\pm}}$, according to

\begin{equation}\label{eqsigma}
  \sigma(e^+ p \rightarrow e^+ D^{*\pm} X) = \frac{N_{D^{*\pm}}
  }{{\cal L} \cdot Br \cdot \epsilon
  \cdot(1+\delta_{\text{rad}})}.
\end{equation}

Here, ${\cal L}$ and $Br$ refer to the integrated luminosity and the
branching ratio $Br(D^{*+} \rightarrow D^0 \pi^+) \cdot Br(D^0
\rightarrow K^- \pi^+) = 0.0259$ \cite{branching}. The efficiency
$\epsilon$ is estimated using the RAPGAP Monte Carlo program
\cite{rapgap}. The radiative corrections are obtained using
HERACLES.


\medskip
The inclusive cross section for $D^{*\pm}$ meson production in the
kinematic region $2 \le Q^2 \le 100 \ \mbox{GeV}^2$,
$0.05 \le y \le 0.7$ and in the visible $D^{*+}$ range $1.5 \le
p_{t,D^\ast} \le 15\ \mbox{GeV}$ and $|\eta_{D^\ast}| \le 1.5$ is
found to be
$$\sigma_{vis}(e^+p \rightarrow e^+D^{*\pm} X)=
7.72 \pm 0.23 (\rm{stat.})\ \pm 1.09 \, (\rm{syst.})\ \rm{nb}.$$

The errors refer to the statistical and systematic error,
respectively. The largest contribution to the systematic error is
due to the uncertainty in the track reconstruction efficiency.
Other important sources of systematic error include the
uncertainty in the determination of the background shape in the
$\Delta m$ distribution, the $D^0$ mass resolution and the
uncertainty introduced by the difference in the acceptance and 
efficiency corrections obtained by making use of the RAPGAP
and HERWIG Monte Carlos.


The visible inclusive $D^{*\pm}$ meson production cross section
was calculated in the NLO DGLAP scheme with the HVQDIS
program using the CTEQ5F3 proton parton densities \cite{cteq5f3}. 
The predictions range from 4.90~nb for a charm
quark mass $m_c=1.5~\gev$ and Peterson fragmentation parameter
$\epsilon_c=0.10$ to 6.62~nb for $m_c=1.3~\gev$ and
$\epsilon_c=0.035$. The hadronization fraction $f(c\rightarrow
D^{*+})=0.233\pm0.010\pm0.011$ \cite{hadro} was used. For the
same variation of $m_c$ and $\epsilon_c$, calculations based on
the CCFM evolution equation, 
as implemented in the CASCADE program, yield
cross sections of 6.79~nb and 8.82~nb, respectively.
The measured value of the cross section agrees better with the CASCADE
prediction than with that from HVQDIS.

In figure ~\ref{fig3} the inclusive single differential $D^{*\pm}$
cross sections in the visible region are shown as a function of
the event variables $W$, $x$ and $Q^2$ and as a function of the
$D^{*\pm}$ observables $p_t$, $\eta$ and the
inelasticity $z_{D^*}={P\cdot p_{D^*}}/{P\cdot
q}={(E-p_z)_{D^*}}/{2yE_e}$, where $P$, $q$ and $p_{D^*}$ denote
the four-momenta of the incoming proton, the exchanged photon and
the observed $D^{*\pm}$ meson, respectively.

Fig.~\ref{fig3} also includes the expectations from the HVQDIS
program using the CTEQ5F3 parton density. The
charm quark mass and the fragmentation parameter have been varied
from $m_c=1.3$~GeV and $\epsilon_c=0.035$ to $m_c=1.5$~GeV and
$\epsilon_c=0.10$. The dark shaded band indicates the
uncertainties in the predictions due to these variations.
Although the predicted visible cross section is smaller
than that experimentally observed, there is reasonable agreement
with the data in the shapes of the different single differential
cross sections with the exception of the region 
$\eta>0$, where
the measured $D^{*\pm}$ meson production cross section is
larger than that predicted.
Since in the boson gluon fusion process the forward region
($\eta>0$) is correlated with small $z_{D^*}$,
 a similar discrepancy
between data and theory is observed at small $z_{D^*}$.

The predictions of the CASCADE program, 
with the same variations of the charm quark mass and 
fragmentation parameter, are also presented in Fig.~\ref{fig3}.
The expectations from the CASCADE program are found to agree better
with the data, particularly in the positive $\eta$ region.
Similar conclusions were drawn in \cite{DESY01100} based on a
sample of significantly smaller luminosity.

In Fig. \ref{mcxsec1} the cross section is compared with the
expectations of the RAPGAP Monte Carlo when only direct
processes are taken into account, and when the contribution
of resolved processes is also considered. The comparison shows 
that the prediction of RAPGAP with direct processes only
lies slightly below the observed cross section
and that taking into account the resolved contribution 
does not result in a good description of the data, the
prediction then often being too high.

In order to enable the study of correlations among the observables in
$D^{*\pm}$ meson production, Figs.~\ref{fig5}, \ref{fig4},
\ref{fig6} and \ref{fig7}
show the double differential inclusive $D^{*\pm}$ cross sections.
It is evident that the excess observed in the data with respect to
the HVQDIS expectation at large pseudorapidities ($0.5<\eta_{D^*}<1.5$)
is independent of $Q^2$ and is concentrated at small $p_{t\,D^*}$
and small $z_{D^*}$.


\section{Associated Dijet Cross Sections}

The cross section for dijet production associated with a $D^{*\pm}$
meson in deep inelastic $ep$
collisions is obtained from the number of dijet events fulfilling the
dijet criteria which include at least one $D^{*\pm}$ candidate 
in a manner similar to that described for the inclusive
$D^{*\pm}$ meson cross section measurement.

\medskip
The inclusive cross section for dijet and $D^{*\pm}$ meson production in the
kinematic region $2 \le Q^2 \le 100\ \mbox{GeV}^2$,
$0.05 \le y \le 0.7$, 
$1.5 \le p_{t,D^\ast} \le 15\ \mbox{GeV}$ and 
$|\eta_{D^\ast}| \le 1.5$ with jets with Breit frame 
transverse energies $E_{t,\ \text{jet 1}} \ge 4\ \mbox{GeV}$,
$E_{t,\ \text{jet 2}} \ge 3\ \mbox{GeV}$ and laboratory
 pseudorapidities $-1 \le \eta_{\text{jet 1,2}} \le 2.5$
is found to be
$$\sigma_{vis}(e^+p \rightarrow e^+D^{*\pm}\text{dijet} \ X)=
1.63\pm 0.10\, (\rm{stat.}) \pm 0.25 \, (\rm{syst.})\ \rm{nb}.$$

In addition to the systematic errors which 
arise in the measurement
of the $D^{* \pm}$ meson cross sections, additional systematic 
effects contribute in this measurement. 
The most important additional errors arise from the uncertainty of the energy
measurement in the main and backward calorimeters 
and the dependence of the acceptance calculation 
on the Monte Carlo models used.

The purity and the stability of
the sample is above 40 \% in all bins. 

In figure~\ref{jetxsec} the differential $D^{*\pm}$ meson 
dijet cross sections are presented as a function of the event 
variables $Q^2$, $x$, the maximum transverse jet energy
$E_t^{\text{max}}= E_{t,\ \text{jet 1}}$, 
and the rapidity difference of the dijets,
$\Delta\eta=|\eta_{\text{jet 1}}-\eta_{\text{jet 2}}|$,
the latter two being measured in the Breit frame. 
The data are compared with the expectations from 
  CASCADE and RAPGAP for direct and the sum of direct and resolved processes.
Here, for both Monte Carlo predictions,
 the values $m_c = 1.4$ GeV and $\epsilon_c = 0.078$ were
used for the charm quark mass and the fragmentation parameter,
respectively. In CASCADE the initial gluon distribution is fitted
to the inclusive $F_2$ data, while the CTEQ5L proton 
parton density is used in the RAPGAP Monte Carlo.

It can be seen that RAPGAP predictions for direct processes
are below the measured cross sections  particularly for small
Bjorken-$x$, large $E_t^{\text{max}}$ and small $\Delta\eta$.

In figure \ref{ratio} the cross section for the
production of dijets with an associated 
$D^{*\pm}$ meson is shown
versus the $D^{*\pm}$ meson production cross section and 
is compared with the expectation of the RAPGAP, AROMA \cite{aroma},
HERWIG and CASCADE Monte Carlo generators. The models,
even those that provide a good description of the 
inclusive $D^{*\pm}$ meson cross section, do not 
describe the measured associated dijet cross section
in events with a $D^{*\pm}$ meson.




\section{Conclusions}

New measurements of differential cross sections for inclusive 
$D^{*\pm}$ production in deep inelastic $ep$ scattering 
are presented. The data are compared with predictions based on both
NLO DGLAP and CCFM formalisms,  using the HVQDIS program 
and the CASCADE model, respectively. The expectations of the 
CCFM based model provide a better description of the 
inclusive $D^{*\pm}$ data, especially
in the positive pseudorapidity region.

A measurement of the cross section for the production of dijets
and an associated $D^{*\pm}$ meson in DIS is performed and 
 is compared to Monte Carlo predictions.
The RAPGAP Monte Carlo describes the $Q^2$ and $x$ dependence of the 
cross section only when both direct and resolved contributions are
taken into account, lying below the data 
 when only direct processes are considered.
 Measurements of the differential cross sections for associated 
dijet and  $D^{*\pm}$ meson production are presented and compared
with the RAPGAP and CASCADE expectations.
Even though the inclusive $D^{*\pm}$ meson production cross section
is described reasonably well by RAPGAP and is in good agreement with
the expectation using the CCFM based model CASCADE,
the associated dijet cross section is found to be 
less well described by both models.

%
%   References for Inclusive $D^{*\pm}$ meson and associated dijet production
%
\begin{thebibliography}{99}
\bibitem{h1f2c}
C.~Adloff {\it et al.}  [H1 Collaboration], Z.\ Phys.\ C {\bf 72}
(1996) 593 [hep-ex/9607012].
\bibitem{zeusf2c}
J.~Breitweg {\it et al.}  [ZEUS Collaboration], Phys.\ Lett.\ B
{\bf 407} (1997) 402 [hep-ex/9706009].
\bibitem{h1gluon}
C.~Adloff {\it et al.}  [H1 Collaboration], Nucl.\ Phys.\ B {\bf 545}
(1999) 21.
\bibitem{DESY99101}
 J.Breitweg et al. [ZEUS Collaboration], Eur. Phys. J. C12 (2000) 1, 35-52.
\bibitem{DESY01100}
 C. Adloff et al. [H1 Collaboration], Phys. Lett. B528 (2002) 199.
\bibitem{riemersma}
E.~Laenen, S.~Riemersma, J.~Smith and W.~L.~van Neerven, Phys.\
Lett.\ B {\bf 291} (1992) 325.
\bibitem{riemersma2}
E.~Laenen, S.~Riemersma, J.~Smith and W.~L.~van Neerven, Nucl.\
Phys.\ B {\bf 392} (1993) 162; E.~Laenen, S.~Riemersma, J.~Smith
and W.~L.~van Neerven, Nucl.\ Phys.\ B {\bf 392} (1993) 229;
S.~Riemersma, J.~Smith and W.~L.~van Neerven, Phys.\ Lett.\ B {\bf
347} (1995) 143 [hep-ph/9411431].
\bibitem{harris}
B.~W.~Harris and J.~Smith, Nucl.\ Phys.\ B {\bf 452} (1995) 109
[hep-ph/9503484]; B.~W.~Harris and J.~Smith, Phys.\ Lett.\ B {\bf
353} (1995) 535 [Erratum-ibid.\ B {\bf 359} (1995) 423]
[hep-ph/9502312].
\bibitem{dglapref}
V.~N.~Gribov and L.~N.~Lipatov, Yad.\ Fiz.\  {\bf 15} (1972) 781
[Sov.\ J.\ Nucl.\ Phys.\  {\bf 15} (1972) 438];
 V.~N.~Gribov and
L.~N.~Lipatov, Yad.\ Fiz.\  {\bf 15} (1972) 1218 [Sov.\ J.\ Nucl.\
Phys.\  {\bf 15} (1972) 675];
L.~N.~Lipatov, Sov.\ J.\ Nucl.\
Phys.\  {\bf 20} (1975) 94 [Yad.\ Fiz.\  {\bf 20} (1975) 181];
G.~Altarelli and G.~Parisi, Nucl.\ Phys.\ B {\bf 126} (1977) 298;
Y.~L.~Dokshitzer, Sov.\ Phys.\ JETP {\bf 46} (1977) 641 [Zh.\
Eksp.\ Teor.\ Fiz.\ {\bf 73} (1977) 1216].
\bibitem{ccfm}
M.~Ciafaloni, Nucl.\ Phys.\ B {\bf 296} (1988) 49; S.~Catani,
F.~Fiorani and G.~Marchesini, Phys.\ Lett.\ B {\bf 234} (1990)
339; S.~Catani, F.~Fiorani and G.~Marchesini, Nucl.\ Phys.\ B {\bf
336} (1990) 18; G.~Marchesini, Nucl.\ Phys.\ B {\bf 445} (1995) 49
[hep-ph/9412327].
\bibitem{hvqdis}
B.~W.~Harris and J.~Smith, Phys.\ Rev.\ D {\bf 57} (1998) 2806
[hep-ph/9706334].
\bibitem{hannes}
H.~Jung and G.~P.~Salam, Eur.\ Phys.\ J.\ C {\bf 19} (2001) 351
[hep-ph/0012143];
H.~Jung, Comp.\ Phys.\ Proc.\ Comm.\  {\bf 143} (2002) 111
[hep-ph/0109102].
\bibitem{g1}
 T. Ahmed et al. [H1 Collaboration], Phys.\ Lett.\ B {\bf 297} (1992) 205;
 M. Derrick et al. [ZEUS Collaboration], Phys.\ Lett.\ B {\bf 297} (1992) 404;
 I. Abt et al. [H1 Collaboration], Phys.\ Lett.\ B {\bf 314} (1993) 436;
 M. Derrick et al. [ZEUS Collaboration], Phys.\ Lett.\ B {\bf 322} (1994) 287;
 J.Breitweg et al. [ZEUS Collaboration], Eur. Phys. J. C4 (1998) 591;
 C. Adloff et al. [H1 Collaboration], Eur. Phys. J. C1 (1998) 97;
 J.Breitweg et al. [ZEUS Collaboration], Eur. Phys. J. C11 (1999) 35;
 J.Breitweg et al. [ZEUS Collaboration], Eur. Phys. J. C1 (1998) 109.
\bibitem{g2}
 M. Derrick et al. [ZEUS Collaboration], Phys.\ Lett.\ B {\bf 342} (1995) 417;
 M. Derrick et al. [ZEUS Collaboration], Phys.\ Lett.\ B {\bf 348} (1995) 665.
\bibitem{g3}
 W. Bartel et al. [JADE Collaboration], Z.\ Phys.\ C {\bf 24} (1984);
 M. Althoff et al. [TASSO Collaboration], Z.\ Phys.\ C {\bf 31} (1986);
 C. Berger et al. [PLUTO Collaboration], Nucl.\ Phys.\ B {\bf 281} (1987);
 H. Aihara et al. [TPC/2%\gamma$ Collaboration], Z.\ Phys.\ C {\bf 34} (1987);
 M. Acciarri et al. [L3 Collaboration], Phys.\ Lett.\ B {\bf 436} (1998);
 R. Barate et al. [ALEPH Coll.], Comp.\ Phys.\ Comm.\ B {\bf 458} (1999);
 M. Acciarri et al. [L3 Collaboration], Phys.\ Lett.\ B {\bf 447} (1999);
 M. Acciarri et al. [L3 Collaboration], Phys.\ Lett.\ B {\bf 453} (1999).
\bibitem{q2supr}
 J.Breitweg et al. [ZEUS Collaboration], Phys.\ Lett.\ B {\bf 479} (2000) 39;
 C. Adloff et al. [H1 Collaboration], Phys.\ Lett.\ B {\bf 415} (1997) 418;
 C. Adloff et al. [H1 Collaboration], Eur. Phys. J. C13 (2000) 397;
 M. Acciarri et al. [L3 Collaboration], Phys.\ Lett.\ B {\bf 483} (2000).
\bibitem{Detector1}
 I. Abt et al. [H1 Collaboration], Nucl. Instrum. Meth. A386 (1997) 310.
\bibitem{Detector2}
 I. Abt et al. [H1 Collaboration], Nucl. Instrum. Meth. A386 (1997) 348.
\bibitem{rapgap}
H.Jung, Comput.\ Phys.\ Commun.\  {\bf 86} (1995) 147.
\bibitem{ktcluster_alg}
S. Catani et al, Nucl.\ Phys. B\ {\bf 406} (1993) 187;
S.D. Ellis and D.E.Sopoer, Phys.\ Rev.\ D {\bf 48} (1993) 3160.
\bibitem{branching}
 K. Hagiwara et al., Phys.\ Rev.\ D {\bf 66} (2002) 010001.
\bibitem{cteq5f3}
H.L.Lai, J.Fuston, S.Kuhlmann, J.Morfin, F.Olness, J.F.Owens,
J.Pumplin, W.K.Tung
Eur. Phys. J. C12 (2000) 375.
\bibitem{hadro}
R.~Barate {\it et al.}  [ALEPH Collaboration],
Eur.\ Phys.\ J.\ C
{\bf 16} (2000) 597 [hep-ex/9909032].
\bibitem{aroma}
G.~Ingelman, J.~Rathsman and G.~A.~Schuler,
Comput.\ Phys.\ Commun.\  {\bf 101} (1997) 135
[hep-ph/9605285].
\end{thebibliography}


\newpage

\begin{figure}
%%\begin{picture}(15.,19.)
\begin{center}
\mbox{\epsfig{file=H1prelim-03-074.fig1.eps,width=0.6\linewidth,clip=}}
\end{center}
%%\end{picture}
\caption{\label{fig1}{Distribution of the mass difference
$\Delta m = m(K^{\mp}\pi^{\pm}\pi_s^{\pm})-m(K^{\mp}\pi^{\pm})$
for DIS events in the visible range $1.5 \le
p_t \le 15\ \mbox{GeV}$ and $|\eta| \le 1.5$.
The curves represent a fit to the
$m(K^{\mp}\pi^{\pm}\pi_s^{\pm})$ 
distribution
using a Gaussian for the signal and a term $(\Delta m-m_\pi)^\alpha$
for the background.}}
\end{figure}

\vspace*{6mm}

\begin{figure}[htb]
$
\begin{array}{lcr}
  \begin{minipage}{0.45\linewidth}
 \mbox{\epsfig{file=H1prelim-03-074.fig2a.eps,width=1.1\linewidth,clip=}}
  \end{minipage}&
  \begin{minipage}{0.45\linewidth}
 \mbox{\epsfig{file=H1prelim-03-074.fig2b.eps,width=1.1\linewidth,clip=}}
  \end{minipage}
  \end{array}
$
\caption{\label{fig2}
{The reconstructed $E_e^\prime$
and $\theta_e$ for events with $D^{*\pm}$ candidates
(after background subtraction) together with the detector level
 (RAPGAP) prediction (shaded histogram). }}
\end{figure}


\vspace*{-22mm}
\begin{figure}
\begin{center}
\vspace*{-6mm}
\mbox{\epsfig{file=H1prelim-03-074.fig3a.eps,width=0.45\linewidth,clip=}}
\mbox{\epsfig{file=H1prelim-03-074.fig3b.eps,width=0.45\linewidth,clip=}}
\vspace*{3mm}
\mbox{\epsfig{file=H1prelim-03-074.fig3c.eps,width=0.45\linewidth,clip=}}
\mbox{\epsfig{file=H1prelim-03-074.fig3d.eps,width=0.45\linewidth,clip=}}
\vspace*{3mm}
\mbox{\epsfig{file=H1prelim-03-074.fig3e.eps,width=0.45\linewidth,clip=}}
\mbox{\epsfig{file=H1prelim-03-074.fig3f.eps,width=0.45\linewidth,clip=}}
\end{center}
\vspace*{-9mm}
\caption{\label{fig3}{Single
differential inclusive cross section for $D^{*\pm}$ meson production
$\sigma(ep \rightarrow eD^{*\pm} X)$
versus $W$, $x$, $Q^2$, $p_t$, $\eta$ and $z_{D^*}$.
The inner and outer error bars correspond to the
statistical and total errors.
The expectation of the NLO DGLAP calculation using HVQDIS with
CTEQ5F3 parton densities is indicated by the
lower shaded band. The upper shaded band is the expectation
of the CCFM calculations based on the
CASCADE program with the initial gluon distribution fitted
to the inclusive $F_2$ data.
The upper and lower bounds of both calculations correspond
to ($m_c=1.3~\gev$, $\epsilon_c=0.035$) and ($m_c=1.5~\gev$,
$\epsilon_c=0.10$), respectively.}}
\end{figure}

%\newpage

\begin{figure}
\vspace*{-2mm}
\begin{center}
\mbox{\epsfig{file=H1prelim-03-074.fig4a.eps,width=0.45\linewidth,clip=}}
\mbox{\epsfig{file=H1prelim-03-074.fig4b.eps,width=0.45\linewidth,clip=}}
\vspace*{3mm}
\mbox{\epsfig{file=H1prelim-03-074.fig4c.eps,width=0.45\linewidth,clip=}}
\mbox{\epsfig{file=H1prelim-03-074.fig4d.eps,width=0.45\linewidth,clip=}}
\vspace*{3mm}
\mbox{\epsfig{file=H1prelim-03-074.fig4e.eps,width=0.45\linewidth,clip=}}
\mbox{\epsfig{file=H1prelim-03-074.fig4f.eps,width=0.45\linewidth,clip=}}
\end{center}
\vspace*{-8mm}
\caption{\label{mcxsec1}{Single differential inclusive cross
section for $D^{*\pm}$ meson production
$\sigma(ep \rightarrow eD^{*\pm} X)$ versus $W$, $x$,
$Q^2$, $p_t$, $\eta$ and $z_{D^*}$. The inner and
outer error bars correspond to the statistical and total
errors. The expectation of the RAPGAP Monte Carlo (with
$m_c=1.4~\gev$, $\epsilon_c=0.078$ and using the CTEQ5L 
proton parton densities) is shown when
 only direct processes are taken into account
and when the resolved contribution is also considered.
The expectation of the CASCADE program (with $m_c=1.4~\gev$,
$\epsilon_c=0.078$ and the initial gluon distribution fitted
to the inclusive $F_2$ data) is also displayed. }}
\end{figure}

\newpage



\begin{figure}
\begin{center}
\mbox{\epsfig{file=H1prelim-03-074.fig5.eps,width=0.75\linewidth,clip=}}
\end{center}
\vspace*{-8mm}
\caption{\label{fig5}{The double differential inclusive cross section
for $D^{*\pm}$ meson production
${\rm d}^2\sigma/{\rm d}p_{t}{\rm d}Q^2$ in bins of $p_t$.
The inner and outer error bars correspond to the
statistical and total errors.
The expectations of the NLO DGLAP calculation using HVQDIS and
of the CCFM calculations based on the
CASCADE program are also indicated
 (see figure \ref{fig3} for details).}}
\end{figure}


\vspace*{1mm}

\begin{figure}
\vspace*{14mm}
\begin{center}
\hspace*{-6mm}
\mbox{\epsfig{file=H1prelim-03-074.fig6.eps,width=1.07\linewidth,clip=}}
\end{center}
\vspace*{-8mm}
\caption{\label{fig4}{The double differential inclusive cross section
for $D^{*\pm}$ meson production
${\rm d}^2\sigma/{\rm d}\eta{\rm d}Q^2$ in bins of $\eta$.
The inner and outer error bars correspond to the
statistical and total errors.
The data are compared to the expectations of the NLO DGLAP 
calculation using HVQDIS and of the CCFM calculations 
based on the CASCADE program 
 (see figure \ref{fig3} for details).}}
\end{figure}


\begin{figure}
\begin{center}
\hspace*{-6mm}
\mbox{\epsfig{file=H1prelim-03-074.fig7.eps,width=1.07\linewidth,clip=}}
\end{center}
\vspace*{-8mm}
\caption{\label{fig6}{Double differential inclusive cross section
for $D^{*\pm}$ meson production
${\rm d}^2\sigma/{\rm d}p_{t}{\rm d}z_{D^*}$ in bins of $p_t$.
The inner and outer error bars correspond to the
statistical and total errors.
The data are compared to the expectations of the NLO DGLAP 
calculation using HVQDIS and of the CCFM calculations 
based on the CASCADE program 
(see figure \ref{fig3} for details).}}
\end{figure}


\begin{figure}
\vspace*{16mm}
\begin{center}
\hspace*{-6mm}
\mbox{\epsfig{file=H1prelim-03-074.fig8.eps,width=1.07\linewidth,clip=}}
\end{center}
\vspace*{-9mm}
\caption{\label{fig7}{Double differential inclusive cross section
for $D^{*\pm}$ meson production
${\rm d}^2\sigma/{\rm d}p_{t}{\rm d}\eta$ in bins of $p_t$.
The inner and outer error bars correspond to the
statistical and total errors.
The data are compared to the expectations of the NLO DGLAP 
calculation using HVQDIS and of the CCFM calculations 
based on the CASCADE program 
(see figure \ref{fig3} for details).}}
\end{figure}

\vspace*{-5mm}
\begin{figure}
\mbox{\epsfig{file=H1prelim-03-074.fig9a.eps,width=0.5\linewidth,clip=}}
\mbox{\epsfig{file=H1prelim-03-074.fig9b.eps,width=0.5\linewidth,clip=}}

\vspace*{8mm}
\mbox{\epsfig{file=H1prelim-03-074.fig9c.eps,width=0.5\linewidth,clip=}}
\mbox{\epsfig{file=H1prelim-03-074.fig9d.eps,width=0.5\linewidth,clip=}}
\caption{\label{jetxsec}{Dijet cross sections as a function
of $Q^2$, $x$, $E_t^{\text{max}}$ and $\Delta\eta$, the latter two
being measured in the Breit frame,
 for events with $D^{*\pm}$ mesons. The inner and
outer error bars correspond to the statistical and total
errors. The expectation of the RAPGAP Monte Carlo (with
$m_c=1.4~\gev$, $\epsilon_c=0.078$ and using the CTEQ5L parton 
density in the proton) is shown
when only direct processes are taken into account
and when the resolved contribution is also considered.
The data are also compared with the expectation of the
CASCADE Monte Carlo with $m_c=1.4~\gev$, $\epsilon_c=0.078$ and
the initial gluon distribution fitted to the inclusive $F_2$ data.}}
\end{figure}

\newpage

\begin{figure}
\vspace*{-8mm}
\begin{center}
\mbox{\epsfig{file=H1prelim-03-074.fig10.eps,width=0.75\linewidth,clip=}}
\end{center}
\vspace*{-8mm}
\caption{\label{ratio}{The cross section for 
the production of dijets in association with
a $D^{*\pm}$ meson versus the $D^{*\pm}$
meson production cross section. The expectation of the 
RAPGAP Monte Carlo with $\epsilon_c=0.078$ is shown
when only direct processes are taken into account
and when the resolved contribution is also considered.
The predictions of the AROMA Monte Carlo with $\epsilon_c=0.078$
and of the HERWIG Monte Carlo which uses cluster fragmentation 
are also displayed. For the predictions of RAPGAP, AROMA and HERWIG 
 $m_c=1.4~\gev$ and the CTEQ5L proton parton densities are used.
The data are also compared with the expectation of the
CASCADE Monte Carlo  with
the initial gluon distribution fitted to the inclusive $F_2$ data, for
 $m_c=1.4~\gev$, $\epsilon_c=0.078$ for $m_c=1.3~\gev$,
 $\epsilon_c=0.035$ and for $m_c=1.5~\gev$, $\epsilon_c=0.10$.}}
\end{figure}



\end{document}

