%================================================================ % LaTeX file with prefered layout for H1 paper drafts % use: dvips -D600 file-name %================================================================ \documentclass[12pt]{article} \usepackage{epsfig} \usepackage{amsmath} \usepackage{hhline} \usepackage{amssymb} \usepackage{times} \usepackage{cite} \usepackage{graphicx} \usepackage{ifpdf} \usepackage{color} \usepackage{colordvi} \usepackage{epstopdf} \ifpdf \usepackage{epstopdf} \usepackage{pdfsync} \fi %%%%%%%%%%%% Comment the next two lines to remove the line numbering %\usepackage[]{lineno} %\linenumbers %\usepackage{hyperref} %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%% \renewcommand{\topfraction}{1.0} \renewcommand{\bottomfraction}{1.0} \renewcommand{\textfraction}{0.0} \newlength{\dinwidth} \newlength{\dinmargin} \setlength{\dinwidth}{21.0cm} \textheight22.8cm \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============================= \begin{document} % The rest \newcommand{\pom}{{I\!\!P}} \newcommand{\reg}{{I\!\!R}} \def\gsim{\,\lower.25ex\hbox{$\scriptstyle\sim$}\kern-1.30ex% \raise 0.55ex\hbox{$\scriptstyle >$}\,} \def\lsim{\,\lower.25ex\hbox{$\scriptstyle\sim$}\kern-1.30ex% \raise 0.55ex\hbox{$\scriptstyle <$}\,} \newcommand{\trm}{m_{\perp}} \newcommand{\trp}{p_{\perp}} \newcommand{\trmm}{m_{\perp}^2} \newcommand{\trpp}{p_{\perp}^2} \newcommand{\alp}{\alpha_s} \newcommand{\alps}{\alpha_s} \newcommand{\sqrts}{$\sqrt{s}$} \newcommand{\PT}{p_{\perp}} \newcommand{\JPSI}{J/\psi} \newcommand{\PO}{I\!\!P} \newcommand{\xbj}{x} \newcommand{\xpom}{x_{\PO}} \newcommand{\dgr}{^\circ} \newcommand{\gev}{\,\mbox{GeV}} \newcommand{\GeV}{\mathrm{GeV}} \newcommand{\GeVS}{\rm GeV^2} \newcommand{\xp}{x_p} \newcommand{\xpi}{x_\pi} \newcommand{\xg}{x_\gamma} \newcommand{\xgj}{x_\gamma^{jet}} \newcommand{\xpj}{x_p^{jet}} \newcommand{\xpij}{x_\pi^{jet}} \renewcommand{\deg}{^\circ} \newcommand{\qsq}{\ensuremath{Q^2} } \newcommand{\gevsq}{\ensuremath{\mathrm{GeV}^2} } \newcommand{\et}{\ensuremath{E_t^*} } \newcommand{\rap}{\ensuremath{\eta^*} } \newcommand{\gp}{\ensuremath{\gamma^*}p } \newcommand{\der}{{\mathrm d}} \newcommand{\kd}{\textcolor{black}} % Journal macro \def\Journal#1#2#3#4{{#1} {\bf #2}, #4 (#3)} \def\NCA{\em Nuovo Cimento} \def\NIM{\em Nucl. Instrum. Methods} \def\NIMA{{\em Nucl. Instrum. Methods} {\bf A}} \def\NPB{{\em Nucl. Phys.} {\bf B}} \def\PLB{{\em Phys. Lett.} {\bf B}} \def\PRL{\em Phys. Rev. Lett.} \def\PRD{{\em Phys. Rev.} {\bf D}} \def\PR{{\em Phys. Rev.} } \def\ZPC{{\em Z. Phys.} {\bf C}} \def\ZP{{\em Z. Phys.} } \def\EJC{{\em Eur. Phys. J.} {\bf C}} \def\EJA{{\em Eur. Phys. J.} {\bf A}} \def\CPC{\em Comp. Phys. Commun.} \begin{titlepage} \begin{flushleft} {\tt DESY 14-035 \hfill ISSN 0418-9833} \\ {\tt March 2014} \\ \end{flushleft} %\vspace{3mm} \vspace*{10mm} \rm \begin{center} \begin{Large} {\boldmath \bf Measurement of Feynman-$x$ Spectra of Photons and Neutrons in the Very Forward Direction in Deep-Inelastic Scattering at HERA } \vspace{2cm} \rm H1 Collaboration \end{Large} \end{center} \vspace{2cm} % \begin{abstract} \noindent \rm Measurements of normalised cross sections for the production of photons and neutrons at very small angles with respect to the proton beam direction in deep-inelastic $ep$ scattering at HERA are presented as a function of the Feynman variable $x_F$ and of the centre-of-mass energy of the virtual photon-proton system $W$. % The data are taken with the H1 detector in the years 2006 and 2007 and correspond to an integrated luminosity of $131~\mathrm{pb}^{-1}$. The measurement is restricted to photons and neutrons in the pseudorapidity range $\eta>7.9$ and covers the range of negative four momentum transfer squared at the positron vertex $67.9$ for forward neutrons and photons. The pseudorapidity range $\eta>7.9$ corresponds to polar angles $\theta<0.75$~mrad\kd{, the geometrical acceptance limit of the FNC.} % In the virtual photon-proton CM frame \kd{the $x_F$ of the neutron and photon are restricted to $0.17.9$ and are restricted to the range $07.9$} \\ $\eta>7.9$ & $\eta>7.9$ \\ $0.111~\GeV$ and a polar angle $156\deg<\theta_e'<175\deg$. The \mbox{$z$-coordinate} of the primary event vertex is required to be within $\pm 35$~cm of the nominal interaction point. % The hadronic final state is reconstructed using an energy flow algorithm which combines charged particles measured in the trackers with information from the SpaCal and LAr calorimeters~\cite{Peez:2003zd,Hellwig:2004yp}. % To suppress events with hard initial state QED radiation, as well as events originating from non-$ep$ interactions, the quantity $\sum{E - p_z}$, summed over all reconstructed particles including the positron, is required to lie between $35~\GeV$ and $70~\GeV$. % This cut also efficiently removes events from photoproduction processes, where the positron is scattered into the backward beam-pipe and a particle from the hadronic final state fakes the positron signature in the SpaCal. % The kinematic variables $Q^2$ and $y$ are reconstructed using a technique which optimises the resolution throughout the measured $y$ range, exploiting information from both the scattered positron and the hadronic final state \cite{Adloff:1997sc}. Events are restricted to the range $67.9$ and in the range of Feynman-$x$ of $0.1