% p_T symbol not installed in tables! % y_cm symbol not installed in tables! % % % figure 1 should be a drawing of the 1990 configuration of the spectrometer % why does figure 2 have such coarse binning? % %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%% %PHYSICAL REVIEW D sub_prd.asc %ARTICLE SUBMISSION FORM revised 9/96 % %Title: % %Authors: Fermilab E706 Collaboration, L. Apanasevich et al. % %Correspondent: George Ginther % %Email: ginther@fnal.gov % %Address: George Ginther % Fermilab MS 359 % Batavia IL 60510 % %Phone: 630-840-2263 % %Fax: 630-840-2269 % %Please consider as a: Compuscript Submission of a Regular Article for PRD1 % %For Comment/Reply: %(Provide author and volume/page or code number of object article) % %Suggest a principal PACS code. This will allow more efficient processing and %will assist in correctly placing your manuscript in the Table of Contents. %You may assign three additional PACS codes that further describe the contents %of your paper. To access the 1996 PACS via the World Wide Web, use the %following URL: http://publish.aps.org/PACS/pacsgen.html % %Suggested PACS numbers. Select ONE Principal PACS number and NO MORE THAN %THREE additional numbers. Use a separate line for each. % %Principal: 12.38 %Additional: 13.85 % 13.75.G % 25.80.E % 25.80.L % % %Contributors are encouraged to suggest names and institutions of potential %referees (no limit): %1. %2. %3. %4. %5. % %Submitted by: George Ginther % %Date: 4 Feb 1997 % %Submission of this manuscript implies acceptance by the authors of the %established procedures for selecting manuscripts for publication. It %is understood that this manuscript is original work and is not being %considered for publication elsewhere. % %Please ensure that the following items are provided: % % Double-spaced manuscript, including abstract, captions, and references % Signed copyright form % Signed color figure form (if applicable) % If this is a transfer from PRL, please indicate manuscript code ( ) % "Original" scanner reproducible figures % %Provide additional information for the Editors (e.g., undesirable referees, %etc.) below. % %Xinfo: %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%% % % setup draft ``watermark'' on each page % 0. = black, 1. = white (GA gave it with 0.95) % %\special{!userdict begin /bop-hook{gsave 200 30 translate %65 rotate /Times-Roman findfont 216 scalefont setfont %0 0 moveto 0.99 setgray (DRAFT) show grestore}def end} % % % \documentstyle[preprint,eqsecnum,prd,aps,epsf]{revtex} % Preprint format %\documentstyle[preprint,eqsecnum,prd,aps]{revtex} % Preprint format %\documentstyle[tighten,preprint,eqsecnum,prd,aps]{revtex} % Preprint format %\documentstyle[aps]{revtex} % APS style - galley format %\documentstyle[prd,aps]{revtex} % APS style - galley format \def\btt#1{{\tt$\backslash$#1}} % % % %----------------------------------------------------------------------------- \def\pt{\mbox{$p_T$}} \newcommand{\er}{\mbox{$E_{R}$}} \newcommand{\ephi}{\mbox{$E_{\Phi}$}} \newcommand{\eft}{\mbox{$E_{\mathrm{front}}/E_{\mathrm{total}}$}} \newcommand{\ksh}{\mbox{$K_{S}^{0}$}} \newcommand{\pim}{\mbox{$\pi^{-}$}} \newcommand{\piz}{\mbox{$\pi^{0}$}} \newcommand{\epem}{\mbox{$e^{+}e^{-}$}} \newcommand{\ycm}{\mbox{$y_{\rm{CM}}$}} %\def\kt{$k_T$} %\def\pythiakt{${\rm k}_\perp$} %\def\NLOkt2{${\langle {\rm k_T^2} \rangle}$} %----------------------------------------------------------------------------- % \tolerance=12000 \begin{document} % % \draft command makes the pacs numbers print \draft % % \preprint{FERMILAB-Pub-97/???-E} % % % input title, authors and abstract % \title{Draft 2.0 of \\ \piz\ and $\eta$ meson production at large transverse momenta \\ in \pim-Be interactions at 515~GeV/$c$ } % input the collaboration list \input list_of_authors % \date{\today} \maketitle % \begin{abstract} We present results on the production of high transverse momentum neutral mesons in \pim\ Be interactions at ${ 515 \: {\rm GeV}/c}$ The data span the kinematic ranges of ${ 0.6 \: \le \: \pt\ \: \le 12 \,{\rm GeV}/c}$ in transverse momentum and ${ -0.75 \le \ycm\ \le 0.75}$ in rapidity (center of mass frame). We have measured inclusive differential cross sections for \piz\ and $\eta$ meson production. The cross sections are compared with next-to-leading log QCD calculations for several choices of $Q^2$ and fragmentation models. \end{abstract} % \pacs{PACS numbers: 12.38, 13.85, 13.75.G, 25.80.E, 25.80.L} \narrowtext \section{INTRODUCTION} The study of inclusive single-hadron production at large transverse momentum (\pt) continues to be a useful avenue in the development of QCD~\cite{geist,mccubbin}. Early in the evolution of the parton model, a departure from an exponential dependence of particle production at low \pt\ was interpreted in terms of the onset of interactions between pointlike partons contained in hadrons; and the increase of inclusive hadron cross sections with center-of-mass energy at large \pt\ was interpreted as evidence for scale dependent interactions. Large \pt\ is a regime where perturbative methods can be applied to QCD to provide a quantitative comparison with data. Such comparisons yield information on the validity of QCD matrix elements, and on the effective product of the parton distribution functions of hadrons and the fragmentation functions of partons. This paper reports a substantially broader experimental measurement than previously available and comparisons with recent next to leading log QCD calculations~\cite{aversa,greco}. \section{THE EXPERIMENTAL SETUP} Fermilab experiment E706 is a second generation fixed-target experiment designed to measure direct photon production and the underlying event structure. Figure~\ref{layout} shows a plan view of various components of the Meson West spectrometer used in this analysis. The E706 apparatus and the downstream muon spectrometer of E672 were deployed simultaneously in the beamline and latched their data with triggers from either experiment. This aggregate data set allowed cross checks for both experiments. Several papers have recently been published describing physics results of that collaboration.~\cite{chi90,psi90,B90} First results from E706 were reported previously in this journal~\cite{pi088,dp88,bigpaper}. Enhancements were made to nearly all the spectrometer elements for the subsequent data samples reported here. The following sections briefly describe the experimental layout and the analysis procedures used to extract the neutral meson signals. Particular attention will be paid to those changed from our earlier analysis. E706 utilized a charged particle tracking system consisting of silicon strip detectors (SSDs)~\cite{ssd2}, a dipole analysis magnet, proportional wire chambers (PWCs), and cylindrical drift tubes (Straws)~\cite{straws}. Six 3x3~cm SSD planes were located upstream of the target and used to reconstruct beam tracks. The target consisted of two 0.8~mm thick copper foils followed by two cylinders of beryllium (3.7~cm and 1.1~cm in length). Two hybrid 5x5~cm SSD planes (25~$\mu$m pitch strips in the central 1~cm, 50~$\mu$m beyond) were located 3~cm downstream of the target. These were followed by eight 5x5~cm planes of 50~$\mu$m pitch silicon. The SSDs were instrumented to cover the solid angle to 170~mr. Figure~\ref{target} shows a distribution of reconstructed vertices clearly distinguishing the various target elements. The analysis dipole imparted a nominal transverse momentum impulse (in the horizontal plane) of $\approx~450~{\rm MeV}/c$ to charged particles. The downstream track segment was measured using four stations of four views ($XYUV$) of 2.54~mm pitch PWCs and two new stations of eight (4$X$4$Y$) layers of 1~cm diameter straw drift tubes resulting in a threefold improvement in angular resolution. A liquid argon electromagnetic calorimeter (EMLAC) with fine segmentation was the central element of the experiment~\cite{lac}. The calorimeter had an $R$, $\Phi$ geometry with a full radius of 150~cm and a 20~cm radius beam hole in the center. There were four structural quadrants containing 66~cells in depth for a total length of 27 radiation lengths. Each cell consisted of a 2~mm lead sheet followed by an anode board segmented in strips of constant radius or angle in alternate layers. The gap spacing for the argon drift volume was 2.5~mm. The strips in two orthogonal views provided spacial resolution with fewer channels than a pad geometry; the radial symmetry simplified the processing of EMLAC information in a transverse momentum trigger. Strips from the first 11~layers in each view were ganged together into a single readout amplifier. Similarly for the last 22~layers. This division in depth provided some discrimination against hadrons. %(Do I need to %provide the LAC picture again ???) (Define octants ???) Data acquisition and trigger-signal processing for the EMLAC was performed using the FNAL RABBIT system~\cite{rabbit}. The zero suppression features of this system were extensively used in the first run in order to achieve tolerable deadtimes. However, the entanglement of issues of pedestal measurements, out of time showers and broad hadron showers, made detailed detector studies difficult. FASTBUS modules (the ICBM - Intelligent Control and Buffering Module - and the Wolf interface~\cite{ICBM,wolf}) were developed by E706 to replace the original MX readout controllers and allow significantly reduced thresholds. The experiment's trigger was designed to operate at $10^6$ interactions per second and sample a wide range of transverse momentum. The triggering process took place in three steps: defining a beam particle, an interaction, and a final trigger requiring energy deposition in the EMLAC. Presence of a beam particle was defined using hodoscopes with 1~mm scintillator elements. A signal from one and only one element was required in at least two of the three stations ($XYU$ orientations with a 45~degree stereo angle). Interaction definition was satisfied by signals from any two of four scintillation counters whose matrix covered the solid angle 6--100~milliradian from the beamline. A trigger \pt\ was formed by weighting the energy in each EMLAC radial strip according to the distance from the center of this strip to the beam line $(E \, \sin{\theta})$ and summed into overlapping groups of 16~(local) and full octants (global). These sums were each tested against high and low thresholds. \section{\piz\ AND $\eta$ ANALYSIS} The data sample for this analysis corresponds to an integrated luminosity of $8.6 \,{\rm events/pb}$. The following subsections describe the event reconstruction procedures and the methods used to correct the data for losses due to inefficiencies and selection biases. \subsection{Event reconstruction} The two major aspects of the event reconstruction procedure were particle track and calorimeter shower reconstruction. The charged-track reconstruction algorithm produced track segments, upstream of the magnet using the SSD planes, and downstream of the magnet using the PWC and straw planes. These were projected to the center of the magnet and linked to form the final reconstructed track whose calculated momentum, charge and direction were used for the physics analysis. Major improvements in this procedure were the incorporation of the straw chambers to improve linking downstream and upstream tracks, improved vertex resolution from the finer pitch SSDs, and generally improved track finding efficiency. The readout in each EMLAC quadrant consisted of four ``views": left $R$ and right $R$, (radial strips of each octant in that quadrant), and inner $\Phi$ and outer $\Phi$ (azimuthal strips divided at $R = 40.2~{\rm cm}$.) Strip energies from clusters in each view were fit to the shape of an electromagnetic shower, determined from electron calibration data and Monte Carlo simulations and used to calculate the view position and energy of the peak. Shower positions and energies were obtained by correlating peaks of approximately the same energy in the $R$ and $\Phi$ views within the same half octant. \subsection{Energy calibration} Due to the steep \pt\ dependence of inclusive cross sections, a small change in the energy calibration of the EMLAC can produce large changes in the measured cross section at a specific energy. Because of this sensitivity, the calibration must be determined with great care. A separate article on the E706 electromagnetic calorimeter describes that process in greater detail.~\cite{lac_cal90,lac_cal}. The results of that calibration can be summarized with the signals shown in Fig.~\ref{3neutral_cal}. The $\pi^{0}$ and $\eta$ masses were found to be $134.93~\pm~0.03~{\rm MeV}/c^2$ and $547.4 \pm 0.3 \, {\rm MeV}/c^2$, respectively, using a single calibration for photon showers. This simultaneous agreement to better than $0.1\%$ of their accepted values is encouraging but possibly not a good measure of calibration accuracy since both samples were included in the calibration procedure. The $\omega$ signal in its decay mode $\omega \rightarrow \piz\gamma$ provides an independent check on our energy scale as it was not used in the calibration studies. Its fit mass of $778 \pm 2 \, {\rm MeV}/c^2$ confirms the establishment of a consistent energy scale between the reconstructed \piz s and higher mass mesons (whose decays have widely separated photons). The deviation of the $\omega$ mass from current world average, combined with the systematic uncertainties from the calibration indicate a systematic uncertainty in the overall energy scale of $\leq~0.5~\%$. % ??? omega mass is supposed to be 782 right ? That indicates a .6% error. \subsection{Data sample selection and corrections} %While many corrections for cuts could be determined from the data using %various cross checks, some required the Monte Carlo simulation %techniques to determine their values. The active region of the LAC was specified by fiducial cuts to exclude areas with reduced sensitivity. In particular, regions of the detector near quadrant boundaries (which abutted steel support plates), the central beam hole, the outer radius of the EMLAC, and octant boundaries were excluded. A simple ray-tracing Monte Carlo was sufficient to determine the correction for these requirements. Binned in \pt, rapidity, and vertex position, \piz\ mesons were decayed to two photons with randomly distributed orientation. These photons were then projected to the LAC and the fiducial cuts applied. The fraction cut yielded the correction. A similar method determined the correction for the $\eta$ acceptance. The correction for losses due to conversion of one or more of the meson decay photons into \epem\ pairs was determined by projecting each reconstructed photon from the event vertex to the reconstructed position in the LAC. The total radiation length of material traversed was extracted from the detector databases. From there the photon conversion probability was determined and used to account for those cut events. For other corrections to the cross section (primarily for reconstruction smearing and losses) a full event simulation was required. We studied both {\sc pythia}~\cite{pythia57} and {\sc herwig}~\cite{herwig} event generators and selected {\sc herwig} based on a better match in multiplicities with default parameters. The production spectrum in \pt\ and rapidity was found to differ from our data measurements at the 50\% level and was weighted to the data shape to account for this difference. The Monte Carlo simulation of the spectrometer used the {\sc geant}~\cite{geant3} package. While calorimeter shower simulation using this program is extremely computing intensive it has the benefit of correlating fluctuations between photon conversion point, lateral shower spread and energy loss in non-sensitive material. We adopted a hybrid approach using {\sc geant} tracking through the magnetic spectrometer and the early sections of the calorimeter. Most of the time spent in shower simulation deals with tracking the myriad of low energy particles in the cascade. We used standard {\sc geant} tracking for particles above 10 MeV after which the energy deposition was parameterized. This cutoff was selected as the point at which bremsstrahlung dominates the energy loss and reasonable improvement in processing speed. Even so, the Monte Carlo remained very computing intensive and we took advantage of the advances in computational power by using the FNAL Unix farms~\cite{farm}. Events containing leading neutral mesons were generated from the full event simulator and then reconstructed using the standard reconstruction program. The ratio of reconstructed to generated events was determined for bins in rapidity and \pt. These ratios were then fit with a smooth two dimensional surface which yielded the final efficiency correction. The reconstruction efficiency accounted for losses due to reconstruction problems, resolution smearing of energy and position distorting the \pt\ distribution, confusion and accidental overlap with energy deposited from other particles in the event, etc. For our study of \piz\ production, a \piz\ candidate was defined as any two-photon combination with energy asymmetry ($A_{\gamma\gamma} = |E _{\gamma_1}-E_{\gamma_2}|/ (E_{\gamma_1}+ E_{\gamma_2})$) less than 0.75, and invariant mass, $M_{\gamma \gamma}$, in the range $110~{\rm MeV}/c^2~<~M_{\gamma \gamma}~<~160~{\rm MeV}/c^2$. An $\eta$ candidate was defined as any two-photon combination with $A_{\gamma\gamma}~<~0.75$ and $450~{\rm MeV}/c^2~<~M_{\gamma \gamma}~<~650~{\rm MeV}/c^2$. %Both photons were required to occupy the same octant. The minimum \pt\ value employed in the analysis was determined by the trigger threshold used in the corresponding data taking. To account for combinatorial background under the \piz\ and $\eta$ signals, sidebands were defined to cover the equivalent mass range of the \piz\ and $\eta$ peaks. Distributions from these side bands were then subtracted from the distributions within the \piz\ and $\eta$ mass ranges to obtain the respective signals. The resulting distribution for combinations with \pt\ of at least 4.0 GeV/$c$ is shown compared with that from the Monte Carlo simulation in Fig.~\ref{mcmass}. Another useful comparison between data and Monte Carlo simulation is a comparison of the energy asymmetry distribution for \piz\ candidates. This comparison is shown in Fig.~\ref{asym_comp} for two ranges in \pt. %For a spin 0 %particle like the \piz\ production is expected to be flat in %asymmetry. The falloff at high asymmetry reflect the loss of low %energy photons from the decay. The uniform level at low asymmetry %in the higher \pt\ interval indicates little problem resolving the %two photons from higher energy \piz s. This is evidence for %agreement in the reconstruction of soft photons from \piz\ decays %and the lack of prominent coallescence effects. \subsection{Trigger} %As Fig.~\ref{pixs_full} shows, the \piz\ cross section measured by %this experiment spans 13 orders of magnitude. The measurement was achieved by %using a composite of samples from several triggers. The uncorrected spectum %from the various triggers are shown below the %final curve to illustrate regions of applicability. The trigger decisions were based on global (octant sum) and local (16 strips) sums of EM transverse momentum. With the large event sample we were able to measure the efficiency for each trigger element as a function of energy reconstructed in that trigger region (local or global). These were measured in octants opposite the triggering octant to provide an unbiased sample. If a minimum trigger \pt\ value was exceeded for an octant, a preliminary weight was calculated inversely proportional to the probability of satisfying any trigger in that octant. A search was then performed along a circle of constant azimuth (corresponding to fixed rapidity) to determine whether this octant's energy deposition pattern would have satisfied the trigger in other octants as well. The event was then weighted to take into account any loss of triggers caused by higher threshold settings or by dead channels in other octants. We thus corrected for trigger variations at fixed rapidity for all octants. \subsection{Normalization} We used two methods to determine the absolute normalization for our cross section measurements. For the primary method, we logged the contents of electronic scalers which counted beam particles traversing the spectrometer when it was ready to record an event. This method has several corrections for multiple particles in the same RF bucket, beam outside the fiducial target region, etc. and is cross checked with the second method. We recorded events using prescaled beam and interaction signals and are able to reconstruct a \piz\ signal in these events. For these samples the absolute normalization can be obtained independently of the scalers simply by counting events in the sample. The net systematic uncertainty in the overall normalization due to the corrections listed above, as well as from several smaller effects (at the 1\%~level) that have not been described, is $\approx~10\%$. \subsection{Summary of systematic uncertainties} The primary contributions to the systematic uncertainty arise from the following sources: Energy scale (5--12\%), reconstruction efficiency and resolution unsmearing (5--10\%), and normalization (10\%). Several of these uncertainties (e.g. normalization) are strongly correlated between the various bins. Others (e.g. reconstruction efficiency) need not be. The point to point component of the systematic uncertainties, combined in quadrature, are quoted with cross sections in the appropriate tables. Combining all systematic uncertainties yields a net uncertainty of $15\%$ for \piz\ and $20\%$ for $\eta$. The beam momentum was determined to have a mean momentum of $517~\pm~2~{\rm GeV}/c$ with an estimated halfwidth of $30~{\rm GeV}/c$. This introduces a small uncertainty ($\approx 5\%$) in calculating predictions from theory and comparisons with other data. \section{CROSS SECTIONS} \subsection{\piz\ meson} Table~\ref{pi0_table} catalogues the invariant cross section per nucleon for \piz\ production in $515 \, {\rm GeV}/c$ $\pim{\rm Be}$ interactions averaged over bins in \pt\ and rapidity. % This next sentence makes Tom ill: %The results show the richness of this data sample. Figure~\ref{pixs_pt} shows the cross section for large transverse momentum averaged over the rapidity range $-0.75 \, < \, \ycm\ \, < \, 0.75$. The curves represent next-to-leading-log QCD predictions from Aversa {\it et al.}~\cite{aversa}, using parton distribution functions for the pion and nucleon from Aurenche {\it et al.}~\cite{abfow,abfkw}. %(Which set do we want to use and should we use %linear comparison ???)? The two choices for the factorization scale are $Q^2 \, = \, \pt ^2$ and $Q^2 \, = \, \pt ^2/4$. Agreement between data and theory (for the smaller choice of scale) is excellent for the \pim\ data over the full \pt\ range shown. Figure~\ref{pixs_rap} shows the cross section versus rapidity for several bins in \pt. The expected peaking at scattering near 90 degrees in the center of mass (\ycm\ = 0) develops slowly over the kinematicly available region. The slight forward asymmetry is expected in pion-proton collisions due to the harder pion parton distribution functions. \subsection{$\eta$ meson} Cross section measurements for the inclusive productions of $\eta$ mesons are tabulated in Table~\ref{eta_table} and plotted in Fig.~\ref{etaxs} versus \pt\ integrated over the rapidity range $-0.75 \, < \, \ycm\ \, < \, 0.75$. The curves represent next-to-leading-log QCD predictions from Greco {\it et al.}~\cite{greco}, using parton distribution functions for the pion and nucleon from Aurenche {\it et al.}~\cite{abfow,abfkw}. %(Should match pizero sets ???)? There is an additional free parameter in these comparisons in the $\eta$ fragmentation function is evolved from the {\sc herwig} Monte Carlo due to the limited range of earlier experimental measurements. The two curves represent two choices for the fragmentation function. Comparison with the neutral pion production is demonstrated in Fig.~\ref{etapi} versus \pt\ and versus rapidity in the \pt\ bins $3.0 < \pt\ < 4.5$ and $4.5 < \pt\ < 8.0$. We see no significant \pt\ dependence - the data average to a value of $0.49 \pm .01$ - there are possible hints of an increase relative $\eta$ production at forward rapidities. \section{SUMMARY} The invariant cross sections for \piz\ and $\eta$ production have been measured for $\pim{\rm Be}$ collisions as a function of \pt\ and \ycm. The $\eta$ cross sections compare favorably with next-to-leading-log expectations from QCD in terms of shape but tend to prefer a lower choice of renormalization scale. The \piz\ cross section comparisons are quite sensitive to choice of both scale and fragmentation function as well as treatment of residual sources of transverse momentum such as that induced by initial state radiation. \acknowledgments We wish to thank the U.~S. Department of Energy, the National Science Foundation, including its Office of International Programs and the Universities Grants Commission of India, for their support of this research. The staff and management of Fermilab are to be thanked for their efforts in making available the beam and computing facilities that made this work possible. We are also pleased to acknowledge the contributions of our colleagues on Fermilab experiment E672. We would also like to thank M.~Greco, S.~Rolli, J.~Owens for many helpful discussions and for providing us with their QCD calculations. In addition, we wish to thank our following colleagues for their invaluable help in the operation and upgrade of the MWEST spectrometer: W.~Dickerson, E.~Pothier from Northeastern University; % E.~Barsotti~Jr., C.~Dong, H.~Koecher, D.~Petravick, R.~Tokarek, J.~Tweed, hydrogen target designers and cryo crew from Fermi National Accelerator Laboratory; % T.~Haelen, C.~Benson, L.~Kuntz, and D.~Ruggiero from the University of Rochester; % straw tube builders from Michigan State University; % %from University of Delhi; % Straw tube builders from Pennsylvania State University. % SSD constructors from University of Pittsburgh % FFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFF \renewcommand{\baselinestretch}{1.} % \newpage \bibliography{meson} \bibliographystyle{prsty} %\begin{references} % now the references. directly read in your .bbl file if you use bibtex. %\end{references} % % Figures \widetext % \newpage \noindent % % \begin{figure} \epsfxsize=3truein %\epsffile{e706-nocolor.ps} %% The unix trick to translate ^M to ^J (CR to LF) is %% tr ``\15'' ``\12'' < infile > outfile % \epsfxsize=3truein \epsffile{e706.epsf} %\epsfxsize=3truein %\epsffile{mwest_gg.ps} \caption{Plan View of the Fermilab E706 spectrometer. \label{layout}} \end{figure} % \newpage \begin{figure} \epsfxsize=3truein \centerline{\epsffile{vertex.ps}} \caption{Typical Reconstructed Vertex Distribution. The various target elements can clearly be distinguished: two 0.8~mm copper foils and two beryllium cylinders. The two silicon strip detectors immediately upstream and four downstream can also be resolved.} \label{target} \end{figure} % \newpage \begin{figure} \epsfxsize=3truein \centerline{\epsffile{pi_eta_omega.ps}} \caption{Invariant mass distribution in the \piz, $\eta$ and $\omega$ mass regions. Fits indicate a consistent energy scale between overlapping and widely separated showers. \label{3neutral_cal}} \end{figure} % \newpage \begin{figure} \epsfxsize=3truein %\centerline{\epsffile{comp_mass.ps}} \centerline{\epsffile{mass.ps}} \caption{Comparison of the two photon invariant mass distributions between Monte Carlo (circles) and data (histogram) for the \piz\ and $\eta$ mass regions. The agreement is excellent in both signal widths and background levels indicating a good simulation of our resolution and event topologies. %The arrows indicate the signal region. \label{mcmass}} \end{figure} % \newpage \begin{figure} \epsfxsize=3truein \centerline{\epsffile{pi0_asym.ps}} \caption{Comparison of the \piz\ asymmetry distribution between data and the Monte Carlo simulation. The inset displays comparisons in the \pt\ interval $7.0 < \pt\ < 8.5$ while the full graph shows the interval from $3.5 < \pt\ < 4.0$. The agreement is quite good across most of the asymmetry range for both \pt\ intervals. \label{asym_comp}} \end{figure} % \newpage \begin{figure} \epsfxsize=3truein \centerline{\epsffile{pi0_fullxs.ps}} \caption{Invariant cross section per nucleon for \piz\ production for \pim\ interactions with Be. Cross sections are shown versus \pt\ over the full rapidity range, $-0.75 \, < \, \ycm\ \, < \, 0.75$. The lower curves are uncorrected spectra from interaction, pretrigger, global low and local high trigger samples. The arrows indicate the transition regions from one trigger to another for our cross section results. \label{pixs_full}} \end{figure} % \newpage \begin{figure} \epsfxsize=3truein \centerline{\epsffile{pi0_qcd.ps}} \caption{Invariant cross section per nucleon for \piz\ production for \pim\ interactions with Be. Cross sections are shown versus \pt\ averaged over the full rapidity range, $-0.75 \, < \, \ycm\ \, < \, 0.75$. Curves indicate theoretical predictions for scale choices of $Q^2 = \pt^2$ and $\pt^2/4$ for a representative set of parton distribution functions. \label{pixs_pt}} \end{figure} % \newpage \begin{figure} \epsfxsize=3truein \centerline{\epsffile{pi0_rap.ps}} \caption{Invariant cross section per nucleon for \piz\ production for \pim\ interactions with Be. Cross sections are shown versus $Y$ in several \pt\ bins. The curves indicate the NLL theoretical predictions using ABFKW (CTEQ3M) parton distribution functions for the pion (proton) and BKK fragmentation function. The theory is normalized to the data in this plot. \label{pixs_rap}} \end{figure} % \newpage \begin{figure} \epsfxsize=3truein %%\epsfysize=7.in \centerline{\epsffile{eta_qcd.ps}} \caption{Invariant cross section per nucleon for $\eta$ production for \pim\ interactions with Be. Cross sections are shown versus \pt\ over the full rapidity range, $-0.75 \, < \, \ycm\ \, < \, 0.75$. The curves illustrate the results of NLL QCD calculations using a scale choice of $Q^2 = \pt^2/4$ and two different determinations of the $\eta$ fragmentation function from Greco, {\it et al}. \label{etaxs}} \end{figure} % \newpage \begin{figure} \epsfxsize=3truein \centerline{\epsffile{etapi_pt.ps}} \caption{Ratio of the invariant cross section for $\eta$ production over \piz\ cross section as a function of \pt. \label{etapi}} \end{figure} % \newpage \begin{figure} \epsfxsize=3truein \centerline{\epsffile{etapi_rap.ps}} \caption{Ratio of the invariant cross section for $\eta$ production over \piz\ cross section as a function of Y for two \pt\ ranges. \label{etapi_rap}} \end{figure} % % % Tables % %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%% \newpage \narrowtext \begin{table} \caption{ Compilation of systematic uncertainties for inclusive \piz\ and $\eta$ cross sections. } \begin{tabular}{ccc} Source\\ of Uncertainty & $\pim\ {\rm Be} \rightarrow \piz X $ & $\pim\ {\rm Be} \rightarrow \eta X$ \\ \tableline % Normalization Beam Count & 5\% & 5\% \\ Vertex Finding & 5\% & 5\% \\ Energy Scale & $5\% \rightarrow 12\%$ & $5\% \rightarrow 12\%$ \\ Beam Absorption & 0.5\% & 0.5\% \\ Fiducial Target Cut & 1\% & 1\% \\ Interaction Def'n & 2\% & 2\% \\ Photon Conversions & 1\% & 1\% \\ %Point to point Reconstruction Eff. & 5\% & 10\% \\ Geometrical Acceptance & 1\% & 1\% \\ MC Spectrum Weighting & 2\% & 2\% \\ Trigger & $5\% \rightarrow 0\%$ & $10\% \rightarrow 0\%$ \\ Directionality & 1\% & 0.5\% \\ Muon Wall cuts & 0.5\% & 0.5\% \\ Ef/Et cut & 1.0\% & 0.5\% \\ Pt Balance & 0.5\% & 0.5\% \\ Background Subtraction & 0\% & 2\% \\ %MC Run (Time) Distribution & \multicolumn{2}{c}{2\%} \\ \tableline Total & $12\% \rightarrow 15\%$ & $ 17\% \rightarrow 18\%$ \\ \end{tabular} \label{syserrs} \end{table} %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%% %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%% \newpage % % Try splitting the table into two parts. \widetext \begin{table} \caption{Invariant differential cross section %$\left( d \sigma/\pi d(\pt^2) d(y) \right)$ $\left( Ed^3 \sigma/d^3p \right)$ for the inclusive reaction $\pim\ + {\rm Be} \rightarrow \piz + X$. } \begin{tabular}{r@{}l@{ -- }r@{}l r@{}l@{${}\pm{}$}r@{}l@{${}\pm{}$}r@{}l r@{}l@{${}\pm{}$}r@{}l@{${}\pm{}$}r@{}l r@{}l@{${}\pm{}$}r@{}l@{${}\pm{}$}r@{}l r@{}l@{${}\pm{}$}r@{}l@{${}\pm{}$}r@{}l} \multicolumn{4}{c}{$p_T$} &\multicolumn{24}{c}{$y_{cm}$}\\ \multicolumn{4}{c}{ } &\multicolumn{6}{c}{-.75\ - \ -.5} & \multicolumn{6}{c}{-.5\ - \ -.3} & \multicolumn{6}{c}{-.3\ - \ -.1} & \multicolumn{6}{c}{-.1\ - \ .1} \\ \multicolumn{4}{c}{$(GeV)$} & \multicolumn{6}{c}{$\mu{~b}/(GeV/c)^{2}$} &\multicolumn{6}{c}{$\mu{~b}/(GeV/c)^{2}$} &\multicolumn{6}{c}{$\mu{~b}/(GeV/c)^{2}$} &\multicolumn{6}{c}{$\mu{~b}/(GeV/c)^{2}$} \\ \tableline 2&.000 & 2&.125 & 4&.180& 0&.280& 0&.840 & 4&.740& 0&.280& 0&.950 & 4&.730& 0&.200& 0&.950 & 4&.500& 0&.150& 0&.900 \\ 2&.125 & 2&.250 & 2&.570& 0&.190& 0&.510 & 2&.800& 0&.180& 0&.560 & 3&.060& 0&.150& 0&.610 & 2&.890& 0&.110& 0&.580 \\ 2&.250 & 2&.375 & 1&.800& 0&.130& 0&.360 & 1&.760& 0&.130& 0&.350 & 1&.800& 0&.095& 0&.360 & 1&.820& 0&.077& 0&.360 \\ 2&.375 & 2&.500 & 1&.130& 0&.081& 0&.230 & 1&.020& 0&.080& 0&.200 & 1&.070& 0&.061& 0&.210 & 1&.060& 0&.056& 0&.210 \\ 2&.500 & 2&.625 & 0&.677& 0&.058& 0&.140 & 0&.816& 0&.080& 0&.160 & 0&.704& 0&.049& 0&.140 & 0&.688& 0&.042& 0&.140 \\ 2&.625 & 2&.750 & 0&.447& 0&.038& 0&.089 & 0&.491& 0&.052& 0&.098 & 0&.467& 0&.039& 0&.093 & 0&.448& 0&.032& 0&.090 \\ 2&.750 & 2&.825 & 0&.258& 0&.026& 0&.052 & 0&.267& 0&.020& 0&.053 & 0&.292& 0&.028& 0&.058 & 0&.260& 0&.024& 0&.052 \\ 2&.825 & 3&.000 & 0&.170& 0&.024& 0&.034 & 0&.199& 0&.011& 0&.040 & 0&.222& 0&.012& 0&.044 & 0&.213& 0&.021& 0&.043 \\ 3&.000 & 3&.125 & 0&.098& 0&.013& 0&.020 & 0&.153& 0&.009& 0&.031 & 0&.143& 0&.005& 0&.029 & 0&.139& 0&.015& 0&.028 \\ 3&.125 & 3&.250 & 0&.081& 0&.008& 0&.016 & 0&.095& 0&.006& 0&.019 & 0&.103& 0&.004& 0&.021 & 0&.103& 0&.003& 0&.021 \\ \tableline \multicolumn{4}{c}{ } & \multicolumn{6}{c}{$nb/(GeV/c)^{2}$} & \multicolumn{6}{c}{$nb/(GeV/c)^{2}$} & \multicolumn{6}{c}{$nb/(GeV/c)^{2}$} & \multicolumn{6}{c}{$nb/(GeV/c)^{2}$}\\ \tableline 3&.250 & 3&.375 & 60&.200& 4&.100&12&.000 &60&.800& 4&.300&12&.000 & 67&.500& 2&.600&13&.000 &67&.700& 2&.100&14&.000 \\ 3&.375 & 3&.500 & 43&.800& 3&.100& 8&.800 &43&.300& 3&.100& 8&.700 & 43&.500& 2&.000& 8&.700 &44&.500& 1&.500& 8&.900 \\ 3&.500 & 3&.625 & 30&.600& 2&.300& 6&.100 &27&.300& 2&.300& 5&.500 & 31&.300& 1&.500& 6&.300 &30&.800& 1&.200& 6&.200 \\ 3&.625 & 3&.750 & 19&.200& 1&.700& 3&.800 &20&.300& 1&.700& 4&.100 & 18&.900& 0&.960& 3&.800 &20&.900& 1&.000& 4&.200 \\ 3&.750 & 3&.825 & 14&.400& 1&.200& 2&.900 &13&.300& 1&.400& 2&.700 & 13&.300& 0&.150& 2&.700 &13&.900& 0&.780& 2&.800 \\ 3&.825 & 4&.000 & 9&.310& 0&.900& 1&.900 & 9&.850& 1&.000& 2&.000 & 9&.350& 0&.110& 1&.900 & 9&.980& 0&.330& 2&.000 \\ 4&.000 & 4&.125 & 5&.470& 0&.660& 1&.100 & 5&.790& 0&.100& 1&.200 & 6&.570& 0&.089& 1&.300 & 6&.930& 0&.080& 1&.400 \\ 4&.125 & 4&.250 & 4&.430& 0&.530& 0&.890 & 3&.990& 0&.074& 0&.800 & 4&.640& 0&.070& 0&.930 & 4&.920& 0&.066& 0&.980 \\ 4&.250 & 4&.375 & 2&.250& 0&.300& 0&.450 & 2&.920& 0&.059& 0&.580 & 3&.360& 0&.057& 0&.670 & 3&.500& 0&.054& 0&.700 \\ 4&.375 & 4&.500 & 2&.040& 0&.280& 0&.410 & 2&.070& 0&.048& 0&.410 & 2&.370& 0&.048& 0&.470 & 2&.580& 0&.046& 0&.520 \\ 4&.500 & 4&.625 & 1&.050& 0&.040& 0&.210 & 1&.460& 0&.038& 0&.290 & 1&.750& 0&.039& 0&.350 & 1&.880& 0&.038& 0&.380 \\ 4&.625 & 4&.750 & 0&.745& 0&.031& 0&.150 & 1&.090& 0&.030& 0&.220 & 1&.170& 0&.031& 0&.230 & 1&.360& 0&.032& 0&.270 \\ 4&.750 & 4&.825 & 0&.549& 0&.025& 0&.110 & 0&.776& 0&.025& 0&.160 & 0&.893& 0&.027& 0&.180 & 0&.961& 0&.027& 0&.190 \\ 4&.825 & 5&.000 & 0&.428& 0&.022& 0&.086 & 0&.542& 0&.020& 0&.110 & 0&.661& 0&.023& 0&.130 & 0&.787& 0&.023& 0&.160 \\ 5&.00 & 5&.25 & 0&.263& 0&.010& 0&.053 & 0&.366& 0&.012& 0&.073 & 0&.427& 0&.012& 0&.085 & 0&.481& 0&.013& 0&.096 \\ 5&.25 & 5&.50 & 0&.135& 0&.007& 0&.027 & 0&.199& 0&.008& 0&.040 & 0&.245& 0&.009& 0&.049 & 0&.267& 0&.009& 0&.053 \\ 5&.50 & 5&.75 & 0&.083& 0&.005& 0&.017 & 0&.111& 0&.006& 0&.022 & 0&.142& 0&.007& 0&.028 & 0&.164& 0&.007& 0&.033 \\ 5&.75 & 6&.00 & 0&.042& 0&.003& 0&.008 & 0&.070& 0&.004& 0&.014 & 0&.075& 0&.005& 0&.015 & 0&.094& 0&.005& 0&.019 \\ \tableline \multicolumn{4}{c}{ } & \multicolumn{6}{c}{$pb/(GeV/c)^{2}$} & \multicolumn{6}{c}{$pb/(GeV/c)^{2}$} & \multicolumn{6}{c}{$pb/(GeV/c)^{2}$} & \multicolumn{6}{c}{$pb/(GeV/c)^{2}$}\\ \tableline 6&.0 & 6&.5 & 18&.400& 1&.600& 3&.700 &27&.300& 1&.900& 5&.500 & 38&.800& 2&.500& 7&.800 &44&.300& 2&.400& 8&.900 \\ 6&.5 & 7&.0 & 4&.930& 0&.740& 0&.990 & 8&.820& 1&.000& 1&.800 & 13&.600& 1&.300& 2&.700 &15&.900& 1&.400& 3&.200 \\ 7&.0 & 7&.5 & 1&.410& 0&.370& 0&.280 & 2&.960& 0&.570& 0&.590 & 5&.230& 0&.830& 1&.000 & 5&.730& 0&.770& 1&.100 \\ 7&.5 & 8&.5 & 0&.112& 0&.065& 0&.022 & 0&.718& 0&.200& 0&.140 & 0&.913& 0&.240& 0&.180 & 1&.610& 0&.300& 0&.320 \\ 8&.5 & 10&.0 & 0&.105& 0&.054& 0&.021 & 0&.023& 0&.023& 0&.005 & 0&.223& 0&.085& 0&.045 & 0&.043& 0&.057& 0&.009 \\ \end{tabular} \newpage \begin{tabular}{r@{}l@{ -- }r@{}l r@{}l@{${}\pm{}$}r@{}l@{${}\pm{}$}r@{}l r@{}l@{${}\pm{}$}r@{}l@{${}\pm{}$}r@{}l r@{}l@{${}\pm{}$}r@{}l@{${}\pm{}$}r@{}l r@{}l@{${}\pm{}$}r@{}l@{${}\pm{}$}r@{}l} \multicolumn{4}{c}{$p_T$} &\multicolumn{24}{c}{$y_{cm}$}\\ \multicolumn{4}{c}{ } & \multicolumn{6}{c}{.1 - .3} & \multicolumn{6}{c}{.3 - .4} & \multicolumn{6}{c}{.5 - .75} & \multicolumn{6}{c}{-.75 - .75} \\ \multicolumn{4}{c}{$(GeV)$} & \multicolumn{6}{c}{$\mu{~b}/(GeV/c)^{2}$} &\multicolumn{6}{c}{$\mu{~b}/(GeV/c)^{2}$} &\multicolumn{6}{c}{$\mu{~b}/(GeV/c)^{2}$} &\multicolumn{6}{c}{$\mu{~b}/(GeV/c)^{2}$} \\ \tableline 2&.000 & 2&.125 & 4&.320& 0&.140& 0&.860 & 3&.930& 0&.140& 0&.790 & 3&.960& 0&.140& 0&.790 & 4&.190& 0&.075& 0&.630 \\ 2&.125 & 2&.250 & 3&.000& 0&.100& 0&.600 & 2&.500& 0&.100& 0&.500 & 2&.260& 0&.093& 0&.450 & 2&.630& 0&.052& 0&.390 \\ 2&.250 & 2&.375 & 1&.720& 0&.075& 0&.340 & 1&.480& 0&.075& 0&.300 & 1&.520& 0&.070& 0&.300 & 1&.650& 0&.037& 0&.250 \\ 2&.375 & 2&.500 & 1&.040& 0&.055& 0&.210 & 1&.050& 0&.056& 0&.210 & 0&.903& 0&.053& 0&.180 & 1&.010& 0&.024& 0&.150 \\ 2&.500 & 2&.625 & 0&.662& 0&.041& 0&.130 & 0&.557& 0&.042& 0&.110 & 0&.632& 0&.040& 0&.130 & 0&.654& 0&.019& 0&.098 \\ 2&.625 & 2&.750 & 0&.502& 0&.033& 0&.100 & 0&.360& 0&.032& 0&.072 & 0&.430& 0&.031& 0&.086 & 0&.434& 0&.014& 0&.065 \\ 2&.750 & 2&.825 & 0&.292& 0&.016& 0&.058 & 0&.300& 0&.006& 0&.060 & 0&.262& 0&.005& 0&.052 & 0&.266& 0&.007& 0&.040 \\ 2&.825 & 3&.000 & 0&.223& 0&.004& 0&.045 & 0&.211& 0&.004& 0&.042 & 0&.184& 0&.004& 0&.037 & 0&.195& 0&.005& 0&.029 \\ 3&.000 & 3&.125 & 0&.148& 0&.003& 0&.030 & 0&.140& 0&.003& 0&.028 & 0&.131& 0&.003& 0&.026 & 0&.130& 0&.003& 0&.020 \\ 3&.125 & 3&.250 & 0&.104& 0&.002& 0&.021 & 0&.094& 0&.003& 0&.019 & 0&.088& 0&.002& 0&.018 & 0&.092& 0&.002& 0&.014 \\ \tableline \multicolumn{4}{c}{ } & \multicolumn{6}{c}{$nb/(GeV/c)^{2}$} & \multicolumn{6}{c}{$nb/(GeV/c)^{2}$} & \multicolumn{6}{c}{$nb/(GeV/c)^{2}$} & \multicolumn{6}{c}{$nb/(GeV/c)^{2}$}\\ \tableline 3&.250 & 3&.375 & 65&.200& 2&.000&13&.000 & 63&.600& 2&.100&13&.000 &61&.600& 1&.900&12&.000 &61&.600& 1&.100& 9&.200 \\ 3&.375 & 3&.500 & 46&.400& 1&.600& 9&.300 & 42&.500& 1&.600& 8&.500 &40&.000& 1&.600& 8&.000 &42&.000& 0&.820& 6&.300 \\ 3&.500 & 3&.625 & 30&.100& 1&.200& 6&.000 & 27&.000& 0&.230& 5&.400 &26&.800& 1&.100& 5&.400 &28&.200& 0&.600& 4&.200 \\ 3&.625 & 3&.750 & 22&.300& 1&.000& 4&.500 & 19&.300& 0&.170& 3&.900 &19&.800& 0&.760& 4&.000 &19&.400& 0&.440& 2&.900 \\ 3&.750 & 3&.825 & 14&.900& 0&.810& 3&.000 & 14&.300& 0&.140& 2&.900 &14&.400& 0&.650& 2&.900 &13&.600& 0&.330& 2&.000 \\ 3&.825 & 4&.000 & 9&.650& 0&.650& 1&.900 & 9&.640& 0&.110& 1&.900 & 9&.430& 0&.480& 1&.900 & 9&.270& 0&.230& 1&.400 \\ 4&.000 & 4&.125 & 7&.340& 0&.084& 1&.500 & 6&.940& 0&.087& 1&.400 & 7&.170& 0&.430& 1&.400 & 6&.340& 0&.130& 0&.950 \\ 4&.125 & 4&.250 & 5&.070& 0&.067& 1&.000 & 5&.120& 0&.072& 1&.000 & 4&.660& 0&.260& 0&.930 & 4&.520& 0&.097& 0&.680 \\ 4&.250 & 4&.375 & 3&.690& 0&.055& 0&.740 & 3&.580& 0&.059& 0&.720 & 3&.260& 0&.052& 0&.650 & 3&.080& 0&.053& 0&.460 \\ 4&.375 & 4&.500 & 2&.650& 0&.046& 0&.530 & 2&.680& 0&.049& 0&.540 & 2&.350& 0&.043& 0&.470 & 2&.300& 0&.049& 0&.350 \\ 4&.500 & 4&.625 & 1&.950& 0&.038& 0&.390 & 1&.870& 0&.040& 0&.370 & 1&.670& 0&.034& 0&.330 & 1&.580& 0&.014& 0&.240 \\ 4&.625 & 4&.750 & 1&.380& 0&.031& 0&.280 & 1&.380& 0&.033& 0&.280 & 1&.230& 0&.029& 0&.250 & 1&.140& 0&.011& 0&.170 \\ 4&.750 & 4&.825 & 1&.040& 0&.027& 0&.210 & 1&.010& 0&.028& 0&.200 & 0&.928& 0&.025& 0&.190 & 0&.840& 0&.010& 0&.130 \\ 4&.825 & 5&.000 & 0&.776& 0&.023& 0&.160 & 0&.738& 0&.023& 0&.150 & 0&.624& 0&.020& 0&.120 & 0&.622& 0&.008& 0&.093 \\ 5&.00 & 5&.25 & 0&.511& 0&.013& 0&.100 & 0&.479& 0&.013& 0&.096 & 0&.431& 0&.011& 0&.086 & 0&.403& 0&.004& 0&.060 \\ 5&.25 & 5&.50 & 0&.295& 0&.009& 0&.059 & 0&.292& 0&.010& 0&.058 & 0&.244& 0&.008& 0&.049 & 0&.228& 0&.003& 0&.034 \\ 5&.50 & 5&.75 & 0&.168& 0&.007& 0&.034 & 0&.146& 0&.007& 0&.029 & 0&.140& 0&.006& 0&.028 & 0&.130& 0&.002& 0&.019 \\ 5&.75 & 6&.00 & 0&.095& 0&.005& 0&.019 & 0&.090& 0&.005& 0&.018 & 0&.074& 0&.005& 0&.015 & 0&.073& 0&.002& 0&.011 \\ \tableline \multicolumn{4}{c}{ } & \multicolumn{6}{c}{$pb/(GeV/c)^{2}$} & \multicolumn{6}{c}{$pb/(GeV/c)^{2}$} & \multicolumn{6}{c}{$pb/(GeV/c)^{2}$} & \multicolumn{6}{c}{$pb/(GeV/c)^{2}$}\\ \tableline 6&.0 & 6&.5 & 45&.400& 2&.400& 9&.100 & 41&.600& 2&.600& 8&.300 &36&.200& 2&.100& 7&.200 &34&.200& 0&.800& 5&.100 \\ 6&.5 & 7&.0 & 18&.800& 1&.500& 3&.800 & 14&.800& 1&.400& 3&.000 &13&.600& 1&.300& 2&.700 &12&.200& 0&.450& 1&.800 \\ 7&.0 & 7&.5 & 6&.710& 0&.890& 1&.300 & 5&.810& 0&.830& 1&.200 & 4&.690& 0&.820& 0&.940 & 4&.390& 0&.270& 0&.660 \\ 7&.5 & 8&.5 & 1&.310& 0&.270& 0&.260 & 1&.250& 0&.290& 0&.250 & 0&.843& 0&.250& 0&.170 & 0&.904& 0&.085& 0&.140 \\ 8&.5 & 10&.0 & 0&.172& 0&.077& 0&.034 & 0&.144& 0&.085& 0&.029 & 0&.000& 0&.000& 0&.000 & 0&.098& 0&.023& 0&.015 \\ \end{tabular} \label{pi0_table} \end{table} %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%% \widetext \begin{table} \caption{Invariant differential cross sections $\left( Ed^3 \sigma/d^3p \right)$ %$\left( d \sigma/\pi d(\pt^2) d(y) \right)$ for the inclusive reaction $\pim\ + {\rm Be} \rightarrow \eta + X$.} \begin{tabular}{r@{}l@{ -- }r@{}l r@{}l@{${}\pm{}$}r@{}l@{${}\pm{}$}r@{}l r@{}l@{${}\pm{}$}r@{}l@{${}\pm{}$}r@{}l r@{}l@{${}\pm{}$}r@{}l@{${}\pm{}$}r@{}l r@{}l@{${}\pm{}$}r@{}l@{${}\pm{}$}r@{}l} \multicolumn{4}{c}{$p_T$} &\multicolumn{24}{c}{$y_{cm}$}\\ \multicolumn{4}{c}{ } &\multicolumn{6}{c}{-.75 - -.25} & \multicolumn{6}{c}{-.25 - .25} & \multicolumn{6}{c}{.25 - .75} & \multicolumn{6}{c}{-.75 - .75} \\ \multicolumn{4}{c}{$(GeV)$} & \multicolumn{6}{c}{$nb/(GeV/c)^{2}$} & \multicolumn{6}{c}{$nb/(GeV/c)^{2}$} & \multicolumn{6}{c}{$nb/(GeV/c)^{2}$} & \multicolumn{6}{c}{$nb/(GeV/c)^{2}$} \\ \tableline 2&.50 & 2&.75 & 403&.00& 80&.00& 81&.00 & 326&.00& 62&.00& 65&.00 & 238&.00& 77&.00& 48&.00 &322&.00& 42&.00& 64&.00 \\ 2&.75 & 3&.00 & 64&.90& 37&.00& 13&.00 & 161&.00& 34&.00& 32&.00 & 122&.00& 31&.00& 24&.00 &116&.00& 20&.00& 23&.00 \\ 3&.00 & 3&.25 & 37&.40& 16&.00& 7&.50 & 40&.30& 19&.00& 8&.10 & 87&.30& 21&.00& 17&.00 & 55&.00& 11&.00& 11&.00 \\ 3&.25 & 3&.50 & 23&.80& 4&.60& 4&.80 & 24&.80& 2&.70& 5&.00 & 27&.00& 2&.60& 5&.40 & 25&.20& 2&.00& 5&.00 \\ 3&.50 & 3&.75 & 7&.33& 2&.20& 1&.50 & 14&.70& 1&.60& 2&.90 & 14&.10& 1&.40& 2&.80 & 12&.00& 1&.00& 2&.40 \\ 3&.75 & 4&.00 & 4&.90& 1&.00& 0&.98 & 5&.81& 0&.97& 1&.20 & 6&.03& 0&.86& 1&.20 & 5&.58& 0&.56& 1&.10 \\ 4&.00 & 4&.25 & 2&.47& 0&.62& 0&.49 & 2&.79& 0&.59& 0&.56 & 3&.76& 0&.56& 0&.75 & 3&.01& 0&.34& 0&.60 \\ 4&.25 & 4&.50 & 1&.86& 0&.47& 0&.37 & 0&.70& 0&.32& 0&.14 & 1&.85& 0&.36& 0&.37 & 1&.47& 0&.22& 0&.29 \\ 4&.50 & 4&.75 & 0&.85& 0&.24& 0&.17 & 0&.65& 0&.27& 0&.13 & 0&.95& 0&.25& 0&.19 & 0&.82& 0&.15& 0&.16 \\ \tableline \multicolumn{4}{c}{ } &\multicolumn{6}{c}{$pb/(GeV/c)^{2}$} & \multicolumn{6}{c}{$pb/(GeV/c)^{2}$} & \multicolumn{6}{c}{$pb/(GeV/c)^{2}$} & \multicolumn{6}{c}{$pb/(GeV/c)^{2}$} \\ \tableline 4&.75 & 5&.00 & 262&.00& 29&.00& 52&.00 & 415&.00& 28&.00& 83&.00 & 442&.00& 26&.00& 88&.00 &373&.00& 16&.00& 75&.00 \\ 5&.00 & 5&.50 & 102&.00& 10&.00& 20&.00 & 152&.00& 12&.00& 30&.00 & 212&.00& 10&.00& 42&.00 &155&.00& 6&.20& 31&.00 \\ 5&.50 & 6&.00 & 31&.60& 4&.70& 6&.30 & 56&.80& 5&.60& 11&.00 & 65&.10& 5&.30& 13&.00 & 51&.10& 3&.00& 10&.00 \\ 6&.00 & 7&.00 & 7&.35& 1&.20& 1&.50 & 16&.80& 1&.70& 3&.40 & 17&.30& 1&.60& 3&.50 & 13&.80& 0&.88& 2&.80 \\ 7&.00 & 8&.00 & 0&.09& 0&.27& 0&.02 & 2&.32& 0&.54& 0&.46 & 2&.00& 0&.48& 0&.40 & 1&.47& 0&.26& 0&.29 \\ 8&.00 & 9&.00 & 0&.12& 0&.13& 0&.03 & 0&.38& 0&.21& 0&.08 & 0&.36& 0&.14& 0&.07 & 0&.29& 0&.09& 0&.06 \\ \end{tabular} \label{eta_table} \end{table} % %\vfil \end{document}