S. Hagopian

We report on the test beam results and calibration methods using high energy electrons, pions and muons with the CMS forward calorimeter (HF). The HF calorimeter covers a large pseudorapidity region ( $3\leq|\eta|\leq5$ ), and is essential for a large number of physics channels with missing transverse energy. It is also expected to play a prominent role in the measurement of forward tagging jets in weak boson fusion channels in Higgs production. The HF calorimeter is based on steel absorber with embedded fused-silica-core optical fibers where Cherenkov radiation forms the basis of signal generation. Thus, the detector is essentially sensitive only to the electromagnetic shower core and is highly non-compensating (e/h≈5). This feature is also manifest in narrow and relatively short showers compared to similar calorimeters based on ionization. The choice of fused-silica optical fibers as active material is dictated by its exceptional radiation hardness. The electromagnetic energy resolution is dominated by photoelectron statistics and can be expressed in the customary form as $\frac{a}{\sqrt{E}}\oplus{b}$ . The stochastic term a is 198% and the constant term b is 9%. The hadronic energy resolution is largely determined by the fluctuations in the neutral pion production in showers, and when it is expressed as in the electromagnetic case, a = 280% and b = 11%.

This paper describes the mechanical design, the readout chain, the production, testing and the installation of the Silicon Microstrip Tracker of the D0 experiment at the Fermilab Tevatron collider. In addition, we describe the performance and operational experience of the detector during the experiment data collection between 2001 and 2010.

Extensive measurements have been made with pions, electrons and muons on four production wedges of the compact muon solenoid (CMS) hadron barrel (HB) calorimeter in the H2 beam line at CERN with particle momenta varying from 20 to 300 GeV/c. The time structure of the events was measured with the full chain of preproduction front-end electronics running at 34 MHz. Moving-wire radioactive source data were also collected for all scintillator layers in the HB. The energy dependent time slewing effect was measured and tuned for optimal performance.

Neutral-strange-particle production has been studied in a 46000-picture exposure in the Fermilab 15-ft bubble chamber. Cross sections for inclusive production of ${K}_{s}^{0}$, $\ensuremath{\Lambda}$, and $\overline{\ensuremath{\Lambda}}$ are given and compared with data at lower energies. The ${K}_{s}^{0}$'s are produced principally in the central region of rapidity with a cross section which increases with energy. The $\ensuremath{\Lambda}$'s are produced principally by proton fragmentation, whereas the $\overline{\ensuremath{\Lambda}}$'s are centrally produced. Correlations of ${K}_{s}^{0}{\ensuremath{\pi}}^{+}$ and ${K}_{s}^{0}{K}_{s}^{0}$ are shown to be different from those for ${\ensuremath{\pi}}^{\ensuremath{-}}{\ensuremath{\pi}}^{+}$.

Evidence for a bound ${\ensuremath{\Delta}}_{33}(1236)\ensuremath{-}{\ensuremath{\Delta}}_{33}(1236)$ component of the deuteron is sought by using ${\ensuremath{\pi}}^{+}$, ${\ensuremath{\pi}}^{\ensuremath{-}}$, and ${K}^{+}$ mesons as probes of nuclear structure. Events are observed which might contain $\ensuremath{\Delta}(1236)$ "spectators" in the breakup of a deuteron in a $\ensuremath{\Delta}\ensuremath{\Delta}$ state. However, other mechanisms may contribute to the signal, and we cannot unambiguously ascribe our events to a $\ensuremath{\Delta}\ensuremath{\Delta}$ contribution in the deuteron. With certain assumptions we obtain an upper limit of \ensuremath{\sim}0.7% for the $\ensuremath{\Delta}\ensuremath{\Delta}$ component of the deuteron.

We describe the results of beam tests of three uranium-liquid argon calorimeter modules constructed for the DØ detector at the Fermilab Tevatron collider. As part of the calibration procedure, these modules were exposed to beams of electrons, pions and muons between 10 and 150 GeV/c before their installation in the end calorimeter of the completed DØ detector. We obtain an electromagnetic sampling resolution of 15.7%/√E and constant term of 0.3%. The hadronic sampling resolution is 45%/√E (degraded to 50%/√E by the effects of upstream material) and the constant term is 4%. The calorimeter is linear to 0.5%, and the electromagnetic to hadronic response ratio is between 1.02 and 1.09 over this range of momenta. For an electron efficiency of 95% we obtain a rejection factor against pions of ∼ 900-3000 for particles in the momentum range between 50 and 150 GeV/c. We also compare our results with the predictions of a detailed Monte Carlo simulation.

We present the results of tests made on two types of uranium/liquid argon calorimeter modules, one electromagnetic and one hadronic, constructed for the D0 detector at the Fermilab Tevatron Collider. For electrons and hadrons with energies between 10 and 150 GeV, we present measurements of energy resolution, linearity of response, electromagnetic to hadronic response ratio (eπ), and longitudinal hadronic shower development. We have also investigated the effects of adding small amounts of methane to the liquid argon.

In a sample of 8300 events of the type ${\ensuremath{\pi}}^{\ensuremath{-}}+p\ensuremath{\rightarrow}{\ensuremath{\pi}}^{\ensuremath{-}}+{\ensuremath{\pi}}^{+}+n$ obtained from a hydrogen bubble chamber exposure, a strong sharp $\ensuremath{\omega}\ensuremath{\rightarrow}{\ensuremath{\pi}}^{\ensuremath{-}}+{\ensuremath{\pi}}^{+}$ peak is observed. Analysis indicates that this $\ensuremath{\omega}\ensuremath{\rightarrow}2\ensuremath{\pi}$ decay interferes almost perfectly constructively with the prominent decay of ${\ensuremath{\rho}}^{0}\ensuremath{\rightarrow}{\ensuremath{\pi}}^{\ensuremath{-}}+{\ensuremath{\pi}}^{+}$. The interference phase is determined to be -15\ifmmode^\circ\else\textdegree\fi{}\ifmmode\pm\else\textpm\fi{}30\ifmmode^\circ\else\textdegree\fi{}. This phase is consistent with predictions of $\ensuremath{\pi}\ensuremath{-}B$ degeneracy using Regge-pole methods.

The Outer Hadron Calorimeter (HCAL HO) of the CMS detector is designed to measure the energy that is not contained by the barrel (HCAL HB) and electromagnetic (ECAL EB) calorimeters. Due to space limitation the barrel calorimeters do not contain completely the hadronic shower and an outer calorimeter (HO) was designed, constructed and inserted in the muon system of CMS to measure the energy leakage. Testing and calibration of the HO was carried out in a 300 GeV/c test beam that improved the linearity and resolution. HO will provide a net improvement in missing E T measurements at LHC energies. Information from HO will also be used for the muon trigger in CMS.

In a sample of 8300 events of the type ${\ensuremath{\pi}}^{\ensuremath{-}}p\ensuremath{\rightarrow}{\ensuremath{\pi}}^{\ensuremath{-}}{\ensuremath{\pi}}^{+}n$ and 6800 events of the type ${\ensuremath{\pi}}^{\ensuremath{-}}p\ensuremath{\rightarrow}{\ensuremath{\pi}}^{\ensuremath{-}}{\ensuremath{\pi}}^{0}p$ obtained with 2.3-BeV/c incident ${\ensuremath{\pi}}^{\ensuremath{-}}$, substantial backward ${\ensuremath{\rho}}^{0}$ production is seen. The decay angular distribution of these backward ${\ensuremath{\rho}}^{0}$ events was found to be anisotropic. The $u$ distribution for the backward ${\ensuremath{\rho}}^{0}'\mathrm{s}$ is compared with the theoretical predictions of the strong-cut Reggeized absorption model. A small amount of backward ${\ensuremath{\rho}}^{\ensuremath{-}}$ production is also seen.

We present results on the production of jets and "jetlike" clusters in 800-GeV/c proton-nucleus ($pA$) collisions. Events with high values of transverse energy in the central kinematic region were selected for nuclear targets of H, Be, C, Cu, and Pb. A jet-finding algorithm was used in analyzing the data. The $A$ dependence of the jet and dijet cross sections was parametrized as ${A}^{\ensuremath{\alpha}}$. The values of $\ensuremath{\alpha}$ for events with "jetlike" cluster pairs found by the algorithm without any additional kinematic cuts reach a plateau of approximately 1.5 at dijet transverse energies > GeV. The collimation of observed "jetlike" clusters decreases with $A$, and the fragmentation is softer for heavier target nuclei. However, nuclear effects become less pronounced with the increasing cluster or cluster-pair transverse energy. We argue that the observed nuclear enhancement for the production of "jetlike" clusters is due to underlying event or/and soft-scattering contributions to the heavy-nuclei data. We show that the nuclear enhancement becomes consistent with a value of $\ensuremath{\alpha}$ within 0.10 from unity once the data are corrected for the underlying event or kinematic cuts enhancing clear jet structure are applied.

Data from a 15-GeV/c ${\ensuremath{\pi}}^{+}d$ experiment have been used to search for both short- and long-lived narrow resonances. No statistically significant high-mass narrow resonance has been observed up to a mass of 5 GeV. There is a single long-lived $V$ that remains unexplained. Cross-section limits (95% confidence level) of 0.7 \ensuremath{\mu}b for the long-lived possibility and 2 to 4 \ensuremath{\mu}b for the short-lived possibilities have been obtained.

The correlation between surface morphology and texture (distribution of crystal orientations) has been analyzed to determine how nitrogen provides a competitive growth advantage for the formation of 〈001〉 texture in diamond films. The film morphologies were measured using TappingMode™ atomic force microscopy. Corresponding texture studies were performed using X-ray diffraction with a four-circle goniometer to measure (111), (220) and (400) pole figures. Orientation distributions were generated from the pole figures, from which inverse pole figures were made to quantify how texture was affected by process variables. After 2 h of growth, with and without nitrogen, similar textures were observed. With increasing time, nitrogen stimulates the growth of orientations between 〈001〉, 〈114〉, and 〈104〉. Without nitrogen, the majority orientation is 〈101〉 with a secondary component near 〈113〉. Examination of fracture surfaces indicates correlations with the observed texture and morphology changes.

Properties of events produced with high values of transverse energy (Et) in 800-GeV/c proton-nucleus collisions are presented. Both full-azimuth and limited-aperture high-Et triggers were used to select events from six targets (H, Be, C, Al, Cu, and Pb). The events were collected using the large-acceptance Fermilab multiparticle spectrometer that recorded almost 95% of the incoming beam energy. The A dependence of the cross sections at a given Et was parametrized as Aα. The value of α increases from 0.7 at low Et to a plateau at high Et of approximately 1.6. The high-Et value of α is slightly smaller for the limited-aperture triggers. A strong dependence of α on the event structure is observed; ‘‘jetlike’’ events exhibit an A dependence consistent with α≊1.0, while for more isotropic events α is much larger. This observation is consistent with the expected behavior for jet production in pA collisions.Received 1 December 1986DOI:https://doi.org/10.1103/PhysRevD.35.2736©1987 American Physical Society

3114 events of the reaction ${\ensuremath{\pi}}^{+}d\ensuremath{\rightarrow}{\ensuremath{\pi}}^{+}{\ensuremath{\pi}}^{\ensuremath{-}}p{p}_{s}$, where ${p}_{s}$ is a nonparticipating spectator, were studied in the SLAC 82-inch bubble chamber. A longitudinal-phase-space (LPS) analysis was performed to separate the various $t$-channel exchange mechanisms, e.g., $\ensuremath{\pi}$ or Pomeron exchange. The validity of the LPS method was tested for pion exchange by generating events using the one-pion-exchange model modified by absorption (OPEA). The model and the data agreed extremely well. The principal features of the data include the ${\ensuremath{\rho}}^{0}$, ${f}^{0}$, ${\ensuremath{\Delta}}^{0}$, and ${N}^{*}'\mathrm{s}$. The LPS analysis also reveals the ${g}^{0}$, but a slight modification of the standard LPS selection criteria enhances the ${g}^{0}$, as expected by OPEA-model calculations.

About 1800 events of the reaction ${\ensuremath{\pi}}^{+}d\ensuremath{\rightarrow}{\ensuremath{\pi}}^{+}{\ensuremath{\pi}}^{+}{\ensuremath{\pi}}^{\ensuremath{-}}d$ have been obtained from 387 000 photographs of the SLAC 82-in. bubble chamber corresponding to a 495 \ifmmode\pm\else\textpm\fi{} 25 \ensuremath{\mu}b cross section. The increasing cross section of this reaction with beam momentum is explained in terms of minimum momentum-transfer cutoff. The ${D}^{*}(2200)$ is observed as both $d{\ensuremath{\pi}}^{+}$ and $d{\ensuremath{\pi}}^{\ensuremath{-}}$ mass peaks. The ${A}_{1}({\ensuremath{\rho}}^{0}{\ensuremath{\pi}}^{+})$ is consistent with a Deck-type mechanism. The ${A}_{3}({f}^{0}{\ensuremath{\pi}}^{+})$ is also observed, but the ${A}_{4}$ peak recently claimed is not seen in these data. There is no statistically significant $3\ensuremath{\pi}$ mass enhancement at the ${A}_{2}$ region, but indirect evidence indicates some ${A}_{2}$ production.

${{\ensuremath{\Xi}}^{*}}^{\ensuremath{-}}$ production was studied in the reaction ${K}^{\ensuremath{-}}+p\ensuremath{\rightarrow}{{K}^{+}}_{\mathrm{slow}}+{X}^{\ensuremath{-}}$ at 5 GeV/c. The slow ${K}^{+}$ was electronically detected, while the ${X}^{\ensuremath{-}}$ was observed as a missing mass, thus allowing for observation of all ${\ensuremath{\Xi}}^{*}$ independent of decay mode. The observed $\ensuremath{\Xi}$ states were $\ensuremath{\Xi}(1320)$, $\ensuremath{\Xi}(1530)$, $\ensuremath{\Xi}(1820)$, $\ensuremath{\Xi}(2030)$, $\ensuremath{\Xi}(2250)$, $\ensuremath{\Xi}(2370)$, and $\ensuremath{\Xi}(2500)$. These data establish and confirm the existence of $\ensuremath{\Xi}(2250)$ and indicate a peculiar production-cross-section behavior for the ${\ensuremath{\Xi}}^{*}(2370)$.

For the reaction ${\ensuremath{\pi}}^{\mathrm{\ensuremath{-}}}$N\ensuremath{\rightarrow}${V}^{0}$X, where ${V}^{0}$ is a ${K}_{s}^{0}$, \ensuremath{\Lambda}, and \ensuremath{\Lambda}\ifmmode\bar\else\textasciimacron\fi{} and X are charged particles, we measured the transverse- and longitudinal-momentum distributions, and inclusive cross sections for the ${V}^{0}$ and for ${K}^{\mathrm{*}\ifmmode\pm\else\textpm\fi{}}$(892), ${\ensuremath{\Sigma}}^{\ifmmode\pm\else\textpm\fi{}}$(1385), and ${\ensuremath{\Xi}}^{\ifmmode\pm\else\textpm\fi{}}$(1321). We compare our results with predictions of quark-counting rules, and conclude that valence quarks play an important role in strange-particle production.

The production of phi-meson pairs has been observed in 400-GeV/c proton-nucleon interactions at the Fermilab multiparticle spectrometer in the inclusive reaction pN..-->..phiphi+X, where each phi decays to a K/sup +/K/sup -/ pair. A fast (200 nsec)= high-level processor was used to selectively trigger on events containing two pairs of oppositely charged kaons having low invariant masses. The experimental apparatus and trigger processor are described. The cross section for phiphi production and an upper limit for eta/sub c/ production are presented.

An integrated sensor processor architecture to compute the center point of a light spot is described. The architecture uses CMOS based light sensors and includes circuits that weight and sum sensed values along rows and columns. The one-dimensional column and row outputs can then be processed on chip to compute the center of the light spot. Alternately, their analog values can be converted to digital format and processed by a conventional processor or DSP. Several algorithms, all of which can be executed on the architecture, are detailed. These methods span a wide range of techniques, from the simplest approximate center locator to the most sophisticated centroiding technique, The architecture can be very compact and needs little power to operate. A VLSI chip based on this architecture could be used towards object recognition and positioning based on visual patterns or cues.

The diffractive dissociation of a 200-GeV/c ${\ensuremath{\pi}}^{\ensuremath{-}}$ beam into ${K}_{S}^{0}{K}_{S}^{0}{\ensuremath{\pi}}^{+}{\ensuremath{\pi}}^{\ensuremath{-}}{\ensuremath{\pi}}^{\ensuremath{-}}$ has been observed. The diffractive ${K}_{S}^{0}{K}_{S}^{0}{\ensuremath{\pi}}^{+}{\ensuremath{\pi}}^{\ensuremath{-}}{\ensuremath{\pi}}^{\ensuremath{-}}$ cross section is 1.59\ifmmode\pm\else\textpm\fi{}0.78 \ensuremath{\mu}b. The ratio of the diffractive ${K}_{S}^{0}{K}_{S}^{0}{\ensuremath{\pi}}^{+}{\ensuremath{\pi}}^{\ensuremath{-}}{\ensuremath{\pi}}^{\ensuremath{-}}$ cross section to the diffractive ${K}_{S}^{0}{K}_{S}^{0}{\ensuremath{\pi}}^{\ensuremath{-}}$ cross section is 0.40\ifmmode\pm\else\textpm\fi{}0.13, which is in good agreement with a diffractive-fragmentation-model prediction of 0.36. There is evidence for simultaneous production of ${K}^{*\ensuremath{-}}$ and ${K}^{*+}$ in the diffractive ${K}_{S}^{0}{K}_{S}^{0}{\ensuremath{\pi}}^{+}{\ensuremath{\pi}}^{\ensuremath{-}}{\ensuremath{\pi}}^{\ensuremath{-}}$ sample. The ${K}^{*+\ensuremath{-}}{K}_{S}^{0}{\ensuremath{\pi}}^{\ensuremath{-}+}$ mass distribution shows an enhancement near 1.95 GeV.

Neutral-pion production in 250-GeV/c ${\ensuremath{\pi}}^{\ensuremath{-}}p$ interactions are studied using the Fermilab 15-ft bubble chamber. The mean number of neutral pions produced is 3.54\ifmmode\pm\else\textpm\fi{}0.15 per inelastic collision and a fit to a linear dependence on the charged multiplicity gives $〈{n}_{0}〉=1.30+0.56{n}_{\ensuremath{-}}$. The ${\ensuremath{\pi}}^{0}$ transverse- and longitudinal-momentum distributions are obtained from the inclusive $\ensuremath{\gamma}$-ray data and compared with the distribution obtained from those ${\ensuremath{\pi}}^{0}$'s which have both decay $\ensuremath{\gamma}$ rays converting in the bubble chamber.

The reaction ${\ensuremath{\pi}}^{\ensuremath{-}}+p\ensuremath{\rightarrow}{\ensuremath{\pi}}^{\ensuremath{-}}+p$ has been studied in the 15-in. bubble chamber at the Princeton-Pennsylvania Accelerator. The elastic scattering cross section was determined to be 8.5 \ifmmode\pm\else\textpm\fi{} 0.2 mb. The forward peak fits to an exponential in $t$ with a slope of 8.1 \ifmmode\pm\else\textpm\fi{} 0.2 ${(\mathrm{G}\mathrm{e}\mathrm{V}/\mathit{c})}^{\ensuremath{-}2}$. The forward differential cross section $\frac{d\ensuremath{\sigma}}{d\ensuremath{\Omega}}(0)=17.9\ifmmode\pm\else\textpm\fi{}0.7$ mb/sr. A fit of the center-of-mass angular distribution to Legendre polynomials needed terms up to the 12th order, corresponding to the highest nonzero partial wave of $L=6$.

The charged-particle multiplicity distribution from 250-GeV/c ${\ensuremath{\pi}}^{\ensuremath{-}}p$ interactions in the Fermilab 15-ft bubble chamber is presented. The corrections to the raw data are described. Fits to these data along with other high-energy bubble-chamber data show that cluster models with two components---a low-multiplicity, diffractive component and a high-multiplicity, nondiffractive component---describe the data fairly well. The charged multiplicity of each cluster is found to be \ensuremath{\sim}2, while the number of clusters for each component grows linearly with $\mathrm{ln}(s)$. The multiplicity moments are consistent with other experiments. We find $〈{n}_{c}〉=8.427\ifmmode\pm\else\textpm\fi{}0.059$, ${f}_{2}^{\mathrm{cc}}=8.66\ifmmode\pm\else\textpm\fi{}0.11$, $\frac{〈{n}_{c}〉}{D}=2.038\ifmmode\pm\else\textpm\fi{}0.023$. The total inelastic cross section is ${\ensuremath{\sigma}}_{I}=21.42\ifmmode\pm\else\textpm\fi{}0.50$ mb.

The reaction π−N→KS0KS0π−N′ at 200 GeV/c has been observed with a sensitivity of 450±150 events/μb. The KS0KS0π− system exhibits substantial K*−(890)K0 production. Also produced are f0(1270)π−, f′(1515)π−, and K*−(1430)K0 final states. These resonances occur predominantly at threshold. The diffractive KS0KS0π− cross section is 3.4±1.1 μb. An enhancement near the A3−(1680) is observed in the KS0KS0π− invariant-mass distribution.Received 29 March 1983DOI:https://doi.org/10.1103/PhysRevD.28.2304©1983 American Physical Society

Baryon production and subsequent decay into ${K}_{s}^{0}{\ensuremath{\Lambda}}^{0}$, ${\ensuremath{\Lambda}}^{0}{\ensuremath{\pi}}^{\ifmmode\pm\else\textpm\fi{}}$, ${K}_{s}^{0}{\ensuremath{\Lambda}}^{0}{\ensuremath{\pi}}^{\ifmmode\pm\else\textpm\fi{}}$ and ${\ensuremath{\Lambda}}^{0}{\ensuremath{\pi}}^{+}{\ensuremath{\pi}}^{\ensuremath{-}}$ final states is studied. Evidence for the states $N(1710)$, $\ensuremath{\Sigma}(1385)$, $\ensuremath{\Sigma}(1620)$, $\ensuremath{\Sigma}(1690)$, $\ensuremath{\Sigma}(2250)$, $\ensuremath{\Xi}(1320)$, $\ensuremath{\Xi}(1530)$, $\ensuremath{\Xi}(1820)$, and $\ensuremath{\Xi}(1940)$ is presented. Ratios of ${x}_{f}$ distributions and cross sections are compared to the predictions of phenomenological models.

We observe a narrow enhancement in $\ensuremath{\varphi}{K}^{+}{K}^{\ensuremath{-}}$ and $\ensuremath{\varphi}{\ensuremath{\pi}}^{+}{\ensuremath{\varphi}}^{\ensuremath{-}}$ final states, with a mass of 2.141 \ifmmode\pm\else\textpm\fi{} 0.012 \ifmmode\pm\else\textpm\fi{} 0.010 GeV/${\mathit{c}}^{2}$ and width of 0.049 \ifmmode\pm\else\textpm\fi{} 0.028 GeV/${\mathit{c}}^{2}$. The relative branching ratio is $\frac{B(M\ensuremath{\rightarrow}\ensuremath{\varphi}{K}^{+}{K}^{\ensuremath{-}})}{B(M\ensuremath{\rightarrow}\ensuremath{\varphi}{\ensuremath{\pi}}^{+}{\ensuremath{\pi}}^{\ensuremath{-}})}=0.49\ifmmode\pm\else\textpm\fi{}0.16$, inconsistent with $M$ being a $q\overline{q}$ state.

The average fraction, , of jet momentum carried by the associated charged leading hadron has been determined in the reactionp+N→h 1+h 2+X whereN is the target nucleon;h 1,h 2 are the leading particles of two jets produced at highP ⊥. An 800 GeV/c proton beam and 4 nuclear targets: Be, Al, Fe and W were used. The distributions agree with the QCD-parton model predictions for single independent protonnucleon scattering and independent fragmentation process.

Fermilab experiment 711 has investigated proton-nucleus collisions in which two high-transverse-momentum hadrons are produced forming high-mass ++, +-, and -- charged states, using an 800-GeV/c proton beam on targets of beryllium, aluminum, iron, and tungsten. Our data cover the range in dihadron mass from 6 to 15 GeV/${\mathit{c}}^{2}$. We show here that the dependence of the cross section on atomic weight A can be parametrized as ${\mathit{A}}^{\mathrm{\ensuremath{\alpha}}}$ where \ensuremath{\alpha}=1.043\ifmmode\pm\else\textpm\fi{}0.011(stat)\ifmmode\pm\else\textpm\fi{}0.025 (syst), and is independent of the charge state of the dihadron system.

Abstract We observe the Cabibbo-suppressed decay D ± → φπ ± in pN interaction at 400 GeV c incident proton momentum. No evidence for F ± → φπ ± decays is seen.

Abstract The D0 experiment has used the ‘Structured Analysis/Structured Design’ (SA/SD) methodology in its software development for the past year. The data flow diagrams and data dictionaries of structured analysis were the primary tools used in development of an ideal model of the D0 software system. These and the structure charts developed during the design phase form the basic documentation of the system. Real-time structured development techniques, e.g. state transition diagrams, are employed to describe control functions in some areas, e.g. in the calibration software. The SA/SD methodology has proven to be valuable in the formulation of ideas and in communication between software developers. The methodology and its application to D0 software are described and the benefits and problems are assessed. Problems finding adequate software tools for the VAX environment are discussed and a data dictionary manager developed by D0 using DEC RDB is described.

Two-particle correlation functions $R(\ensuremath{\Delta}y)$ have been studied for ${\ensuremath{\pi}}^{+}{\ensuremath{\pi}}^{\ensuremath{-}}$, ${K}_{S}^{0}{K}_{S}^{0}$, ${K}_{S}^{0}{\ensuremath{\pi}}^{\ifmmode\pm\else\textpm\fi{}}$, $\ensuremath{\Lambda}{\ensuremath{\pi}}^{\ifmmode\pm\else\textpm\fi{}}$, and $\overline{\ensuremath{\Lambda}}{\ensuremath{\pi}}^{\ifmmode\pm\else\textpm\fi{}}$ pairs in ${\ensuremath{\pi}}^{\ensuremath{-}}p$ interactions at 250 GeV/c. Dynamical correlations are estimated by subtracting a Monte Carlo calculation containing only energy and momentum conservation correlations. ${K}_{S}^{0}{K}_{S}^{0}$ correlation is found to be considerably larger than ${\ensuremath{\pi}}^{+}{\ensuremath{\pi}}^{\ensuremath{-}}$ correlation, while ${K}_{S}^{0}{\ensuremath{\pi}}^{\ifmmode\pm\else\textpm\fi{}}$, $\ensuremath{\Lambda}{\ensuremath{\pi}}^{\ifmmode\pm\else\textpm\fi{}}$, and $\ensuremath{\Lambda}{\ensuremath{\pi}}^{\ifmmode\pm\else\textpm\fi{}}$ correlations are small.

The synchronization and timing of the hadron calorimeter (HCAL) for the Compact Muon Solenoid has been extensively studied with test beams at CERN during the period 2003-4, including runs with 40 MHz structured beam. The relative phases of the signals from different calorimeter segments are timed to 1 ns accuracy using a laser and equalized using programmable delay settings in the front-end electronics. The beam was used to verify the timing and to map out the entire range of pulse shapes over the 25 ns interval between beam crossings. These data were used to make detailed measurements of energy-dependent time slewing effects and to tune the electronics for optimal performance.

The nuclear ($A$) dependence of the event structure in the central and forward (projectile fragmentation) regions has been studied for highly inelastic proton-nucleus ($pA$) collisions at an incident momentum of 800 GeV/c. Events with high values of transverse energy (${E}_{t}$) were selected using the large-acceptance Fermilab multiparticle spectrometer. The multiplicity distributions and energy flows in different regions of phase space are presented for six nuclear targets: H, Be, C, Al, Cu, and Pb. The event structure for highly inelastic $pA$ collisions is strongly dependent on the transverse energy observed in the central region. However at a fixed ${E}_{t}$, there is only a weak nuclear dependence of event structure in the central and forward fragmentation regions. This observation is consistent with a thermodynamical description of inelastic $pA$ interactions and suggests that the observed ${E}_{t}$ is a good measure of the inelasticity of the reaction. The nuclear dependence of event structure on the particle density and the energy in the forward fragmentation region is also discussed. In contrast with ${E}_{t}$ as a variable, the particle density and the forward missing energy provide measures of event inelasticity that are $A$ dependent.

K∗±(892) production is studied in the reaction π−N → KS0KS0 + X where X includes up to five observed charged particles. An excess of K∗− over K∗+ is observed for Feynman-x > 0.1. The ratio of K∗+ to K∗− decreases with x as predicted by QCD counting rules. KS0 and K∗ production are compared to recent D and D∗ data from other experiments.

A system, RESURX, which is inexpensive to implement, has been developed and used to increase the efficiency of an automatic data processing system of a large experiment in a bubble chamber. The system includes a storage display CRT either connected to a dedicated small computer or as a time-sharing terminal of a large computer. Human intervention is accomplished by commands entered via the CRT keyboard. The RESURX system computer codes, written almost completely in FORTRAN, are modular in nature, transportable, and easily modified as a diagnostic or production tool for other applications which involve digitized trajectories. The design of the system and processing results are presented.

An analog integrated cellular image sensor-processor (CISP) is described. The architecture uses CMOS light sensors and exploits circuit dynamics in computing image functions. Analog CISP is loosely based on the cellular neural network paradigm, but the related dynamic equations have been modified to make physical implementation more practical and robust.

We report data on proton-nucleon collisions obtained on Fermilab experiment E711, in which high transverse momentum hadrons are produced near 90\ifmmode^\circ\else\textdegree\fi{} in the proton-nucleon center of mass forming high mass states, using an 800 GeV/c proton beam on targets of beryllium, aluminum, iron, and tungsten. The data presented cover the mass range from 7 to 15 GeV/${\mathit{c}}^{2}$, the three dihadron charge states ++, +-, and --, and parton-parton scattering angles up to ${cos\ensuremath{\theta}}^{*}=0.50$. We present the differential mass dihadron cross section, as well as the angular and charge dependence of the measurement. The cross section as a function of the parton-parton scattering angle for the three charge states is shown to vary linearly with the value of the atomic weight. While the angular distributions are shown to be independent of the target type, a small dependence on the charge state of the distributions is observed. The data are shown to be in good agreement with extrapolations from previous measurements and phenomenological QCD calculations.

The average number of charged pions produced in ${\ensuremath{\pi}}^{+}d$ reactions at 15-GeV/c ${\ensuremath{\pi}}^{+}$ momentum is 3.6\ifmmode\pm\else\textpm\fi{}0.1 and the average number of ${\ensuremath{\pi}}^{0}$'s is 1.9\ifmmode\pm\else\textpm\fi{}0.2. The average number of ${\ensuremath{\pi}}^{0}$'s produced is essentially independent of the number of charged pions. About 45% of the events have four or more charged pions in the final state. The exclusive final states with four or more charged pions with zero or one ${\ensuremath{\pi}}^{0}$ are presented and compared with modified phase-space background computations. Other than the well-known resonances, such as the ${\ensuremath{\rho}}^{0}$, no new peaks have been observed. Coherently produced multipion systems with up to seven pions are also discussed. Detailed cross-section information for every final state is presented.

Semi-inclusive ${\ensuremath{\pi}}^{0}$ multiplicity distributions for 2-14 charged prongs are obtained using a generating-function approach based on an expansion in terms of Mueller moments. The four-prong data require the explicit assumption of a two-component model. Under this assumption and the further assumption of no three-neutral-particle correlations, the total pion multiplicity is obtained. The total multiplicity shows peaking at even prongs, indicative of $G$-parity-conserving diffractive processes which dominate at lower multiplicities. The cross section for these processes is \ensuremath{\sim}4 mb.

Walter Selove, an emeritus professor of physics at the University of Pennsylvania, passed away on 24 August 2010 in Wynnewood, Pennsylvania. An experimental high-energy physicist and an expert in electronic detection systems, he made significant discoveries with bubble chambers and spectrometers. His research career spanned more than 50 years, and he is credited with five patents and one particle discovery.Selove was born on 11 September 1921 in Chicago and studied physics at the University of Chicago, where he obtained a BS degree in 1942. World War II interrupted his studies, and like many other young physicists at the time, he contributed to the war effort; he worked on radar development at MIT. Selove used to tell his graduate students in the early 1960s stories about how everyone at MIT felt motivated to do their utmost for the war effort and how he was often pleasantly surprised when he asked the machine shop workers to build some complicated hardware and would get the finished product the next day.After the war Selove went back to the University of Chicago, where he studied under Enrico Fermi and Edward Teller. Like Fermi, Selove developed a reputation for his back-of-the-envelope calculations. He obtained his PhD degree in 1949 with a thesis titled "A Rotating-Shutter Time-of-Flight Neutron Spectrometer for the Resonance Region." He then used the detector he made for his thesis to study several nuclear resonances. He joined Harvard University as an instructor in 1950 and in 1952 became an assistant professor there. On 18 December 1955 he married Fay Ajzenberg, herself a renowned nuclear physicist. Selove was a great support to his wife at a time when the physics community had biases against women.In 1957 Selove joined the physics department faculty at the University of Pennsylvania as an associate professor; he became a professor in 1961 and 31 years later was made an emeritus professor. Even after retiring, he continued to work on various high-energy physics experiments.Even though his background was in nuclear physics, Selove and three other experimental physics faculty members at Penn created a strong high-energy physics program. Selove was an electronics wizard, and the experiments in which he was a crucial member often benefited from his design ability. One of the first users of computers in high-energy physics, he started with the Univac and then used a series of other systems.Selove began his high-energy physics career performing counter experiments at Brookhaven National Laboratory. In 1961 he realized that bubble-chamber physics was a much better way to study meson resonances. With eight graduate students, including two of us (the Hagopians), Selove studied meson resonances for the next dozen years. With resonances being announced frequently, it was an exciting time in physics. In 1962, using the lab's 20-inch bubble chamber, his group found a new π+π− resonance at about 1260 MeV. Selove told us that when he married Fay, he promised to name the first particle he discovered after her. So we named the particle the fayon, or f2, with the 2 designating the particle's spin. We are happy that the name has stayed, even though many other resonances were renamed to bring order to the naming chaos.Selove also worked at the Princeton–Pennsylvania Accelerator rapid-cycling bubble chamber and observed for the first time the predicted interference between the production of ρ and ω mesons. His bubble-chamber program was one of the first to use the Hough–Powell device, an automated computerized instrument that measured the particle tracks on film with a tiny light source. In total he advised 12 PhD students, many of whom have had successful science careers.Bubble-chamber physics was exciting, but only resonances with large cross sections could be observed. So in the early 1970s, Selove switched back to counter experiments, working with colleagues at Brookhaven and then at Fermilab. In the 1980s, with groups from the University of Wisconsin, Fermilab, and Lehigh University, he conducted a series of experiments using calorimeters that he and his colleagues had developed to study high-momentum-transfer jets that yielded information on quarks and gluons. Selove was one of the original designers of the D0 collider experiment at Fermilab. Later he switched to studying CP violations, and with researchers from 18 other institutions, he studied the B meson. For that experiment he and his group at Penn were the prime movers of the silicon tracker, trigger electronics, and the muon trigger. His last experimental effort, BTeV at Fermilab, was canceled in 2005 by the US Department of Energy before construction began.Walter Selove was passionate about physics. He argued strongly for what he believed was right and often buttressed his views with quick calculations. But in the infrequent instances when he was wrong, good arguments could persuade him to change his mind. He wanted to know every detail of an experiment. He treated his students, collaborators, and staff as colleagues and worried about their well-being. He was a scholar and a gentleman who will be dearly missed by his wife, his students, and his many friends and collaborators.Walter SelovePPT|High resolution© 2011 American Institute of Physics.

It is shown from experimental data that the extrapolated cross section for the reaction ${\ensuremath{\pi}}^{\ensuremath{-}}p\ensuremath{\rightarrow}{\ensuremath{\pi}}^{\ensuremath{-}}{\ensuremath{\pi}}^{+}n$ at 2.3 GeV/c is not only nonzero at $t=0$, but negative. This is in contrast with higher-energy results where the cross section at $t=0$ is positive. One-pion-exchange calculations modified by absorptive corrections give results in general agreement with these experiments.

A digital integrated cellular image sensor processor (CISP) is described. The architecture uses binary CMOS light sensors with programmable circuits that perform various logic operations and template matching. The computing is carried out using all digital circuits. Complete chip design, implementation, and test results are presented.

The ${K}_{S}{K}_{S}$ mass spectrum is studied in a ${\ensuremath{\pi}}^{+}d$ experiment at 15 GeV/c. Two separate mass enhancements at (1047\ifmmode\pm\else\textpm\fi{}10) and (1190\ifmmode\pm\else\textpm\fi{}10) MeV are observed. The lower mass enhancement is most likely associated with the ${S}^{*}$ and the $\ensuremath{\delta}$ while the one at 1190 MeV could be a new resonance or the ${A}_{1.5}$. Neither enhancement is produced peripherally. An interesting interpretation of this nonperipherality is that the decay of the ${S}^{*}$ or $\ensuremath{\delta}$ is dependent on the charge of the beam meson.

The production of ${\ensuremath{\pi}}^{+}{\ensuremath{\pi}}^{\ensuremath{-}}{\ensuremath{\pi}}^{0}$ events allows the study of pure $I=1$ exchange without the complicating presence of the $\ensuremath{\Delta}(1236)$ which appears with proton targets. A total of 4218 events, corresponding to 8.5 events/\ensuremath{\mu}b, were analyzed from an exposure of the SLAC 82-inch deuterium bubble chamber. The low-mass resonances [$\ensuremath{\eta}$, $\ensuremath{\omega}$, ${A}_{2}$, and $\ensuremath{\omega}(1675)$] are clearly observed. In addition, enhancements due to possible higher-mass resonances are observed by using the technique of ${p}_{\ensuremath{\perp}}$ cuts.

The Tevatron experiments, D0 and CDF, have searched for excited electrons and excited and exotic muons in Run II. Using 1 fb{sup -1} of data, D0 has searched for excited electrons. No excess above the standard model background is observed. Choosing the scale for contact interactions to be {Lambda} = 1 TeV, excited electron masses below 756 GeV are excluded at the 95% C.L. CDF has searched for excited and exotic muons using 371 fb{sup -1} of data. Using gauge mediated models with {Lambda}/f = m{sub {mu}*}, exotic muons are excluded for masses below 221 GeV. For compositeness models with {Lambda} = m{sub {mu}*}, masses below 853 GeV are excluded. Using a similar size data set, D0 get similar limits.

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Search for fractionally charged particles of charge 1 3 ze with z in the range of 4 to 4. Production is through collisions of the primary proton beam (200 GeV or higher) with nucleons in a target.The detection method is a hydrogen bubble chamber where fractionally charged particles in the beam will have an ionization less than minimum defined for z = 1.We propose an exposure of 10,000 pictures with a negatively charged beam and 10,000 pictures with a positively charged beam, both unseparated.'w. F. Baku r £!.

The data from π− + p ⇒ ρ0 + n and π− + p ⇒ ρ− + p at 2.3 GeV/c is consistant with a dip in dσ/dt at t∼ − 0.6 (GeV/c)2 for ρ− production and a break at t∼ − 0.6 (GeV/c)2 for ρ0 production, in agreement with theoretical predictions and some other experiments.

From a study of 15-GeV/c ${\ensuremath{\pi}}^{+}$-deuterium interactions obtained in an 890 000-picture exposure in the SLAC 82-inch bubble chamber, evidence is presented for at least two broad dipion states beyond the $g(1680)$ region. These states appear in the spectrum representing highly peripheral interactions, and in the spectra obtained by eliminating those interactions for which the transverse momentum of each pion is less than a specified minimum value. Further, examination of the ${\ensuremath{\pi}}^{+}{\ensuremath{\pi}}^{\ensuremath{-}}\mathrm{MM}$ (missing mass) spectrum from the reaction ${\ensuremath{\pi}}^{+}n\ensuremath{\rightarrow}p{\ensuremath{\pi}}^{+}{\ensuremath{\pi}}^{\ensuremath{-}}(\mathrm{MM})$ indicates that agreement with the previously obtained branching ratios is possible only if higher-mass dipion states are present. Evidence is also presented which suggests a finite decay probability of the $g$ (or a state of similar mass) into ${\ensuremath{\pi}}^{+}{\ensuremath{\pi}}^{\ensuremath{-}}\ensuremath{\eta}$ and/or ${\ensuremath{\pi}}^{+}{\ensuremath{\pi}}^{\ensuremath{-}}{\ensuremath{\eta}}^{\ensuremath{'}}$.

We describe the results of four new searches based on data samples from the 1992 - 1996 proton-antiproton 1.8 TeV Collider run at Fermilab. DZERO has searched for resonant slepton production in the two muon plus two jet channel. Using the R-parity violating mSUGRA model, smuon and smuon neutrino masses up to 280 GeV/c2 are excluded. CDF has searched for R-parity violating scalar top quark decays in two tau plus two jet events and set a mass limit of 119 GeV/c2. DZERO has searched for evidence of large extra dimensions in monojet production. Limits are set on M_D the fundamental mass scale, of 0.68 and 0.63 TeV for n = 4 and n = 6 extra dimensions. CDF has interpreted a search for new physics in photon + missing energy events as a search for a gravitino and alternatively as a search for effects of graviton production. A gravitino mass limit of 1.17*10**(-5) eV is set. Limits on M_D of 0.55, 0.58, and 0.60 TeV for n = 4, 6, and 8 are also determined.

A programmable convolution array (PCA) architecture is described. The architecture uses CMOS light sensors, each connected to an amplifier. The aggregate of amplifiers yields a sum of products and computes convolution of the image with kernels of arbitrary size. A chip based on this architecture and test results are presented.

The data are from a 46,000 picture exposure of the 15-foot hydrogen bubble chamber at Fermilab to a 250-GeV/c $pi$$sup -$run. An inelastic cross section of 21.1 +- 0.6 mb was obtained. Topological cross sections and multiplicity moments are presented and compared with results at lower energies. The energy dependence of the mean charged multiplicity, (n), and the second moment, f$sub 2$, are well fit by a polynomial in log's for $pi$$sup -$p experiment from 10 to 250 GeV/c. (auth)

This paper analyzes ${\ensuremath{\pi}}^{\mathrm{\ensuremath{-}}}$N\ensuremath{\rightarrow}${\ensuremath{\pi}}^{\mathrm{\ensuremath{-}}}$${\ensuremath{\pi}}^{\mathrm{\ensuremath{-}}}$${\ensuremath{\pi}}^{+}$N events from Fermilab experiment E-580, using 200-GeV/c particles on a segmented target of plastic scintillator. Starting with 48 657 triggers, data-quality cuts and a cut on missing mass squared of ${M}^{2}$16 ${\mathrm{GeV}}^{2}$ lead to a final sample of 7205 events. The ${x}_{F}$ distribution of the 3\ensuremath{\pi} system shows almost all events in a sharp peak at ${x}_{F}$=1, suggesting the presence of beam diffraction into three pions. The overall t' distribution is fit to the sum of three exponential terms corresponding to coherent diffraction from carbon nuclei, diffraction from individual nucleons, and background. Cross sections per nucleon and exponential slopes are reported for each of the three components as a function of 3\ensuremath{\pi} effective mass. The cross section for diffraction from the nucleons in the target is 0.34\ifmmode\pm\else\textpm\fi{}0.04 mb/nucleon. The cross section for coherent diffraction from carbon is 1.08\ifmmode\pm\else\textpm\fi{}0.12 mb/nucleus. The exponential slope for diffraction is observed to decrease with increasing 3\ensuremath{\pi} effective mass. The fraction of coherent carbon diffraction in the total cross section is observed to decrease with increasing 3\ensuremath{\pi} effective mass. In the ${\ensuremath{\pi}}^{\mathrm{\ensuremath{-}}}$${\ensuremath{\pi}}^{+}$ effective-mass spectrum the ${\ensuremath{\rho}}^{0}$(770) and ${f}^{0}$(1270) are observed and their cross sections per nucleon are calculated. In the ${\ensuremath{\pi}}^{\mathrm{\ensuremath{-}}}$${\ensuremath{\pi}}^{\mathrm{\ensuremath{-}}}$${\ensuremath{\pi}}^{+}$ effective-mass spectrum the ${A}_{1}^{\mathrm{\ensuremath{-}}}$/${A}_{2}^{\mathrm{\ensuremath{-}}}$ and ${A}_{3}^{\mathrm{\ensuremath{-}}}$ enhancements are observed and a cross section for the ${A}_{3}^{\mathrm{\ensuremath{-}}}$ is calculated.

This document proposes a comprehensive program to implement and study a large scale liquid argon-uranium absorber calorimeter sytem in a Fermilab beam. This system is modelled after and contains many of the components of the calorimeters being constructed for use in the D0 Detector at Fermilab. It is also a test bed for testing techniques for possible SSC calorimeters. This program involves the construction of calorimeter modules and supports: a 4000 gallon liquid argon cryostat and associated cryogenics; a transporter capable of precisely positioning a 100 ton load in three dimensions; a clean electronic environment: and prototype electronics and data acquisition system. It is expected that this system will be a permanent installation in a Fermilab test beam, allowing continued use as a reference for data being taken at D0.

Searches have been made for first generation scalar and vector leptoquarks by the D0 collaboration and for second generation scalar leptoquarks by the CDF collaboration. Lower leptoquark mass limits were set. A search for squarks and gluinos, predicted by Supersymmetric models, was made by D0 in the three or more jets plus missing Et channel. The number of events observed was consistent with background. Squark and gluino mass limits were set.

Properties of energetic secondaries produced at large angles using 800 GeV incident protons are presented. H/sub 2/, Be, C, Al, Cu and Pb targets were used for the study. The yields for producing such secondaries vary as A/sup ..cap alpha../ where A is the atomic mass number of the target and ..cap alpha.. attains values as large as 1.6. There is evidence that jet-like events have ..cap alpha.. values approaching unity, indicating a hard scattering mechanism may be occurring. Events with large values of target-fragmentation energy have, on average, large values of energy in the central region and small values of forward-going energy. Energy flows and number of secondaries are independent of the target when events with similar amounts of energy in the central region are studied.

Searches have been made for first generation scalar and vector leptoquarks by the D0 collaboration and for second generation scalar leptoquarks by the CDF collaboration. The data sample is from the 1992-93 p{bar p} run at {radical}s = 1.8 TeV at the Fermilab Tevatron Collider. Assuming that leptoquarks are pair produced and decay into charged leptons and quarks with branching fraction {beta}, mass limits at the 95% Confidence Level (CL) have been obtained. For first generation scalar leptoquarks the lower mass limit is 130 GeV/c{sup 2} for {beta} = 1.0 and 116 GeV/c{sup 2} for {beta} = 0.5. For first generation vector leptoquarks with {kappa}, the anomalous coupling, of 1.0 and {beta} = 1.0, the lower mass limit is 240 GeV/c{sup 2} and for {kappa} = 1.0, {beta} = 0.5, the lower mass limit is 240 GeV/c{sup 2}. For {kappa} = 0 and {beta} = 1.0, the lower mass limits is 190 GeV/c{sup 2} and for {kappa} = 0, {beta} = 0.5, the lower mass limit is 185 GeV/c{sup 2}. For second generation scalar leptoquarks, the mass limits are 133 GeV/c{sup 2} for {beta} = 1.0 and 98 GeV/c{sup 2} for {beta} = 0.5. A search for squarks and gluinos,more » predicted by Supersymmetric models, was made by D0 in the three or more jets plus E{sub t} channel. The number of events observed was consistent with background. For heavy squarks, a lower gluino mass limit of 146 GeV/c{sup 2} was obtained, and for equal squark and gluino masses a mass limit of 205 GeV/c{sup 2} was obtained at the 95% CL.« less

Searches have been made for first generation scalar and vector leptoquarks by the D0 collaboration and for second generation scalar leptoquarks by the CDF collaboration. The data sample is from the 1992-93 p{bar p} run at {radical}s = 1.8 TeV at the Fermilab Tevatron Collider. Assuming that leptoquarks are pair produced and decay into charged leptons and quarks with branching fraction {beta}, mass limits at the 95% Confidence Level (CL) have been obtained. For first generation scalar leptoquarks the lower mass limit is 130 GeV/c{sup 2} for {beta} = 1.0 and 116 GeV/c{sup 2} for {beta} = 0.5. For first generation vector leptoquarks with {kappa}, the anomalous coupling, of 1.0 and {beta} = 1.0, the lower mass limit is 240 GeV/c{sup 2} and for {kappa} = 1.0, {beta} = 0.5, the lower mass limit is 240 GeV/c{sup 2}. For {kappa} = 0 and {beta} = 1.0, the lower mass limits is 190 GeV/c{sup 2} and for {kappa} = 0, {beta} = 0.5, the lower mass limit is 185 GeV/c{sup 2}. For second generation scalar leptoquarks, the mass limits are 133 GeV/c{sup 2} for {beta} = 1.0 and 98 GeV/c{sup 2} for {beta} = 0.5. A search for squarks and gluinos,more » predicted by Supersymmetric models, was made by D0 in the three or more jets plus E{sub t} channel. The number of events observed was consistent with background. For heavy squarks, a lower gluino mass limit of 146 GeV/c{sup 2} was obtained, and for equal squark and gluino masses a mass limit of 205 GeV/c{sup 2} was obtained at the 95% CL.« less