J. Rohlf

We report the observation of four electron-positron pairs and one muon pair which have the signature of a two-body decay of a particle of mass ∼ 95 GeV/c2. These events fit well the hypothesis that they are produced by the process p̄+ p→Z0+X(with Z0→ ℓ++ ℓ−), where Z0 is the Intermediate Vector Boson postulated by the electroweak theories as the mediator of weak neutral currents.

A fourth state in the upsilon energy region has been seen in ${e}^{+}{e}^{\ensuremath{-}}$ collisions at the Cornell Electron Storage Ring. A resonance is observed with a mass 1112\ifmmode\pm\else\textpm\fi{}5 MeV above the lowest upsilon state. The 9.6-MeV rms width is greater than the 4.6-MeV energy resolution of the ${e}^{+}{e}^{\ensuremath{-}}$ beams. The observed characteristics of the new state make it a likely candidate for the $4^{3}S$ state of the $b\overline{b}$ system, lying above the threshold for the production of $B$ mesons.

The construction and performance of a large aperture magnetic detector designed for use at the Cornell Electon Storage Ring is descr bed.

$B$-meson decays to final states consisting of a ${D}^{0}$ or ${D}^{*\ifmmode\pm\else\textpm\fi{}}$ and one or two charged pions have been observed. The charged-$B$ mass is 5270.8 \ifmmode\pm\else\textpm\fi{} 2.3 \ifmmode\pm\else\textpm\fi{} 2.0 MeV and the neutral-$B$ mass is 5274.2 \ifmmode\pm\else\textpm\fi{} 1.9 \ifmmode\pm\else\textpm\fi{} 2.0 MeV.

An enhancement has been observed in the inclusive cross section for direct single electrons produced in ${e}^{+}{e}^{\ensuremath{-}}$ annihilations at the $\ensuremath{\Upsilon}(4S)$. This is interpreted as evidence for a new weakly decaying particle, the $B$ meson. A branching ratio for $B\ensuremath{\rightarrow}\mathrm{Xe}\ensuremath{\nu}$ of [13\ifmmode\pm\else\textpm\fi{}3 (\ifmmode\pm\else\textpm\fi{}3)]% is inferred, where the first set of errors is statistical and the estimated systematic error is enclosed in parentheses.

An enhancement in the inclusive cross section for single muons produced in ${e}^{+}{e}^{\ensuremath{-}}$ annihilation at the $\ensuremath{\Upsilon}(4S)$ is observed, confirming the interpretation that a new bare flavor ($B$ mesons) is produced at the $\ensuremath{\Upsilon}(4S)$. A branching ratio for $B\ensuremath{\rightarrow}X\ensuremath{\mu}\ensuremath{\nu}$ of (9.4\ifmmode\pm\else\textpm\fi{}3.6)% is obtained. The two-muon decay, $B\ensuremath{\rightarrow}X{\ensuremath{\mu}}^{+}{\ensuremath{\mu}}^{\ensuremath{-}}$ is not observed, providing a 90%-confidence-level upper limit for the branching ratio for that decay of 1.7%. Combining this with our previously reported limit of 5% for $B\ensuremath{\rightarrow}X{e}^{+}{e}^{\ensuremath{-}}$, we obtain 1.3% as an upper limit for $B\ensuremath{\rightarrow}X{l}^{+}{l}^{\ensuremath{-}}$.

Data are presented on production by 200-GeV/c hadrons incident on beryllium of both single particles and jets (groups of particles) with high ${p}_{T}$ (transverse momentum). The experiment was performed in a wide-aperture multiparticle spectrometer at Fermilab. The jet and single-particle cross sections have a similar shape from ${p}_{T}=3 \mathrm{to} 5$ GeV/c but the jet cross section is over two orders of magnitude larger. The distributions of charged-particle momenta show striking similarities to those observed in lepton-induced processes.

The AMC13 provides clock, timing and DAQ service for many subdetectors and central systems in the upgraded CMS detector. This year we have developed an upgraded module, the AMC13XG, which supports 10 gigabit optical fiber and backplane interfaces. Many of these modules are now being installed in the CMS experiment during the current LHC shutdown. We describe the implementation using Xilinx Kintex-7™ FPGAs, commissioning, production testing and integration in the CMS HCAL and other subsystems.

The observation of an apparent excess of radiative Z0 decays into e+e−γ and μ+μ−γ has prompted the search for massive eνγ and μνγ final states containing an energetic photon. No events were found other than those consistent with QED radiative effects in leptonic W decays. The data sample corresponds to an integrated luminosity of 0.136 pb−1 produced at the CERN super proton synchrotron (SPS) collider. An upper limit on the occurrence of such events is given.

The charged multiplicity has been measured at the $\ensuremath{\Upsilon}(4S)$ and a value of 5.75\ifmmode\pm\else\textpm\fi{}0.1\ifmmode\pm\else\textpm\fi{}0.2 has been obtained for the mean charged multiplicity in $B$-meson decay. Combining this result with the measurement of prompt leptons from $B$ decay, the values 4.1\ifmmode\pm\else\textpm\fi{}0.35\ifmmode\pm\else\textpm\fi{}0.2 and 6.3\ifmmode\pm\else\textpm\fi{}0.2\ifmmode\pm\else\textpm\fi{}0.2 are found for the semileptonic and nonleptonic charged multiplicities, respectively. If $b\ensuremath{\rightarrow}c$ dominance is assumed for the weak decay of the $B$ meson, then the semileptonic multiplicity is consistent with the recoil mass determined from the lepton momentum spectrum.

This paper presents results from an experiment on the production of jets (groups of particles) with high ${p}_{\ensuremath{\perp}}$ produced in 200-GeV/c interactions. Results are presented on the comparison of jet cross sections on aluminum and hydrogen targets. The jet fragmentation distributions are also examined. Both the cross section and the jet structure are found to depend strongly on the beam and target types.

We present results from an experiment studying the production of single particles and jets (groups of particles) with high p⊥ (transverse momentum) in 200 GeV/c interactions on a beryllium target. We give a detailed discussion of the ambiguities in the jet definition. The jet and single-particle cross sections have a similar shape but the jet cross section is over two orders of magnitude larger. The events show evidence for the coplanar structure suggested by constituent models, and the momentum distributions of charged particles give strong support to a simple quark-quark scattering model.

Survey of Particles and Forces. Distribution Functions and kT. Planck's Constant. Special Relativity. Wave Properties of Particles and the Uncertainty Principle. Rutherford Scattering. The Schrodinger Equation. The Hydrogen Atom. Beyond the Hydrogen Atom. Molecules and Molecular Spectra. The Nucleus. Quantum Statistics. Masers and Lasers. Conductors, Insulators, and Semiconductors. Superconductivity. High-Energy Physics: The Gadgets. High-Energy Physics: Classification of the Particles. High-Energy Physics: Unification of the Forces. The Early Universe. Appendices. Answers to Selected Problems. Indexes.

We report on the measurement of the radiation hardness of silicon photomultipliers (SiPMs) manufactured by Fondazione Bruno Kessler in Italy (1 and 6.2mm2), Center of Perspective Technology and Apparatus in Russia (1 and 4.4mm2), and Hamamatsu Corporation in Japan (1mm2). The SiPMs were irradiated using a beam of 212 MeV protons at Massachusetts General Hospital, receiving fluences of up to 3×1010 protons per cm2 with the SiPMs at operating voltage. Leakage currents were read continuously during the irradiation. The delivery of the protons was paused periodically to record scope traces in response to calibrated light pulses to monitor the gains, photon detection efficiencies, and dark counts of the SiPMs. The leakage current and dark noise are found to increase with fluence. The leakage current is found to be proportional to the mean square deviation of the noise distribution, indicating the dark counts are due to increased random individual pixel activation, while SiPMs remain fully functional as photon detectors. The SiPMs are found to anneal at room temperature with a reduction in the leakage current by a factor of 2 in about 100 days.

A measurement is presented of inclusive charged D*(2010) production from nonresonant e+e− annihilation in the center-of-mass energy (W) range 10.2 GeV<W<10.6 GeV. Charged D* mesons are identified by the decays D*+→D0π+→K−π+π+ and the charge conjugate mode. It is found that 40 ± 7 ± 13% of the charm quarks from the process e+e−→cc¯ result in D* mesons with z>0.7 (z=2EW, where E is the D* energy).Received 26 May 1982DOI:https://doi.org/10.1103/PhysRevLett.49.610©1982 American Physical Society

Using the CLEO detector at the Cornell Electron Storage Ring, the authors have measured the leptonic branching fractions, ${B}_{\ensuremath{\mu}\ensuremath{\mu}}$, of the $\ensuremath{\Upsilon}(1S)$, $\ensuremath{\Upsilon}(2S)$, and $\ensuremath{\Upsilon}(3S)$ to be 2.7\ifmmode\pm\else\textpm\fi{}0.3\ifmmode\pm\else\textpm\fi{}0.3%, 1.9\ifmmode\pm\else\textpm\fi{}1.3\ifmmode\pm\else\textpm\fi{}0.5%, and 3.3\ifmmode\pm\else\textpm\fi{}1.3\ifmmode\pm\else\textpm\fi{}0.7%, respectively. Combining these values of ${B}_{\ensuremath{\mu}\ensuremath{\mu}}$ with previous measurements of the leptonic widths of these resonances, the authors find the total widths of the $\ensuremath{\Upsilon}(1S)$, $\ensuremath{\Upsilon}(2S)$, and $\ensuremath{\Upsilon}(3S)$ to be 48\ifmmode\pm\else\textpm\fi{}4\ifmmode\pm\else\textpm\fi{}4, 27\ifmmode\pm\else\textpm\fi{}17\ifmmode\pm\else\textpm\fi{}6, and 13\ifmmode\pm\else\textpm\fi{}4\ifmmode\pm\else\textpm\fi{}3 keV.

We have observed the decay of the $\ensuremath{\Upsilon}(2S)$ into the $\ensuremath{\Upsilon}(1S)$, obtaining a branching ratio of 19.1\ifmmode\pm\else\textpm\fi{}3.1\ifmmode\pm\else\textpm\fi{}2.9% for the mode $\ensuremath{\Upsilon}(2S)\ensuremath{\rightarrow}{\ensuremath{\pi}}^{+}{\ensuremath{\pi}}^{\ensuremath{-}}+\ensuremath{\Upsilon}(1S)$. The di-pion mass spectrum peaks at large invariant mass, and the angular distribution of the di-pion system is consistent with $s$-wave production.

Data on inclusive kaon production in ${e}^{+}{e}^{\ensuremath{-}}$ annihilations at energies in the vicinity of the $\ensuremath{\Upsilon}(4S)$ resonance are presented. A clear excess of kaons is observed on the $\ensuremath{\Upsilon}(4S)$ compared to the continuum. Under the assumption that the $\ensuremath{\Upsilon}(4S)$ decays into $B\overline{B}$, a total of 3.38\ifmmode\pm\else\textpm\fi{}0.34\ifmmode\pm\else\textpm\fi{}0.68 kaons per $\ensuremath{\Upsilon}(4S)$ decay is found. In the context of the standard $B$-decay model this leads to a value for $\frac{(b\ensuremath{\rightarrow}c)}{(b\ensuremath{\rightarrow}\mathrm{all})}$ of 1.09\ifmmode\pm\else\textpm\fi{}0.33\ifmmode\pm\else\textpm\fi{}0.13.

Morphology-performance (M-P) mapping seems to be predictive of how morphology may evolve along “functional lines of least resistance”, regardless of genetic effect, but as yet it is not clear the strict (or mathematical) definition of the least functional resistance and how M-P mapping determines it. We recorded station-holding and swimming performance using a published critical swimming speed (Ucrit) test in Chinese sturgeon Acipenser sinensis, and used Ucrit as a proxy for fitness. We addressed a geometric morphometric framework to initiate Arnold’s “morphology-performance-fitness” path model (Arnold, 1983), assessing and visualizing apparent and direct M-P mapping. We quantified them as that one unit of the most-performance-covaried shape vector generated fapparent and f units of standardized performance, respectively. We defined the least functional resistance as the theoretically minimum morphological variation on an arbitrary direction in morphospace required by one unit of standardized fitness, (|b-1|min), which was calculated as a multivariate function of direct M-P mapping (f), together with the angle between paired most-performance-covaried shape vectors in morphospace (θ) and direct performance effect on fitness (w), given dual performance systems. The simulated and empirical data suggested that |b-1|min was constrained by larger sum of absolute direct effects (|fhold| + |fswim|) and absolute functional interaction (|fhold fswim cos θ|), and its direction was biased by magnitude of direct M-P mapping.

We have searched for decays of the $\ensuremath{\Upsilon}(1S)$ into a single high-energy photon and a noninter-acting long-lived particle, using the CLEO detector at the Cornell Electron Storage Ring. An upper limit of 3 \ifmmode\times\else\texttimes\fi{} ${10}^{\ensuremath{-}4}$ (at 90% confidence level) is obtained for the branching ratio for such decays.

We have studied the production of B mesons in e+e− annihilations and present new measurements of the semileptonic branching fractions for B-meson decay. We find B(B→eνX)=0.127±0.017±0.013 and B(B→μνX)=0.122±0.017±0.031, where the errors are statistical and systematic, respectively. The observed lepton momentum spectra from B decays are presented. From these spectra we find the mean hadronic mass (MX) recoiling against the detected lepton to be MX=2.2±0.2 GeV/c2. We have also observed an enhancement in the lepton yield from the continuum above BB¯ threshold. This enhancement is interpreted as continuum B production and is consistent with what is expected from the naive quark model.Received 9 August 1982DOI:https://doi.org/10.1103/PhysRevD.27.475©1983 American Physical Society

The branching ratio of $\ensuremath{\Upsilon}(3S)\ensuremath{\rightarrow}{\ensuremath{\pi}}^{+}{\ensuremath{\pi}}^{\ensuremath{-}}\ensuremath{\Upsilon}(1S)$ has been measured to be (4.9 \ifmmode\pm\else\textpm\fi{} 0.9 \ifmmode\pm\else\textpm\fi{} 0.5)%. The di-pion invariant-mass distribution for this decay is flatter than that for the decays $\ensuremath{\Upsilon}(2S)\ensuremath{\rightarrow}{\ensuremath{\pi}}^{+}{\ensuremath{\pi}}^{\ensuremath{-}}\ensuremath{\Upsilon}(1S)$ and ${\ensuremath{\psi}}^{\ensuremath{'}}\ensuremath{\rightarrow}{\ensuremath{\pi}}^{+}{\ensuremath{\pi}}^{\ensuremath{-}}\ensuremath{\psi}$.

Data on inclusive jet production in the transverse-momentum (${p}_{\ensuremath{\perp}}$) range 0-8 GeV/c for 200-GeV/c $p$, ${\ensuremath{\pi}}^{\ensuremath{-}}$, ${\ensuremath{\pi}}^{+}$, ${K}^{\ensuremath{-}}$, ${K}^{+}$, and $\overline{p}$ incident on a hydrogen target are presented. The jet cross section is fully corrected for losses and biases, and compared with the predictions of a model based on quantum chromodynamics. Both the absolute cross section and the inclusive charged-particle distributions inside and outside the jet are in qualitative agreement with the model.

We have measured the performance of silicon photomultipliers (SiPMs) together with the front-end electronics developed for the Compact Muon Solenoid hadron calorimeter. We find a clean separation of the single PE peak above pedestal noise fluctuations, providing a signal to noise of about 8. The SiPMs may be useful in the near term for readout of the outer (HO) scintillators to significantly enhance the sensitivity to minimum ionizing particles for use in the muon trigger. In the longer term, the SiPMs may be useful for upgrading the detector to accommodate a luminosity upgrade.

Results are presented on the production of single charged particles with transverse momentum in the range of 0.8-4.5 GeV/c in ${\ensuremath{\pi}}^{\ifmmode\pm\else\textpm\fi{}}p$, ${K}^{\ensuremath{-}}p$, and $\mathrm{pp}$ collisions at 200 GeV/c and on correlations between the trigger particle and particles with opposite azimuthal angle.

We consider three broad classes of nonstandard models for b quark decay: (1) b → ℓℓq with charged or neutral leptons of arbitrary flavor; (2) b → ℓqq; and (3) b → qa− where a− is a Higgs boson or hyperpion. For these classes of models we have calculated the charged energy fraction and the inclusive yields of electrons, muons, protons, and lambdas. We demonstrate that these model predictions are inconsistent with CLEO measurements at the γ (4S).

The branching fraction for the decay of the $\ensuremath{\Upsilon}(1S)$ into $\ensuremath{\tau}$ paris has been measured to be (3.4\ifmmode\pm\else\textpm\fi{}0.4\ifmmode\pm\else\textpm\fi{}0.4)%. This result agrees with the previously measured branching ratio of the decay into muon pairs.

Abstract We present experimental details from a study of hadron jet production at high transverse momentum (p⊥) in 130 and 200 GeV hadron-proton collisions. Jet definition and acceptance of the apparatus are discussed thoroughly. Jet cross sections are measured for p , π − , π + , K − , K + , and p incident on a liquid hydrogen target. These cross sections depend strongly on the number of valence quarks in the beam. The p⊥ dependence of the jet cross section is measured to be significantly flatter than that for single particles. We show that a model based on quantum chromodynamics (QCD) is able to qualitatively explain both the large jet cross section and the event structure on the trigger and away sides. We present evidence for scale breaking; higher transverse momentum jets are seen to be composed of a greater number of lower momentum particles. The average momentum ( ) of these particles transverse to the jet direction is observed to increase with increasing jet p⊥. Charged particle correlations on both the trigger and away sides are given for both pion and proton beams.

We report on the measurement of pulse shape, gain, leakage current, and photon detection efficiency in 4–9 mm <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</sup> state-of-the-art silicon photomultipliers (SiPMs) obtained recently from the Center of Perspective Technology and Appa- ratus (CPTA) in Russia, Center for Scientific and Technological Research (ITC-irst) in Italy, and Hamamatsu Corporation in Japan. The CPTA and IRST SiPMs were used to read out a hodoscope of scintillators designed for the outer layer of the hadron calorimeter of the Compact Muon Solenoid (CMS) with muon and pion beams at CERN. A direct comparison with CMS production hybrid photodiodes (HPDs) show that the SiPMs give an order of magnitude improvement in the signal to noise for single minimum ionizing particles (MIPs) and that the dynamic range is sufficient to detect up to 450 MIPs for use as a tail-catcher for late-developing hadronic showers in CMS.

A typical scintillating tile sampling calorimeter consists of multiple layers of scintillators coupled to wavelength shifting fibers viewed by a suitable photo-detector. Long clear fibers are used to connect the tiles to the readout modules. We have investigated the use of silicon photomultipliers (SiPMs) at the Super Lagre Hadron Collider (SLHC). Because radiation hardness is the main concern, two sets of radiation data were taken using a 212 MeV proton beam at Massachusetts General Hospital. In the first data set we radiated up to a dose of 3×10 <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">10</sup> protons per cm <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</sup> using diodes from three different manufactures (i.e., FBK, CPTA and Hamamatsu). At a dose of 3x10 <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">10</sup> protons per cm <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</sup> only small effects of PDE loss were detected due to very high dark count always occupying one or more cells in a multi-cell SiPM. A second set of data up to 10 <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">13</sup> protons per cm <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</sup> using very high pixel density MAPDs with up to 40,000 cells per mm <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</sup> . After each small radiation dose multiple scope traces were taken to look at the PDE and dark count of the devices. The increase in dark count due to the radiation was compared to the DC leakage current. Also a comparison was made between multi-cell and single-cell samples of the FBK-IRST diodes.

We have developed a novel and generic open-source platform - Apollo - which simplifies the design of custom Advanced Telecommunications Computing Architecture (ATCA) blades by factoring the design into generic infrastructure and application-specific parts. The Apollo "Service Module" provides the required ATCA Intelligent Platform Management Controller, power entry and conditioning, a powerful system-on-module computer, and flexible clock and communications infrastructure. The Apollo "Command Module" is customized for each application and typically includes two large field-programmable gate arrays, several hundred optical fiber interfaces operating at speeds up to 28 Gbps, memories, and other supporting infrastructure. The command and service module boards can be operated together or independently on the bench without need for an ATCA shelf.

The qualitative predictions of quantum chromodynamics for high-energy hadron-nucleus scattering are expounded. Inclusive particle distributions from hadron interactions on proton and aluminum targets are compared to the theoretical expectations for both low and high transverse momentum (p⊥) scattering. In the latter case, we present data on the nuclear effects in the fragmentation of both the beam and scattered partons. At low p⊥, we show evidence for short-range correlations between the final particles produced in hadron-aluminum collisions.

The performance of the Compact Muon Solenoid detector for measuring missing transverse energy is evaluated using fully simulated pp collisions at a center-of-mass energy of 14 TeV at the Large Hadron Collider. For minimum bias events without pileup, a resolution of 6.1 GeV is computed, corresponding to a stochastic contribution of $0.63\sqrt{\Sigma{}E_{\text{T}}} \mathrm{GeV^{1/2}}$ , where ΣET is the summed transverse energy in all calorimeter towers. When the contribution of pileup is included, the resolution degrades according to the overall deposited ΣET with the same stochastic coefficient. For QCD dijet events with event pileup corresponding to a luminosity $\mathcal{L}=2\times10^{33}\mathrm{cm^{-2}s^{-1}}$ , we compute $\sigma=[({3.8} \mathrm{GeV})^2+({0.97} \mathrm{GeV^{1/2}}\sqrt{\Sigma{}E_{\text{T}}})^2+(0.012\Sigma{}E_{\text{T}})^2]^{1/2}$ resulting in a resolution of 45 GeV for jet events with reconstructed transverse momentum of 800 GeV/c. Monte Carlo samples of tt̄ and W+jet events with high-momentum (pT>20 GeV/c) lepton decays leading to true missing transverse energy were used to determine the azimuthal angle resolution to be 0.1 radians (0.2 radians) for a reconstructed missing transverse energy of 200 GeV (100 GeV).

The jet reconstruction algorithms and calibration techniq ues implemented in the CMS reconstruction software are studied with high-statistics Monte Carlo samples of QCD dijet events. Generated events are passed through a full detector-level simulation of the CMS detector including readout digitization in the presence of pile-up at an instantaneous luminosity of L = 2×10 33 cm 2 s 1 . Effects of detector resolution and granularity on the jet resolutions, effic iencies and instrumental background rates are estimated. These measures of performance are compared for a set of jet algorithms, algorithm parameters, and calorimeter cell thresholds. The uniformity and linearity of the jet response are evaluated by comparing particle-level and reconstructed jets over a wide range of transverse momenta throughout the angular coverage of the calorimeters. Fits to the ratio o f reconstructed to generated jet transverse energy give a transverse energy resolution of 10-15% (8-10%) at 100 GeV (200 GeV) over the pseudorapidity range 0 < |�| < 5. The angular resolution for 100 GeV (200 GeV) jets is 0.02-0.035 (0.02) radians.

A full-scale prototype position detector has been built and tested for the uranium-tetramethylpentane (TMP) calorimeter which is presently being constructed for the UA1 experiment at the CERN proton-antiproton collider. The position detector consists of a sealed stainless steel box containing TMP and three electrode planes, where the middle plane is used for energy measurement, and the other two are highly segmented to enable a precise measurement of the position of electromagnetic showers. The position detector has been operated in electron and muon test beams at CERN. The detector performs well, both as an element of the calorimeter and as a device for measuring shower positions, and yields a spatial resolution of about 1 mm for high energy electron showers.

Abstract Relative calibration of the scintillator tiles used in the hadronic calorimeter for the Compact Muon Solenoid detector at the CERN Large Hadron Collider is established and maintained using a radioactive source technique. A movable source can be positioned remotely to illuminate each scintillator tile individually, and the resulting photo-detector current is measured to provide the relative calibration. The unique measurement technique described here makes use of the normal high-speed data acquisition system required for signal digitization at the 40 MHz collider frequency. The data paths for collider measurements and source measurements are then identical, and systematic uncertainties associated with having different signal paths are avoided. In this high-speed mode, the source signal is observed as a Poisson photo-electron distribution with a mean that is smaller than the width of the electronics noise (pedestal) distribution. We report demonstration of the technique using prototype electronics for the complete readout chain and show the typical response observed with a 144 channel test beam system. The electronics noise has a root-mean-square of 1.6 least counts, and a 1 mCi source produces a shift of the mean value of 0.1 least counts. Because of the speed of the data acquisition system, this shift can be measured to a statistical precision better than a fraction of a percent on a millisecond time scale. The result is reproducible to better than 2% over a time scale of 1 month.

We are developing a Micro TCA Carrier Hub card which provides timing, control and data acquisition functions in a Micro TCA crate for HL-LHC readout electronics. This module may be mounted in the primary or redundant MCH slot in a Micro TCA crate, and distributes low-jitter LHC RF clock and encoded fast timing signals to up to 12 AMC modules. In addition, it receives buffer status signals and DAQ data at up to 600 MBytes/sec from each AMC. The prototype module is built on a commercial MCH base board with a custom mezzanine board stack. The latest Xilinx® Virtex®-6 FPGA are used to provide a clear upgrade path. Prototype modules have been developed for a CMS HCAL test beam in summer 2010. We describe the specifications of the module, its application in a Micro TCA system beyond CMS HCAL, and our experience in commissioning the module for the test beam.

Hadron Outer (HO) scintillators located around the CMS coil are sensitive to muons. They can be used in coincidence with RPC chambers for the Muon Trigger. This paper contains a brief description of the two systems and the proposal of how they can be integrated. Backgrounds, efficiencies, and trigger rates have been calculated. The conclusion is that rate reduction factors as high as 100 can be obtained for ∼90% efficiency.

The challenging conditions of the High-Luminosity LHC require tailored hardware designs for the trigger and data acquisition systems. The Apollo platform features a "Service Module" with a powerful system-on-module computer that provides standard ATCA communications and application-specific "Command Module"s with large FPGAs and high-speed optical fiber links. The CMS version of Apollo will be used for the track finder and the pixel readout. It features up to two large FPGAs and more than 100 optical links with speeds up to 25\,Gb/s. We study carefully the design and performance of the board by using customized firmware to test power consumption, heat dissipation, and optical link integrity. This paper presents the results of these performance tests, design updates, and future plans.

A measurement of charged-particle production is reported for the forward region in events triggered by high-transverse-momentum (${p}_{\ensuremath{\perp}}$) jets and single particles. The momentum distributions of forward-going particles are observed to scale in a simple ${p}_{\ensuremath{\perp}}$-dependent longitudinal variable. Forward-going (beam) jets are observed to be tilted away from the original direction by an amount which agrees with muon-pair data when interpreted in a parton (quantum-chromodynamics) model.

Drift tubes of 1.9-mm radius and 25- mu wall thickness were exposed to neutrons and associated gamma radiation from uranium fission at the MIT Research Reactor. In 45 hours of irradiation, the drift tubes received a neutron fluence with energy greater than 0.5 MeV of 1.1*10/sup 13/ cm/sup -2/ And accumulated a charge per wire length of 0.08 coul cm/sup -1/, about that expected for three years of operation at the SSC for a lead scintillator calorimeter at a 1-m radius and for drift tubes at a distance of several tens of centimeters from the beam axis. Measurement of the pulse height, pulse shape, counting rates, andcurrents showed no degradation in drift tube performance. Fast (few nanosecond rise time), sharp (20-ns width) pulses were observed at counting rates of 5 MHz using CF/sub 4/ as the drift gas.< <ETX xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">&gt;</ETX>

The physics reach of the Compact Muon Solenoid, under construction to study proton-proton collisions at a centre-of-mass energy of 14 TeV, is presented at design luminosity of 1034cm–2s–1 and beyond (1035cm–2s–1). The sensitivity for detection of the standard-model Higgs boson in the channels qqH (W fusion), WH, and tH is discussed with the result that the Higgs boson is observable in multiple decay modes over entire mass range, 0.1-1 TeV/c2. Higgs boson searches for decays involving taus in the context of the Minimal Supersymmetric Standard Model result in a limit of about 0.6 TeV/c2 at tanβ=25. Sparticle reconstruction for decays containing leptons and jets results in a squark/gluino mass reach in the range 2.5-3 TeV/c2. Limits on Kaluza-Klein excitations of the graviton or a new heavy vector boson are in the 5-6 TeV/c2 range. The scattering of vector bosons at high energy and discovery potential for compositeness is described. PACS: 11.30.Pb – 12.38.Qk; 12.60.Fr – 12.60.Fr – 12.60.Jv – 12.60.Rc – 14.60.Cd – 14.60.Ef – 14.60.Fg – 14.65.Fy – 14.65.Ha – 14.80.Bn – 14.80.Cp – 14.80.Ly – 14.70.Fm – 14.70.Hp – 14.70.Pw

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 CMS HCAL Upper Level Readout system processes data from 9300 detector channels in a system of about 26 VME Crates. Each crate contains about 18 readout cards, whose outputs are are combined on a Data Concentrator Card, with real-time synchronization and error-checking and a throughput of 200 Mbytes/s. The implementation is modular and based on industry and CERN standards: PCI bus, PCI-MIP and PMC carrier boards, S-Link and LVDS serial links. A prototype system including front-end emulator, HTR cards and Data Concentrator has been prototyped and tested. A VME motherboard provides a standard platform for the data concentrator. Implementation details and current status are described. H R C On−detector Front End: QIE ADC Gigabit Optical Link Tx Fanout Optical TTC 18 HTR Cards per VME crate H T R H T R H T R 3 Channels/fiber @ 1.6 Gbit/s

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Detailed measurements have been made of 9 mm2 SiPMs from Hamamatsu (MPPC) and Zecotek (MAPD) after room temperature annealing after exposure to fluences of 1012 to 1013 cm-2. The data was used to complete the final ADR report.

The current funding is for continued work on the Compact Muon Solenoid (CMS) at the CERN Large Hadron Collider (LHC) as part of the Energy Frontier experimental program. The current budget year covers the first year of physics running at 13 TeV (Run 2). During this period we have concentrated on commisioning of the μTCA electronics, a new standard for distribution of CMS trigger and timing control signals and high bandwidth data aquistiion as well as participating in Run 2 physics.

The Compact Muon Solenoid hadronic barrel (CMS HB) calorimeter consists of 17 layers of scintillator in a brass absorber. Each scintillator consists of 16 tiles comprising one layer of the corresponding towers in pseudo-rapidity. The light from each tile is routed into a single 0.96 mm wavelength shifting fiber. In the current design, the 17 fibers from the full tower depth are directed into one pixel of a multi-channel hybrid photo-diode (HPD). Thus, no longitudinal shower information is readout. In the last year we have developed 18 element MAPD arrays (Micro-pixel Avalanche Photo Diodes) on 8 inch wafers with Zecotek in Singapore. A special prototype 20 pin ceramic package was made by Kyocera in Germany. By using 18 element G-APD strips (Geiger mode Avalanche photo diodes) we could readout each layer separately, so that 17 of these strips replace one HPD. Because of the large linear range requirement in the hadronic calorimeter and radiation hardness needed, we used the new generation high cell density Zecotek MAPDs with 15,000 cells per strip element. Due to the higher PDE (photon detection efficiency) versus the HPD (30% vs. 12%) we got 5 p.e. per layer for a MIP. Due to limited availability of electronic channels for these tests, analog signals from multiple strips were added together providing digital readout from four depth segments. Non uniformity between strips was calibrated using muons and measurements of breakdown voltage of each element of the array. After calibration of the 4 longitudinal depth segments, the linearity and detector resolution was studied using pions with energies from 30 to 300 GeV.

Abstract The article contains sections titled: Introduction Brief History The Birth of Particle Colliders Ingredients of Colliders Famous Colliders Stanford Positron Electron Accelerating Ring PETRA CERN Proton–Antiproton Collider Fermilab Tevatron Collider Large Electron–Positron Project The Energy Frontier: CERN Large Hadron Collider LHC Basic Parameters Beam Dump LHC Layout Cryogenics Injection Scheme Radio Frequency Acceleration Beam Vacuum Super LHC The Next Frontier International Linear Collider Compact Linear Collider Very Large Hadron Collider

The specification of the interface between the CMS Calorimeter Trigger Primitive Generator and the Level 1 Regional Calorimeter Trigger (RCT) electronics crates is updated. The cabling, data format, and timing are described. Changes from CMS Internal Note 2001/016 include the mapping and destination of the Forward Calorimeter towers, crate arrangement in the USC55 racks, and bunch crossing zero (BC0) specification instead of the “Gap Flag”. Note: This document was updated July 2004 to include updated versions of Figures 2, 3, and 5 with revised  mapping necessary to reduce trigger primitive cable lengths and overall latency.

The feasibility of discovering the Standard Model Higgs boson via Vector Boson Fusion in H ! W + W ! ‘ jj channel is investigated. A comprehensive strategy of Higgs mass (mH) reconstruction is developed using detector jets, lepton and missing transverse energy (E miss ). At an integrated luminosity of 30 fb 1 , a 5 discovery can be achieved for 140 < mH < 200 GeV=c 2 . Several important techniques including forward jet tagging, central jet selection, hadronic and leptonic W reconstruction, E miss selection, lepton-W correlation and lepton isolation, are optimized to increase the signal to background ratio. Data driven analysis methods are developed to further identify the experimental signature of the signal in addition to the reconstructed Higgs mass peak and reduce the effect of a variety of detector systematic uncertainties.

The challenging conditions of the High-Luminosity LHC require tailored hardware designs for the trigger and data acquisition systems. The Apollo platform features a "Service Module" with a powerful system-on-module computer that provides standard ATCA communications and an application-specific "Command Module"s with large FPGAs and high-speed optical fiber links. The CMS version of Apollo will be used for the track finder and the pixel readout. It features up to two large FPGAs and more than 100 optical links with speeds up to 25\,Gb/s. We study carefully the design and performance of the board by using customized firmware to test power consumption, heat dissipation, and optical link integrity. This paper presents the results of these performance tests, design updates, and future plans.

interactions. We request 200,000 pictures with the beam protons hitting the shield directly and 200,000 pictures with the normal high energy {upsilon}{sub {mu}} beam. In the latter pictures we will study deep inelastic {upsilon}{sub {mu}} scattering, search for muonless {upsilon}{sub {mu}} interactions, search for {upsilon}{sub {mu}} diffractive processes and search for {Delta}S = -{Delta}Q in strange particle production processes. This experiment does not require the E{Pi} or a plate in the bubble chamber although the latter would be very useful and can run without the horn.

to their masses. Precision measurements of particle masses for e.g. the top quark and the W boson can hereby provide indirect constraints on the Higgs boson mass. Since in the standard model top quarks couple almost exclusively to bottom quarks (t → Wb), top quark decays provide a window on the standard model through the direct measurement of the Cabibbo-Kobayashi-Maskawa quark mixing matrix element Vtb. In the same way any lack of top quark decays into W bosons could imply the existence of decay channels beyond the standard model, for example charged Higgs bosons as expected in two-doublet Higgs models: t → H+b. Within the standard model top quark decays can be classified by the (lepton or quark) W boson decay products. Depending on the decay of each of the W bosons, t$$\bar{t}$$ pair decays can involve either no leptons at all, or one or two isolated leptons from direct W → e$$\bar{v}$${sub e} and W → μ$$\bar{v}$$μ decays. Cascade decays like b → Wc → e$$\bar{v}$$ec can lead to additional non-isolated leptons. The fully hadronic decay channel, in which both Ws decay into a quark-antiquark pair, has the largest branching fraction of all t$$\bar{t}$$ decay channels and is the only kinematically complete (i.e. neutrino-less) channel. It lacks, however, the clear isolated lepton signature and is therefore hard to distinguish from the multi-jet QCD background. It is important to measure the cross section (or branching fraction) in each channel independently to fully verify the standard model. Top quark pair production proceeds through the strong interaction, placing the scene for top quark physics at hadron colliders. This adds an additional challenge: the huge background from multi-jet QCD processes. At the Tevatron, for example, t$$\bar{t}$$ production is completely hidden in light q$$\bar{q}$$ pair production. The light (i.e. not bottom or top) quark pair production cross section is six orders of magnitude larger than that for t$$\bar{t}$$ production. Even including the full signature of hadronic t$$\bar{t}$$ decays, two b-jets and four additional jets, the QCD cross section for processes with similar signature is more than five times larger than for t$$\bar{t}$$ production. The presence of isolated leptons in the (semi)leptonic t$$\bar{t}$$ decay channels provides a clear characteristic to distinguish the t$$\bar{t}$$ signal from QCD background but introduces a multitude of W- and Z-related backgrounds.

This report is a renewal proposal to continue Harvard`s participation in the UA1 experiment on proton-antiproton collisions. The proposed activity emphasizes events with large missing energy and W and Z neutral decays. (LSP)

of the muon program with the future NuMI program, delivering 10{sup 20} protons per year at 8 GeV for the muon program at the cost of a modest ({approx}10%) reduction in the protons available to the neutrino program.

Predictions for jet physics at SSC energies are reviewed. Comparison is made with data at CERN collider energies. The work of the Jet-Study Group had much overlap with the work of the Detector Groups and the Fragmentation Group. 22 references.

This proposal is to the Department of Energy for 501.6K dollars (349.6K operations and 152K equipment) for continued participation in the UA1 experiment on proton-antiproton collisions. The UA1 experiment is the study of high-energy proton-antiproton collisions in the Super-Proton-synchrotron (SPS) Collider at CERN. A major upgrade of the UA1 detector is in progress for operation with the upgraded antiproton source (ACOL). The US groups have played an increasingly prominent role in UA1 during the past few years. This paper discusses the data analysis that has been done by the group of the position detector and it's hardware.