S. Wimpenny

The spin asymmetry in deep inelastic scattering of longitudinally polarised muons by longitudinally polarised protons has been measured over a large x range (0.01<x<0.7). The spin-dependent structure function g1(x) for the proton has been determined and its integral over x found to be 0.114±0.012±0.026, in disagreement with the Ellis-Jaffe sum rule. Assuming the validity of the Bjorken sum rule, this result implies a significant negative value for the integral of g1 for the neutron. These values for the integrals of g1 lead to the conclusion that the total quark spin constitutes a rather small fraction of the spin of the nucleon.

The spin asymmetry in deep inelastic scattering of longitudinally polarised muons by longitudinally polarised protons has been measured in the range 0.01<×<0.7. The spin dependent structure function g1(x) for the proton has been determined and, combining the data with earlier SLAC measurements, its integral over x found to be 0.126±0.010(stat.)±0.015(syst.), in disagreement with the Ellis-Jaffe sum rule. Assuming the validity of the Biorken sum rule, this result implies a significant negative value for the integral of g1 for the neutron. These integrals lead to the conclusion, in the naïve quark parton model, that the total quark spin constitutes a rather small fraction of the spin of the nucleon. Results are also presented on the asymmetries in inclusive hadron production which are consistent with the above picture.

Using the data on deep inelastic muon scattering on iron and deuterium the ratio of the nucleon structure functions F2N(Fe)/F2N(D) is presented. The observed x-dependence of this ratio is in disagreement with existing theoretical predictions.

Results are presented on the ratios of the deep inelastic muon-nucleus cross sections for carbon, copper and tin nuclei to those measured on deuterium. The data confirm that the structure functions of the nucleon measured in nuclei are different from those measured on quasi-free nucleons in deuterium. The kinematic range of the data is such that 〈Q2〉 ∼ 5 GeV2 at x ∼ 0.03, increasing to 〈Q2〉 ∼ 35 GeV2 for x ∼ 0.65. The measured cross section ratios are less than unity for x ≲ 0.05 and for 0.25 ≲ x < 0.7. The decrease of the ratio below unity for low x becomes larger as A increases as might be expected from nuclear shadowing. However, this occurs at relatively large values of Q2 (∼ 5 GeV2) indicating that such shadowing is of patrionic origin.

A new and rigorous light-front formalism for electron deep inelastic scattering on unpolarized nuclei, in Bjorken limit, is proposed. It preserves Poincaré covariance, macroscopic locality, both number of particles and momentum sum rules. The approach is applied to the A=3 iso-doublet, very relevant for the flavor decomposition of the parton distribution functions and in view of the planned operation with unpolarized and polarized beams at the Electron-Ion Collider. At variance with previous light-front estimates, our procedure, including a realistic nuclear description and free-nucleon structure functions, predicts a sizable European Muon Collaboration effect for 3He. This will allow to analyze deviations from the proposed baseline in terms of genuine QCD effects. The extension to heavier nuclei is straightforward, although numerically challenging.

The x and Q2 dependence of the single photon exchange cross section d2σ/dQ2dx and the proton structure functions F2(x,Q2) and R(x,Q2) have been measured in deep inelastic muon proton scattering in the region 0.02 < x < 0.8 and 3 < Q2 < 190 GeV2. By comparing data at different incident muon energies R was found to have little kinematic dependence and an average value of −0.010 ± 0.037 (stat.) ± 0.102 (stat.). The observed deviations from scaling gave the value of ΛMS, the QCD mass scale parameter, to be 105−45+55 (stat.)−45+85 (syst.) MeV. The fraction of the momentum of the nucleon carried by gluons was found to be ∼56% at Q2∼22.5 GeV2. It is shown that to obtain a description of the data for F2(x, Q2) together with that measured in deep inelastic electron-proton scattering at lower Q2 it is necessary to include additional higher twist contributions. The value of ΛMS remains unchanged with the inclusion of these contributions which were found to have an x-dependence of the form x3/(1 − x).

Dimuon and trimuon events produced by the interaction of 250 GeV muons in an iron target have been studied and are shown to originate predominantly from charm production. The data are used to measure the contribution of charm to the nucleon structure function F2. The cross sections for real photoproduction (Q2=0) of charm in the current fragmentation region are derived as a function of photon energy and are found to be ∼0.6% of the total, hadronic photoproduction cross section in this energy range. The measured cross sections are found to be well represented by the photon-gluon fusion model. The charmed quark fragmentation function is obtained by using this model to fit the measured decay muon energy distribution and is found to be well represented by exp(1.6±1.6)Z. The data are used to study the momentum distribution of the gluons in the nucleon. An upper limit of 1.4% (90% confidence level) is set on the branching ratio D→μν and a model-dependent upper limit on the branching ratio F→μν is derived.

The European Muon Collaboration has built a large magnetic spectrometer system for deep inelastic muon scattering experiments at the CERN SPS muon beam. The general characteristics of the apparatus — composed of a target of either liquid hydrogen or deuterium, or iron plus scintillator, followed by a large magnet with wire chambers before and after it for precise angle and momentum measurement, a muon identifier, large trigger hodoscopes, and hadron identifiers — are explained and each part is described in some detail. The main features of the data-acquisition and apparatus-monitoring systems and of the off-line event reconstruction are given.

The production of J/ϑ and ϑ′ has been measured in 250 GeV muon iron interactions. The measured total cross sections are σ(μN → μJ/ϑX)=0.74±0.14 nb and σ(μN → μϑ′X)=0.16 ± 0.07 nb. An upper limit on the cross section times branching ratio for ϒ production of BR · σ (μN → μϒX) < 5.2 × 10−38 cm2 (at 90% confidence level) is obtained. About half the J/ϑ cross section is found to have Z ⩾ 0.95 (where Z=E(J/ϑ/ν). The first-order photon-gluon fusion model agrees well with the measured Q2 and ν dependence of the J/ϑ data and is used to extract the gluon momentum distribution. However, higher order QCD effects are needed to explain the Z distribution of the J/ϑ and the observed broadening of the Pt2 distribution with decreasing Z. The decay angular distributions of the J/ϑ are found to be flat in the s-channel frame, but there is evidence for polarisation in the t-channel frame.

Differential multiplicities of forward produced hadrons in deep inelastic muon scattering on nuclear targets have been compared with those from deuterium. The ratios are observed to increase towards unity as the virtual photon energy increases with no significant dependence on the other muon kinematic variables. The hadron transverse momentum distribution is observed to be broadened in nuclear targets. The dependence on the remaining hadron variables is investigated and the results are discussed in the framework of intranuclear interaction models and in the context of the EMC effect.

We present a study of how temperature affects the change in the depletion voltage of silicon PIN detectors damaged by radiation. We study the initial radiation damage and the short-term and long-term annealing of that damage as a function of temperature in the range from −10°C to +50°C, and as a function of 800 MeV proton fluence up to 1.5×1014 p/cm2. We express the pronounced temperature dependences in a simple model in terms of two annealing time constants which depend exponentially on the temperature.

The deuteron structure function F2d has been measured in 280 GeV μ+ d interactions. Existing measurements of F2p, made with the same apparatus, are used to calculate F2p−F2n and F2nF2p. The ratio F2nF2p has a similar x dependence to that of earlier measurements at lower Q2.

The proton structure function F2 has been measured in the range 2.5 ⪕ Q2 ⪕ 170 GeV2and 0.03 ⪕ x ⪕ 0.65. Scaling violation is clearly seen in the data. Results of fits to leading-order QCD are presented, together with values of the scale-breaking parameter λ.

Charm production has been studied through multimuon events produced in 250 GeV μ+-interactions. The measured dimuon cross section is in agreement with the photon gluon fusion model at low values of Bjorken x within statistical and systematic errors. At larger values of xBi the data do not support the magnitude of intrinsic charm used to explain hadro-production of charm. Upper limits on the intrinsic charm content of the nucleon are derived from the data.

Results are presented on the ratios of the nucleon structure function in copper to deuterium from two separate experiments. The data confirm that the nucleon structure function,F 2, is different for bound nucleons than for the quasi-free ones in the deuteron. The redistribution in the fraction of the nucleon's momentum carried by quarks is investigated and it is found that the data are compatible with no integral loss of quark momenta due to nuclear effects.

A measurement of the nucleon structure function F2 on iron is presented. The data cover a kinematic range of 3.25 ⪕ Q2 ⪕ 200 GeV2and 0.05 ⪕ x ⪕ 0.65. The data clearly show scaling violation. Fits in leading-order QCD have been made and values for the scale breaking parameter λ are given.

The transverse momenta of charged hadrons produced in high energy muon-proton scattering have been studied. The average squared transverse momentum 〈p2⊥〉 shows a strong dependence on z = Eh/v characteristic of intrinsic momentum effects and a significant rise as a function of s = W2. The W2, q2, x and z dependences of the data are compared with the predictions of a perturbative QCD model.

We present an up-to-date overview of the problem of top quark mass determination. We assess the need for precision in the top mass extraction in the LHC era together with the main theoretical and experimental issues arising in precision top mass determination. We collect and document existing results on top mass determination at hadron colliders and map the prospects for future precision top mass determination at $$e^+e^-$$ colliders. We present a collection of estimates for the ultimate precision of various methods for top quark mass extraction at the LHC.

Exclusive ϱ0 production has been measured in 120, 200 and 280 GeV muon-proton interactions at high Q2 (1 GeV2 < Q2 < 25 GeV2) and W (6 GeV < W < 19 GeV). The photoproduction cross section decreases as 1/Q4. A shallow t distribution, typical of a hard scattering process is observed and the ϱ0 is found to be dominantly in the helicity zero spin state. The ϱ0s are mainly produced by transverse photons and s-channel helicity conservation seems to be invalid. The data cannot be described by the vector meson dominance model. These data show that at high Q2 even exclusive ϱ0 muoproduction is a hard scattering process and that the soft hadron-like properties of the photon have disappeared.

Virtual photoproduction of J/ψ mesons has been measured for 280 GeV muon iron interactions in an iron/scintillator calorimeter target. The J/ψ's were identified by their decay into muon pairs. 315 events were observed, about half of which were elastic. The t, Q2 and v distributions of these elastic events are presented. The v dependence is measured between 40 and 180 Mev and compared with lower energy photoproduction results. The Q2 dependence is compared with the predictions of the vector dominance model.

Motivated by the large particle fluences anticipated for the SSC and LHC, we are performing a systematic study of radiation damage to silicon microstrip detectors. Here we report radiation effects on detectors cooled to 0°C (the proposed operating point for a large SSC silicon tracker) including leakage currents and change in depletion voltage. We also present results on the annealing behavior of the radiation damage. Finally, we report results of charge collection measurements of the damaged detectors made with an 241Am α source.

Results on moments of the azimuthal angle ϕ of final state hadrons from 120 GeV and 280 GeV μp scattering are presented. A ϕ asymmetry is observed and its W2, Q2, z and pT dependences compared with model calculations which include intrinsic transverse momentum and first order QCD corrections. These studies indicate that the observed asymmetry is mainly due to intrinsic transverse momentum kT.

The radiation damage resulting from the large particle fluences predicted at the Superconducting Super Collider induces significant leakage currents in Si detectors. In order to limit these currents, the detectors are operated at reduced temperatures ( approximately 0 degrees C). Results are presented of a study of temperature effects on both the initial radiation damage and the long-term annealing of that damage in Si PIN detectors. Depletion voltage results are reported. The detectors are exposed to approximately 10/sup 14//cm/sup 2/ 650-MeV protons. Very pronounced temperature dependences are observed.< <ETX xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">&gt;</ETX>

Final data measured with the EMC forward spectrometer are presented on the production of forward charged hadrons in μp and μd scattering at incident beam energies between 100 and 280 GeV. The large statistic of 373 000 events allows a study of the semi-inclusive hadron production as a function ofz,p 2 and 〈p 2 〉 in smallQ 2,x Bj andW bins. Charge multiplicity ratios and differences as a function ofz andx Bj are given forp, d andn-targets. From the differences of charge multiplicities the ratio of the valence quark distributions of the protond v (x)/u v (x) is determined for the first time in charged lepton scattering. The Gronau et al. sum rule is tested, the measured sum being 0.31±0.06 stat. ±0.05 syst., compared with the theoretical expectation of 2/7≈0.286. The measured sum corresponds to an absolute value of the ratio of thed andu quark charge of 0.44±0.10 stat.±0.08 syst.

The cross sections for Jψ production have been measured in interactions of 280 GeV μ+ on hydrogen and deuterium (H, D) and also in interactions of 250 GeV μ+ on iron. The single-nucleon cross sections in iron are found to be larger than those in H, D. The mean ratio of the iron to H, D photoproduction cross sections in the range 60 < v < 200 GeV is 1.45 ±0.12 (statistical) ±0.22 (systematic error). Within the framework of the photon-gluon fusion model, this indicates that the gluon density per nucleon is ∼45% larger in iron than in H, D in the range 0.026 < x < 0.085, on a mass scale Q2eff ∼M2Jψ.

The measurements of the z and pT2 distribution of hadrons produced in the interactions of 200 GeV muons with copper and carbon nuclei are shown in different xBj and virtual photon energy intervals. Effects of the jet scattering are seen at the lowest virtual photon energies while for energies above 70 GeV there is no evidence of these effects. Comparison with a theoretical model indicates that at high jet energies the parton fragmentation distance is greater than the nuclear radius and that the parton absorption cross section is less than 10 mb.

This report summarizes the work of the Energy Frontier Top Quark working group of the 2013 Community Summer Study (Snowmass).

The final states of charged hadrons produced in 280 GeV μp scattering are analysed with respect to their planarity and jet structure. Distributions of p⊥2 in and p⊥ out2 are presented. A two jet structure in the forward hemisphere is observed for events with high p⊥ tracks are predicted by QCD models.

The fragmentation functions of u-quarks into positive and negative pions are determined from an analysis of identified pions produced in deep inelastic muon-deuterium scattering. The method adopted is not sensitive to the knowledge of the primary quark distribution functions. The fragmentation of u quarks to positive pions is found to fall less steeply in z than that to negative pions as expected in the quark parton model.

A significant rate of forward proton and antiproton production has been observed in 120 and 280 GeV muon-proton scattering. The z and pT2 distributions are presented. The dependence of the normalized production cross section on the muon variables x and Q2 is studied.

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.

A QCD analysis in leading and next to leading order of the structure function F2 measured in deep inelastic muon nucleon scattering is presented. Taking into account several phenomenological uncertainties, including the gluon description and the charm contribution, fits to the data give values of the QCD scale parameter ΛLO in the range 7-–250 MeV. A consistent description of muon scattering and lower Q2 electron scattering requires the presence of higher twist 1/Q2 contributions to the scale breaking which are then determined as a function of x from the data.

Dimuon production has been observed in 280 GeV μ+ iron interactions. Cross sections are presented for this process in the kinematic regions covered by the apparatus acceptance. The data are compared with calculations from charm production using a photon gluon fusion model and found to be in a good agreement. Contributions from other known processes are found to be relatively small.

Data are presented on exclusive ρ0 and ϕ production in deep inelastic muon scattering from a target consisting mainly of nitrogen. The ratio of the total cross sections for ρ0 and ϕ production is found to be 9∶(1.6±0.4) at 〈Q 2〉=7.5 GeV2, consistent with theSU(3) prediction of 9∶2. Thet dependence for exclusive ρ0 production is found to become shallover asQ 2 increases and, for largeQ 2, thet dependence is typical of that for a hard scattering process. Furthermore, the ratio of the cross sections for coherent: incoherent production from nitrogen is found to decrease rapidly withQ 2. Such behaviour indicates that even for exclusive vector meson production the virtual photon behaves predominantly as an electromagnetic probe.

Two trimuon events of the type μ+N→μ+μ+μ+X and one μ+N→μ+μ−μ−X have been observed in 250 GeV μ+ -iron interactions. The expected rate from the decay of hadrons (charm, π, K) is about one event. Other processes that may contribute are both beauty production and charm production with D0−D0 mixing. The data give upper limits of 12×10−36 cm2 for the cross section of beauty pair production by muons, and 20% for D0↔D0 transitions due to mixing, both at 90% confidence level.

Measurements are presented of the distributions in scaled energy of the hadrons produced in high energy muon scattering. The observed dependence on x (non-factorisation) and Q2 (scaling violation) is similar to that expected from next to leading order QCD calculations. These variations in the data can be equivalently represented by a dependence on the single variable W2.

In 280 GeV μ+ iron interactions the inelastic production of muon pairs has been observed in excess of QED processes. For energies greater than 20 GeV deposited in the target calorimeter the interactions are found to be mainly hadronic. Cross sections are presented for this process in the mass range 1−2.5 GeV/c2 and in the kinematic regions covered by the apparatus acceptance. The data are in good agreement with a photon-gluon fusion model for charmed particle production.

Inclusive ϱ0 meson production has been measured in 120 GeV and 280 GeV muon-proton interactions. Distributions of z and pT2 are presented. Primary ϱ0 production is found to be equal to that of π0 production within errors.

As part of a program to develop a silicon strip central tracking detector system for the Superconducting Super Collider (SSC), the effects of radiation damage in silicon detectors and their associated front-end readout electronics are being studied. The authors report on the results of neutron and proton irradiations at the Los Alamos National Laboratory and gamma -ray irradiations at UC Santa Cruz. Individual components on single-sided AC-coupled silicon strip detectors and on test structures were tested. Circuits fabricated in a radiation-hard CMOS process and individual transistors fabricated using dielectric isolation bipolar technology were also studied. Bulk damage to the silicon itself is seen as the limiting factor in the lifetime of a detector system. In particular, it is the acceptor site creation in the active volume of the silicon detector that will limit the lifetime to approximately 10 yr for the innermost detectors.< <ETX xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">&gt;</ETX>

The ratio R = σLσT of the longitudinal to the tranverse photon absorption cross section has been determined from deep inelastic muon-proton scattering at incident energies of 120, 200 and 280 GeV. The results are given as a function of the variables x, Q2 and ν of the interaction. In the kinematic range 60 ⩽ ν ⩽ 160 GeV at 〈Q2〉 = 22.5 GeV2 an average value of R = 0.00 ± 0.10 has been obtained.

New results on the forward produced protons and antiprotons in high energy muon-nucleon scattering are presented. Their W2, z and p2T dependences are compared with those of the other charged hadrons. Significant differences are observed which can be related to the flavour content of the target and to a difference between the baryon content of quark and gluon jets.

Data are presented on the balance of transverse momenta of final state charged hadrons in 280 GeV muon-proton scattering. In particular the way in which the transverse momentum of either leading particles (z > 0.5) f high pT particles (pT2 > 2 GeV2) is compensated by further hadrons in the forward hemisphere is studied. The results are consistent with a QCD based model. The agreement is achieved by including in the model the emission of soft gluons and assuming that the partons have a distribution of primordial transverse momentum with 〈kT2〉 ⋍ 0.2 GeV2, a value considerably less then found in previous analyses.

▪ Abstract Since the discovery of the bottom quark in 1977, physicists have searched for the top quark, the weak isospin partner of the bottom quark. Indirect evidence and estimates of its mass have been made; however, direct observation eluded scientists until recently. In the spring of 1995, two experiments, CDF and DØ, at Fermi National Accelerator Laboratory showed top-antitop quark pairs created from proton-antiproton collisions. In this report, we summarize the experimental status prior to 1995 and discuss the experiments and techniques that in March of 1995 resulted in discovery of the top quark. Studies of the top quark's properties, such as its mass and production cross section, are just beginning. We present an overview of the current status of these measurements and a perspective on the prospects for the future.

The inclusive yield of photons has been measured from deep inelastic interactions of 200 GeV muons on hydrogen. After subtracting the contributions from hadron electromagnetic decays and Bethe-Heitler muon bremsstrahlung, residual photons are observed at low pT and low z at a mean level of 0.15±0.06 per interaction. The quark Compton scattering process is unable to explain the data, thus indicating an anomalous photon production.

Measurements are presented of the inclusive distributions of theJ/Ψ meson produced by muons of energy 200 GeV from an ammonia target. The gluon distribution of the nucleon has been derived from the data in the range 0.04<x<0.36 using a technique based on the colour singlet model. An arbitrary normalisation factor is required to obtain a reasonable integral of the gluon distribution. Some comments are made on the use ofJ/Ψ productionby virtual photons to extract the gluon distribution at HERA.

Inclusive D0(D0) production in deep inelastic scattering of 280 GeV and 240 GeV muons on hydrogen and deuterium targets has been measured; differential cross sections are given and the total cross sections extrapolated to Q2 = 0. They are compared with the results of photoproduction experiments and with measurements of the muoproduction of charm detected indirectly by multimuon events.

The properties of events having the topology and kinematic features of double Pomeron exchange are described. The data were taken at the CERN $p\overline{p}$ collider at $\sqrt{s}=0.63$ TeV in the UA1 detector. A calorimeter trigger was used to isolate events in which a central cluster of particles was separated from forward particles by large rapidity gaps. The invariant mass $M$ of the central cluster (possibly a colliding Pomeron-Pomeron system) covers the range 10-70 GeV/${\mathit{c}}^{2}$. The $M$ dependence of charged particle multiplicity distributions in these double Pomeron events is strikingly different from their $\sqrt{s}$ dependence in $\mathrm{pp}$ and $p\overline{p}$ interactions.

Dimuon and trimuon events have been studied in deep inelastic muon scattering on an iron target at an incident muon energy of 200 GeV. The events are shown to originate mainly from charm production. Comparison of the measured cross sections with data taken at higher muon energies shows that charm production originates predominantly from transverse virtual photons. Within the framework of the photon gluon fusion model this indicates that the parity of the gluon is odd.

The hadronic distributions inQ 2,y, z, p T and ϕ in deep inelastic muon proton scattering have been studied to search for higher twist effects in the hadronic final state. The expected effects are not observed.

μ+μ− pairs have been observed in deep inelastic muon-nucleon scattering and their masses measured with high resolution. No significant signal was observed at the D0 mass. These data allow an upper limit of 3.4 × 10−4 (90% confidence level) to be placed on the branching ratio for the decay mode D0 → μ+μ−.

Thez andp 2 distributions of π0 mesons produced by the interaction of 200 GeV muons on hydrogen are presented. Comparisons are made with other π0 and charged hadron data and with the predictions of perturbative QCD. The data show a rise of 〈p 2 〉 withW 2 which is consistent with QCD, and withz 2 which requires a contribution from a primordialk T . The fraction of total energy which appears as π0 mesons is 0.27±0.05.

The strong coupling constant ${\ensuremath{\alpha}}_{s}$ has been determined from a study of the reaction $\overline{p}p\ensuremath{\rightarrow}{W}^{\ifmmode\pm\else\textpm\fi{}}X$, $W\ensuremath{\rightarrow}e\ensuremath{\nu}$ at $\sqrt{s}$ of 630 GeV in the UA1 experiment at CERN. The measurement is based upon a study of jet production in association with $W$ bosons. The result obtained is ${\ensuremath{\alpha}}_{s}({M}_{W}^{2})=0.127\ifmmode\pm\else\textpm\fi{}0.026(\mathrm{stat})\ifmmode\pm\else\textpm\fi{}0.034(\mathrm{syst})$.

The yield of wide angle bremsstrahlung photons produced by 120 GeV muons incident on a liquid hydrogen target has been measured in the kinematic range 0.3<y<0.8 and 0.02<x<0.15. These measurements have been compared with the predictions of the standard treatment of radiative corrections and no inconsistencies found in this kinematic range.

A search was made at the CERN SPS for long-lived fractionally charged particles produced in deep inelastic muon interactions on a Be target using the existing muon beam line as a spectrometer. No such particles were found, leading to upper limits for the production cross section of the order of 10−36 cm2 for 200 GeV incident muon momentum and quark masses below 9 GeV for the 23 charge and 15 GeV for 13 charge.

Using a lead glass detector installed in the EMC forward spectrometer radiative photons have been measured in 200 GeV muon-hydrogen collisions. The results are compared with the standard QED one photon emission theory of Mo and Tsai and also with the more recent predictions of a multiphoton emission theory of Chahine. We conclude that there is no evidence for any deviation from the standard theory, in terms of the yield and angular distribution of photons with fractional energy,z>0.7.

A new VME-based high-voltage power supply has been developed for the D0 experiment at Fermilab. There are three types of supplies delivering up to +or-5.6 kV at 1.0 mA or +2.0 kV at 3.0 mA with a set accuracy of 1.5 V and extremely low voltage ripples. Complete computer control has allowed many special features to be developed for the supply, including user-defined control and monitor groups, variable ramp rates, and advanced histogram and graphic functions.< <ETX xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">&gt;</ETX>

The response of nucleons and complex nuclei to an external electromagnetic probe at intermediate and high energy is illustrated by considering both inclusive and semi-inclusive electron scattering. Gauge invariance and current conservation allow one to define form factors for elastic scattering and structure functions for inelastic scattering which contain the relevant information on the structure and dynamics of the target hadron system under investigation. They are derived and discussed in some specific examples, also taking into account polarization observables.

We present preliminary results from tests of uranium-liquid argon calorimeter modules for the D-Zero experiment at Fermilab [1]. Results are given for the electron and hadron response of the first of the production central calorimeter electromagnetic modules and for the final prototype of the end cap calorimeter middle hadronic module. In addition results are presented from a study of doping liquid argon with small quantities of methane.

The energy distribution of inclusive hadrons produced by 280 GeV muons on hydrogen and deuterium targets are compared. The sum of the scaled energy distributions of the positive and negative hadrons is found to be the same for the two targets. The difference of these distributions is observed to factorise inx andz and thez-dependence is found to be independent of the target type and have a form (1−z)2.1±0.2. The net charge of the hadronic jet is positive at highx even in the case when the scattering takes place on the neutron. These results are in good agreement with the expectations of the Quark Parton Model.

We have designed and prototyped a new VME based high voltage system for the D-Zero experiment at Fermilab [1,2]. The power supply and control system are both new designs and combined have more flexibility and dynamic range than anything available on the commercial market.

Summary form only given, as follows. As part of a program to develop silicon central tracking systems for the next generation of high-energy, high-luminosity accelerators such as the Superconducting Super Collider and the Relativistic Heavy Ion Collider, the effects of radiation damage in silicon detectors are being studied in detail. Results on neutron and proton irradiations at Los Alamos National Laboratory and gamma ray irradiations at UC Santa Cruz have been obtained. The devices being tested include both single-sided and double-sided silicon strip detectors, as well as test structures. Results of measurements of leakage current, acceptor state creation, charge trapping, pulse shapes, and changes in interstrip resistance as a function dose and operating temperature have been obtained.< <ETX xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">&gt;</ETX>

Annals of the New York Academy of SciencesVolume 535, Issue 1 p. 29-34 Results on Light Neutrino Counting from the UA1 Collaborationa STEPHEN J. WIMPENNY, STEPHEN J. WIMPENNY Department of Physics University of California Riverside, California 92521Search for more papers by this author STEPHEN J. WIMPENNY, STEPHEN J. WIMPENNY Department of Physics University of California Riverside, California 92521Search for more papers by this author First published: July 1988 https://doi.org/10.1111/j.1749-6632.1988.tb51497.x a This UA1 Collaboration is from CERN, Geneva, Switzerland. AboutPDF ToolsRequest permissionExport citationAdd to favoritesTrack citation ShareShare Give accessShare full text accessShare full-text accessPlease review our Terms and Conditions of Use and check box below to share full-text version of article.I have read and accept the Wiley Online Library Terms and Conditions of UseShareable LinkUse the link below to share a full-text version of this article with your friends and colleagues. Learn more.Copy URL Share a linkShare onEmailFacebookTwitterLinkedInRedditWechat References 1 Albajar, C., et al. UA1 Collaboration. Studies of the properties of WD̊ and Z0 events at the CERN Proton-Antiproton Collider. In preparation; Google Scholar 2 Ibid. 1987. Phys. Lett. 193B: 389; 10.1016/0370-2693(87)91257-3 Web of Science®Google Scholar 3 Arnison, G., et al. UA1 Collaboration. 1986. Europhys. Lett. 1: 327; 10.1209/0295-5075/1/7/002 Google Scholar 4 1986. Phys. Lett. 166B: 484; 10.1016/0370-2693(86)91603-5 Web of Science®Google Scholar 5 1985. Nuovo Cimento Lett. 44: 1. 10.1007/BF02746944 Google Scholar 2 Ansari, R., et al. ua2 collaboration. 1987. Phys. Lett. 186B: 440; 1987. CERN- EP/87–04; 1987. CERN-EP/87-48; 10.1016/0370-2693(87)90324-8 Web of Science®Google Scholar 7 Appel, J. A., et al. UA2 Collaboration. 1986. Z. Phys. C. Part. Fields 30: 1. 10.1007/BF01560673 Web of Science®Google Scholar 3 Albajar, C., et al. UA1 Collaboration. 1987. Phys. Lett. 185B: 241. 10.1016/0370-2693(87)91562-0 Web of Science®Google Scholar 4 Albajar, C., et al. UA1 Collaboration. CERN-EP/87-190. Google Scholar 10 Wingerter, I. 1988. These proceedings. Google Scholar 5 Ma, E. K. & J. Okada. 1978. Phys. Rev. Lett. 41: 287; 10.1103/PhysRevLett.41.287 CASWeb of Science®Google Scholar 12 Gaemers, K. F. J., R. Gastmans & F. M. Renard. 1979. Phys. Rev. D19: 1605. Google Scholar 6 Hearty, C., et al. ASP Collaboration. 1987. Phys. Rev. Lett. 17: 1711; 10.1103/PhysRevLett.58.1711 Web of Science®Google Scholar 14 Bartha, G., et al. ASP Collaboration. 1986. Phys. Rev. Lett. 56: 685; 10.1103/PhysRevLett.56.685 CASPubMedWeb of Science®Google Scholar 15 Ford, W. T., et al. MAC Collaboration. 1986. Phys. Rev. D33: 3472; Google Scholar 16 Behrend, H-J., et al. CELLO Collaboration. 1986. Phys. Lett. B176: 247; 10.1016/0370-2693(86)90958-5 Web of Science®Google Scholar 17 Bartel, W., et al. JADE Collaboration. 1985. Phys. Lett. 152B: 385. 10.1016/0370-2693(85)90516-7 CASWeb of Science®Google Scholar 7 Albajar, C., et al. UA1 Collaboration. 1987. Phys. Lett. B185: 241. 10.1016/0370-2693(87)91562-0 Web of Science®Google Scholar 8 Halzen, F. & K. Mursala. 1983. Phys. Rev. Lett. 51: 857; 10.1103/PhysRevLett.51.857 CASWeb of Science®Google Scholar 20 Hikasa, K. 1984. Phys. Rev. D29: 1939; Google Scholar 21 Deshpande, N. G., et al. 1985. Phys. Rev. Lett. 54: 1757; 10.1103/PhysRevLett.54.1757 CASPubMedWeb of Science®Google Scholar 22 Discus, D. A. & S. Willenbrock. 1986. Phys. Rev. D34: 148; Google Scholar 23 1985. Phys. Rev. Lett. 55: 132. Web of Science®Google Scholar 9 Albajar, C., et al. UA1 Collaboration 1987. CERN-EP/87-149. Google Scholar 10 Diemoz, M., et al. 1987. CERN-TH 4751. Google Scholar 11 Halzen. F., C. S. Kim & S. Willenbrock. 1987. MAD/PH/342. Google Scholar 27 Martin, A. D., R. G. Roberts & W. J. Stirling. 1987. RAL-87-002. Google Scholar 12 Halzen. F. 1987. mad/ph/372 and references contained therein. Google Scholar 13 Aguilar, M., et al. Particle Data Group. 1986. Phys. Lett. 170B: 1. Google Scholar 14 Steigman, G., D. N. Schramm & J. E. Gunn. 1977. Phys. Lett. 66B: 202; 10.1016/0370-2693(77)90176-9 CASWeb of Science®Google Scholar 31 Yang, J., et al. YTSSO. 1984. Astrophys. J. 281: 493; 10.1086/162123 CASWeb of Science®Google Scholar 32 Ellis, J., et al. EENS. 1986. Phys. Lett. 167B: 457; 10.1016/0370-2693(86)91301-8 CASWeb of Science®Google Scholar 33 Steigman, G., et al. SOST. 1986. Phys. Lett. 176B: 33. 10.1016/0370-2693(86)90920-2 Web of Science®Google Scholar Volume535, Issue1International Symposium on Production and Decay of Heavy FlavorsJuly 1988Pages 29-34 ReferencesRelatedInformation

The silicon microstrip detectors that will be used in the SDC experiment at the Superconducting Super Collider (SSC) will be exposed to very large fluences of charged particles, neutrons, and gammas. The authors present a study of how temperature affects the change in the depletion voltage of silicon PIN detectors damaged by radiation. They study the initial radiation damage and the short-term and long-term annealing of that damage as a function of temperature in the range from {minus}10{degrees}C to +50{degrees}C, and as a function of 800 MeV proton fluence up to 1.5 {times} 10{sup 14} p/cm{sup 2}. They express the pronounced temperature dependencies in a simple model in terms of two annealing time constants which depend exponentially on the temperature.