Jean-Pierre Merlo

We have searched for νμ oscillations by comparing the rates of νgm charged-current interactions in two detectors located 130 and 885 m from the target, which was struck by a 9.2 GeV/c proton beam from the CERN Proton Synchroton. No evidence for νμ oscillations was found. At the 90% confidence level, Δm2 values between 0.26 and 90 eV2 are excluded for maximal mixing. The most restrictive limit on the neutrino mixing-angle parameter sin22θ is 0.053 at Δm2=2.5 eV2.

A high-statistics measurement of the differential cross-sections for neutrino-iron scattering in the wide-band neutrino beam at the CERN SPS is presented. Nucleon structure functions are extracted and theirQ 2 evolution is compared with the predictions of quantum chromodynamics.

We present results on charged current inclusive neutrino and antineutrino scattering in the neutrino energy range 30–200 GeV. The results include a) total cross-sections; b)y distributions; c) structure functions; and d) scaling violations observed in the structure functions. The results, as well as their comparison with the results of electron and muon inclusive scattering, are in agreement with the expectations of the quark parton model and QCD.

A large sample of opposite-sign dimuons, produced by the interaction of neutrinos and antineutrinos in iron, is analysed. The data agree very well with the hypothesis that the extra muon is the product of charm decay. They yield information on the strength and space-time structure of the charmproducing weak current. The strange-sea structure functionxs(x) is determined. The difference between neutrino and antineutrino dimuon production is analysed to provide a value of the Kobayashi-Maskawa weak mixing angleθ 2.

The ratio ${R}_{\ensuremath{\nu}}$ of the neutral- to charged-current cross sections of neutrinos in iron has been measured in an exposure of the CERN-Dortmund-Heidelberg-Saclay neutrino detector to a 160-GeV/c neutrino narrow-band beam at the CERN Super Proton Synchrotron. The result is ${R}_{\ensuremath{\nu}}=0.3072\ifmmode\pm\else\textpm\fi{}0.0025(\mathrm{stat})\ifmmode\pm\else\textpm\fi{}0.0020(\mathrm{syst})$, for hadronic energy greater than 10 GeV. The electroweak mixing parameter is ${sin}^{2}{\ensuremath{\theta}}_{W}=0.225\ifmmode\pm\else\textpm\fi{}0.005(\mathrm{expt})\ifmmode\pm\else\textpm\fi{}0.003(\mathrm{theor})+0.013({m}_{c}\ensuremath{-}1.5 \frac{\mathrm{GeV}}{{c}^{2}})$, where ${m}_{c}$ is the charm-quark mass.

The energy resolution and response of a segmented iron-scintillator total absorption calorimeter has been measured for pion energies from 10 to 140 GeV and for electron energies up to 50 GeV. A procedure has been found to weight individual counter responses for hadron showers which results in improved energy resolution at high energies and a nearly linear dependence of response on hadron energy above 30 GeV. There is evidence in the data that this weighting procedure compensates for fluctuations in energy deposition due to the electromagnetic component of the hadronic shower. For an iron sampling thickness of 2.5 cm the hadron energy resolution follows a 0.58E law, while the resolution for electromagnetic showers is 0.23E.

Inclusive charged-current interactions of high-energy neutrinos and antineutrinos have been studied with high statistics in a counter experiment at the CERN Super Proton Synchrotron. The energy dependence of the total cross-sections, the longitudinal structure function, and the nucleon structure functionsF 2,xF 3, and $$\bar q^{\bar v} $$ are determined from these data. The analysis of theQ 2-dependence of the structure functions is used to test quantum chromodynamics, to determine the scale parameter Λ and the gluon distribution in the nucleon.

The CDHS neutrino detector has been used to measure events originating in a tank of liquid hydrogen and in the iron of the detector. Total cross-sections, differential cross-sections, and structure functions are given for hydrogen and compared with those in iron. The measurements are in agreement with the expectations of the quark parton model. No significant differences indicative of nuclear binding effects in corresponding structure functions of protons and iron are observed. This may be of special interest in the case of the sea structure functions, since large differences are expected in some models.

The structure functions F2(x, Q2) and xF3(x, Q2) measured in high-energy neutrino charged-current interactions on nuclei are compared with QCD predictions. Solutions to the moment equations of QCD are found which are in good agreement with the data and yield simple parametrisations of the structure functions. For the scale parameter Λ we find Λ = 0.5 ± 0.2 GeV. The analysis also results in values for the width of the gluon distribution as a function of Q2. We find 〈x〉gluons = 0.16 ± 0.03 for Q2 = 10 GeV2.

The helicity amplitudes are determined at 6 GeVc, for both isospin I=0 and I=1 states in the crossed channel. The analysis is extended to the interval from t=0 to t=−1.0 (GeV/c)2. At 16 GeVc, the number of independent experiments is still insufficient. Only the amplitudes for I=0 exchange are calculated, in the interval from t=0 to t=−0.5 (GeVc2.

In the standard minimal low-energy supersymmetric model, superpartners are produced only in pairs and the lightest superpartner is stable. At hadron colliders missing transverse energy is the most important signature for this model. There are two other minimal supersymmetric models: one has lepton-number violation, the other baryon-number violation. In both models superpartners can be singly produced and the lightest superpartner is unstable. At hadron colliders missing transverse energy is a poor signature for these models. However, there are several important signatures. The most spectacular signatures have two charged leptons without jets. There are also events with two or more isolated charged leptons and jets. Superpartner masses may be reconstructed from combinations of lepton-lepton or lepton-jet invariant masses and from jet spectroscopy. Cross sections are presented for the most important single and pair superparticle production mechanisms in p-p\ifmmode\bar\else\textasciimacron\fi{} collisions. Present limits from CERN collider data are given and a variety of signatures, events, and backgrounds at \ensuremath{\surd}s =2 TeV are discussed. For example, Drell-Yan fusion of a single superpartner gives a bump in the cross section for ${\mathit{e}}^{+}$${\mathit{e}}^{\mathrm{\ensuremath{-}}}$ pairs or jet pairs with invariant mass at the superpartner mass. Squark pair production could yield events with two jets and two isolated charged leptons. If the lightest superpartner is long lived, it can give rise to secondary vertices or to signatures in stable-particle searches. A run of 10 ${\mathrm{pb}}^{\mathrm{\ensuremath{-}}1}$ at \ensuremath{\surd}s =2 TeV will enable a large region of the parameter space to be explored.

The final results from the WA 1/2 neutrino experiment in the 1984 CERN 160 GeV narrow band beam are presented. The ratiosR ν and $$R_{\bar v} $$ of neutral to charged current interaction rates of neutrinos and antineutrinos in iron are measured to beR ν=0.3072±0.0033 and $$R_{\bar v} $$ =0.382±0.016. A value of the electroweak parameter sin2 θ w = 1 −m 2 /m 2 is extracted fromR ν. The result is sin2 θ w =0.228+0.013(m c −1.5)±0.0003 (theor.) wherem c is the mass of the charmed quark in GeV form t =60 GeV,M H =100 GeV, ρ=1. CombiningR ν and $$R_{\bar v} $$ one obtains a value for ρ=0.991+0.023(m c −1.5)±0.020(exp.). Alternatively,R ν and $$R_{\bar v} $$ yield a precise value of the ratio of intermediate vector boson massesm W /m Z =0.880−0.007(m c −1.5)±0.002(exp.)±0.002(theor.). Comparison of these results with those from direct measurements of the vector boson masses are presented. In a model-independent analysis the left- and right-handed neutral current coupling constants,g 2 andg 2 , are determined.

The observed scaling violations of the nucleon structure functionF 2 and $$\bar q$$ have been analysed in the framework of perturbative QCD to determine the shape and magnitude of the gluon distribution. The data are in good agreement with leading order QCD, and the simultaneous use ofF 2 and $$\bar q$$ structure functions permits, for the first time, a reliable determination of the gluon structure function.

We present moments (both ordinary and Nachtmann) of the nucleon valence structure function measured in high Q2νFE scattering, supplemented by data from deep inelastic eD scattering. These data seem to agree with QCD predictions for vector gluons. The QCD parameter Λ is found to be of the order 0.5 GeV.

The polarization parameter P has been measured for elastic π+p, K+p and pp scattering at 45 GeV/c. Four-momentum transfer ranges from −0.08 to −1.1 (GeV/)2 for pp, and from −0.08 to −0.9 (GeV/)2 for π+p and K+p. The energy dependence of the polarization P(t) in π+p and in K+p above 6 GeV/c incident momentum is compatible with interference between pomeron and Regge poles. On the other hand, the polarization in p p elastic scattering decreases faster than ordinary Regge model predictions. This result can be explained by interference between non flip and flip amplitudes of the pomeron, leading to negative values for the polarization.

The spin rotation parameter R has been measured at CERN, for π±p at 6 GeVc and for π−p at 16 GeVc, with t ranging from −0.19 to −0.51 (GeVc)2. The parameter A was measured for π−p at 6 GeVc in the interval between t=−0.19 and minus;0.41 (GeVc)2. The averaged values are the following; R(+6)=−0.08±0.04, R(−6)=−0.23±0.05 and R(−16)=−0.23±0.05. The values obtained for A are close to +1.

A significant intermittency signal is observed in 630 GeV pp collisions measured in the UA1 central detector. It occurs with similar magnitude in different variables: pseudorapidity, rapidity and azimuthal angle. The signal increases with decreasing charged particle multiplicity in the event. Its strength in a sample of low p⊥ tracks and its multiplicity dependence are not reproduced by commonly used Monte Carlo models of high energy interactions.

Neutrino and antineutrino total charged current cross sections on iron were measured in the 100, 160, and 200 GeV narrow band beams at the CERN SPS in the energy range 10 to 200 GeV. Assuming σ/E to be constant, the values corrected for non-isoscalarity are σv/E = (0.686 ± 0.019) * 10−38 cm2/ (GeV · nucleon) and σv/E = (0.339 ± 0.010) * 10−38 cm2/ (GeV·nucleon). Between 50 and 150 GeV no energy dependence of σ/E was observed within ±3% for neutrino and ±4% for antineutrino interactions.

We report on a search for the decays B0→ μ+μ−, B→ μ+ μ−X and Bd0 → μ+ μ−K0∗, which are expected to be rare if mediated by flavor changing neutral currents. Using data collected during the 1984–1989 CERN pp̄ Collider runs, the UA1 search was carried out using μ+ μ− events with 3.9<Mμμ < 5.5 GeV/c2. We find 90% confidence level upper limits on the branching for BR → μ+μ− of 8.3 × 10−6, for B → μ+μ−X of 5.0 × 10−5, and for B0d→μ+μ−K0∗ of of 2.3 × 10−5. Implicatitions for upper limits on the t-quark mass are discussed.

We report final results on the polarization parameter P in elastic scattering of π−, K− and antiprotons at 40 GeV/c incident momentum. The energy dependence of P(t) in π−p above 10 GeV/c is well fitted by P(t) α sαR(t)-αP(t) where αR(t) are the effective Regge and Pomeron trajectories respectively. The data in K−p are compatible with exchange degeneracy. The results inp¯p show an important structure for |t|> 0.3 (GeV/c)2 demonstrating the existence of a large helicity flip amplitude.

A systematic investigation of the properties of cerium fluoride monocrystals has been performed by the “Crystal Clear” collaboration in view of a p

290 events of the type νFe→μ−μ−X and 53 events from the reaction νFe→μ+μ+X withEν>30GeV and muon momenta pμ>6.5GeV/c have been observed in the CDHS detector. After subtracting the background from charged-current processes with one π or K meson of the hadronic shower decaying into μ−ν(or μ+μ), we obtain for neutrinos a rate of prompt like- sign dimuon production of (3.4±1.8)×10−5 relative to the rate of charged-current events with the same cuts, or (4.1 ± 2.2)% relative to the prompt μ−μ+ rate, and for antineutrinos the corresponding relative rates (4.3±2.3)×10−5 and (4.2 ± 2.3)%. A possible explanation for the events is charm pair production at a level of 10−3 relative to all charged-current reactions.

The differential cross sections for elastic π−p, K−p, pp and π+p, pp scattering at 39 and 44.5 GeV/c, respectively, have been measured in the interval of momentum transfer squared 0.15 ≤ ovbt| ≤ 2 (GeV/c)2.

We present the results of beam tests with high-energy (8–375 GeV) electrons, pions, protons and muons of a sampling calorimeter based on the detection of Cherenkov light produced by shower particles. The detector, a prototype for the very forward calorimeters in the CMS experiment, consists of thin quartz fibers embedded in a copper matrix. Results are given on the light yield of this device, on its energy resolution for electron and hadron detection, and on the signal uniformity and linearity. The signal generation mechanism gives this type of detector unique properties, especially for the detection of hadron showers: narrow, shallow shower profiles and extremely fast signals. These specific properties were measured in detail. The implications for measurements in the high-rate, high-radiation Large Hadron Collider (LHC) environment are discussed.

We investigated the darkening of two high OH- content quartz fibres irradiated with 24 GeV protons at the Cern PS facility IRRAD. The two tested fibres have a 0.6 mm quartz core diameter, one with hard plastic cladding (qp) and the other with quartz cladding (qq). These fibres were exposed at about 1.25 Grad in 3 weeks. The fibres became opaque below 380 nm and in the range 580–650 nm. The darkening under irradiation and damage recovery after irradiation as a function of dose and time are similar to what we observed with electrons. The typical attenuation at 455 nm are 1.44±0.22 and 2.20±0.15dB/m at 100 Mrad for qp and qq fibres, respectively. The maximum damage recovery is also observed near this wavelength.

Most designs of inertial confinement fusion (ICF) targets require ablators in the form of hollow spherical shells with an outer diameter of ∼1−3 mm and a wall thickness of ∼20−200 microns. Vapor deposition onto rolling spherical substrates (templates) is the generally preferred method for the fabrication of ICF ablators. Amorphous boron carbide (B4C) is a promising material for use as an ablator due to its favorable properties. However, the challenge lies in creating ultrathick B4C coatings with submicron-scale density uniformity on rolling spherical substrates. Here, we show examples from our ongoing systematic study of the deposition of B4C onto 2-mm-diameter Si spheres by radio-frequency magnetron sputtering (RFMS). We start with a RFMS recipe developed for depositing planar amorphous B4C films with close-to-zero residual stress and transfer the deposition process from stationary planar substrates to rolling spherical substrates. A major challenge of the deposition onto rolling spheres is preventing the formation of so-called nodular defects, attributed to the incorporation of particulates into the growing film. To address this challenge, we explore ways to minimize the generation and accumulation of particulates on the substrate holder by a combination of enhanced film adhesion to the substrate holder surface and removal of particulates from the holder area where spherical substrates are rolling. With this approach, we demonstrate the deposition of an ∼75-micron-thick B4C coating on a Si sphere.

Sputter deposition of ultrathick (≈20μm) Au–Ta alloy coatings on sphero-cylindrical substrates is key for the fabrication of hohlraums for magnetically assisted inertial confinement fusion. Here, we study the deposition of AuTa4 alloy coatings onto rotating substrates. We use high-power impulse magnetron sputtering (HiPIMS) in a constant peak target voltage mode. Results show that the target erosion state has a strong impact on the dominant crystallographic phase, microstructure, surface morphology, and electrical resistivity of AuTa4 films. This is due to effects of changes in the confining magnetic field with target erosion on the HiPIMS discharge characteristics and the sputter source output. We quantify these effects via plasma diagnostics and discuss the optimization of HiPIMS deposition of ultrathick films for cases when target erosion effects dominate film properties.

We present the results of experimental studies of hadron showers in a copper/quartz-fiber calorimeter, based on the detection of Cherenkov light. These studies show that there are very significant differences between the signals from protons and pions at the same energies. In the energy range between 200 and 375 GeV, where these studies were performed, the calorimeter's response to protons was typically 10% smaller than the response to pions. On the other hand, the energy resolution was about 25% better for protons. In addition, the protons had a Gaussian line shape, whereas the pion response curve was asymmetric. These differences can be understood from the requirements of baryon number conservation in the shower development. They are expected to be present in any non-compensating calorimeter, to a degree determined by the e/h value.

We investigated the darkening of nine high OH− fibre types irradiated with 500MeV electrons from the Linac Injector of LEP (LIL) at CERN. The transmission of Xe light was measured in situ in the 350–800nm range. The induced attenuation at 450nm is typically 1.52±0.15dB/m for a 100Mrad absorbed dose. Two-parameter fits for darkening and recovery are presented. After irradiation the tensile strength remains essentially unchanged. For Polymicro quartz core fibres the tensile strength is typically 4.6±0.4GPa.

Right handed weak quark currents coupled to the usual left handed weak lepton current would be seen in inclusive antineutrino scattering on nuclei as a contribution at largey with the quark (not antiquark) structure function. We do not see such a term, and can therefore put an upper limit on the relative strengths of such right handed currents: $$\varrho ^2 = \frac{{\sigma _R }}{{\sigma _L }}< 0.009$$ , 90% confidence. This measurement puts limits on the mixing angle of left-right symmetric models. In distinction to similar limits derived from muon decay or β decay, our limits are also valid if the right handed neutrino is heavy.

In the interactions of 400 GeV/c protons with copper nuclei, a flux of prompt neutrinos is observed. The reactions produced by these neutrinos in our apparatus appear consistent with those of electron- and muon-neutrinos. The prompt neutrino fluxes are interpreted as being due to associated production and subsequent semileptonic decay of charmed hadrons. The prompt flux ratio $$\bar v_\mu /v_\mu = 0.46_{ - 0.16}^{ + 0.21} $$ suggests a sizeable production of charmed baryons near the forward direction. The ratio of prompte −+e + toµ −+µ + event rates is 0.64 −0.15 +0.22 , where unity is expected frome-μ universality.

The spin rotation parameter R has been measured for elastic π−p scattering at 40 GeV/c, at four momentum transfers t ranging from −0.19 to −0.52 (GeV/c)2. The average value within this interval is Rπ−p = -0.200± 0.023. The resulting constraints on the πN scattering amplitudes are discussed. The experiments also yields an average value for K−p scattering, RK−p scattering, RK−p = -0.16±0.16.

A new measurement of the ratio R = σL/σT of longitudinal and transverse structure functions in neutrino interactions on iron between 30 and 190 GeV neutrino energy is reported. The result is given as a function of the scale parameter x and the inelasticity ν of the interaction. The average value is R = 0.10 ± 0.07 around ν ≈ 50 GeV and is in accordance with a prediction from the QCD theory.

Abstract The main parts of an apparatus for simultaneous measurements of the polarization and spin-rotation parameters in high-energy elastic scattering on polarized protons are described, including the beam design, the polarized target, detectors, fast electronics, and the data acquisition. Measurements have been performed in 1972 to 1974 at the Serpukhov accelerator with π − , K − and p of 40 GeV/ c , and with p, π + and K + of 45 Ge V / c incident momentum. In addition to the results for P and R , the experiment also yields information on the unpolarized differential cross section.

Abstract The spin rotation parameter R in elastic proton-proton scattering has been determined at incident momenta 6 and 16 GeV/ c in the interval from t = −0.18 (GeV/ c ) 2 to −0.54 (GeV/ c ) 2 . R pp at 16 GeV/ c is close to the val obtained for R in π − p elastic scattering at the same incident momentum. Equality of R pp ( s , t ) and R π p ( s , t ) is expected if Pomeron exchange dominates and if factorization holds. The t -dependence of R at 16 GeV/ c is consistent with weak helicity flip.

The polarization P in proton-proton elastic scattering has been measured at 3.83 GeV/c for 0.35 ⩽ |t| ⩽ 3.0 (GeV/c)2, i.e. 29° ⩽ θc.m. ⩽ 93°. The polarization shows a minimum at − ⋍ 1.0 (GeV/c)2 followed by a maximum at −⋍1.5 (GeV/c)2. At the same energy the spin rotation parameter R has been measured in the interval 0.18 ⩽ |t| ⩽ 0.57 (GeV/c)2. Comparison with the results at 6.0 and 15.75 GeV/c shows a similar t-dependence and the same average value at all three energies.

Measurements of spin-rotation parameters allow a complete determination of the pion-nucleon scattering amplitudes when the differential cross-section and the polarization normal to the scattering plane are known. This requires to scatter pions off a proton target that is polarized along a direction in the scattering plane, and to analyze the polarization of the recoil protons in a carbon plate polarimeter. Scintillation counter hodoscopes associated with fast logic allow the spark chambers of the polarimeter to be triggered mainly on elastic scatterings off the free protons in the target.

The spin rotation sf R in pp and π+p elastic scattering at 45 GeV/c has been measured at the Seppukhov accelarator, for z.sfnc;t|; ranging from 0.2 to 0.5 (GeV/)2. The results are presented, together with previous R measurements at lower energies. The equality of the values for R in proton-proton and pion-proton scattering, within the experimental errors, is a test of factorization of the residues in the pomeron exchange.

Experimental evidence for the diffractive production ofΨmesons in weak neutral current reactions is reported. The spectrum-averaged cross section for this process isσdiff = (4.2±1.5) × 10−41cm2/nucleon, in agreement with gluonfusion models, but at variance with vector dominance calculations.

From exposures of the CDHS detector at the CERN SPS we have obtained 367μ + μ − events in neutrino beams and 73μ + μ + events in an antineutrino beam. The magnitude of a prompt like-sign signal has been controversial in the past and moreover could not be explained by known production mechanisms. A critical discussion of the experimental situation is given. We have tried to reduce the systematic uncertainties of previous experiments and to get more information on the dependence of the signal with energy and the muon momentum cut-off. This experiment yields a signal of 2.8σ (2.4σ) of prompt like-sign dimuon events in the case of neutrinos (antineutrinos). The rate to charged current events is of the order of 10−4 forp μ<9GeV andE>100 GeV. The prompt signal has all the properties expected from the production and decay of charm-anticharm events. The magnitude, however, is substantially higher then the prediction of perturbative QCD but lower than some other experiments.

Due to an expected increase in radiation damage under super-LHC conditions, we propose to substitute the scintillator tiles in the original design of the hadronic endcap (HE) calorimeter with quartz plates. Quartz is proved to be radiation hard by the radiation damage tests with electron, proton, neutron and gamma beams. Using wavelength shifting fibers, it is possible to collect efficiently the Cherenkov light generated in quartz plates. This paper summarizes the results from various test beams, bench tests, and Geant4 simulations done on methods of collecting light from quartz plates, as well as radiation hardness tests on quartz material.

We report our first measurements of the polarization in the elastic scattering of negative pions from polarized protons at an incident pion momentum of 40 GeV/c. The momentum-transfer region covered was 0.08 < |t| < 1.3 (GeV/c)2. The angular distribution of the polarization exhibits a first minimum of ∼ − 5% and the well-known zero around t ≈ − 0.6 (GeV/c)2. The energy variation of the first minimum (at around t = − 0.2) may be expressed in a simple form, Pavr= −(0.48±0.06) s −0.52±0.05.

We have measured the rate of D∗± meson production inside the jets produced in pp collisions at √s = 630 GeV. For jets in the transverse energy range 15<ET<60 GeV we find a production rate of 0.10±0.04±0.03 D∗± per jet, which is in good agreement with perturbative QCD calculations. In addition, we find that the D∗± fragmentation distribution is strongly peaked towards low z consistent with gluon splitting as the dominant production mechanism.

The first pre-production-prototype (PPP-I) of the quartz fibre calorimeter of the CMS detector has been tested at CERN. The calorimeter consists of quartz fibres embedded in an iron matrix. Results are presented on the energy resolution and on the signal uniformity of the prototype for electrons and pions and the signal uniformity and linearity.

The longitudinal and lateral shower profiles for 500MeV electrons in iron are studied using dosimetry and activation techniques. The results are compared with Monte Carlo simulations and other previously published data. The agreement between the data and the EGS4 simulation results is good; a simple shower profile parametrization of type kzα−1exp(−βz) does not represent the experimental data well at and around the shower maximum. The differences observed in the activation and dose profiles clearly show the role of photons in electromagnetic showers. The photon fraction increases as the shower develops deeper and they carry a larger energy fraction farther into the absorber. Photodisintegration reactions are responsible for the activation of the iron and we identified Mn54,Fe53 and Mn56 as more active isotopes among several others. These studies were performed for estimating the dose and its profile for the CMS quartz fiber calorimeter radiation damage work performed at LIL (CERN).

Abstract Eight μ + μ + μ − events have been observed in the CDHS detector during the 330 GeV and 350 GeV antineutrino wide-band beam exposures at CERN. The corresponding average trimuon rate relative to the single-muon rate is (1.8 ± 0.6) × 10 −5 for visible energy ⩾ 30 GeV and muon momenta ⩾ 4.5 GeV c . Some characteristics of these antineutrino trimuon events are compared with μ − μ − μ + events produced by neutrinos.

The experiments at the Large Hadron Collider (LHC) will have to deal with unprecedented radiation levels. In the large-rapidity regions, close to the beam pipe, these levels reach megagrays per year. The detectors to be installed in these regions, the HF Calorimeters, are designed to operate under these conditions. In this paper, we describe the results of studies in which a prototype calorimeter was exposed to radiation of the type and intensity expected at the LHC. These studies made it possible to estimate the effects of this radiation on the response and the resolution of the calorimeter as a function of time during LHC operation.

Abstract The helicity amplitudes for isospin-0 exchange are determined at 40 GeV/ c . For isospin-1 exchange only partial information is obtained. The model-independent analysis is extended to the four-momentum transfer interval from t = 0 to t = −0.6 (GeV/ c ) 2 . One of the two solutions presented has a behaviour similar to the previous results at lower energy.

A calorimeter with optical quartz fibers embedded into an absorber matrix was proposed for the small angle region of the CMS detector at LHC (CERN). This type of calorimeter is expected to be radiation hard and to produce extremely fast signal. Some results from beam tests of the quartz fiber calorimeter prototype are presented.

A study of a possible layout of a Silicon tracker has been done. The design is based on simulations done in the context of the Compact Muon Solenoid (CMS) detector for the LHC. The high granularity of the silicon strip detectors yields to low occupancies. New type of a silicon strip detector, single sided stereo angle detector (SSSD), has been designed to match the requirements of a LHC tracker. This detector allows a z-coordinate measurement without increasing the number of channels i.e. power consumption and it facilitates a tracker design with reasonable complicity.

Tests of quartz fiber prototypes, based on the detection of Cherenkov light from showering particles, demonstrate a detector possessing all of the desirable characteristics for a forward calorimeter. A prototype for the CMS experiment consists of 0.3 mm diameter fibers embedded in a copper matrix. The response to high energy (10–375 GeV) electrons, pions, protons and muons, the light yield, energy and position resolutions, and signal uniformity and linearity, are discussed. The signal generation mechanism gives this type of detector unique properties, especially for the detection of hadronic showers: Narrow, shallow shower profiles, hermeticity and extremely feast signals. The implications for measurements in the high-rate, high-radiation LHC environment are discussed.

The design, construction and operation of a five-layer silicon microstrip detector is described. The detector consisted of silicon microstrip wafers bonded to the RAL Microplex MX2 readout chip. The readout chip provided amplification with double-correlated sampling for each microstrip channel and multiplexing of 128 signals. The circuitry controlling the chip, the readout electronics, the stage holding the microstrip wafers and their alignment, are also described. A single-layer resolution of 10±0.6 μm was obtained in a test beam. This work is part of a program to design a microvertex detector for UA1 at the CERN pp collider.

CMS very forward calorimeter is based on a quartz fibre technology. The calorimeter prototype composed of two longitudinal segments was tested at CERN in 1996. We present the test beam data analysis of this prototype. It was shown that the mean values of responses for pions and electrons of the same energy could be equalised using the appropriate ratio of calibration constants for longitudinal segments. The beam test data were used to simulate the calorimeter response to hadron jets.

We present test-beam data analysis of a quartzfibre calorimeter prototype composed of a single active section with a passive absorber in front of it. The partial suppression of the electromagnetic showers leads to the equalization of the response to electrons and pions for a given depth of this passive section. Results are compared with the Monte-Carlo expectations.

Two HF calorimeters are in the range 3 < 1111 <5 of CMS detector, made up of iron and quartz fibers assembled in towers red out by PMT's. Cherenkov light is produced in fibers by secondary electrons of showering particles. Accumulated luminosity decreases the light coming from fibers. A raddam device monitors this loss and is used to conect energies. Since 2010, 29 tb· 1 were accumulated and Raddam runs were taken in beam stops. The raddam data are compared to our light transmission measurements of inadiated fibers. A FLUKA simulation of dose at 14 TeV for a luminosity accumulated of3000 fb. 1 is presented.

Memorial Volume for Jack Steinberger, pp. 95-99 (2022) No AccessQCD ANALYSIS OF CHARGED-CURRENT STRUCTURE FUNCTIONSJ.G.H. de GROOT, T. HANSL, M. HOLDER, J. KNOBLOCH, J. MAY, H.P. PAAR, P. PALAZZI, A. PARA, F. RANJARD, D. SCHLATTER, J. STEINBERGER, H. SUTER, W. von RÜDEN, H. WAHL, S. WHITAKER, E.G.H. WILLIAMS, F. EISELE, K. KLEINKNECHT, H. LIERL, G. SPAHN, H.J. WILLUTZKI, W. DORTH, F. DYDAK, C. GEWENIGER, V. HEPP, K. TITTEL, J. WOTSCHACK, P. BLOCH, B. DEVAUX, S. LOUCATOS, J. MAILLARD, J.P. MERLO, B. PEYAUD, J. RANDER, A. SAVOY-NAVARRO, R. TURLAY, and F.L. NAVARRIAJ.G.H. de GROOTCERN, Geneva, Switzerland, T. HANSLCERN, Geneva, Switzerland, M. HOLDERCERN, Geneva, Switzerland, J. KNOBLOCHCERN, Geneva, Switzerland, J. MAYCERN, Geneva, Switzerland, H.P. PAARCERN, Geneva, Switzerland, P. PALAZZICERN, Geneva, Switzerland, A. PARACERN, Geneva, Switzerland, F. RANJARDCERN, Geneva, Switzerland, D. SCHLATTERCERN, Geneva, Switzerland, J. STEINBERGERCERN, Geneva, Switzerland, H. SUTERCERN, Geneva, Switzerland, W. von RÜDENCERN, Geneva, Switzerland, H. WAHLCERN, Geneva, Switzerland, S. WHITAKERCERN, Geneva, Switzerland, E.G.H. WILLIAMSCERN, Geneva, Switzerland, F. EISELEInstitut für Physik der Universität, Dortmund, Germany, K. KLEINKNECHTInstitut für Physik der Universität, Dortmund, Germany, H. LIERLInstitut für Physik der Universität, Dortmund, Germany, G. SPAHNInstitut für Physik der Universität, Dortmund, Germany, H.J. WILLUTZKIInstitut für Physik der Universität, Dortmund, Germany, W. DORTHInstitut für Hochenergiephysik der Universität Heidelberg, Germany, F. DYDAKInstitut für Hochenergiephysik der Universität Heidelberg, Germany, C. GEWENIGERInstitut für Hochenergiephysik der Universität Heidelberg, Germany, V. HEPPInstitut für Hochenergiephysik der Universität Heidelberg, Germany, K. TITTELInstitut für Hochenergiephysik der Universität Heidelberg, Germany, J. WOTSCHACKInstitut für Hochenergiephysik der Universität Heidelberg, Germany, P. BLOCHD.Ph.P.E., CEN-Saclay, France, B. DEVAUXD.Ph.P.E., CEN-Saclay, France, S. LOUCATOSD.Ph.P.E., CEN-Saclay, France, J. MAILLARDD.Ph.P.E., CEN-Saclay, France, J.P. MERLOD.Ph.P.E., CEN-Saclay, France, B. PEYAUDD.Ph.P.E., CEN-Saclay, France, J. RANDERD.Ph.P.E., CEN-Saclay, France, A. SAVOY-NAVARROD.Ph.P.E., CEN-Saclay, France, R. TURLAYD.Ph.P.E., CEN-Saclay, France, and F.L. NAVARRIAIstituto di Fisica dell'Università, Bologna, Italyhttps://doi.org/10.1142/9789811264436_0018Cited by:0 (Source: Crossref) PreviousNext AboutSectionsPDF/EPUB ToolsAdd to favoritesDownload CitationsTrack CitationsRecommend to Library ShareShare onFacebookTwitterLinked InRedditEmail Abstract: The structure functions F2(x, Q2) and xF3(x, Q2) measured in high-energy neutrino charged-current interactions on nuclei are compared with QCD predictions. Solutions to the moment equations of QCD are found which are in good agreement with the data and yield simple parametrisations of the structure functions. For the scale parameter Λ we find Λ = 0.5 + 0.2 GeV. The analysis also results in values for the width of the gluon distribution as a function of Q2. We find (x)gluons = 0.16 ± 0.03 for Q2 = 10 GeV2. Reprinted from Physics Letters B, Vol. 82, J.G.H. de Groot et al., QCD analysis of charged-current structure functions, pp. 456–460, Copyright (1979), with permission from Elsevier. FiguresReferencesRelatedDetails Recommended Memorial Volume for Jack SteinbergerMetrics History PDF download