G. Mantovani

We report the results of a search for single isolated electrons of high transverse momentum at the CERN pp collider. Above 15 GeV/c, four events are found having large missing transverse energy along a direction opposite in azimuth to that of the high-pT electron. Both the configuration of the events and their number are consistent with the expectations from the process p+p→W±+anything, with W→e+ν, where W± is the charged Intermediate Vector Boso postulated by the unified electroweak theory.

From a search for electron pairs produced in pp collisions at s = 550 GeV we report the observation of eight events which we interpret as resulting from the process p+p→Z0+ anything, followed by the decay Z0→e++e− or Z0→e++e−+γ, where Z0 is the neutral Intermediate Vector Boson postulated by the unified electroweak theory. We use four of these events to measure the Z0 mass MZ = 91.9 ± 1.3 ± 1.4 (systematic) GeV/c2.

The distribution of total tranverse energy ΣET over the pseudorapidity interval −1 < η < 1 and an azimuthal range Δφ=300° has been measured in the UA2 experiment at the CERN pp collider (s = 540 GeV) using a highly segmented total absorption caloriter. In the events with very large ΣET (ΣET⪆60 GeV) most of the transverse energy is found to be contained in small angular regions as expected for high transverse momentum hadron jets. We discuss the properties of a sample of two-jet events with invariant two-jet masses up to 140 GeVc2 and we measure the cross section for inclusive jet production in the range of jet transverse momenta between 15 and 60 GeVc.

A study has been made of the decays W → ev and Z → e+e−, using the UA2 detector at the CERN p̄p Collider. The data correspond to an integrated luminosity of 142 nb−1 at a centre-of-mass collision energy √s=546 GeV, and 768 nb−1 at √s=630 GeV. Measurements of the standard model parameters from samples of 251 W decay and 39 Z decay candidates are compared with expectations of the standard electroweak model.

This paper addresses the problem of thermal energy control in shopping centers through the application of model predictive control (MPC) strategies. In particular, this paper uses an existing shopping center as pilot case, which is characterized by a large common multifloor space, which, in turn, gives rise to a significant vertical thermal stratification. This paper explores the importance of MPC parameters to energy efficiency and comfort levels. In addition, it addresses some notable extensions, from economic optimization, which paves the way to real-time pricing techniques, to integration with renewables, to robustness enforcement through Kalman filters, to hybrid control with switching signals mixed with continuous signals.

Using a sample of events collected by UA2 and corresponding to an integrated luminosity of 116 nb−1. we have searched for electron-“neutrino” pairs in which the transverse momenta of the electron and of the “neutrino” exceed 15 GeV/c and 25 GeV/c respectively. A total of 35 events are observed in low background conditions. Most events can be interpreted in terms of W± production from QCD processes. Events in which the observation of hard jets makes this interpretation unlikely are described in detail. Possible sources of background contamination are considered.

We present a measurement of the b-quark inclusive fragmentation function in ${Z}^{0}$ decays using a novel kinematic B-hadron energy reconstruction technique. The measurement was performed using 350 000 hadronic ${Z}^{0}$ events recorded in the SLD experiment at SLAC between 1997 and 1998. The small and stable SLC beam spot and the charge-coupled-device--based vertex detector were used to reconstruct B-decay vertices with high efficiency and purity, and to provide precise measurements of the kinematic quantities used in this technique. We measured the B energy with good efficiency and resolution over the full kinematic range. We compared the scaled B-hadron energy distribution with models of b-quark fragmentation and with several ad hoc functional forms. A number of models and functions are excluded by the data. The average scaled energy of weakly decaying B hadrons was measured to be $〈{x}_{b}〉=0.709\ifmmode\pm\else\textpm\fi{}0.003(\mathrm{stat})\ifmmode\pm\else\textpm\fi{}0.003(\mathrm{syst})\ifmmode\pm\else\textpm\fi{}0.002(\mathrm{model}).$

The production of very large transverse momentum (pT) hadron jets has been measured in the UA2 experiment at the CERN pp Collider for s=630 GeV. The inclusive jet production cross sections exhibit a pT-dependent increase with respect to the s=546 GeV data from previous Collider runs. This increase can be described both by QCD calculations and by approximate xT=2pT/√s scaling. No significant deviation of the data from QCD predictions is observed at very large pT, placing a lower limit on the characteristic scale Λc of a hypothetical superstrong contact interaction responsible for the binding of preons in the quark (Λc>370 GeV at 95% CL).

Jet production properties at s = 540 GeV have been measured in the UA2 detector at the CERN pp Collider. Results on the total transverse momentum of the jet system, on the parton density in the nucleon (structure function) and on the two-jet angular distributions are reported. The data are compared with QCD predictions and extrapolations from lower energy experiments.

Transverse momentum distributions of pions, kaons and protons have been measured around 90° in the UA2 detector at the SPS pp collider, at a CM energy of 540 GeV. All the cross sections have increased by more than a factor of 2 over those measured at ISR energies and exhibit a flatter behaviour with respect to transverse momentum.

A study has been made of the production characteristics of W and Z bosons produced at the CERN pp Collider. The event sample consists of 251 W→ev decays, and 39 Z→e+e− decays, identified by the UA2 detector, and corresponds to an integrated luminosity of 142 nb−1 at √s = 546 GeV, and 768 nb−1 at √s = 630 GeV. Measurements of W and Z production cross sections, of longitudinal and transverse momentum distributions, and of associated jet production, are presented. These measurements are compared with theoretical expectations, which include higher order QCD effects.

In view of the possible production of heavy leptons or charmed states in ${e}^{+}{e}^{\ensuremath{-}}$ collisions, we searched for anomalous muons with momenta ${p}_{\ensuremath{\mu}}\ensuremath{\gtrsim}1$ GeV/c. The inclusive cross section for ${n}_{\mathrm{ch}}&gt;~3$ has an upper limit of 96 pb (assuming isotropy). For ${n}_{\mathrm{ch}}=2$ and noncoplanarity &gt; 20\ifmmode^\circ\else\textdegree\fi{}, an excess of muonic events is observed, corresponding to ${(\frac{d\ensuremath{\sigma}}{d\ensuremath{\Omega}})|}_{90\ifmmode^\circ\else\textdegree\fi{}}={23}_{\ensuremath{-}9}^{+12}$ pb/sr; the probability that known processes produce the observed events is 2\ifmmode\times\else\texttimes\fi{}${10}^{\ensuremath{-}4}$.

We present a measurement of the left-right cross-section asymmetry ( A(LR)) for Z boson production by e(+)e(-) collisions. The measurement includes the final data taken with the SLD detector at the SLAC Linear Collider during the period 1996-1998. Using a sample of 383 487 Z decays collected during the 1996-1998 runs we measure the pole value of the asymmetry, A(0)(LR), to be 0.150 56+/-0.002 39 which is equivalent to an effective weak mixing angle of sin (2)straight theta(eff)(W) = 0.231 07+/-0.000 30. Our result for the complete 1992-1998 data set comprising approximately 537 000 Z decays is sin (2)straight theta(eff)(W) = 0.230 97+/-0.000 27.

The production of very large transverse momentum hadron jets has been measured in the UA2 experiment at the CERN pp Collider for s = 540 GeV using a highly segmented calorimeter. The range of previously available cross sections for inclusive jet production is extended to pT = 150 GeV and the two-jet invariant mass distribution to mjj = 280 GeV with the largely increased data sample collected during the 1983 running period. The results are compared with the predictions of QCD models.

The total UA2 data sample at the CERN pp̄ Collider corresponds to an integrated luminosity of 910 nb−1. Limits on various hypothetical processes, such as production of excited electrons, additional charged or neutral vector bosons, or supersymmetric particles, are presented from the analysis of this sample.

Inclusive π0 production has been measured at the CERN pp̄ collider, s=540 GeV, for 90° production angle and in a range of transverse momenta between 1.5 and 4.5 GeV/c. The invariant production cross section is larger than that measured at s= 53 GeV for p-p collisions. The production of μ mesons aand of direct photons is also investigated.

The production and properties of high transverse momentum hadron jets have been measured in the UA2 experiment at the CERN $$\bar pp$$ Collider $$(\sqrt s = 540 GEV)$$ using a highly segmented total absorption calorimeter. The characteristics of a sample of two-jet events with invariant mass up to 200 GeV/c2 are discussed, including measurements of their fragmentation properties, angular and rapidity distributions, and the properties of the additional energy clusters accompanying the two-jet system. Cross sections for inclusive jet production in the jet transverse momentum range between 30 and 100 GeV/c and for the two-jet invariant mass distribution in the mass range from 60–200 GeV/c2 are reported.

We present improved measurements of the differential production rates of stable charged particles in hadronic Z0 decays, and of charged pions, kaons and protons identified over a wide momentum range using the SLD Cherenkov Ring Imaging Detector. In addition to flavor-inclusive Z0 decays, measurements are made for Z0 decays into light (u, d, s), c and b primary flavors, selected using the upgraded Vertex Detector. Large differences between the flavors are observed that are qualitatively consistent with expectations based upon previously measured production and decay properties of heavy hadrons. These results are used to test the predictions of QCD in the Modified Leading Logarithm Approximation, with the ansatz of Local Parton-Hadron Duality, and the predictions of three models of the hadronization process. The light-flavor results provide improved tests of these predictions, as they do not include the contribution of heavy-hadron production and decay; the heavy-flavor results provide complementary model tests. In addition we have compared hadron and antihadron production in light quark (as opposed to antiquark) jets. Differences are observed at high momentum for all three charged hadron species, providing direct probes of leading particle effects, and stringent constraints on models.

Using the UA2 apparatus, the inclusive cross section has been measured for production of high-pT direct photons in p̄p collisions at s=546 GeV and s=630 GeV. The results are in good agreement with QCD predictions.

A study ofW ± andZ 0 properties has been performed using the UA2 detector at the $$\bar pp$$ collider. The data correspond to a total integrated luminosity of 142 nb−1 at $$\sqrt s $$ =546 GeV, and of 310 nb−1 at $$\sqrt s $$ =630 GeV. The experimental results are compared with the predictions of the Standard Model of the unified electroweak theory.

Inclusive particle production cross-sections have been measured at the $$Sp\bar pS$$ collider using the UA2 detector in various ranges of transverse momentum (P T ) and pseudo-rapidity (η). Cross-section measurements are presented forπ 0 production (P T ≦15 GeV/c, |η|≦0.85 andP T ≦40 GeV/c, 1.0≦|η|≦1.8), for η meson production (3≦P T ≦6 GeV/c, |η|≦0.85) and for charged particle production (P T ≦10 GeV/c, 1.0≦|η|≦1.8). Results are compared with the predictions of QCD calculations.

The invariant mass distribution of jet pairs observed in the UA2 central calorimeter is examined in the search for an excess of events in the region of the W± and Z bosons, which would reveal their decays into quark-antiquark pairs. We give a detailed account of the methods of analysis used to optimize the mass resolution achieving ≅±10%. A structure is observed at the level of ≅ 3 standard deviations in the mass region of W± and Z with shape and position consistent with expectation from their qq̄decays. It contains 632 ± 190 events, 1.4 standard deviations above the standard model prediction of 340 ± 80 events.

We present experimental results on proton-deuteron and deuteron-deuteron elastic scattering measured at the two highest ISR energies, √s = 53 GeV and √s = 63 GeV. The data cover the single- and multiple-scattering regions over a wide interval of four-momentum transfer t. In both reactions we find clear evidence for a substantial t-dependent contribution of inelastic intermediate states in the multiple-scattering region, as well as in single scattering. In the analysis we use the Glauber multiple-scattering theory extended to include inelastic shadow effects. This extension of the basic theory contains as input a triple-Regge parametrization describing the high-mass inclusive spectrum. The analysis of inelastic corrections to multiple scattering on deuterons at high energies is shown to provide a sensitive test of different parametrization of inclusive production in proton-proton collisions.

This paper presents an innovative control scheme for the management of energy consumption in commercial buildings with local energy production, such as photovoltaic panels or wind turbine and an energy storage unit. The presented scheme is based on distributed model predictive controllers, which manage the storage system and the building space heating and cooling. The proposed approach is implemented and tested in SYSLAB, the experimental facility for distributed energy systems at the Technical University of Denmark, Risø Campus. The experimental setup consists of wind and solar renewable sources, a vanadium redox battery system, resistive load, and a point of common coupling to the national grid. Several experiments are carried to assess the performance of the control scheme in managing local energy production and consumption.

We present final measurements of the Z boson-lepton coupling asymmetry parameters Ae, Aμ, and Aτ with the complete sample of polarized Z bosons collected by the SLD detector at the SLAC Linear Collider. From the left-right production and decay polar angle asymmetries in leptonic Z decays we measure Ae=0.1544±0.0060, Aμ=0.142±0.015, and Aτ=0.136±0.015. Combined with our left-right asymmetry measured from hadronic decays, we find Ae=0.1516±0.0021. Assuming lepton universality, we obtain a combined effective weak mixing angle of sin2θeffW=0.23098±0.00026.Received 6 October 2000DOI:https://doi.org/10.1103/PhysRevLett.86.1162©2001 American Physical Society

The production of electrons with very high transverse momentum has been studied in the UA2 experiment at the CERN $$\bar pp$$ collider ( $$\sqrt s$$ =540 GeV). From a sample of events containing an electron candidate withp T >15 GeV/c, we extract a clear signal resulting from the production of the charged intermediate vector bosonW ±, which subsequently decays into an electron and a neutrino. We study theW production and decay properties. Further-more, we refine our results on the production and decay of the neutral vector bosonZ 0. Finally, we compare the experimental results to the predictions of the standard model of the unified electro-weak theory.

Fragmentation properties of a sample of two-jet events measured by the UA2 detector at the CERN pp Collider are described. The energy flow is compared with different model predictions. The charged particle multiplicity in jets is found to exceed extrapolations from lower energy e+e− jet data.

The UA2 experiment, running at the CERN SPS $$\bar pp$$ Collider, has performed a study of events containing three hard jets in the final state. The angular distributions of the three jets show evidence for gluon bremsstrahlung, in good agreement with a QCD model to leading order in the strong coupling constant αs. The yield of three-jet events relative to that of two-jet events provides a measure of the strong coupling constant: ;3 K 3/K 2=0.23±0.01±0.04, whereK 2 andK 3 represent the contributions arising from higher order corrections in α3 to the two- and three-jet exclusive cross-sections. A detailed discussion of the systematic and theoretical uncertainties is given.

A measurement of the direct production of photons with high transverse momentum from $$\bar pp$$ collisions at $$\sqrt s = 630$$ GeV is presented. The structure of events containing a high transverse momentum photon is studied. The results support predictions from QCD theory.

Neutron diffraction dissociation has been measured at the ISR in proton-neutron interactions at 37 GeV c.m. energy. The data were taken with the Split Field Magnet detector, during a short deuteron storage test run with colliding p-d beams. Differential mass and momentum transfer distributions are reported; the value of the total cross-section shows a weak s-dependence when compared to lower energy data.

Interstrip and backplane capacitances on silicon microstrip detectors with p+ strip on n substrate of 320μm thickness were measured for pitches between 60 and 240μm and width over pitch ratios between 0.13 and 0.5. Parametrisations of capacitance w.r.t. pitch and width were compared with data. The detectors were measured before and after being irradiated to a fluence of 4×1014protons/cm2 of 24GeV/c momentum. The effect of the crystal orientation of the silicon has been found to have a relevant influence on the surface radiation damage, favouring the choice of a 〈100〉 substrate. Working at high bias (up to 500 V in CMS) might be critical for the stability of detector, for a small width over pitch ratio. The influence of having a metal strip larger than the p+ implant has been studied and found to enhance the stability.

We report on experimental results on deuteron-deuteron elastic scattering at a centre-of-mass energy of √s = 53 GeV. The data were obtained using the Split Field Magnet detector at the CERN intersecting Storage Rings. The t-dependence of the elastic cross section is measured up to − = 1.5 GeV2. We observed a narrow interference minimum in the differential cross section at − = 0.18 GeV2. The inclusion of inelastic intermeduate states in the multiple scattering Glauber theory is essential in the description of the data over the entire t-range where discrepancies of up to 25% are observed with the basic theory.

A heuristic model is used to describe data collected by the UA2 experiment at √s = 630 GeV. Distributions of the energy sharing between the leading clusters and the rest of the event are examined. The main features of these distributions can be described by a two-component model with soft, collective interactions dominating at low transverse energy and hard, constituent interactions dominating at high transverse energy. This model provides a simple picture of the emergence of two-jet dominance at SPS pp Collider energies.

The UA2 experiment at the CERN pp Collider has identified a total sample of 251 W→eν events. Among this sample 221 events are found without jets and 29 with one jet. The yield of one-jet events relative to that of zero-jet events provides a measurement of the strong coupling constant: αs(Mw2)=0.13±0.03(stat)±0.03±(syst1)±0.02(syst2), where syst1 represents the experimental systematic error and syst2 is an estimate of the theoretical uncertainty.

This paper presents an innovative solution based on distributed model predictive controllers to integrate the control and management of energy consumption, energy storage, PV and wind generation at customer side. The overall goal is to enable an advanced prosumer to auto-produce part of the energy he needs with renewable sources and, at the same time, to optimally exploit the thermal and electrical storages, to trade off its comfort requirements with different pricing schemes (including real-time pricing), and apply optimal control techniques rather than sub-optimal heuristics.

We present the first direct measurement of A(s), the parity-violating coupling of the Z0 boson to the strange quark, using approximately 550 000 e(+)e(-)-->Z0-->hadrons events recorded by the SLC Large Detector with a polarized e(-) beam. We tagged Z0-->s&smacr; events by the absence of B or D hadrons and the presence in each hemisphere of a high momentum K+/- or K(0)(s). Fitting the polar angle distributions of the strangeness-signed thrust axis gave A(s) = 0.895+/-0.066(stat)+/-0.062(syst). The analyzing power and uu+d&dmacr; background were constrained using the data, greatly reducing any model dependence.

Abstract A large hadron calorimeter and muon tracking device using plastic streamer tubes has been constructed in the iron flux-return structure for the SLD detector at SLAC. Various studies of the operating characteristics of the streamer tubes of this system are presented. Emphasis is placed on the tracking capabilities of the device and on the optimization of the high voltage and readout electronics.

We analyze the energy density distribution in harronic final states as a function of their total transverse energy measured in the segmented central calorimeter of the UA2 detector. The energy dependence of collective shape variables is investigated. The data, collected at the CERN $$\bar p$$ p Collider at $$\sqrt s = 630$$ GeV, exhibit strong variations in all these variables over the transverse energy range between 15 and 210 GeV, corresponding to substantial modifications in the structure of multihadronic final states. The evolution of the energy density distribution and of the collective shape variables shows a clear transition between two extreme dynamical regimes, respectively dominated byp T -limited phase space and by collimated two-jet configurations. A study of the relative populations of two-and three-jet systems reveals two different sources of configurations having three distinct lobes in the pattern of the energy-flow. A first component, steeply falling with energy, receives substantial contributions from soft parton collisions at lower transverse energies. Above 60 GeV a new hard component emerges, characterized by an approximately constant rate with respect to the dominant two-jet structures.

In the paper, the modeling, control and energy management of a large-commercial building is presented. This study is finalized to improving the building energy performances through an extensive use of automation and control strategies. Shown results demonstrate the effectiveness of such techniques, leading to the research of further solutions to decrease energy consumptions in large buildings.

The iron flux-return structure for the SLC Large Detector (SLD) has been instrumented with plastic streamer tubes covering an area of about 4500 m2, to provide muon identification plus energy measurement of hadron showers. A description is given of the production techniques used to construct this large detector system, with an emphasis on the methods by which high reliability and a small number of defects in the completed assembly were ensured.

We present results from a study of high-momentum inclusive hadron production in electron-positron interactions at $\sqrt{s}=3.8 \mathrm{and} 4.8$ GeV. Comparison of the momentum spectra at these energies shows no scaling violation in the region $x(=\frac{E}{{E}_{\mathrm{beam}}})&gt;0.7$. At $\sqrt{s}=4.8$ GeV the $\frac{K}{\ensuremath{\pi}}$ ratio for hadrons with momenta &gt;1.1 GeV/c is 0.27\ifmmode\pm\else\textpm\fi{}0.08, and the average number of charged hadrons is 3.6\ifmmode\pm\else\textpm\fi{}0.3 for those events which have at least one charged hadron with momentum greater than 1.1 GeV/c.

The system of multiplane drift chambers for the forward-backward toroidal spectrometers of the UA2 experiment at the SPS pp̄ collider is described. Details about mechanical design and construction techniques are given. Results on the performance of the chambers are reported.

The parity violation parameters A(b) and A(c) of the Zb(b) and Zc(c) couplings have been measured directly, using the polar angle dependence of the polarized cross sections at the Z(0) pole. Bottom and charmed hadrons were tagged via their semileptonic decays. Both the electron and muon analyses take advantage of new multivariate techniques to increase the analyzing power. Based on the 1993-1998 SLD sample of 550,000 Z(0) decays produced with highly polarized electron beams, we measure A(b) = 0.919+/-0.030(stat)+/-0.024(syst), and A(c) = 0.583+/-0.055(stat)+/-0.055(syst).

Final results from combined measurements of single and double diffraction of protons neutrons into (Nπ) and (Nππ) final states are presented. The experiments were performed at the CERN Intersecting Storage Rings with the Split Field Magnet detector using proton and deuteron colliding beams. The general properties of the dissociating vertex in single and double diffractive reactions are essentially identical. Mass spectra and decay angular distributions are compared with the predictions of a dual resonant Deck model. Decay angular correlations and a strong slope-mass correlation are observed also in double diffraction. Detailed tests of factorization indicate its validity over the full range of all kinematical variables and in their correlations. A model-independent analysis gives strong support to the peripheral nature of diffraction dissociation, with double diffraction being concentrated in a narrow gaussian ring at the edge of the proton. Both the exclusive and the inclusive double diffractive cross sections display a marked increase over the ISR energy range. Both mechanisms yield comparable contributions to the peripheral increase of the total pp cross section, with an approximate saturation of the Pumplin bound.

We report the results of two beam tests performed in July and September 1995 at CERN using silicon microstrip detectors of various types: single sided, double sided with small angle stereo strips, double sided with orthogonal strips, double sided with pads. For the read-out electronics use was made of Preshape32, Premux128 and VA1 chips. The signal to noise ratio and the resolution of the detectors was studied for different incident angles of the incoming particles and for different values of the detector bias voltage. The goal of these tests was to check and improve the performances of the prototypes for the CMS Central Detector.

detected with the split-field magnet (SFM) facil i ty at the CERN intersecting storage rings at e.m.s, energies between 23 and 53 GeV. The apparatus, tr igger and procedure of analysis are described in greater detai l in another paper (1). The experiment is a imed at s tudying double-diffraction dissociation in reaction (1). In this paper we analyse the propert ies of the mass spectra of the two (p7:+7: -) systems and we present evidence for double ~ * production. The phase-space region populated by our events and the kinematical selections applied identify two (pT:+~:-) systems separated by a large rap id i ty gap and produoed at small values of the four-momentum transfer. In addition, the energy dependence of the to ta l cross-section for reaction (1) and the propert ies of the differential crosssections as measured in this experiment (1.3) s trongly support the diffractive nature of the double-dissociation events of our sample.

We present the analysis of a combined measurement of neutron and proton diffraction dissociation into (Nπ) and (Nππ) final states, both on proton and deuteron targets. The experiment was performed at the CERN Intersecting Storage Rings with the Split Field Magnet detector using proton and deuteron colliding beams. Mass spectra and decay angular distributions are compared with the predictions of a dual-reggeized Deck model. Strong decay angular correlations are observed in all cases. Pronounced structures observed in the differential cross sections of the coherent diffractive processes for small produced masses are interpreted in terms of constructive interference between the single- and double-scattering terms in a Glauber analysis. These interference effects cannot be reproduced by a central dissociation mechanism and require a peripheral description of the elementary nucleon-nucleon diffractive production amplitudes.

We report a search for B s 0 -B s 0 ¯oscillations using a sample of 400 000 hadronic Z 0 decays collected by the SLD experiment.The analysis takes advantage of the electron beam polarization as well as information from the hemisphere opposite that of the reconstructed B decay to tag the B production flavor.The excellent PHYSICAL REVIEW D 67, 012006 ͑2003͒

We have measured gluon splitting into bottom quarks, g→bb̄, in hadronic Z0 decays collected by SLD between 1996 and 1998. The analysis was performed by looking for secondary bottom production in 4-jet events of any primary flavor. 4-jet events were identified, and in each event a topological vertex-mass technique was applied to the two jets closest in angle in order to identify them as b or b̄ jets. The upgraded CCD-based vertex detector gives very high B-tagging efficiency, especially for B hadrons with the low energies typical of this process. We measured the rate of g→bb̄ production per hadronic event, gbb̄, to be (2.44±0.59(stat.)±0.34(syst.))×10−3.

Neutron-neutron interactions have been observed at the CERN ISR with deutron colliding beams. The double - diffraction dissociation process →(pπp−)(pπ−) has been measured with the Split Field Magnet at √s = 26 GeV detecting all final state particles, including the two spectator protons. Mass and t distributions are presented and compared with corresponding spectra observed in single neutron diffraction in the same energy range with supporting evidence for factorization. The cross-section of the process is 11.5±2.8 μb and can be directly related to the corresponding value for double diffraction dissociation of protons in the same energy range.

Results on exclusive double diffraction dissociation in (Nπ) and (Nππ) final states are reported for neutron-neutron interactions at √s= 26.4 GeV and for the proton-neutron interactions at √s= 37.2 GeV. The data have been obtained at the CERN intersecting storage rings using split field magnet detector with proton-deuteron and deuteron-deuteron colliding beams. Factorization is shown to be verified to a very high degree in both mass- and t-differential cross-sections. The data confirm the previously observed rise in the proton-proton double diffractive cross-section as a function of c.m. energy.

We measure the hadronic branching ratios of the Z0 boson into heavy quarks: Rb=ΓZ0→bb¯/ΓZ0→hadrons and Rc=ΓZ0→cc¯/ΓZ0→hadrons using a multitag technique. The measurement was performed using about 400 000 hadronic Z0 events recorded in the SLC Large Detector experiment at SLAC between 1996 and 1998. The small and stable SLAC Linear Collider beam spot and the CCD-based vertex detector were used to reconstruct bottom and charm hadron decay vertices with high efficiency and purity, which enables us to measure most efficiencies from data. We obtain, Rb=0.21604±0.00098(stat.)±0.00073(syst.)∓0.00012(Rc) and, Rc=0.1744±0.0031(stat.)±0.0020(syst.)∓0.0006(Rb).1 MoreReceived 18 May 2005DOI:https://doi.org/10.1103/PhysRevD.71.112004©2005 American Physical Society

This paper describes the main features of the proposed low energy solar neutrino detector Borexino, planned to be installed at the Gran Sasso Laboratory. This real time detector is based on a massive, calorimetric, liquid scintillation spectroscopy technique, whose high luminosity is the base for the attempt to achieve a low signal detection threshold. After a description of the main structural components of the detector, of its performances in term of spatial and energy resolution, and of the neutrino reactions occurring in the liquid scintillator, a description of the crucial background topic is given. Finally the main implications of the physics program of the experiment are briefly illustrated.

Abstract The gas mixtures presently used in plastic limited streamer tubes (“Iarocci tubes” or LSTs) have a high hydrocarbon content and are very flammable when mixed with air, posing a potential safety hazard in modern large underground experiments. The SLD Warm Iron Calorimeter group has therefore made an extensive investigation of nonflammable ternary mixtures based on CO 2 . Ar and various hydrocarbons. We present here brief results of this research. In particular, we describe a detailed study of a nonflammable gas mixture (2.5% Ar: 9.5% iC 4 H 10 : 88% CO 2 ) which indicates that this mixture has properties comparable to those of the two commonly used gases (25% Ar: 75% iC 4 H 10 and 21% Ar: 37% nC 5 H 12 : 42% CO 2 ) and could successfully replace these mixtures in LST-based tracking devices and hadron calorimeters.

We present results obtained with full-size wedge silicon microstrip detectors bonded to APV6 (Raymond et al., Proceedings of the 3rd Workshop on Electronics for LHC Experiments, CERN/LHCC/97-60) readout chips. We used two identical modules, each consisting of two crystals bonded together. One module was irradiated with 1.7×1014neutrons/cm2. The detectors have been characterized both in the laboratory and by exposing them to a beam of minimum ionizing particles. The results obtained are a good starting point for the evaluation of the performance of the “ensemble” detector plus readout chip in a version very similar to the final production one. We detected the signal from minimum ionizing particles with a signal-to-noise ratio ranging from 9.3 for the irradiated detector up to 20.5 for the non-irradiated detector, provided the parameters of the readout chips are carefully tuned.

We present a direct measurement of the parity-violation parameter A c in the coupling of the Z 0 to c quarks with the SLD detector.The measurement is based on a sample of 530 k hadronic Z 0 decays, produced with a mean electron-beam polarization of ͉P e ͉ϭ73%.The tagging of c-quark events is performed using two methods: the exclusive reconstruction of D* ϩ , D ϩ , and D 0 mesons, and the soft pions ( s ) produced in the decay PHYSICAL REVIEW D, VOLUME 63, 032005

We report on a search for relativistic particles with fractional electric charge at the CERN pp colider, using a telescope of scintillation counters to detect particles with anomalously low ionization. Since no event survives the selection criteria, upper limits on quark production are deduced from this experiment. At 90% confidence level and in the limit of very light quarks with charge ±12 and ±23 they are 2.8×10−6 and 5.6×10−5, respectively, per single charged particle. These limits increase rapidly with increasing quark mass and are nearly two and one order of magnitude better than previously measured by UA2.

We present the results of a systematic analysis of charge-exchange double dissociation in proton-proton collisions at the CERN Intersecting Storage Rings. The data, obtained with the Split-Field Magnet detector, cover the entire ISR energy range between s = 23 GeV and s = 63 GeV at five standard energies. Double resonance production is observed in the Δ++Δ0 and Δ++N0(1688) final states. The mass spectra of the pπ− system show more pronounced resonant signals in the backward Jackson hemisphere. A detailed analysis of differential cross sections shows a forward peak typical of absorbed pion exchange decreasing as s−1.81±0.06, followed by a much gentler exponential behaviour associated with a trajectory typical of ϱ-A2 exchange. The high-energy transition to this regime is also indicated by a dramatic change in the s-dependence of total cross sections as compared with low-energy data. Power-law fits in the form sn for all three (pπ+)(pπ−), Δ++Δ0, and Δ++N0(1688) channels reach an s−1 behaviour with exponents n = −1.03 ± 0.01, −0.94 ± 0.01, and n = −1.04 ± 0.01, respectively.

A search for Bs0-Bs0bar oscillations is performed using a sample of 400,000 hadronic Z0 decays collected by the SLD experiment. The Bs0 candidates are reconstructed in the Bs0 to Ds-,X channel with Ds- to phi,pi- or K*0K-. The Bs0 production flavor is determined using the large forward-backward asymmetry of polarized Z0 to b,bbar decays and charge information in the hemisphere opposite that of the Bs0 candidate. The decay flavor is tagged by the charge of the Ds+/-. From a sample of 361 candidates with an average Bs0 purity of 40%, we exclude the following values of the oscillation frequency: Delta m_s < 1.4 ps^{-1} and 2.4 < Delta m_s < 5.3 ps^{-1} at the 95% confidence level.

Exploiting the manipulation of the SLAC Linear Collider electron-beam polarization, we present precise direct measurements of the parity-violation parameters ${A}_{c}$ and ${A}_{b}$ in the $Z$-boson--$c$-quark and $Z$-boson--$b$-quark coupling. Quark-antiquark discrimination is accomplished via a unique algorithm that takes advantage of the precise SLAC Large Detector charge coupled device vertex detector, employing the net charge of displaced vertices as well as the charge of kaons that emanate from those vertices. From the 1996--1998 sample of 400 000 $Z$ decays, produced with an average beam polarization of 73.4%, we find ${A}_{c}=0.673\ifmmode\pm\else\textpm\fi{}0.029(\mathrm{s}\mathrm{t}\mathrm{a}\mathrm{t})\ifmmode\pm\else\textpm\fi{}0.023(\mathrm{s}\mathrm{y}\mathrm{s}\mathrm{t})$ and ${A}_{b}=0.919\ifmmode\pm\else\textpm\fi{}0.018(\mathrm{s}\mathrm{t}\mathrm{a}\mathrm{t})\ifmmode\pm\else\textpm\fi{}0.017(\mathrm{s}\mathrm{y}\mathrm{s}\mathrm{t})$.

A proposal for a pixel-based Level 1 trigger for the Super-LHC is presented. The trigger is based on fast track reconstruction using the full pixel granularity exploiting a readout which connects different layers in specific trigger towers. The trigger will implement the current CMS high level trigger functionality in a novel concept of intelligent detector. A possible layout is discussed and implications on data links are evaluated.

The paper focuses on the problem of methods and tools to assist the specification generation, proposal generation and design of automated production systems. The solutions adopted use meta-modeling techniques, web services, hierarchical models, and mechatronic model of plant components integrating four different views of the systems, namely mechanical, electrical, hydro-pneumatic and control ones. For the specification, also the implementation is here discussed, which is based on distributed databases to store the models, and web services and interfaces to remotely access and modify them.

An upgrade of the L3 central tracking system, a silicon muvertex detector (SMD), is described. The detector consists of two layers of silicon, each equipped for rφ and z readout with resolution ≈ 6 μm and ≈ 20 μm respectively. The SMD will provide full azimuthal coverage over the polar angular range 22°≤θ≤158°. The total thickness is ≈0.9% of one radiation length.

This paper describes the main achievements in the development of radiation resistant silicon detectors to be used in the CMS tracker. After a general description of the basic requirements for the operation of large semiconductor systems in the LHC environment, the issue of radiation resistance is discussed in detail. Advantages and disadvantages of the different technological options are presented for comparison. Laboratory measurements and test beam data are used to check the performance of several series of prototypes fabricated by different companies. The expected performance of the final detector modules are presented together with preliminary test beam results on system prototypes.

We present the beam test results of single-sided silicon microstrip detectors, with different substrate resistivities. The effects of radiation damage are studied for a detector irradiated to a fluence of 2.4×1014n/cm2. The detectors are read out with the APV6 chip, which is compatible with the 40MHz LHC clock. The performance of different detectors and readout modes are studied in terms of signal-to-noise ratio and efficiency.

A search for relativistic particles with fractional electric charge has been performed at the CERN pp collider using a telescope of scintillation counters to detect particles with abnormally low ionisation. The thickness of the detector (∼40 gr cm−2) limits this search to particles without strong absorption in matter. No evidence for such particles has been found. This negative result is used to set an upper limit for the ratio of quark yield to that of particles with unit electric charge. For quark masses below 2 GeV/c2 the 90% confidence level upper limits range from 2 × 10−4 to 2.5 × 10−3 depending on the quark mass and elect́ric charge.

We have measured the charge-exchange reaction pp → (pπ+) (pπ−) at s = 23, 31, 45, 53, and 63 GeV at the ISR, using the Split Field Magnet detector. The data are characterized by a sharp forward peak of width 0.02 (GeV/c)2, followed by a much gentler slope at higher |t|; sizeable Δ++, Δ0, and N0 production is observed in the (Nπ) mass spectra. Two different components are present in the data following power-law energy dependence of the type plab−n with n1 = −1.63 ± 0.13 and n2 = −0.96 ± 0.07, respectively, indicating the onset of mechanisms in competition with pion exchange at ISR energies.

We report results on a new measurement of the double diffractive reaction pp → (pπ+π−) (pπ+π−) at the ISR obtained with the Split Field Magnet detector. Experimental procedures and data analysis are discussed in detail. The cross section measured at the five standard ISR energies exhibits an increase of (55 ± 7)% in the s-range from 549 to 3892 GeV2.

The CMS experiment at the LHC will comprise a large silicon strip tracker. This article highlights some of the results obtained in the R&D studies for the optimization of its silicon sensors. Measurements of the capacitances and of the high voltage stability of the devices are presented before and after irradiation to the dose expected after the full lifetime of the tracker.

We present an improved direct measurement of the parity-violation parameter A(b) in the Z boson-b-quark coupling using a self-calibrating track-charge technique applied to a sample enriched in Z-->bb events via the topological reconstruction of the B hadron mass. Manipulation of the Stanford Linear Collider electron-beam polarization permits the measurement of A(b) to be made independently of other Z-pole coupling parameters. From the 1996-1998 sample of 400,000 hadronic Z decays, produced with an average beam polarization of 73.4%, we find A(b)=0.906+/-0.022(stat)+/-0.023(syst).

In this paper the problem of energy efficiency in large commercial buildings is analyzed. In particular, after the introduction of the thermal model with vertical temperature stratification of an existing centre, temperature control schemes are applied with decoupling and feed-forward techniques. It is shown that it is possible to reduce significantly energy consumption and at the same time improve the user's comfort. Finally, the paper highlights also the convenience of introducing some structural changes in the energy distribution plants inside the building.

A somewhat unusual diffusion cloud chamber is described, constructed in order to carry out a general investigation of the photoreactions on 3He.

Abstract We have studied the characteristics of CF 4 -based nonflammable gas mixtures for plastic streamer tubes. For various combinations of CF 4 + hydrocarbon and CF 4 + hydrocarbon + Ar we measured the singles counting rate plateau, the charge spectrum and the average drift time over the cell. The hydrocarbons used were respectively isobutane, n-pentane and n-hexane. The stability of these mixtures is good, and their spurious streamer activity is compared with the standard binary or ternary mixture. The drift velocity is at least twice as high as in the standard mixtures.

From an integrated luminosity of ∫Ldt = 116 nb-1, 10events are found which contain an electron pair of mass in the range 12 < Mee < 26 GeVc2 and electron transverse momenta pTe > 5 GeVc. THe sample are described, as well as some featruyres of the The production characteristics of this sample are described, as well as some features of the estimated to be 2.2±0.6 events. The production characteristics of this sample are described, as well as some features of the associated event topology. Comparisons are made with the expectations for such electron pair production from the Drell-Yan mechanism and from the semi-leptonic decay of heavy flavours.

The CMS Silicon tracker consists of 70m2 of microstrip sensors which design will be finalized at the end of 1999 on the basis of systematic studies of device characteristics as function of the most important parameters. A fundamental constraint comes from the fact that the detector has to be operated in a very hostile radiation environment with full efficiency. We present an overview of the current results and prospects for converging on a final set of parameters for the silicon tracker sensors.

New experimental data on the reaction $\ensuremath{\gamma}+^{4}\mathrm{He}\ensuremath{\rightarrow}{\ensuremath{\pi}}^{+}+n+t$ are presented, which extend the preliminary results already published by the authors. They confirm the characteristic features of the previous ones, for which the existence of a $^{4}\mathrm{H}$ state unstable against dissociation could be a likely explanation.

For the construction of the silicon microstrip detectors for the Tracker of the CMS experiment, two different substrate choices were investigated: A high-resistivity (6 k cm) substrate with (111) crystalorientation and a low-resistivity (2k cm) one with (100) crystalorientation. The interstrip and backplane capacitances were measured before and after the exposure to radiation in a range of strip pitches from 60 μm to 240 μm and for values of the width-over-pitch ratio between 0.1 and 0.5.

Abstract A large quantity of silicon microstrip detectors is foreseen to be used as part of the CMS tracker. A specific research and development program has been carried out with the aim of defining layouts and technological solutions suitable for the use of silicon detectors in high radiation environment. Results presented here summarise this work on many research areas such as techniques for device manufacturing, pre- and post-irradiation electrical characterization, silicon bulk defects analysis and simulations, system performance analytical calculations and simulations and test beam analysis. As a result of this work we have chosen to use single-sided, AC-coupled, poly silicon biased, 300 μm thick, p + on n substrate detectors. We feel confident that these devices will match the required performances for the CMS tracker provided they can be operated at bias voltages as high as 500 V. Such high-voltage devices have been succesfully manufactured and we are now concentrating our efforts in enhancing yield and reliability.

The breakdown performance of CMS barrelmodule prototype detectors and test devices with single and multi-guard structures were studied before and after neutron irradiation up to 2·1014 1 MeV equivalent neutrons. Before irradiation avalanche breakdown occurred at the guard ring implant edges. We measured 100–300 V higher breakdown voltage values for the devices with multi-guard than for devices with single-guard ring. After irradiation and type inversion the breakdown was smoother than before irradiation and the breakdown voltage value increased to 500–600 V for most of the devices.

Abstract This paper presents the design, implementation and test of hardware in the loop simulation architecture for integration of Smart Buildings and distributed energy resources in Micro Grids. The rationale for this work is the integration of off-the-shelves devices in a HIL simulation setup within software development. The architecture and preliminary results are presented, together with a case study for integrating flexible units, such as a space heating system and Electric Vehicles in a Smart Building equipped with local solar energy production.

Il presente lavoro di tesi mira a studiare il problema del controllo dell’energia termica in grandi edifici commerciali caratterizzati da ampi spazi aperti, all’interno dei quali si trovano diverse zone termiche controllate separatamente. In particolare il lavoro di ricerca studia come sia possibile utilizzare tecniche di controllo model-based avanzate al fine di ridurre i consumi energetici degli edifici e migliorare il comfort termico in termini di stratificazione verticale della temperatura. Vengono utilizzati appropriati modelli a “grey-box”, tarati sulla base di informazioni fisiche e di utilizzo dell’edificio (parte “white-box”) o attraverso misurazioni e rilevazioni sul campo (parte “black-box”). Il modello multi-zona ottenuto e sufficientemente dettagliato per riprodurre tutte le dinamiche rilevanti ai fini della determinazione del comfort interno e dei consumi energetici, ma allo stesso tempo semplice abbastanza da essere utilizzato per la taratura di controllori dell’energia. Nello specifico viene utilizzata un’architettura di controllo basata su Model Predictive Control (MPC), ottenendo interessanti passi in avanti rispetto allo stato dell’arte, tra cui una formalizzazione matematica sistematica e riproducibile per far fronte alle dinamiche non lineari degli attuatori termici nei sistemi di riscaldamento, raffrescamento e ventilazione (in inglese Heating, Ventilation and Air Conditioning, HVAC) che caratterizzano edifici di grandi dimensioni. Il sistema dimostra inoltre un notevole grado di robustezza, che gli permette di lavorare in condizioni operative incerte, modificando e caratterizzando i carichi in funzione dello specifico contesto di utilizzo e di condizioni ambientali. L’architettura descritta si presta ad un ulteriore passo in avanti verso l’integrazione degli smart building in uno scenario piu complesso che integra altri attori di diverso tipo. In particolare, il lavoro di tesi estende il controllo del singolo edificio al controllo della microrete (in inglese microgrid) che include l’edificio stesso, fonti di generazione rinnovabile distribuite (fotovoltaico ed eolico) e una batteria per l’immagazzinamento di energia elettrica. E stata svolta un’analisi di dettaglio del sistema, seguita da attivita di modellazione, simulazione in modo da ottenere un controllo ottimo dell’intero sistema che minimizza il costo energetico complessivo, tenendo conto dei disturbi causati dalle reali condizioni di lavoro, della non predicibilita delle rinnovabili e delle perdite di energia relazionate all’uso della batteria. L’architettura di controllo distribuita che gestisce la microrete e in grado di perseguire obiettivi differenti a seconda di come sono tarati i parametri. Infine, l’architettura e stata validata e testata in modo estensivo ed approfondito su una microrete esistente, equipaggiata con una batteria al vanadio, pannelli fotovoltaici e turbine eoliche, provandone la fattibilita per l’implementazione nelle microreti del futuro.

Experimental results are reported on single and double π photoproduction on 3He up to Eγ = 800 MeV. The cross sections per equivalent quantum, total cross sections as a function of the photon energy and angular distributions are given, In the double charged photoproduction channel the Pπ+ and Pπ− invariant mass distributions are presented and compared with the predictions of an isobaric model assuming the impulse approximation. There is also evidence for π+π+ photoproduction in analogy with π+π+ and π−π− production on 4He seen in a previous experiment. The data seem generally consistent with the available theoretical predictions based on the impulse approximation.

This paper describes the Silicon microstrip Tracker of the CMS experiment at LHC. It consists of a barrel part with 5 layers and two endcaps with 10 disks each. About 10 000 single-sided equivalent modules have to be built, each one carrying two daisy-chained silicon detectors and their front-end electronics. Back-to-back modules are used to read-out the radial coordinate. The tracker will be operated in an environment kept at a temperature of T=−10°C to minimize the Si sensors radiation damage. Heavily irradiated detectors will be safely operated due to the high-voltage capability of the sensors. Full-size mechanical prototypes have been built to check the system aspects before starting the construction.