Showing papers by "Cristina Riccardi published in 2007"
TL;DR: In this article, the authors present a detailed analysis of the performance of the Large Hadron Collider (CMS) at 14 TeV and compare it with the state-of-the-art analytical tools.
Abstract: CMS is a general purpose experiment, designed to study the physics of pp collisions at 14 TeV at the Large Hadron Collider (LHC). It currently involves more than 2000 physicists from more than 150 institutes and 37 countries. The LHC will provide extraordinary opportunities for particle physics based on its unprecedented collision energy and luminosity when it begins operation in 2007. The principal aim of this report is to present the strategy of CMS to explore the rich physics programme offered by the LHC. This volume demonstrates the physics capability of the CMS experiment. The prime goals of CMS are to explore physics at the TeV scale and to study the mechanism of electroweak symmetry breaking--through the discovery of the Higgs particle or otherwise. To carry out this task, CMS must be prepared to search for new particles, such as the Higgs boson or supersymmetric partners of the Standard Model particles, from the start-up of the LHC since new physics at the TeV scale may manifest itself with modest data samples of the order of a few fb−1 or less. The analysis tools that have been developed are applied to study in great detail and with all the methodology of performing an analysis on CMS data specific benchmark processes upon which to gauge the performance of CMS. These processes cover several Higgs boson decay channels, the production and decay of new particles such as Z' and supersymmetric particles, Bs production and processes in heavy ion collisions. The simulation of these benchmark processes includes subtle effects such as possible detector miscalibration and misalignment. Besides these benchmark processes, the physics reach of CMS is studied for a large number of signatures arising in the Standard Model and also in theories beyond the Standard Model for integrated luminosities ranging from 1 fb−1 to 30 fb−1. The Standard Model processes include QCD, B-physics, diffraction, detailed studies of the top quark properties, and electroweak physics topics such as the W and Z0 boson properties. The production and decay of the Higgs particle is studied for many observable decays, and the precision with which the Higgs boson properties can be derived is determined. About ten different supersymmetry benchmark points are analysed using full simulation. The CMS discovery reach is evaluated in the SUSY parameter space covering a large variety of decay signatures. Furthermore, the discovery reach for a plethora of alternative models for new physics is explored, notably extra dimensions, new vector boson high mass states, little Higgs models, technicolour and others. Methods to discriminate between models have been investigated. This report is organized as follows. Chapter 1, the Introduction, describes the context of this document. Chapters 2-6 describe examples of full analyses, with photons, electrons, muons, jets, missing ET, B-mesons and τ's, and for quarkonia in heavy ion collisions. Chapters 7-15 describe the physics reach for Standard Model processes, Higgs discovery and searches for new physics beyond the Standard Model
973 citations
TL;DR: In this paper, the capabilities of the CERN Large Hadron Collider (LHC) experiment to explore the rich heavy-ion physics program offered by the LHC are presented, and the potential of the CMS experiment to carry out a series of representative Pb-Pb measurements.
Abstract: This report presents the capabilities of the CMS experiment to explore the rich heavy-ion physics programme offered by the CERN Large Hadron Collider (LHC). The collisions of lead nuclei at energies , will probe quark and gluon matter at unprecedented values of energy density. The prime goal of this research is to study the fundamental theory of the strong interaction ? Quantum Chromodynamics (QCD) ? in extreme conditions of temperature, density and parton momentum fraction (low-x).This report covers in detail the potential of CMS to carry out a series of representative Pb-Pb measurements. These include bulk observables, (charged hadron multiplicity, low pT inclusive hadron identified spectra and elliptic flow) which provide information on the collective properties of the system, as well as perturbative probes such as quarkonia, heavy-quarks, jets and high pT hadrons which yield tomographic information of the hottest and densest phases of the reaction.
361 citations
TL;DR: In this paper, polyethylene glycol (PEG) chains with different lengths were covalently bonded to polypropylene membranes by means of RF plasma polymerisation of acrylic acid (pp-Aac) followed by mono-amino PEG attachment in liquid phase.
Abstract: Polyethylene glycol (PEG) chains with different lengths were covalently bonded to polypropylene membranes by means of RF plasma polymerisation of acrylic acid (pp-Aac) followed by mono-amino PEG attachment in liquid phase. Two reactor configurations were tested for the plasma deposition of ppAAc in order to obtain high retention of carboxylic groups in the deposited thin films. A best configuration was assessed evaluating the membrane surface modifications by means of water droplet adsorption time and contact angles measurements, attenuated total reflection (ATR) spectroscopy and X-ray photoelectron spectroscopy (XPS) analysis. PEG chains were covalently bonded to the best plasma modified membranes and the resulting anti-fouling properties were evaluated.
67 citations
University of California, Davis1, CINVESTAV2, University of Colorado Boulder3, Fermilab4, Universidad de Guanajuato5, University of Illinois at Urbana–Champaign6, Indiana University7, Korea University8, Kyungpook National University9, University of Milan10, University of North Carolina at Chapel Hill11, Pontifical Catholic University of Rio de Janeiro12, University of Puerto Rico at Mayagüez13, University of South Carolina14, University of Tennessee15, Vanderbilt University16, University of Wisconsin-Madison17, Durham University18
TL;DR: In this article, the authors performed a Dalitz plot analysis of the Cabibbo favored decay D{sup +} {yields} K{sup -{pi}{sup +}{pi}{ sup +}, and used 53653 Dalitzplot events with a signal fraction of approximately 97%.
51 citations
TL;DR: In this paper, SiOxCyHz thin films were deposited from hexamethyldisiloxane (HMDSO)/O2 mixtures in a parallel plate, capacitively coupled, RF plasma reactor.
38 citations
TL;DR: Experimental characterization of the plasma state as well as the neutral gas phase in a low pressure discharge is presented in this article, where a radiofrequency supply produces plasma driving an electrical discharge in a gas mixture through a resonant inductive coupling.
28 citations
TL;DR: In this paper, the surface modification of polyethylene terephthalate (PET) films after exposure both to low-pressure plasma (film deposition by plasma enhanced chemical vapour deposition) and to an atmospheric pressure dielectric barrier discharge (surface etching).
26 citations
TL;DR: In this article, the results of a study of Higgs bosons produced in association with top quarks and decaying via H → bb are presented as realistically as possible by employing a full and detailed Monte Carlo simulation of the CMS detector followed by the application of trigger and reconstruction algorithms.
Abstract: The decay, H → bb, is dominant for a Standard Model Higgs boson in the mass range just above the exclusion limit of 114.4 GeV/c 2 reported by the LEP experiments. Unfortunately, an overwhelming abundance of b¯ b events arising from more mundane sources, together with the lack of precision inherent in the reconstruction of the Higgs mass, renders this decay modeaprioriundetectable in the case of direct Higgs production at the LHC. It is therefore of no small interest to investigate whether H → bb can be observed in those cases where the Higgs is produced in association with other massive particles. In this note, the results of a study of Higgs bosons produced in association with top quarks and decaying via H → bb are presented. The study was performed as realistically as possible by employing a full and detailed Monte Carlo simulation of the CMS detector followed by the application of trigger and reconstruction algorithms that were developed for use with real data. Important systematic effects resulting from such sources as the uncertainties in the jet energy scale and the estimated rates for correctly tagging b jets or mistagging non-b jets have been taken into account. The impact of large theoretical uncertainties in the cross sections for t tp lusN jets processes due to an absence of next-to-leading order calculations is also considered.
16 citations
01 Jan 2007
TL;DR: In this paper, the capabilities of the CERN Large Hadron Collider (LHC) experiment to explore the rich heavy-ion physics program offered by the LHC are presented, and the potential of the CMS experiment to carry out a series of representative Pb-Pb measurements.
Abstract: This report presents the capabilities of the CMS experiment to explore the rich heavy-ion physics programme offered by the CERN Large Hadron Collider (LHC). The collisions of lead nuclei at energies , will probe quark and gluon matter at unprecedented values of energy density. The prime goal of this research is to study the fundamental theory of the strong interaction ? Quantum Chromodynamics (QCD) ? in extreme conditions of temperature, density and parton momentum fraction (low-x).This report covers in detail the potential of CMS to carry out a series of representative Pb-Pb measurements. These include bulk observables, (charged hadron multiplicity, low pT inclusive hadron identified spectra and elliptic flow) which provide information on the collective properties of the system, as well as perturbative probes such as quarkonia, heavy-quarks, jets and high pT hadrons which yield tomographic information of the hottest and densest phases of the reaction.
15 citations
TL;DR: In this paper, a characterisation of a low pressure SF 6 discharge was performed by means of plasma diagnostics, including radiofrequency electrical probes, Langmuir probes and optical emission spectroscopy.
Abstract: A characterisation of a low pressure SF 6 discharge was undertaken, by means of plasma diagnostics, including radiofrequency electrical probes, Langmuir probes and optical emission spectroscopy. Chemical kinetics modeling of the discharge was performed too. This was aimed to the understanding of a reported transition in the plasma induced surface modification on poly(ethylene terephthalate) (PET) fibres by SF 6 plasma treatment which can be characterized as a striking wettability modification reverse displayed by plasma treated fibres as the SF 6 pressure in the discharge exceeds a threshold value. Here we have investigated the modification also on different polymeric surface such as that of a PET film and of cellulose (paper). We point out that the observed transition could be understood as a switch between an increased surface hydrophilicity, induced by plasma treatment at low pressure, which produces also surface etching and activation, and an increased surface hydrophobicity, imparted by plasma treatment at higher pressures, due to extended surface fluorination.
Patent•
19 Jan 2007TL;DR: The object invention of the present patent relates to both vacuum and atmospheric pressure plasma processes to confer stone materials and composites surface properties such as water repepellency, oil-repellency and resistance to chemical aggressions by acids, bases etc., UV resistance, resistance to the bleaching of the substrate, antibacterial properties, anti-adhesive properties with relation to atmospheric dusts specifically in an urban environment as discussed by the authors.
Abstract: The object invention of the present patent relates to both vacuum and atmospheric pressure plasma processes to confer stone materials and composites surface properties such as water-repellency, oil-repellency, resistance to chemical aggressions by acids, bases etc., UV resistance, resistance to the bleaching of the substrate, anti-bacterial properties, anti-adhesive properties with relation to atmospheric dusts specifically in an urban environment, anti-sliding properties and increase in the friction coefficient.
12 Mar 2007
TL;DR: In this paper, the authors present a search for a pentaquark decaying strongly to $Xi ∆(1530)€ 0$ in collisions at a center-of-mass energy up to 25 GeV/c^ 2.
University of California, Davis1, CINVESTAV2, University of Colorado Boulder3, Fermilab4, Universidad de Guanajuato5, University of Illinois at Urbana–Champaign6, Indiana University7, Korea University8, Kyungpook National University9, University of Milan10, University of North Carolina at Chapel Hill11, Pontifical Catholic University of Rio de Janeiro12, University of Puerto Rico at Mayagüez13, University of South Carolina14, University of Tennessee15, Vanderbilt University16, University of Wisconsin-Madison17
TL;DR: In this article, the authors measured the branching ratio for the Cabibbo-suppressed decay mode of the E831 channel and showed that the decay rate of this decay channel can reach 0.0914 and 0.0018, respectively.
Abstract: Using data from the FOCUS (E831) experiment at Fermilab, we present new measurements for the Cabibbo-suppressed decay mode ${D}^{0}\ensuremath{\rightarrow}{\ensuremath{\pi}}^{\ensuremath{-}}{\ensuremath{\pi}}^{+}{\ensuremath{\pi}}^{\ensuremath{-}}{\ensuremath{\pi}}^{+}$. We measure the branching ratio $\ensuremath{\Gamma}({D}^{0}\ensuremath{\rightarrow}{\ensuremath{\pi}}^{+}{\ensuremath{\pi}}^{\ensuremath{-}}{\ensuremath{\pi}}^{+}{\ensuremath{\pi}}^{\ensuremath{-}})/\ensuremath{\Gamma}({D}^{0}\ensuremath{\rightarrow}{K}^{\ensuremath{-}}{\ensuremath{\pi}}^{+}{\ensuremath{\pi}}^{\ensuremath{-}}{\ensuremath{\pi}}^{+})=0.0914\ifmmode\pm\else\textpm\fi{}0.0018\ifmmode\pm\else\textpm\fi{}0.0022$. An amplitude analysis has been performed, a first for this channel, in order to determine the resonant substructure of this decay mode. The dominant component is the decay ${D}^{0}\ensuremath{\rightarrow}{a}_{1}(1260{)}^{+}{\ensuremath{\pi}}^{\ensuremath{-}}$, accounting for 60% of the decay rate. The second most dominant contribution comes from the decay ${D}^{0}\ensuremath{\rightarrow}\ensuremath{\rho}(770{)}^{0}\ensuremath{\rho}(770{)}^{0}$, with a fraction of 25%. We also study the ${a}_{1}(1260)$ line shape and resonant substructure. Using the helicity formalism for the angular distribution of the decay ${D}^{0}\ensuremath{\rightarrow}\ensuremath{\rho}(770{)}^{0}\ensuremath{\rho}(770{)}^{0}$, we measure a longitudinal polarization of ${P}_{L}=(71\ifmmode\pm\else\textpm\fi{}4\ifmmode\pm\else\textpm\fi{}2)%$.
TL;DR: How a focused ion beam combined with a scanning electron microscope (FIB/SEM machine) can be adopted to characterize composite fibers with different electrical behavior and to gain information about their production and modification is shown.
Abstract: The aim of this paper is to show how a focused ion beam combined with a scanning electron microscope (FIB/SEM machine) can be adopted to characterize composite fibers with different electrical behavior and to gain information about their production and modification. This comparative morphology investigation is carried out on polyacrylonitrile (PAN) carbon fibers and their chemical precursor (the oxidized PAN or oxypan) which has different electrical properties. Fibers are imaged by electron and ion beams and sectioned by the focused ion beam (FIB). A sample of oxypan fibers processed by a radio frequency (RF) plasma is also investigated and the role of the conductive carbon layer around their unmodified, insulating bulk is discussed. A suitable developed edge detection technique (EDT) on electron, ion images, and after the FIB sectioning, provides quantitative information about the thickness of the created layer.
University of California, Davis1, CINVESTAV2, University of Colorado Boulder3, Fermilab4, Universidad de Guanajuato5, University of Illinois at Urbana–Champaign6, Indiana University7, Korea University8, Kyungpook National University9, University of Milan10, University of North Carolina at Chapel Hill11, Pontifical Catholic University of Rio de Janeiro12, University of Puerto Rico at Mayagüez13, University of South Carolina14, University of Tennessee15, Vanderbilt University16, University of Wisconsin-Madison17
TL;DR: In this paper, the first nonparametric analysis of the K{sup -pi-sup +} amplitudes in D{sup+} {yields} K {sup -}K{sup +}{pi+} decays collected by the FOCUS photoproduction experiment at Fermilab was presented.