C. Vander Velde
A5077132743- Particle physics theoretical and experimental studies
- High-Energy Particle Collisions Research
- Quantum Chromodynamics and Particle Interactions
- Particle Detector Development and Performance
- Dark Matter and Cosmic Phenomena
- Computational Physics and Python Applications
- Cosmology and Gravitation Theories
- Neutrino Physics Research
- Astrophysics and Cosmic Phenomena
- Black Holes and Theoretical Physics
- Particle Accelerators and Free-Electron Lasers
- Medical Imaging Techniques and Applications
- Distributed and Parallel Computing Systems
- Radiation Detection and Scintillator Technologies
- Superconducting Materials and Applications
- CCD and CMOS Imaging Sensors
- Atomic and Subatomic Physics Research
- Particle accelerators and beam dynamics
- Nuclear reactor physics and engineering
- Radiation Therapy and Dosimetry
- International Science and Diplomacy
- Nuclear physics research studies
- Gamma-ray bursts and supernovae
- Big Data Technologies and Applications
- Optical properties and cooling technologies in crystalline materials
Université Libre de Bruxelles
2016-2025
Institute of High Energy Physics
2013-2024
University of Antwerp
1992-2024
A. Alikhanyan National Laboratory
2022-2024
Ghent University Hospital
2023
Wayne State University
2017
European Organization for Nuclear Research
1989-2013
Saha Institute of Nuclear Physics
2013
University of Mons
1992-2012
Austrian Academy of Sciences
2012
This paper describes the CMS trigger system and its performance during Run 1 of LHC. The consists two levels designed to select events potential physics interest from a GHz (MHz) interaction rate proton-proton (heavy ion) collisions. first level is implemented in hardware, selects containing detector signals consistent with an electron, photon, muon, τ lepton, jet, or missing transverse energy. A programmable menu up 128 object-based algorithms used for subsequent processing. thresholds are...
Properties of the Higgs boson with mass near 125 $$\,\text {GeV}$$ are measured in proton-proton collisions CMS experiment at LHC. Comprehensive sets production and decay measurements combined. The channels include $$\gamma \gamma $$ , $$\mathrm{Z}\mathrm{Z}$$ $$\mathrm{W}\mathrm{W}$$ $$\tau \tau $$\mathrm{b} \mathrm{b} $$\mu \mu pairs. data samples were collected 2011 2012 correspond to integrated luminosities up 5.1 {fb}^\text {-1}$$ 7 {TeV}$$ 19.7 8 . From high-resolution channels, is...
Jet production in PbPb collisions at a nucleon-nucleon center-of-mass energy of 2.76 TeV was studied with the CMS detector LHC, using data sample corresponding to an integrated luminosity 6.7 inverse microbarns. Jets are reconstructed deposited calorimeters and as function collision centrality. With increasing centrality, striking imbalance dijet transverse momentum is observed, consistent jet quenching. The observed effect extends from lower cut-off used this study (jet = 120 GeV/c) up...
Improved jet energy scale corrections, based on a data sample corresponding to an integrated luminosity of 19.7 inverse-femtobarns collected by the CMS experiment in proton-proton collisions at center-of-mass 8 TeV, are presented. The corrections as function pseudorapidity eta and transverse momentum pT extracted from simulated events combining several channels methods. They account successively for effects pileup, uniformity detector response, residual data-simulation differences. Further...
Charged-hadron transverse-momentum and pseudorapidity distributions in proton-proton collisions at $\sqrt{s}=7\text{ }\text{ }\mathrm{TeV}$ are measured with the inner tracking system of CMS detector LHC. The charged-hadron yield is obtained by counting number reconstructed hits, hit pairs, fully charged-particle tracks. combination three methods gives a multiplicity per unit...
The transverse momentum spectra of charged particles have been measured in pp and PbPb collisions at $\sqrt{s_{NN}}=2.76~\mathrm{TeV}$ by the CMS experiment LHC. In range p T=5–10 GeV/c, particle yield most central is suppressed up to a factor 7 compared scaled number incoherent nucleon–nucleon collisions. At higher T, this suppression significantly reduced, approaching roughly 2 for with T T=40–100 GeV/c.
Results are presented from a search for particle dark matter (DM), extra dimensions, and unparticles using events containing jet an imbalance in transverse momentum. The data were collected by the CMS detector proton-proton collisions at LHC correspond to integrated luminosity of 19.7 inverse femtobarns centre-of-mass energy 8 TeV. number observed is found be consistent with standard model prediction. Limits placed on DM-nucleon scattering cross section as function DM mass spin-dependent...
A study is presented of the mass and spin-parity new boson recently observed at LHC a near 125 GeV. An integrated luminosity 17.3 fb(-1), collected by CMS experiment in proton-proton collisions center-of-mass energies 7 8 TeV, used. The measured ZZ channel, where both Z bosons decay to e or μ pairs, 126.2 ± 0.6(stat) 0.2(syst) angular distributions lepton pairs this channel are sensitive boson. Under assumption spin 0, present data consistent with pure scalar hypothesis, while disfavoring...
The study of the spin-parity and tensor structure interactions recently discovered Higgs boson is performed using H to ZZ, Z gamma*, gamma* 4 l, WW l nu nu, gamma decay modes. full dataset recorded by CMS experiment during LHC Run 1 used, corresponding an integrated luminosity up 5.1 inverse femtobarns at a center-of-mass energy 7 TeV 19.7 8 TeV. A wide range spin-two models excluded 99% confidence level or higher, 99.87% for minimal gravity-like couplings, regardless whether assumptions are...
Results are presented from a search for the rare decays ${B}_{s}^{0}\ensuremath{\rightarrow}{\ensuremath{\mu}}^{+}{\ensuremath{\mu}}^{\ensuremath{-}}$ and ${B}^{0}\ensuremath{\rightarrow}{\ensuremath{\mu}}^{+}{\ensuremath{\mu}}^{\ensuremath{-}}$ in $pp$ collisions at $\sqrt{s}=7$ 8 TeV, with data samples corresponding to integrated luminosities of 5 $20\text{ }\text{ }{\mathrm{fb}}^{\ensuremath{-}1}$, respectively, collected by CMS experiment LHC. An unbinned maximum-likelihood fit dimuon...
A bstract search for the standard model Higgs boson decaying to a W-boson pair at LHC is reported. The event sample corresponds an integrated luminosity of 4.9 fb −1 and 19.4 collected with CMS detector in pp collisions $ \sqrt{s} = 7 8 TeV, respectively. candidates are selected events two or three charged leptons. An excess above background observed, consistent expectation from mass around 125 GeV. probability observe equal larger than one seen, under background-only hypothesis,...
In July 2012, the ATLAS and CMS collaborations at CERN Large Hadron Collider announced observation of a Higgs boson mass around 125 gigaelectronvolts. Ten years later, with data corresponding to production 30-times larger number bosons, we have learnt much more about properties boson. The experiment has observed in numerous fermionic bosonic decay channels, established its spin-parity quantum numbers, determined measured cross-sections various modes. Here Collaboration reports most...
The suppression of the individual Upsilon(nS) states in PbPb collisions with respect to their yields pp data has been measured. and sets used analysis correspond integrated luminosities 150 inverse microbarns 230 nanobarns, respectively, collected 2011 by CMS experiment at LHC, a center-of-mass energy per nucleon pair 2.76 TeV. are measured from dimuon invariant mass spectra. relative scaled number nucleon-nucleon collisions, R[AA], is as function collision centrality. Integrated over...
Measurements of inclusive W and Z boson production cross sections in pp collisions at $ \sqrt {s} = 7 TeV are presented, based on 2.9 pb−1 data recorded by the CMS detector LHC. The measurements, performed electron muon decay channels, combined to give \sigma \left( {{\text{pp}} \to {\text{W}}X} \right) \times \mathcal{B}\left( {{\text{W}} \ell \nu } 9.95\pm 0.07\left( {{\text{stat}}{.}} \right)\pm 0.28\left( {{\text{syst}}{.}} 1.09 (lumi.) nb {\text{Z}}X} {Z {\ell^{+} }{\ell^{-} }} 0.931\pm...
A search for the standard model Higgs boson ($H$) decaying to $b\overline{b}$ when produced in association with a weak vector ($V$) is reported following channels: $W(\ensuremath{\mu}\ensuremath{\nu})H$, $W(e\ensuremath{\nu})H$, $W(\ensuremath{\tau}\ensuremath{\nu})H$, $Z(\ensuremath{\mu}\ensuremath{\mu})H$, $Z(ee)H$, and $Z(\ensuremath{\nu}\ensuremath{\nu})H$. The performed data samples corresponding integrated luminosities of up 5.1 inverse femtobarns at $\sqrt{s}=7\text{ }\text{...
A bstract Properties of the Higgs boson are measured in H → ZZ 4ℓ (ℓ = e, μ ) decay channel. data sample proton-proton collisions at $$ \sqrt{s}=13 <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML"><mml:msqrt><mml:mi>s</mml:mi></mml:msqrt><mml:mo>=</mml:mo><mml:mn>13</mml:mn></mml:math> TeV, collected with CMS detector LHC and corresponding to an integrated luminosity 35.9 fb −1 is used. The signal strength modifier , defined as ratio observed rate channel standard model expectation,...
The measurement of the luminosity recorded by CMS detector installed at LHC interaction point 5, using proton-proton collisions s=13TeV in 2015 and 2016, is reported. absolute scale measured for individual bunch crossings beam-separation scans (the van der Meer method), with a relative precision 1.3 1.0% respectively. dominant sources uncertainty are related to residual differences between beam positions ones provided operational settings magnets, factorizability proton spatial density...
Results of searches for heavy stable charged particles produced in pp collisions at sqrt(s) = 7 and 8 TeV are presented corresponding to an integrated luminosity 5.0 inverse femtobarns 18.8 femtobarns, respectively. Data collected with the CMS detector used study momentum, energy deposition, time-of-flight signal candidates. Leptons electric charge between e/3 8e, as well bound states that can undergo exchange material, studied. Analysis results various combinations signatures inner tracker...
The second-order azimuthal anisotropy Fourier harmonics, v2, are obtained in p−Pb and PbPb collisions over a wide pseudorapidity (η) range based on correlations among six or more charged particles. p-Pb data, corresponding to an integrated luminosity of 35 nb−1, were collected during the 2013 LHC run at nucleon-nucleon center-of-mass energy 5.02 TeV by CMS experiment. A sample semiperipheral collision data √sNN=2.76 TeV, 2.5 μb−1 covering similar particle multiplicities as is also analyzed...
A bstract search has been made for events containing an energetic jet and imbalance in transverse momentum using a data sample of pp collisions at center-of-mass energy 7 TeV. This signature is common to both dark matter extra dimensions models. The were collected by the CMS detector LHC correspond integrated luminosity 5.0 fb −1 . number observed consistent with standard model expectation. Constraints on matter-nucleon scattering cross sections are determined spin-independent spin-dependent...
Results from the first study of isolated-photon + jet correlations in relativistic heavy ion collisions are reported. The analysis uses data PbPb at a centre-of-mass energy 2.76TeV per nucleon pair corresponding to an integrated luminosity 150μb−1 recorded by CMS experiment LHC. For events containing isolated photon with transverse momentum pTγ>60GeV/c and associated pTJet>30GeV/c, pT imbalance is studied as function collision centrality compared pp pythia calculations same energy. Using pTγ...
The spectra of charged particles produced within the pseudorapidity window |η| < 1 at $$ \sqrt{s_{\mathrm{N}\;\mathrm{N}}}=5.02 TeV are measured using 404 μb−1 PbPb and 27.4 pb−1 pp data collected by CMS detector LHC in 2015. presented over transverse momentum ranges spanning 0.5 p T 400 GeV 0.7 collisions. corresponding nuclear modification factor, R AA, is bins collision centrality. AA 5% most central collisions shows a maximal suppression factor 7-8 region 6-9 GeV. This dip followed an...
A search for heavy, right-handed neutrinos, N[l] (l = e, mu), and WR bosons, which arise in the left-right symmetric extensions of standard model, has been performed by CMS experiment. The was based on a sample two lepton plus jet events collected proton-proton collisions at center-of-mass energy 8 TeV corresponding to an integrated luminosity 19.7 inverse femtobarns. For models with strict symmetry, assuming only one flavor contributes significantly decay width, region two-dimensional...
The first measurement of jet shapes, defined as the fractional transverse momentum radial distribution, for inclusive jets produced in heavy-ion collisions is presented. Data samples PbPb and pp collisions, corresponding to integrated luminosities 150 inverse microbarns 5.3 picobarns respectively, were collected at a nucleon-nucleon centre-of-mass energy sqrt(s[NN]) = 2.76 TeV with CMS detector LHC. are reconstructed anti-kt algorithm distance parameter R 0.3, shapes measured charged...