R. Frühwirth
A5027832388- 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
- Cosmology and Gravitation Theories
- Drilling and Well Engineering
- Neutrino Physics Research
- Radiation Detection and Scintillator Technologies
- Reservoir Engineering and Simulation Methods
- Computational Physics and Python Applications
- Oil and Gas Production Techniques
- Hydraulic Fracturing and Reservoir Analysis
- Tunneling and Rock Mechanics
- Black Holes and Theoretical Physics
- Statistical Methods and Inference
- Soil Geostatistics and Mapping
- Medical Imaging Techniques and Applications
- Scientific Research and Discoveries
- Mineral Processing and Grinding
- Advanced Statistical Methods and Models
- Seismic Imaging and Inversion Techniques
- Bayesian Methods and Mixture Models
- Geophysical Methods and Applications
- Target Tracking and Data Fusion in Sensor Networks
Montanuniversität Leoben
2012-2024
Institute of High Energy Physics
2014-2023
TU Wien
2012-2023
A. Alikhanyan National Laboratory
2014-2023
Austrian Academy of Sciences
2013-2022
High Energy Accelerator Research Organization
2021
Fermi National Accelerator Laboratory
2021
SLAC National Accelerator Laboratory
2021
Menlo School
2021
Stanford University
2021
Results are presented from searches for the standard model Higgs boson in proton-proton collisions at sqrt(s) = 7 and 8 TeV Compact Muon Solenoid experiment LHC, using data samples corresponding to integrated luminosities of up 5.1 inverse femtobarns 5.3 TeV. The search is performed five decay modes: gamma gamma, ZZ, WW, tau tau, b b-bar. An excess events observed above expected background, with a local significance 5.0 deviations, mass near 125 GeV, signalling production new particle. that...
The Compact Muon Solenoid (CMS) detector is described. operates at the Large Hadron Collider (LHC) CERN. It was conceived to study proton-proton (and lead-lead) collisions a centre-of-mass energy of 14 TeV (5.5 nucleon-nucleon) and luminosities up 1034 cm−2 s−1 (1027 s−1). At core CMS sits high-magnetic-field large-bore superconducting solenoid surrounding an all-silicon pixel strip tracker, lead-tungstate scintillating-crystals electromagnetic calorimeter, brass-scintillator sampling hadron...
Results on two-particle angular correlations for charged particles emitted in proton-proton collisions at center-of-mass energies of 0.9, 2.36, and 7 TeV are presented, using data collected with the CMS detector over a broad range pseudorapidity (eta) azimuthal angle (phi). Short-range Delta(eta), which studied minimum bias events, characterized simple "independent cluster" parametrization order to quantify their strength (cluster size) extent eta decay width). Long-range differentially as...
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...
Combined results are reported from searches for the standard model Higgs boson in proton-proton collisions at sqrt(s)=7 TeV five decay modes: gamma pair, b-quark tau lepton W and Z pair. The explored mass range is 110-600 GeV. analysed data correspond to an integrated luminosity of 4.6-4.8 inverse femtobarns. expected excluded absence 118-543 GeV 95% CL. observed exclude 127-600 CL, 129-525 99% An excess events above background low end making limits weaker than a signal. largest excess, with...
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...
Results on two-particle angular correlations for charged particles emitted in pPb collisions at a nucleon–nucleon center-of-mass energy of 5.02 TeV are presented. The analysis uses two million collected with the CMS detector LHC. studied over broad range pseudorapidity, η, and full azimuth, ϕ, as function particle multiplicity transverse momentum, pT. In high-multiplicity events, long-range (2<|Δη|<4), near-side (Δϕ≈0) structure emerges Δη–Δϕ correlation functions. This is first observation...
A detailed description is reported of the analysis used by CMS Collaboration in search for standard model Higgs boson pp collisions at LHC, which led to observation a new boson. The data sample corresponds integrated luminosities up 5.1 inverse femtobarns sqrt(s) = 7 TeV, and 5.3 8 TeV. results five decay modes gamma gamma, ZZ, WW, tau tau, bb, show combined local significance 5 deviations near 125 GeV, are reviewed. fit invariant mass two high resolution channels, ZZ 4 ell, gives estimate...
New sets of parameters (“tunes”) for the underlying-event (UE) modelling pythia8, pythia6 and herwig++ Monte Carlo event generators are constructed using different parton distribution functions. Combined fits to CMS UE proton–proton ( $$\mathrm {p}\mathrm {p}$$ ) data at $$\sqrt{s} = 7\,\text {TeV} $$ proton–antiproton {p}\overline{\mathrm{p}} from CDF experiment lower $$\sqrt{s}$$ , used study models constrain their parameters, providing thereby improved predictions collisions 13 $$\,\text...
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 properties of a Higgs boson candidate are measured in the $H\ensuremath{\rightarrow}ZZ\ensuremath{\rightarrow}4\ensuremath{\ell}$ decay channel, with $\ensuremath{\ell}=e$, $\ensuremath{\mu}$, using data from $pp$ collisions corresponding to an integrated luminosity $5.1\text{ }\text{ }{\mathrm{fb}}^{\ensuremath{-}1}$ at center-of-mass energy $\sqrt{s}=7\text{ }\mathrm{TeV}$ and $19.7\text{ }{\mathrm{fb}}^{\ensuremath{-}\text{1}}$ $\sqrt{s}=8\text{ }\mathrm{TeV}$, recorded CMS detector...
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...
New sets of CMS underlying-event parameters ("tunes") are presented for the PYTHIA8 event generator. These tunes use NNPDF3.1 parton distribution functions (PDFs) at leading (LO), next-to-leading (NLO), or next-to-next-to-leading (NNLO) orders in perturbative quantum chromodynamics, and strong coupling evolution LO NLO. Measurements charged-particle multiplicity transverse momentum densities various hadron collision energies fit simultaneously to determine tunes. Comparisons predictions new...
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,...
A measurement of inclusive W and Z production cross sections in pp collisions at $ \sqrt {s} = 7 TeV is presented. The electron muon decay channels are analyzed a data sample collected with the CMS detector LHC corresponding to an integrated luminosity 36 pb−1. measured σ(pp → WX) × \mathcal{B}\left( {{\text{W}} \to \ell \nu } \right) 10.31 ± 0.02 (stat.) 0.09 (syst.) 0.10 (th.) 0.41 (lumi.) nb ZX) {{\text{Z}} {\ell^{+} }{\ell^{-} }} 0.974 0.007 0.018 0.039 nb, limited dilepton invariant...
This paper presents a search for the pair production of top squarks in events with single isolated electron or muon, jets, large missing transverse momentum, and mass. The data sample corresponds to an integrated luminosity 19.5 inverse femtobarns pp collisions collected 2012 by CMS experiment at LHC center-of-mass energy sqrt(s) = 8 TeV. No significant excess is observed above expectation from standard model processes. results are interpreted context supersymmetric models that decay either...
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 events with jets and missing transverse energy is performed in a data sample of $pp$ collisions collected at $\sqrt{s}=7\text{ }\text{ }\mathrm{TeV}$ by the CMS experiment LHC. The analyzed corresponds to an integrated luminosity $1.14\text{ }{\mathrm{fb}}^{\ensuremath{-}1}$. In this search, kinematic variable ${\ensuremath{\alpha}}_{\mathrm{T}}$ used as main discriminator between genuine misreconstructed energy. No excess over standard model expectation found. Exclusion limits...
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{...
Dijet production in PbPb collisions at a nucleon–nucleon center-of-mass energy of 2.76 TeV is studied with the CMS detector LHC. A data sample corresponding to an integrated luminosity 150 μb−1 analyzed. Jets are reconstructed using combined information from tracking and calorimetry, anti-kT algorithm R=0.3. The dijet momentum balance angular correlations as function collision centrality leading jet transverse momentum. For most peripheral collisions, good agreement distributions pp...