G. H. Hammad
A5014793807- 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
- Sleep and related disorders
- Cosmology and Gravitation Theories
- Computational Physics and Python Applications
- Sleep and Wakefulness Research
- Medical Imaging Techniques and Applications
- Neutrino Physics Research
- Astrophysics and Cosmic Phenomena
- Black Holes and Theoretical Physics
- Sleep and Work-Related Fatigue
- Circadian rhythm and melatonin
- Health, Environment, Cognitive Aging
- Distributed and Parallel Computing Systems
- Particle Accelerators and Free-Electron Lasers
- Radiation Detection and Scintillator Technologies
- Optical Imaging and Spectroscopy Techniques
- Functional Brain Connectivity Studies
- Scientific Computing and Data Management
- Spaceflight effects on biology
- Multiple Sclerosis Research Studies
- CCD and CMOS Imaging Sensors
University of Surrey
2023-2025
University of Liège
2018-2025
Technical University of Munich
2023-2024
University of Mons
2012-2018
Cyclotron (Netherlands)
2018
Institute of High Energy Physics
2011-2016
European Organization for Nuclear Research
2012-2014
Quaid-i-Azam University
2013
Université Libre de Bruxelles
2008-2012
DSM (Netherlands)
2011
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...
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...
The spectra of strange hadrons are measured in proton-proton collisions, recorded by the CMS experiment at CERN LHC, centre-of-mass energies 0.9 and 7 TeV. K^0_s, Lambda, Xi^- particles their antiparticles reconstructed from decay topologies production rates as functions rapidity transverse momentum. results compared to other experiments predictions PYTHIA Monte Carlo program. momentum distributions found differ substantially exceed up a factor three.
The production of J/ψ mesons is studied in pp collisions at $\sqrt{s} = 7$ TeV with the CMS experiment LHC. measurement based on a dimuon sample corresponding to an integrated luminosity 314 nb−1. differential cross section determined, as function transverse momentum, three rapidity ranges. A fit decay length distribution used separate prompt from non-prompt (b hadron J/ψ) component. Integrated over momentum 6.5 30 GeV/c and range |y|<2.4, measured sections, times branching fraction, are...
A search for neutral Higgs bosons decaying to tau pairs at a center-of-mass energy of 7 TeV is performed using dataset corresponding an integrated luminosity 4.6 inverse femtobarns recorded by the CMS experiment LHC. The sensitive both standard model boson and predicted minimal supersymmetric extension (MSSM). No excess events observed in tau-pair invariant-mass spectrum. For mass range 110-145 GeV upper limits 95% confidence level (CL) on production cross section are determined. We exclude...
A comparison of the relative yields Υ resonances in μ(+)μ(-) decay channel Pb-Pb and pp collisions at a center-of-mass energy per nucleon pair 2.76 TeV is performed with data collected CMS detector LHC. Using muons transverse momentum above 4 GeV/c pseudorapidity below 2.4, double ratio Υ(2S) Υ(3S) excited states to Υ(1S) ground state collisions, [Υ(2S+3S)/Υ(1S)](Pb-Pb)/[Υ(2S+3S)/Υ(1S)](pp), found be 0.31(-0.15)(+0.19)(stat)±0.03(syst). The probability obtain measured value, or lower, if...
Measurements of the normalized rapidity ($y$) and transverse-momentum (${q}_{\mathrm{T}}$) distributions Drell--Yan muon electron pairs in $Z$-boson mass region ($60<{M}_{\ensuremath{\ell}\ensuremath{\ell}}<120\text{ }\text{ }\mathrm{GeV}$) are reported. The results obtained using a data sample proton-proton collisions at center-of-mass energy 7 TeV, collected by CMS experiment Large Hadron Collider (LHC), corresponding to an integrated luminosity $36\text{ }{\mathrm{pb}}^{\ensuremath{-}1}$....
A search for narrow resonances with a mass of at least 1 TeV in the dijet spectrum is performed using pp collisions sqrt(s)=7 corresponding to an integrated luminosity inverse femtobarn, collected by CMS experiment LHC. No are observed. Upper limits 95% confidence level presented on product resonance cross section, branching fraction into dijets, and acceptance, separately decays quark-quark, quark-gluon, gluon-gluon pairs. The data exclude new particles predicted following models level:...
A search for narrow resonances in the dijet mass spectrum is performed using data corresponding to an integrated luminosity of $2.9\text{ }\text{ }{\mathrm{pb}}^{\ensuremath{-}1}$ collected by CMS experiment at Large Hadron Collider. Upper limits 95% confidence level are presented on product resonance cross section, branching fraction into dijets, and acceptance, separately decays quark-quark, quark-gluon, or gluon-gluon pairs. The exclude new particles predicted following models level:...
The first measurement of the cross section for top-quark pair production in pp collisions at LHC center-of-mass energy sqrt(s)= 7 TeV has been performed using 3.1 {\pm} 0.3 inverse pb data recorded by CMS detector. This result utilizes final state with two isolated, highly energetic charged leptons, large missing transverse energy, and or more jets. Backgrounds from Drell-Yan non-W/Z boson are estimated data. Eleven events observed 2.1 1.0 expected background. measured is 194 72 (stat.) 24...
A search for a Higgs boson in the four-lepton decay channel H to ZZ, with each Z decaying an electron or muon pair, is reported. The covers mass hypotheses range 110 < mH 600 GeV. analysis uses data corresponding integrated luminosity of 4.7 inverse femtobarns recorded by CMS detector pp collisions at sqrt(s) = 7 TeV from LHC. Seventy-two events are observed invariant m[4 leptons] > 100 GeV (with thirteen below 160 GeV), while 67.1 +/- 6.0 (9.5 +/-1.3) expected background. distribution...
The difference in angular distributions between top quarks and antiquarks, commonly referred to as the charge asymmetry, is measured pp collisions at LHC with CMS experiment. data sample corresponds an integrated luminosity of 1.09fb−1 a centre-of-mass energy 7 TeV. Top-quark pairs are selected final state electron or muon four more jets. At least one jet identified originating from b-quark hadronization. asymmetry two variables, based on pseudorapidities (η) other their rapidities (y)....
A search for neutral MSSM Higgs bosons in pp collisions at the LHC a center-of-mass energy of 7 TeV is presented. The results are based on data sample corresponding to an integrated luminosity 36 inverse picobarns recorded by CMS experiment. uses decays tau pairs. No excess observed tau-pair invariant-mass spectrum. resulting upper limits boson production cross section times branching fraction pairs, as function pseudoscalar mass, yield stringent new bounds parameter space.
The $ {{\rm t}\bar{\rm t}} production cross section and top quark mass are measured in proton-proton collisions at \sqrt {s} = 7 TeV a data sample corresponding to an integrated luminosity of 36 pb−1 collected by the CMS experiment. measurements performed events with two leptons (electrons or muons) final state. Results measurement without b-quark identification obtained combined. value is {\upsigma_{{{\rm t}}}} 168 ± 18 (stat.) 14 (syst.) (lumi.) pb, consistent predictions from standard...
Measurements of jet production rates in association with W and Z bosons for transverse momenta above 30 GeV are reported, using a sample proton-proton collision events recorded by CMS at sqrt(s) = 7 TeV, corresponding to an integrated luminosity 36 inverse picobarns. The study includes the measurement normalized inclusive jets sigma(V + >= n jets)/sigma(V), where V represents either or Z. In addition, ratio cross sections charge asymmetry as function number associated measured. A test...
A search for microscopic black hole production and decay in pp collisions at a center-of-mass energy of 7 TeV has been conducted by the CMS Collaboration LHC, using data sample corresponding to an integrated luminosity 35 pb−1. Events with large total transverse are analyzed presence multiple high-energy jets, leptons, photons, typical signal expected from hole. Good agreement standard model backgrounds, dominated QCD multijet production, is observed various final-state multiplicities...
A multivariate likelihood method to measure electroweak couplings with the Drell-Yan process at LHC is presented. The described by dilepton rapidity, invariant mass, and decay angle distributions. ambiguity due unknown assignment of scattered constituent quark antiquark two protons in a collision resolved statistically using correlations between observables. applied sample dimuon events from proton-proton collisions sqrt(s) = 7 TeV collected CMS experiment LHC, corresponding an integrated...
This report summarizes the work of Energy Frontier Top Quark working group 2013 Community Summer Study (Snowmass).
Over the past 40 years, actigraphy has been used to study rest-activity patterns in circadian rhythm and sleep research. Furthermore, considering its simplicity of use, there is a growing interest analysis large population-based samples, using actigraphy. Here, we introduce pyActigraphy , comprehensive toolbox for data visualization including multiple detection algorithms variables. This open-source python package implements methods read formats, quantify various properties rhythms,...
Dijet angular distributions are measured over a wide range of dijet invariant masses in $pp$ collisions at $\sqrt{s}=7\text{ }\text{ }\mathrm{TeV}$, the CERN LHC. The event sample, recorded with CMS detector, corresponds to an integrated luminosity $36\text{ }{\mathrm{pb}}^{\ensuremath{-}1}$. data found be good agreement predictions perturbative QCD, and yield no evidence quark compositeness. With modified frequentist approach, lower limit on contact interaction scale for left-handed quarks...
A bstract The inclusive b-jet production cross section in pp collisions at a center-of mass energy of 7 TeV is measured using data collected by the CMS experiment LHC. presented as function jet transverse momentum range 18 < p T 200 GeV for several rapidity intervals. results are also given ratio to section. measurement performed with two different analyses, which differ their trigger selection and identification: analysis that selects events b sample corresponding an integrated...
A measurement of the angular correlations between beauty and anti-beauty hadrons ( $ {\text{B}}\overline {\text{B}} ) produced in pp collisions at a centre-of-mass energy 7 TeV CERN LHC is presented, probing for first time region small separation. The B are identified by presence displaced secondary vertices from their decays. hadron separation reconstructed decay primary-interaction vertex. differential production cross section, measured data sample collected CMS corresponding to an...
A bstract Measurements of jet characteristics from inclusive production in protonproton collisions at a centre-of-mass energy 7 TeV are presented. The data sample was collected with the CMS detector LHC during 2010 and corresponds to an integrated luminosity 36 pb −1 . mean charged-hadron multiplicity, differential integral shape distributions, two independent moments distributions measured as functions transverse momentum for jets reconstructed anti- k T algorithm. observables corrected...
A study of events with missing transverse energy and an energetic jet is performed using pp collision data at a centre-of-mass 7 TeV. The were collected by the CMS detector LHC, correspond to integrated luminosity 36 inverse picobarns. An excess these over standard model contributions signature new physics such as large extra dimensions unparticles. number observed in good agreement prediction model, significant extension current limits on parameters benchmark models achieved.