A. A. Affolder
A5045413701- 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
- Neutrino Physics Research
- Computational Physics and Python Applications
- Cosmology and Gravitation Theories
- Radiation Detection and Scintillator Technologies
- Black Holes and Theoretical Physics
- CCD and CMOS Imaging Sensors
- Particle Accelerators and Free-Electron Lasers
- Superconducting Materials and Applications
- Medical Imaging Techniques and Applications
- Radiation Effects in Electronics
- Atomic and Subatomic Physics Research
- Distributed and Parallel Computing Systems
- Astrophysics and Cosmic Phenomena
- Advancements in Semiconductor Devices and Circuit Design
- Silicon and Solar Cell Technologies
- Electrostatic Discharge in Electronics
- Magnetic Field Sensors Techniques
- 3D IC and TSV technologies
- Advanced Data Storage Technologies
- Advanced Semiconductor Detectors and Materials
University of California, Santa Cruz
2016-2025
University of Bergen
2024
Aix-Marseille Université
2017-2024
University of Geneva
2019-2024
Federación Española de Enfermedades Raras
2024
SR Research (Canada)
2024
Rutherford Appleton Laboratory
2019-2024
Atlas Scientific (United States)
2024
The University of Adelaide
2016-2023
Institut de Microelectrònica de Barcelona
2023
A measurement of the Higgs boson mass is presented based on combined data samples ATLAS and CMS experiments at CERN LHC in H→γγ H→ZZ→4ℓ decay channels. The results are obtained from a simultaneous fit to reconstructed invariant peaks two channels for experiments. measured masses individual found be consistent among themselves. mH=125.09±0.21 (stat)±0.11 (syst) GeV.Received 25 March 2015DOI:https://doi.org/10.1103/PhysRevLett.114.191803This article available under terms Creative Commons...
Observations of exotic structures in the J/ψp channel, which we refer to as charmonium-pentaquark states, Λ0b→J/ψK−p decays are presented. The data sample corresponds an integrated luminosity 3 fb−1 acquired with LHCb detector from 7 and 8 TeV pp collisions. An amplitude analysis three-body final state reproduces two-body mass angular distributions. To obtain a satisfactory fit seen spectrum, it is necessary include two Breit-Wigner amplitudes that each describe resonant state. significance...
A measurement of the ratio branching fractions $B^{+}\rightarrow K^{+}\mu^{+}\mu^{-}$ and K^{+}e^{+}e^{-}$ decays is presented using proton-proton collision data, corresponding to an integrated luminosity 3.0 fb$^{-1}$, recorded with LHCb experiment at center-of-mass energies 7 8 $\mathrm{\,Te\kern -0.1em V}$. The value for dilepton invariant mass squared range $1<q^{2}<6\mathrm{\,Ge\kern V^2\!/}c^4$ measured be $0.745^{+0.090}_{-0.074}\mathrm{\,(stat)}\,\pm0.036\mathrm{\,(syst)}$. This most...
Combined ATLAS and CMS measurements of the Higgs boson production decay rates, as well constraints on its couplings to vector bosons fermions, are presented. The combination is based analysis five processes, namely gluon fusion, associated with a $W$ or $Z$ pair top quarks, six modes $H \to ZZ, WW$, $\gamma\gamma, \tau\tau, bb$, $\mu\mu$. All results reported assuming value 125.09 GeV for mass, result combined measurement by experiments. uses CERN LHC proton--proton collision data recorded...
During 2015 the ATLAS experiment recorded $$3.8\,{\mathrm{fb}}^{-1}$$ of proton–proton collision data at a centre-of-mass energy $$13\,{\mathrm{TeV}}$$ . The trigger system is crucial component experiment, responsible for selecting events interest recording rate approximately 1 kHz from up to 40 MHz collisions. This paper presents short overview changes and acquisition systems during first long shutdown LHC shows performance its components based on data.
We present a new measurement of the inclusive and differential production cross sections $J/\ensuremath{\psi}$ mesons $b$ hadrons in proton-antiproton collisions at $\sqrt{s}=1960\text{ }\text{ }\mathrm{G}\mathrm{e}\mathrm{V}$. The data correspond to an integrated luminosity $39.7\text{ }{\mathrm{p}\mathrm{b}}^{\ensuremath{-}1}$ collected by CDF run II detector. find section for all transverse momenta from 0 $20\text{ }\mathrm{G}\mathrm{e}\mathrm{V}/c$ rapidity range $|y|<0.6$ be...
The branching fraction ratio R(D^{*})≡B(B[over ¯]^{0}→D^{*+}τ^{-}ν[over ¯]_{τ})/B(B[over ¯]^{0}→D^{*+}μ^{-}ν[over ¯]_{μ}) is measured using a sample of proton-proton collision data corresponding to 3.0 fb^{-1} integrated luminosity recorded by the LHCb experiment during 2011 and 2012. tau lepton identified in decay mode τ^{-}→μ^{-}ν[over ¯]_{μ}ν_{τ}. semitauonic sensitive contributions from non-standard-model particles that preferentially couple third generation fermions, particular,...
The LHCb detector is a forward spectrometer at the Large Hadron Collider (LHC) CERN. experiment designed for precision measurements of CP violation and rare decays beauty charm hadrons. In this paper performance various sub-detectors trigger system are described, using data taken from 2010 to 2012. It shown that design criteria have been met. excellent has allowed collaboration publish wide range physics results, demonstrating LHCb's unique role, both as heavy flavour general purpose in region.
We report the observation of a narrow state decaying into $J/\psi\pi^+\pi^-$ and produced in $220 pb^{-1}$ $\bar{p} p $ collisions at $\sqrt{s}=1.96 TeV$ CDF II experiment. observe 730 \pm 90 decays. The mass is measured to be $3871.3 0.7 (stat) 0.4 (syst) MeV/c2$, with an observed width consistent detector resolution. This agreement recent by Belle Collaboration X(3872) meson.
We present a measurement of form-factor-independent angular observables in the decay ${B}^{0}\ensuremath{\rightarrow}{K}^{*}(892{)}^{0}{\ensuremath{\mu}}^{+}{\ensuremath{\mu}}^{\ensuremath{-}}$. The analysis is based on data sample corresponding to an integrated luminosity $1.0\text{ }\text{ }{\mathrm{fb}}^{\ensuremath{-}1}$, collected by LHCb experiment $pp$ collisions at center-of-mass energy 7 TeV. Four are measured six bins dimuon invariant mass squared ${q}^{2}$ range...
This article documents the performance of ATLAS muon identification and reconstruction using first LHC dataset recorded at $\sqrt{s}$ = 13 TeV in 2015. Using a large sample $J/\psi\to\mu\mu$ $Z\to\mu\mu$ decays from 3.2 fb$^{-1}$ $pp$ collision data, measurements efficiency, as well momentum scale resolution, are presented compared to Monte Carlo simulations. The efficiency is measured be close $99\%$ over most covered phase space ($|\eta|<2.5$ $5 < p_{T} 100$ GeV). isolation varies between...
An angular analysis of the B 0 → K *0(→ + π −)μ μ − decay is presented. The dataset corresponds to an integrated luminosity 3.0 fb−1 pp collision data collected at LHCb experiment. complete information from used determine CP-averaged observables and CP asymmetries, taking account possible contamination decays with system in S-wave configuration. their correlations are reported bins q 2, invariant mass squared dimuon system. determined both unbinned maximum likelihood fit by using principal...
Combined measurements of Higgs boson production cross sections and branching fractions are presented. The combination is based on the analyses decay modes $H \to \gamma\gamma$, $ZZ^\ast$, $WW^\ast$, $\tau\tau$, $b\bar{b}$, $\mu\mu$, searches for decays into invisible final states, off-shell production. Up to $79.8$ fb$^{-1}$ proton-proton collision data collected at $\sqrt{s}=$ 13 TeV with ATLAS detector used. Results presented gluon-gluon fusion vector-boson processes, associated vector...
The reconstruction of the signal from hadrons and jets emerging proton-proton collisions at Large Hadron Collider (LHC) entering ATLAS calorimeters is based on a three-dimensional topological clustering individual calorimeter cell signals. cluster formation follows signal-significance patterns generated by electromagnetic hadronic showers. In this, algorithm implicitly performs noise suppression removing cells with insignificant signals which are not in close proximity to significant...
The large rate of multiple simultaneous proton--proton interactions, or pile-up, generated by the Large Hadron Collider in Run 1 required development many new techniques to mitigate adverse effects these conditions. This paper describes methods employed ATLAS experiment correct for impact pile-up on jet energy and shapes, presence spurious additional jets, with a primary focus 20.3 fb$^{-1}$ data sample collected at centre-of-mass $\sqrt{s} = 8$ TeV. correction that incorporate sophisticated...
Resonant structures in B^{0}→ψ^{'}π^{-}K^{+} decays are analyzed by performing a four-dimensional fit of the decay amplitude, using pp collision data corresponding to 3 fb^{-1} collected with LHCb detector. The cannot be described K^{+}π^{-} resonances alone, which is confirmed model-independent approach. A highly significant Z(4430)^{-}→ψ^{'}π^{-} component required, thus confirming existence this state. observed evolution Z(4430)^{-} amplitude ψ^{'}π^{-} mass establishes resonant nature...
A search for the rare decays ${B}_{s}^{0}\ensuremath{\rightarrow}{\ensuremath{\mu}}^{+}{\ensuremath{\mu}}^{\ensuremath{-}}$ and ${B}^{0}\ensuremath{\rightarrow}{\ensuremath{\mu}}^{+}{\ensuremath{\mu}}^{\ensuremath{-}}$ is performed with data collected in 2011 2012 LHCb experiment at Large Hadron Collider. The samples comprise $1.1\text{ }\text{ }{\mathrm{fb}}^{\ensuremath{-}1}$ of proton-proton collisions $\sqrt{s}=8\text{ }\mathrm{TeV}$ $1.0\text{ $\sqrt{s}=7\text{ }\mathrm{TeV}$. We...
The quantum numbers of the X(3872) meson are determined to be JPC = 1++ based on angular correlations in B+ K+ decays, where pi+pi- J/psi and \mu+\mu-. data correspond 1.0 fb-1 pp collisions collected by LHCb detector. only alternative assignment allowed previous measurements, JPC=2-+, is rejected with a confidence level equivalent more than eight Gaussian standard deviations using likelihood-ratio test full phase space. This result favors exotic explanations state.
The observation of Higgs boson production in association with a top quark pair ($t\bar{t}H$), based on the analysis proton-proton collision data at centre-of-mass energy 13 TeV recorded ATLAS detector Large Hadron Collider, is presented. Using corresponding to integrated luminosities up 79.8 fb$^{-1}$, and considering decays into $b\bar{b}$, $WW^*$, $\tau\tau$, $\gamma\gamma$, $ZZ^*$, observed significance 5.8 standard deviations, compared an expectation 4.9 deviations. Combined $t\bar{t}H$...
The Vertex Locator (VELO) is a silicon microstrip detector that surrounds the proton-proton interaction region in LHCb experiment. performance of during first years its physics operation reviewed. system operated vacuum, uses bi-phase CO2 cooling system, and sensors are moved to 7 mm from LHC beam for data taking. stability these characteristic features described, details material budget given. calibration timing processing algorithms implemented FPGAs described. fully characterised. have...
The production of J/psi mesons in proton-proton collisions at sqrt(s)=7 TeV is studied with the LHCb detector LHC. differential cross-section for prompt measured as a function transverse momentum pT and rapidity y fiducial region 0<pT<14 GeV/c 2.0<y<4.5. fraction from b-hadron decays are also same ranges. analysis based on data sample corresponding to an integrated luminosity 5.2pb-1. cross-sections over 10.52 +/- 0.04 1.40 +1.64/-2.20 mub 1.14 0.01 0.16 decays, where first uncertainty...
Jet energy scale measurements and their systematic uncertainties are reported for jets measured with the ATLAS detector using proton-proton collision data a center-of-mass of s=13 TeV, corresponding to an integrated luminosity 3.2 fb−1 collected during 2015 at LHC. Jets reconstructed from deposits forming topological clusters calorimeter cells, anti-kt algorithm radius parameter R=0.4. calibrated series simulation-based corrections in situ techniques. In techniques exploit transverse...
Combined analyses of the Higgs boson production and decay rates as well its coupling strengths to vector bosons fermions are presented. The combinations include results $H\to\gamma\gamma,\, ZZ^*,\, WW^*,\, Z\gamma,\, b\bar{b},\, \tau\tau$ $\mu\mu$ modes, constraints on associated with a pair top quarks off-shell boson. based LHC proton-proton collision datasets, integrated luminosities up 4.7 $\mathrm{fb}^{-1}$ at $\sqrt{s}=7$ TeV 20.3 $\sqrt{s}=8$ TeV, recorded by ATLAS detector in 2011...
A search for high-mass dielectron and dimuon resonances in the mass range of 250 GeV to 6 TeV is presented. The data were recorded by ATLAS experiment proton-proton collisions at a centre-of-mass energy $\sqrt{s}=$13 during Run 2 Large Hadron Collider correspond an integrated luminosity 139 fb$^{-1}$. functional form fitted dilepton invariant-mass distribution model contribution from background processes, generic signal shape used determine significance observed deviations this estimate. No...