Refine
Year of publication
Document Type
- Preprint (680)
- Article (403)
- Book (2)
- Conference Proceeding (2)
- Working Paper (1)
Has Fulltext
- yes (1088)
Is part of the Bibliography
- no (1088)
Keywords
- Heavy Ion Experiments (20)
- Hadron-Hadron Scattering (11)
- Hadron-Hadron scattering (experiments) (11)
- LHC (10)
- Heavy-ion collision (6)
- ALICE experiment (4)
- Collective Flow (4)
- Jets (4)
- Kollisionen schwerer Ionen (4)
- Quark-Gluon Plasma (4)
- heavy ion collisions (4)
- ALICE (3)
- Heavy Ions (3)
- Jets and Jet Substructure (3)
- Magnetic resonance imaging (3)
- Quark Gluon Plasma (3)
- pp collisions (3)
- Algorithms (2)
- Beauty production (2)
- Bone density (2)
- Charm physics (2)
- Experimental nuclear physics (2)
- Experimental particle physics (2)
- Heavy Quark Production (2)
- Image processing (2)
- Lepton-Nucleon Scattering (experiments) (2)
- Multidetector computed tomography (2)
- Osteoporosis (2)
- Particle Correlations and Fluctuations (2)
- Particle and resonance production (2)
- Particle correlations and fluctuations (2)
- Pb–Pb collisions (2)
- QCD (2)
- QGP (2)
- Quark-Gluon-Plasma (2)
- Single electrons (2)
- Spine (2)
- Tomography (x-ray computed) (2)
- UrQMD Modell (2)
- quark-gluon-plasma (2)
- 900 GeV (1)
- ALICE detector (1)
- AML – acute myeloid leukemia (1)
- Age determination by skeleton (1)
- Anti-nuclei (1)
- Arrhenatheretum elatioris (1)
- Artificial intelligence (1)
- Asymmetric Information (1)
- Bipolar disorder (1)
- Bone diseases, Metabolic (1)
- Bone marrow (1)
- Boosted Jets (1)
- COVID-19 (1)
- CT dual-energy computed tomography (1)
- CVID (1)
- Calcium (1)
- Cell biology (1)
- Centrality Class (1)
- Centrality Selection (1)
- Circadian (1)
- Collective Flow, (1)
- Comparison with QCD (1)
- Compression stocking (1)
- Computed tomography, X-ray (1)
- Contrast agent (1)
- Coordination (1)
- DSM (1)
- DTI (1)
- Deep vein thrombosis (1)
- Dehydrogenase Cofactors (1)
- Diagnostic imaging (1)
- Dual-energy computed tomography (1)
- ESR Spectra (1)
- Edema (1)
- Electron-pion identification (1)
- Electroweak interaction (1)
- Elliptic flow (1)
- Energie (1)
- Epilepsy (1)
- European Society for Immunodeficiencies (ESID) (1)
- Eutrophierung (1)
- Femtoscopy (1)
- Fibre/foam sandwich radiator (1)
- German PID-NET registry (1)
- Glatthaferwiesen (1)
- HBT (1)
- Hadron production (1)
- Hadron-Hadron Scattering Heavy (1)
- Hadron-hadron interactions (1)
- Hard Scattering (1)
- Heart transplantation (1)
- Heavy Ion Experiment (1)
- Heavy flavor production (1)
- Heavy flavour production (1)
- Heavy ions (1)
- Heavy-flavour decay muons (1)
- Heavy-flavour production (1)
- Heavy-ion collisions (1)
- Hepatocellular carcinoma (1)
- Herniated disk (1)
- IgG substitution therapy (1)
- Image processing (computer-assisted) (1)
- Inclusive spectra (1)
- Induced pluripotent stem cells (1)
- Intensity interferometry (1)
- Intervertebral disc displacement (1)
- Invariant Mass Distribution (1)
- Ionisation energy loss (1)
- Jet Physics (1)
- Jet Substructure (1)
- LIR interaction, (1)
- Learning Effects (1)
- Leipziger Tieflandsbucht (1)
- Lipiodol (1)
- Managerial Accounting (1)
- Material budget (1)
- Mid-rapidity (1)
- Minimum Bias (1)
- Mitomycin C (1)
- Monte Carlo (1)
- Multi-Parton Interactions (1)
- Multi-strange baryons (1)
- Multi-wire proportional drift chamber (1)
- Necrotic area (1)
- Neonatal brain damage (1)
- Neural circuits (1)
- Neural network (1)
- Nuclear modification factor (1)
- Optogenetics (1)
- Osteoporotic fractures (1)
- Oxidation States (1)
- PID prevalence (1)
- PYTHIA (1)
- Particle and Resonance Production (1)
- Pb–Pb (1)
- Phantoms (imaging) (1)
- Positron emission tomography (1)
- Production Cross Section (1)
- Properties of Hadrons (1)
- Proton–proton (1)
- Psychiatry (1)
- Pulmonary embolism (1)
- Quark Deconfinement (1)
- Quark Production (1)
- Quark gluon plasma (1)
- Quarkonium (1)
- Radiology (1)
- Rapidity Range (1)
- Relativistic heavy ion physics (1)
- Relativistic heavy-ion collisions (1)
- Resolution Parameter (1)
- Response (1)
- Retrospective studies (1)
- Retrospective study (1)
- Ruthenium Complexes (1)
- SPS (1)
- Seasonal variation (1)
- Single muons (1)
- Solar insolation (1)
- Spinal fractures (1)
- Stem-cell differentiation (1)
- Straßenränder (1)
- Suicide (1)
- Sunlight (1)
- Survival (1)
- Systematic Uncertainty (1)
- TACE (1)
- TBSS (1)
- TR (1)
- Target Costing (1)
- Thorax (1)
- Time Projection Chamber (1)
- Tomography (1)
- Tracking (1)
- Transition radiation detector (1)
- Transverse momentum (1)
- Trigger (1)
- Tumor volume (1)
- URQMD (1)
- Ultra-relativistic Quantum Molecular Dynamics model (1)
- Ultrarelativistic Quantum Molecular Dynamics (1)
- Ultrarelativistic Quantum Molecular Model (1)
- Ultrarelativistisches Quant Molekulares Modell (1)
- UrQMD model (1)
- Vasculitis (1)
- Vector Boson Production (1)
- Vegetationstabellen (1)
- Vegetationsveränderungen (1)
- Venous thromboembolism (1)
- Virtual noncalcium reconstructions (1)
- X-ray computed (1)
- Xenon-based gas mixture (1)
- breast cancer (1)
- channelrhodopsin (1)
- computed tomography (1)
- computer-assisted (1)
- conformational changes (1)
- cytarabin (1)
- dE/dx (1)
- detector (1)
- diagnostic imaging (1)
- dual-energy (1)
- electron cryo-microscopy (1)
- energy (1)
- erythropoiesis (1)
- experimental results (1)
- genetically caused iron imbalance (1)
- hadron hadron Kollision (1)
- hadron hadron collision (1)
- heavy ion experiments (1)
- heavy ions (1)
- hemispherotomy (1)
- inhibitors (1)
- intestinal iron loss (1)
- iron (1)
- juvenile brain lesion (1)
- light-gated ion channel (1)
- liver (1)
- microbial rhodopsin (1)
- multidetector computed tomography (1)
- phage display (1)
- plasticity (1)
- portal vein (1)
- primary immunodeficiency (PID) (1)
- quark gluon plasma (1)
- radiomics (1)
- red cells (1)
- registry for primary immunodeficiency (1)
- relativistic (1)
- relativistische (1)
- schwere Ione (1)
- selective autophagy receptor (1)
- short linear motifs (SLiMs) (1)
- spectra (1)
- thrombosis (1)
- vegetationskundliche Software (1)
- α-Iminoketones (1)
- √sN N = 2.76 TeV (1)
Institute
- Physik (1054)
- Frankfurt Institute for Advanced Studies (FIAS) (955)
- Informatik (920)
- Medizin (21)
- Biochemie und Chemie (6)
- Hochschulrechenzentrum (3)
- Informatik und Mathematik (3)
- Biowissenschaften (2)
- MPI für Biophysik (2)
- Exzellenzcluster Makromolekulare Komplexe (1)
We present a study of the inclusive charged-particle transverse momentum (pT) spectra as a function of charged-particle multiplicity density at mid-pseudorapidity, dNch/dη, in pp collisions at s√=5.02 and 13 TeV covering the kinematic range |η|<0.8 and 0.15<pT<20 GeV/c. The results are presented for events with at least one charged particle in |η|<1 (INEL>0). The pT spectra are reported for two multiplicity estimators covering different pseudorapidity regions. The pT spectra normalized to that for INEL>0 show little energy dependence. Moreover, the high-pT yields of charged particles increase faster than the charged-particle multiplicity density. The average pT as a function of multiplicity and transverse spherocity is reported for pp collisions at s√=13 TeV. For low- (high-) spherocity events, corresponding to jet-like (isotropic) events, the average pT is higher (smaller) than that measured in INEL>0 pp collisions. Within uncertainties, the functional form of ⟨pT⟩(Nch) is not affected by the spherocity selection. While EPOS LHC gives a good description of many features of data, PYTHIA overestimates the average pT in jet-like events.
Measurement of the production of charm jets tagged with D0 mesons in pp collisions at √s = 7 TeV
(2019)
The production of charm jets in proton-proton collisions at a center-of-mass energy of s√=7 TeV was measured with the ALICE detector at the CERN Large Hadron Collider. The measurement is based on a data sample corresponding to a total integrated luminosity of 6.23 nb−1, collected using a minimum-bias trigger. Charm jets are identified by the presence of a D0 meson among their constituents. The D0 mesons are reconstructed from their hadronic decay D0 →K−π+. The D0-meson tagged jets are reconstructed using tracks of charged particles (track-based jets) with the anti-kT algorithm in the jet transverse momentum range 5<pchT,jet< 30 GeV/c and pseudorapidity |ηjet| < 0.5. The fraction of charged jets containing a D0-meson increases with pchT,jet from 0.042 ± 0.004 (stat) ± 0.006 (syst) to 0.080 ± 0.009 (stat) ± 0.008 (syst). The distribution of D0-meson tagged jets as a function of the jet momentum fraction carried by the D0 meson in the direction of the jet axis (zch∥) is reported for two ranges of jet transverse momenta, 5<pchT,jet< 15 GeV/c and 15<pchT,jet< 30 GeV/c in the intervals 0.2<zch∥∥<1.0 and 0.4<zch∥∥<1.0, respectively. The data are compared with results from Monte Carlo event generators (PYTHIA 6, PYTHIA 8 and Herwig 7) and with a Next-to-Leading-Order perturbative Quantum Chromodynamics calculation, obtained with the POWHEG method and interfaced with PYTHIA 6 for the generation of the parton shower, fragmentation, hadronisation and underlying event.
Charged-particle pseudorapidity density at mid-rapidity in p-Pb collisions at √sNN = 8.16 TeV
(2019)
The pseudorapidity density of charged particles, dNch/dη, in p–Pb collisions has been measured at a centre-of-mass energy per nucleon–nucleon pair of sNN−−−√ = 8.16 TeV at mid-pseudorapidity for non-single-diffractive events. The results cover 3.6 units of pseudorapidity, |η|<1.8. The dNch/dη value is 19.1±0.7 at |η|<0.5. This quantity divided by ⟨Npart⟩ / 2 is 4.73±0.20, where ⟨Npart⟩is the average number of participating nucleons, is 9.5% higher than the corresponding value for p–Pb collisions at sNN−−−√ = 5.02 TeV. Measurements are compared with models based on different mechanisms for particle production. All models agree within uncertainties with data in the Pb-going side, while HIJING overestimates, showing a symmetric behaviour, and EPOS underestimates the p-going side of the dNch/dη distribution. Saturation-based models reproduce the distributions well for η>−1.3. The dNch/dη is also measured for different centrality estimators, based both on the charged-particle multiplicity and on the energy deposited in the Zero-Degree Calorimeters. A study of the implications of the large multiplicity fluctuations due to the small number of participants for systems like p–Pb in the centrality calculation for multiplicity-based estimators is discussed, demonstrating the advantages of determining the centrality with energy deposited near beam rapidity.
A measurement of the production of prompt +c baryons in Pb–Pb collisions at √sNN = 5.02 TeV with the ALICE detector at the LHC is reported. The +c and − c were reconstructed at midrapidity (|y| < 0.5) via the hadronic decay channel +c → pK0 S (and charge conjugate) in the transverse momentum and centrality intervals 6 < pT < 12 GeV/c and 0–80%. The +c /D0 ratio, which is sensitive to the charm quark hadronisation mechanisms in the medium, is measured and found to be larger than the ratio measured in minimum-bias pp collisions at √s = 7 TeV and in p–Pb collisions at √sNN = 5.02 TeV. In particular, the values in p–Pb and Pb–Pb collisions differ by about two standard deviations of the combined statistical and systematic uncertainties in the common pT interval covered by the measurements in the two collision systems. The + c /D0 ratio is also compared with model calculations including different implementations of charm quark hadronisation. The measured ratio is reproduced by models implementing a pure coalescence scenario, while adding a fragmentation contribution leads to an underestimation. The + c nuclear modification factor, RAA, is also presented. The measured values of the RAA of + c , D+ s and non-strange D mesons are compatible within the combined statistical and systematic uncertainties. They show, however, a hint of a hierarchy (RD0 AA < RD+ s AA < R+ c AA ), conceivable with a contribution from coalescence mechanisms to charm hadron formation in the medium.
The first measurement of e+e− pair production at mid-rapidity (|ηe| < 0.8) in pp collisions at s√=7 TeV with ALICE at the LHC is presented. The dielectron production is studied as a function of the invariant mass (mee < 3.3 GeV/c2), the pair transverse momentum (pT,ee < 8 GeV/c), and the pair transverse impact parameter (DCAee), i.e., the average distance of closest approach of the reconstructed electron and positron tracks to the collision vertex, normalised to its resolution. The results are compared with the expectations from a cocktail of known hadronic sources and are well described when PYTHIA is used to generate the heavy-flavour contributions. In the low-mass region (0.14 < mee < 1.1 GeV/c2), prompt and non-prompt e+e− sources can be separated via the DCAee. In the intermediate-mass region (1.1 < mee < 2.7 GeV/c2), a double-differential fit to the data in mee and pT,ee and a fit of the DCAee distribution allow the total cc¯¯ and bb¯¯¯ cross sections to be extracted. Two different event generators, PYTHIA and POWHEG, can reproduce the shape of the two-dimensional mee and pT,ee spectra, as well as the shape of the DCAee distribution, reasonably well. However, differences in the cc¯¯ and bb¯¯¯ cross sections are observed when using the generators to extrapolate to full phase space. Finally, the ratio of inclusive to decay photons is studied via the measurement of virtual direct photons in the transverse-momentum range 1 < pT < 8 GeV/c. This is found to be unity within the statistical and systematic uncertainties and consistent with expectations from next-to-leading order perturbative quantum chromodynamic calculations.
The production yield of prompt D mesons and their elliptic flow coefficient v2 were measured with the Event-Shape Engineering (ESE) technique applied to mid-central (10–30% and 30–50% centrality classes) Pb-Pb collisions at the centre-of-mass energy per nucleon pair sNN−−−√=5.02 TeV, with the ALICE detector at the LHC. The ESE technique allows the classification of events, belonging to the same centrality, according to the azimuthal anisotropy of soft particle production in the collision. The reported measurements give the opportunity to investigate the dynamics of charm quarks in the Quark-Gluon Plasma and provide information on their participation in the collective expansion of the medium. D mesons were reconstructed via their hadronic decays at mid-rapidity, |η| < 0.8, in the transverse momentum interval 1 < pT < 24 GeV/c. The v2 coefficient is found to be sensitive to the event-shape selection confirming a correlation between the D-meson azimuthal anisotropy and the collective expansion of the bulk matter, while the per-event D-meson yields do not show any significant modification within the current uncertainties.
Medium modification of the shape of small-radius jets in central Pb-Pb collisions at √sNN = 2.76 TeV
(2018)
We present the measurement of a new set of jet shape observables for track-based jets in central Pb-Pb collisions at sNN−−−√=2.76 TeV. The set of jet shapes includes the first radial moment or angularity, g; the momentum dispersion, pTD; and the difference between the leading and sub-leading constituent track transverse momentum, LeSub. These observables provide complementary information on the jet fragmentation and can constrain different aspects of the theoretical description of jet-medium interactions. The jet shapes were measured for a small resolution parameter R = 0.2 and were fully corrected to particle level. The observed jet shape modifications indicate that in-medium fragmentation is harder and more collimated than vacuum fragmentation as obtained by PYTHIA calculations, which were validated with the measurements of the jet shapes in proton-proton collisions at s√=7 TeV. The comparison of the measured distributions to templates for quark and gluon-initiated jets indicates that in-medium fragmentation resembles that of quark jets in vacuum. We further argue that the observed modifications are not consistent with a totally coherent energy loss picture where the jet loses energy as a single colour charge, suggesting that the medium resolves the jet structure at the angular scales probed by our measurements (R = 0.2). Furthermore, we observe that small-R jets can help to isolate purely energy loss effects from other effects that contribute to the modifications of the jet shower in medium such as the correlated background or medium response.
Neutral pion and η meson invariant differential yields were measured in non-single diffractive p–Pb collisions at sNN−−−√ = 5.02 TeV with the ALICE experiment at the CERN LHC. The analysis combines results from three complementary photon measurements, utilizing the PHOS and EMCal calorimeters and the Photon Conversion Method. The invariant differential yields of π0 and η meson inclusive production are measured near mid-rapidity in a broad transverse momentum range of 0.3<pT<20 GeV/c and 0.7<pT<20 GeV/c, respectively. The measured η/π0 ratio increases with pT and saturates for pT > 4 GeV/c at 0.483±0.015stat±0.015sys. A deviation from mT scaling is observed for pT< 2 GeV/c. The measured η/π0 ratio is consistent with previous measurements from proton-nucleus and pp collisions over the full pT range. The measured η/π0 ratio at high pT also agrees within uncertainties with measurements from nucleus–nucleus collisions. The π0 and η yields in p–Pb relative to the scaled pp interpolated reference, RpPb, are presented for 0.3<pT< 20 GeV/c and 0.7<pT< 20 GeV/c, respectively. The results are compared with theoretical model calculations. The values of RpPb are consistent with unity for transverse momenta above 2 GeV/c. These results support the interpretation that the suppressed yield of neutral mesons measured in Pb–Pb collisions at LHC energies is due to parton energy loss in the hot QCD medium.
The ALICE Collaboration has measured the energy dependence of exclusive photoproduction of J/ψ vector mesons off proton targets in ultra–peripheral p–Pb collisions at a centre-of-mass energy per nucleon pair sNN−−−√=5.02 TeV. The e+e− and μ+μ− decay channels are used to measure the cross section as a function of the rapidity of the J/ψ in the range −2.5<y<2.7, corresponding to an energy in the γp centre-of-mass in the interval 40<Wγp<550 GeV. The measurements, which are consistent with a power law dependence of the exclusive J/ψ photoproduction cross section, are compared to previous results from HERA and the LHC and to several theoretical models. They are found to be compatible with previous measurements.
The jet radial structure and particle transverse momentum (pT) composition within jets are presented in centrality-selected Pb–Pb collisions at √sNN = 2.76 TeV. Track-based jets, which are also called charged jets, were reconstructed with a resolution parameter of R = 0.3 at midrapidity |ηch jet| < 0.6 for transverse momenta pT, ch jet = 30–120 GeV/c. Jet–hadron correlations in relative azimuth and pseudorapidity space (Δϕ, Δη) are measured to study the distribution of the associated particles around the jet axis for different pT,assoc-ranges between 1 and 20 GeV/c. The data in Pb–Pb collisions are compared to reference distributions for pp collisions, obtained using embedded PYTHIA simulations. The number of high-pT associate particles (4 < pT,assoc < 20 GeV/c) in Pb–Pb collisions is found to be suppressed compared to the reference by 30 to 10% depending on centrality. The radial particle distribution relative to the jet axis shows a moderate modification in Pb–Pb collisions with respect to PYTHIA. High-pT associate particles are slightly more collimated in Pb–Pb collisions compared to the reference, while low-pT associate particles tend to be broadened. The results, which are presented for the first time down to pT, ch jet = 30 GeV/c in Pb–Pb collisions, are compatible with both previous jet–hadron-related measurements from the CMS Collaboration and jet shape measurements from the ALICE Collaboration at higher pT, and add further support for the established picture of in-medium parton energy loss.