Refine
Year of publication
Document Type
- Preprint (666)
- Article (372)
- Working Paper (1)
Language
- English (1039)
Has Fulltext
- yes (1039)
Is part of the Bibliography
- no (1039)
Keywords
- Heavy Ion Experiments (20)
- Hadron-Hadron Scattering (11)
- Hadron-Hadron scattering (experiments) (11)
- LHC (9)
- Heavy-ion collision (6)
- ALICE experiment (4)
- Collective Flow (4)
- Jets (4)
- Quark-Gluon Plasma (4)
- ALICE (3)
- Heavy Ions (3)
- Jets and Jet Substructure (3)
- pp collisions (3)
- Beauty production (2)
- Charm physics (2)
- Experimental nuclear physics (2)
- Experimental particle physics (2)
- Heavy Quark Production (2)
- Lepton-Nucleon Scattering (experiments) (2)
- Particle Correlations and Fluctuations (2)
- Particle and resonance production (2)
- Particle correlations and fluctuations (2)
- Pb–Pb collisions (2)
- QCD (2)
- Single electrons (2)
- 3 mm RAS instruments (1)
- 3 mm instruments (1)
- 900 GeV (1)
- ALICE detector (1)
- Anti-nuclei (1)
- Attention-Deficit/Hyperactivity Disorder (ADHD) (1)
- Biochemistry and chemical biology (1)
- Boosted Jets (1)
- CRP (1)
- Centrality Class (1)
- Centrality Selection (1)
- Collective Flow, (1)
- Comparison with QCD (1)
- Conformational trapping (1)
- Contingent Negative Variation, CNV (1)
- Continuous Performance Test, CPT (1)
- Cue-P3 (1)
- Developmental biology (1)
- E. colo (1)
- Electron-pion identification (1)
- Electroweak interaction (1)
- Elliptic flow (1)
- Event related potentials (1)
- Femtoscopy (1)
- Fibre/foam sandwich radiator (1)
- HBT (1)
- Hadron production (1)
- Hadron-Hadron Scattering Heavy (1)
- Hadron-hadron interactions (1)
- Haematocrit (1)
- Hard Scattering (1)
- Heat shock protein 27 (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)
- In vitro selection (1)
- Inclusive spectra (1)
- Intensity interferometry (1)
- Invariant Mass Distribution (1)
- Ionisation energy loss (1)
- Jet Physics (1)
- Jet Substructure (1)
- Material budget (1)
- Mean erythrocyte volume (1)
- Medicinal chemistry (1)
- Membrane protein (1)
- Mid-rapidity (1)
- Minimum Bias (1)
- Monte Carlo (1)
- Multi-Parton Interactions (1)
- Multi-strange baryons (1)
- Multi-wire proportional drift chamber (1)
- Nanobody (1)
- Nephrons (1)
- Neural network (1)
- Neurofeedback (1)
- Nuclear modification factor (1)
- Number of platelets (1)
- PYTHIA (1)
- Particle and Resonance Production (1)
- Pb–Pb (1)
- Periodontitis grades B and C (1)
- Phage display (1)
- Pharmacology (1)
- Production Cross Section (1)
- Properties of Hadrons (1)
- Proton–proton (1)
- Quark Deconfinement (1)
- Quark Gluon Plasma (1)
- Quark Production (1)
- Quark gluon plasma (1)
- Quarkonium (1)
- Randomized Controlled Trial (1)
- Rapidity Range (1)
- Relativistic heavy ion physics (1)
- Relativistic heavy-ion collisions (1)
- Resolution Parameter (1)
- Response control (1)
- Retirement planning (1)
- Ribosome display (1)
- Single muons (1)
- Slow Cortical Potentials, SCP (1)
- Small molecules (1)
- Structural biology and molecular biophysics (1)
- Sustained attention (1)
- Systematic Uncertainty (1)
- TR (1)
- Target validation (1)
- Time Projection Chamber (1)
- Tools and ressources (1)
- Tracking (1)
- Transition radiation detector (1)
- Transverse momentum (1)
- Trigger (1)
- Vector Boson Production (1)
- Xenon-based gas mixture (1)
- annuity puzzle (1)
- artifacts (1)
- attention-deficit/hyperactivity disorder (ADHD) (1)
- biogeographic legaciese (1)
- color vision (1)
- contextual modulation (1)
- cytokine(s) (1)
- dE/dx (1)
- data quality (1)
- detector (1)
- efficient coding (1)
- electroencephalography (EEG) (1)
- experimental results (1)
- forest classification (1)
- forest functional similarity (1)
- gamma oscillations (1)
- heavy ion experiments (1)
- kagome lattices (1)
- microlaparoscopy (1)
- minimally invasive surgery (1)
- multi-center magnons (1)
- multicenter study (1)
- neuroscience (1)
- neutrophil elastase (1)
- non-surgical periodontal therapy (1)
- pediatric robotic surgery (1)
- periodontal– systemic disease interactions (1)
- periodontitis (1)
- phased withdrawal accounts (1)
- phylogenetic community distance (1)
- predictive coding (1)
- quark gluon plasma (1)
- research article (1)
- rhesus macaque (1)
- robotically assisted surgery (1)
- robotics (1)
- spectra (1)
- surround suppression (1)
- terahertz magnetometry (1)
- terahertz photons (1)
- tropical forests (1)
- √sN N = 2.76 TeV (1)
Institute
- Physik (1025)
- Frankfurt Institute for Advanced Studies (FIAS) (957)
- Informatik (920)
- Medizin (6)
- Informatik und Mathematik (3)
- MPI für Hirnforschung (3)
- Ernst Strüngmann Institut (2)
- Hochschulrechenzentrum (2)
- Biochemie und Chemie (1)
- Biochemie, Chemie und Pharmazie (1)
The jet angularities are a class of jet substructure observables which characterize the angular and momentum distribution of particles within jets. These observables are sensitive to momentum scales ranging from perturbative hard scatterings to nonperturbative fragmentation into final-state hadrons. We report measurements of several groomed and ungroomed jet angularities in pp collisions at s√ = 5.02 TeV with the ALICE detector. Jets are reconstructed using charged particle tracks at midrapidity (|η| < 0.9). The anti-kT algorithm is used with jet resolution parameters R = 0.2 and R = 0.4 for several transverse momentum pchT jet intervals in the 20–100 GeV/c range. Using the jet grooming algorithm Soft Drop, the sensitivity to softer, wide-angle processes, as well as the underlying event, can be reduced in a way which is well-controlled in theoretical calculations. We report the ungroomed jet angularities, λα, and groomed jet angularities, λα,g, to investigate the interplay between perturbative and nonperturbative effects at low jet momenta. Various angular exponent parameters α = 1, 1.5, 2, and 3 are used to systematically vary the sensitivity of the observable to collinear and soft radiation. Results are compared to analytical predictions at next-to-leading-logarithmic accuracy, which provide a generally good description of the data in the perturbative regime but exhibit discrepancies in the nonperturbative regime. Moreover, these measurements serve as a baseline for future ones in heavy-ion collisions by providing new insight into the interplay between perturbative and nonperturbative effects in the angular and momentum substructure of jets. They supply crucial guidance on the selection of jet resolution parameter, jet transverse momentum, and angular scaling variable for jet quenching studies.
We report on the inclusive J/ψ production cross section measured at the CERN Large Hadron Collider in proton–proton collisions at a center-of-mass energy s√ = 13 TeV. The J/ψ mesons are reconstructed in the e+e− decay channel and the measurements are performed at midrapidity (|y|<0.9) in the transverse-momentum interval 0<pT<40 GeV/c, using a minimum-bias data sample corresponding to an integrated luminosity Lint=32.2 nb−1 and an Electromagnetic Calorimeter triggered data sample with Lint=8.3 pb−1. The pT-integrated J/ψ production cross section at midrapidity, computed using the minimum-bias data sample, is dσ/dy|y=0=8.97±0.24 (stat)±0.48 (syst)±0.15 (lumi) μb. An approximate logarithmic dependence with the collision energy is suggested by these results and available world data, in agreement with model predictions. The integrated and pT-differential measurements are compared with measurements in pp collisions at lower energies and with several recent phenomenological calculations based on the non-relativistic QCD and Color Evaporation models.
The production yield and angular anisotropy of prompt D+ s mesons were measured as a function of transverse momentum (pT) in Pb–Pb collisions at a centre-of-mass energy per nucleon pair √sNN = 5.02 TeV collected with the ALICE detector at the LHC. D+ s mesons and their charge conjugates were reconstructed at midrapidity (|y| < 0.5) from their hadronic decay channel D+ s → φπ+, with φ → K−K+, in the pT intervals 2 < pT < 50 GeV/c and 2 < pT < 36 GeV/c for the 0–10% and 30–50% centrality intervals. For pT > 10 GeV/c, the measured D+ s -meson nuclear modification factor RAA is consistent with the one of non-strange D mesons within uncertainties, while at lower pT a hint for a D+ s -meson RAA larger than that of non-strange D mesons is seen. The enhanced production of D+ s relative to nonstrange D mesons is also studied by comparing the pT-dependent D+ s /D0 production yield ratios in Pb–Pb and in pp collisions. The ratio measured in Pb–Pb collisions is found to be on average higher than that in pp collisions in the interval 2 < pT < 8 GeV/c with a significance of 2.3σ and 2.4σ for the 0–10% and 30–50% centrality intervals. The azimuthal anisotropy coefficient v2 of prompt D+ s mesons was measured in Pb–Pb collisions in the 30–50% centrality interval and is found to be compatible with that of non-strange D mesons. The main features of the measured RAA, D+ s /D0 ratio, and v2 as a function of pT are described by theoretical calculations of charm-quark transport in a hydrodynamically expanding quark–gluon plasma including hadronisation via charm-quark recombination with light quarks from the medium. The pT-integrated production yield of D+s mesons is compatible with the prediction of the statistical hadronisation model.
The transverse momentum (pT) differential cross section of the charm-strange baryon Ξ0c is measured at midrapidity (|y| < 0.5) via its semileptonic decay into e+Ξ−νe in pp collisions at s√ = 5.02 TeV with the ALICE detector at the LHC. The ratio of the pT-differential Ξ0c-baryon and D0-meson production cross sections is also reported. The measurements are compared with simulations with different tunes of the PYTHIA 8 event generator, with predictions from a statistical hadronisation model (SHM) with a largely augmented set of charm-baryon states beyond the current lists of the Particle Data Group, and with models including hadronisation via quark coalescence. The pT-integrated cross section of prompt Ξ0c-baryon production at midrapidity is also reported, which is used to calculate the baryon-to-meson ratio Ξ0c/D0 = 0.20 ± 0.04 (stat.)+0.08−0.07 (syst.). These results provide an additional indication of a modification of the charm fragmentation from e+e− and e−p collisions to pp collisions.
The interaction of Λ and Σ hyperons (Y) with nucleons (N) is strongly influenced by the coupled-channel dynamics. Due to the small mass difference of the NΛ and NΣ systems, the sizable coupling strength of the NΣ ↔ NΛ processes constitutes a crucial element in the determination of the NΛ interaction. In this letter we present the most precise measurements on the interaction of p pairs, from zero relative momentum up to the opening of the NΣ channel. The correlation function in the relative momentum space for p ⊕ p pairs measured in high-multiplicity triggered pp collisions at √s = 13 TeV at the LHC is reported. The opening of the inelastic NΣ channels is visible in the extracted correlation function as a cusp-like structure occurring at relative momentum k∗ = 289 MeV/c. This represents the first direct experimental observation of the NΣ ↔ NΛ coupled channel in the p system. The correlation function is compared with recent chiral effective field theory calculations, based on different strengths of the NΣ ↔ NΛ transition potential. A weaker coupling, as possibly supported by the present measurement, would require a more repulsive three-body NNΛ interaction for a proper description of the in-medium properties, which has implications on the nuclear equation of state and for the presence of hyperons inside neutron stars.
The production of baryons and K0 S mesons (V0 particles) was measured in p–Pb collisions at √sNN = 5.02 TeV and pp collisions at √s = 7 TeV with ALICE at the LHC. The production of these strange particles is studied separately for particles associated with hard scatterings and the underlying event to shed light on the baryon-to-meson ratio enhancement observed at intermediate transverse momentum (pT) in high multiplicity pp and p–Pb collisions. Hard scatterings are selected on an eventby-event basis with jets reconstructed with the anti-kT algorithm using charged particles. The production of strange particles associated with jets pch T, jet > 10 and pch T, jet > 20 GeV/c in p–Pb collisions, and with jet pch T, jet > 10 GeV/c in pp collisions is reported as a function of pT. Its dependence on angular distance from the jet axis, R(V0, jet), for jets with pch T, jet > 10 GeV/c in p–Pb collisions is reported as well. The pT-differential production spectra of strange particles associated with jets are found to be harder compared to that in the underlying event and both differ from the inclusive measurements. In events containing a jet, the density of the V0 particles in the underlying event is found to be larger than the density in the minimum bias events. The /K0 S ratio associated with jets in p–Pb collisions is consistent with the ratio in pp collisions and follows the expectation of jets fragmenting in vacuum. On the other hand, this ratio within jets is consistently lower than the one obtained in the underlying event and it does not show the characteristic enhancement of baryons at intermediate pT often referred to as “baryon anomaly” in the inclusive measurements.
The production of ϕ mesons has been studied in pp collisions at LHC energies with the ALICE detector via the dimuon decay channel in the rapidity region 2.5<y<4. Measurements of the differential cross section d2σ/dydpT are presented as a function of the transverse momentum (pT) at the center-of-mass energies s√=5.02, 8 and 13 TeV and compared with the ALICE results at midrapidity. The differential cross sections at s√=5.02 and 13 TeV are also studied in several rapidity intervals as a function of pT, and as a function of rapidity in three pT intervals. A hardening of the pT-differential cross section with the collision energy is observed, while, for a given energy, pT spectra soften with increasing rapidity and, conversely, rapidity distributions get slightly narrower at increasing pT. The new results, complementing the published measurements at s√=2.76 and 7 TeV, allow one to establish the energy dependence of ϕ meson production and to compare the measured cross sections with phenomenological models. None of the considered models manages to describe the evolution of the cross section with pT and rapidity at all the energies.
Measurements of event-by-event fluctuations of charged-particle multiplicities in Pb–Pb collisions at sNN−−−√ = 2.76 TeV using the ALICE detector at the CERN Large Hadron Collider (LHC) are presented in the pseudorapidity range |η|<0.8 and transverse momentum 0.2<pT<2.0 GeV/c. The amplitude of the fluctuations is expressed in terms of the variance normalized by the mean of the multiplicity distribution. The η and pT dependences of the fluctuations and their evolution with respect to collision centrality are investigated. The multiplicity fluctuations tend to decrease from peripheral to central collisions. The results are compared to those obtained from HIJING and AMPT Monte Carlo event generators as well as to experimental data at lower collision energies. Additionally, the measured multiplicity fluctuations are discussed in the context of the isothermal compressibility of the high-density strongly-interacting system formed in central Pb–Pb collisions.
The pT-differential production cross sections of prompt and non-prompt (produced in beauty-hadron decays) D mesons were measured by the ALICE experiment at midrapidity (|y| < 0.5) in proton-proton collisions at s√ = 5.02 TeV. The data sample used in the analysis corresponds to an integrated luminosity of (19.3 ± 0.4) nb−1. D mesons were reconstructed from their decays D0 → K−π+, D+ → K−π+π+, and D+s→φπ+→K−K+π+ and their charge conjugates. Compared to previous measurements in the same rapidity region, the cross sections of prompt D+ and D+s mesons have an extended pT coverage and total uncertainties reduced by a factor ranging from 1.05 to 1.6, depending on pT, allowing for a more precise determination of their pT-integrated cross sections. The results are well described by perturbative QCD calculations. The fragmentation fraction of heavy quarks to strange mesons divided by the one to non-strange mesons, fs/(fu + fd), is compatible for charm and beauty quarks and with previous measurements at different centre-of-mass energies and collision systems. The bb¯¯¯ production cross section per rapidity unit at midrapidity, estimated from non-prompt D-meson measurements, is dσbb¯¯¯/dy∣∣|y|<0.5=34.5±2.4(stat)+4.7−2.9(tot.syst) μb. It is compatible with previous measurements at the same centre-of-mass energy and with the cross section pre- dicted by perturbative QCD calculations.
In quantum scattering processes between two particles, aspects characterizing the strong and Coulomb forces can be observed in kinematic distributions of the particle pairs. The sensitivity to the interaction potential reaches a maximum at low relative momentum and vanishing distance between the two particles. Ultrarelativistic heavy-ion collisions at the LHC provide an abundant source of many hadron species and can be employed as a measurement method of scattering parameters that is complementary to scattering experiments. This study confirms that momentum correlations of particles produced in Pb-Pb collisions at the LHC provide an accurate measurement of kaon-proton scattering parameters at low relative momentum, allowing precise access to the K−p→K−p process. This work also validates the femtoscopic measurement in ultrarelativistic heavy-ion collisions as an alternative to scattering experiments and a complementary tool to the study of exotic atoms with comparable precision. In this work, the first femtoscopic measurement of momentum correlations of K−p (K+p¯¯¯) and K+p(K−p¯¯¯) pairs in Pb-Pb collisions at centre-of-mass energy per nucleon pair of sNN−−−√=5.02 TeV registered by the ALICE experiment is reported. The components of the K−p complex scattering length are extracted and found to be Rf0=−0.91± 0.03(stat)+0.17−0.03(syst) and If0=0.92± 0.05(stat)+0.12−0.33(syst). The results are compared with chiral effective field theory predictions as well as with existing data from dedicated scattering and exotic kaonic atom experiments.