Refine
Year of publication
Document Type
- Preprint (689)
- Article (460)
- Conference Proceeding (4)
- Report (3)
- Review (1)
- Working Paper (1)
Has Fulltext
- yes (1158)
Is part of the Bibliography
- no (1158)
Keywords
- Heavy Ion Experiments (21)
- 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)
- Epilepsy (3)
- Frieden (3)
- Friedenskonferenz (3)
- Heavy Ions (3)
- Heavy Quark Production (3)
- Jets and Jet Substructure (3)
- MSC (3)
- MSC2013 (3)
- Prostate cancer (3)
- Sicherheitskonferenz (3)
- TAVI (3)
- pp collisions (3)
- radical prostatectomy (3)
- security conference (3)
- Beauty production (2)
- Bipolar disorder (2)
- Charm physics (2)
- Diagnostic markers (2)
- Elliptic flow (2)
- Experimental nuclear physics (2)
- Experimental particle physics (2)
- Heavy-ion collisions (2)
- Lepton-Nucleon Scattering (experiments) (2)
- Machine learning (2)
- München (2)
- Oncology (2)
- Particle Correlations and Fluctuations (2)
- Particle and resonance production (2)
- Particle correlations and fluctuations (2)
- Pb–Pb collisions (2)
- QCD (2)
- Seizure (2)
- Single electrons (2)
- aortic stenosis (2)
- biomarker (2)
- functional outcome (2)
- pelvic packing (2)
- penile cancer (2)
- prostate cancer (2)
- targeted therapy (2)
- 900 GeV (1)
- ACE inhibitor (1)
- AIS (1)
- AKT (1)
- ALICE detector (1)
- AT1 receptor antagonist (1)
- ATM (1)
- Accelerators & Beams (1)
- Accelerators & storage rings (1)
- Alcohol consumption (1)
- Angiomyolipoma (1)
- Anti-nuclei (1)
- Anti-seizure medication (1)
- Anticonvulsant (1)
- Aortic stenosis (1)
- Artesunate (1)
- Artificial Intelligence (1)
- Artificial intelligence (1)
- Atomic & molecular beams (1)
- Atomic and Molecular Physics (1)
- Atomic, Molecular & Optical (1)
- Awareness campaign (1)
- B-slope (1)
- BESIII (1)
- BPDCN (1)
- BPH (1)
- Beam loss (1)
- Benutzeroberfläche (1)
- Biodiversity Data (1)
- Biomarker (1)
- Biomarkers (1)
- Biomedical engineering (1)
- Biomonitoring (1)
- Blood pressure (1)
- Bone cement implantation syndrome (1)
- Boosted Jets (1)
- Botanical Collections (1)
- Breast cancer (1)
- C-clamp (1)
- CDKN2A (1)
- CRPC (1)
- CT (1)
- CVID (1)
- Cancer (1)
- Cancer check up (1)
- Cancer detection and diagnosis (1)
- Cell-to-Cell Spread (1)
- Centrality Class (1)
- Centrality Selection (1)
- Cerebral oxygen saturation (1)
- Cerebrovascular disorders (1)
- Charge-transfer collisions (1)
- Charm quark spatial diffusion coefficient (1)
- Children (1)
- Circadian (1)
- Circular accelerators (1)
- Clinical study (1)
- Coalescence (1)
- Collective Flow, (1)
- Collectivity (1)
- Comparison with QCD (1)
- Computerlinguistik (1)
- Conservation (1)
- Conservation biogeography (1)
- Correlation (1)
- Costs (1)
- Critical point (1)
- Deuteron production (1)
- Diagnostic differentiation (1)
- Diffraction (1)
- Digitization (1)
- Elastic scattering (1)
- Electromagnetic form factors (1)
- Electron-pion identification (1)
- Electronic transitions (1)
- Electroweak interaction (1)
- Esophageal adenocarcinoma (1)
- Europe (1)
- European Society for Immunodeficiencies (ESID) (1)
- Everolimus (1)
- Eyes (1)
- FFLU (1)
- Falciparum (1)
- Femtoscopy (1)
- Fibre/foam sandwich radiator (1)
- Functional outcomes (1)
- FungiScope® registry (1)
- GFAP (1)
- Gadobutrol (1)
- Gadopentate dimeglumine (1)
- Genetic causes of cancer (1)
- Genetic testing (1)
- Genetic wildlife monitoring (1)
- Genetics (1)
- Genetics research (1)
- German PID-NET registry (1)
- Glaucoma (1)
- Gleason Grade Group (1)
- HBT (1)
- HCC (1)
- HNSCC (1)
- Hadron production (1)
- Hadron-Hadron Scattering Heavy (1)
- Hadron-hadron interactions (1)
- Hair sampling (1)
- Hard Scattering (1)
- Heavy Ion Experiment (1)
- Heavy flavor production (1)
- Heavy flavour production (1)
- Heavy ions (1)
- Heavy-Ion Collision (1)
- Heavy-flavor decay electron (1)
- Heavy-flavour decay muons (1)
- Heavy-flavour production (1)
- Herbaria (1)
- Higher moments (1)
- Hip hemiarthroplasty (1)
- Histology (1)
- HoLEP (1)
- Human genetics (1)
- ICU (1)
- IL-10 (1)
- IL-6 (1)
- ISS (1)
- IgG substitution therapy (1)
- Inclusive spectra (1)
- Initial state radiation (1)
- Injury Severity Score (ISS) (1)
- Intensity interferometry (1)
- Invariant Mass Distribution (1)
- Invasive fungal infections (1)
- Ionisation energy loss (1)
- Issue 96 (1)
- Jet Physics (1)
- Jet Substructure (1)
- KRAS (1)
- Lee-type (1)
- Local therapy (1)
- Lomentospora prolificans (1)
- Low & intermediate-energy accelerators (1)
- Lure sticks (1)
- MRI (1)
- MTOR inhibitor (1)
- Malaria (1)
- Material budget (1)
- Medicine (1)
- Metastasis-directed therapy (1)
- Mid-rapidity (1)
- MinION (1)
- Minimum Bias (1)
- Mitochondria (1)
- Monte Carlo (1)
- Morphometry (1)
- Multi-Parton Interactions (1)
- Multi-strange baryons (1)
- Multi-wire proportional drift chamber (1)
- Multiparametric MRI (1)
- NIRS (1)
- NRAS (1)
- NSE (1)
- NVBP (1)
- Nerve fibers (1)
- Neural network (1)
- Noninferiority (1)
- Noninvasive genetic sampling (1)
- Nuclear astrophysics (1)
- Nuclear modification factor (1)
- Nuclear physics of explosive environments (1)
- Nuclear reactions (1)
- Oligometastatic (1)
- Outcome (1)
- Ovarian cancer (1)
- PID prevalence (1)
- PSA screening (1)
- PSA-Screening (1)
- PYTHIA (1)
- Palacos reaction (1)
- Particle and Resonance Production (1)
- Pb–Pb (1)
- Pediatric patients (1)
- Percutaneous (1)
- Photon counting (1)
- Plasmodium (1)
- Pneumonia (1)
- Preclinical research (1)
- Prediction (1)
- Predictive markers (1)
- Preventive medicine (1)
- Production Cross Section (1)
- Properties of Hadrons (1)
- Prostata-specific antigen (1)
- Prostataspezifisches Antigen (1)
- Proteins (1)
- Proteomics (1)
- Proton (1)
- Proton–proton (1)
- Proton–proton collisions (1)
- Prävention (1)
- Psychiatry (1)
- Quantitative features (1)
- Quark Deconfinement (1)
- Quark Gluon Plasma (1)
- Quark Production (1)
- Quark gluon plasma (1)
- Quarkonium (1)
- Quinine (1)
- Radiative capture (1)
- Radical prostatectomy (1)
- Radiomics (1)
- Radiotherapy (1)
- Rapidity Range (1)
- Relativistic heavy ion physics (1)
- Relativistic heavy-ion collisions (1)
- Renal lesions (1)
- Renal replacement therapy (1)
- Research Infrastructure (1)
- Resolution Parameter (1)
- Rhabdomyoma (1)
- Risk factors (1)
- S100b (1)
- SARS-CoV-2 (1)
- SNORD95 (1)
- SR-BI (1)
- SVR (1)
- Scedosporium spp. (1)
- Seasonal variation (1)
- Semantics (1)
- Severe malaria (1)
- Shear viscosity (1)
- Single muons (1)
- Sociodemographic characteristics (1)
- Solar insolation (1)
- Statistical analysis (1)
- Stroke (1)
- Subependymal giant cell astrocytoma (1)
- Suchmaschine (1)
- Suicide (1)
- Sunlight (1)
- Surgery (1)
- Surgical oncology (1)
- Systematic Uncertainty (1)
- Systemic therapy (1)
- TACE (1)
- TILs (1)
- TR (1)
- TSC (1)
- TURP (1)
- Taxonomy (1)
- Thermal model (1)
- Thoracic trauma (1)
- Time Projection Chamber (1)
- Tinnitus (1)
- Tomography (1)
- Tracking (1)
- Transition radiation detector (1)
- Transverse momentum (1)
- Trigger (1)
- Urinary continence (1)
- Urinary incontinence (1)
- VISTA (1)
- Valvular cardiomyopathy (1)
- Vector Boson Production (1)
- Voriconazole (1)
- Vorsorgeuntersuchung (1)
- Xenon-based gas mixture (1)
- adverse events (1)
- algorithm (1)
- allogeneic stem cell transplant (1)
- angiography (1)
- antibiotic resistance (1)
- apex (1)
- assembly (1)
- atherosclerosis (1)
- biopsy cores (1)
- bladder neck stenosis (1)
- blastic plasmacytoid dendritic cell neoplasm (1)
- bloodstream infections (1)
- bundle (1)
- c-MET (1)
- cabozantinib (1)
- cardiac events (1)
- cardiac magnetic resonance (1)
- castration resistance (1)
- cell barrier integrity (1)
- cell lines (1)
- cetuximab (1)
- chemotherapy (1)
- clinical stage (1)
- complications (1)
- confirmatory factor analysis (1)
- coronary calcium (1)
- coronary computed-tomography angiography (CCTA) (1)
- coronary plaques (1)
- cuticular hydrocarbons (1)
- dE/dx (1)
- decision tree (1)
- delirium (1)
- desaturase (1)
- detector (1)
- direct-acting antivirals (1)
- dislocation (1)
- e-scooter (1)
- early tumor stages (1)
- electric scooter (1)
- elongase (1)
- embolization (1)
- endourology (1)
- experimental results (1)
- external fixation (1)
- fixed-links modeling (1)
- fluid intelligence (1)
- formalin-fixed and paraffin-embedded tissue (FFPE) (1)
- formicine (1)
- fracture (1)
- head-and-neck cancer (1)
- heavy ion experiments (1)
- hemodynamic instability (1)
- hemorrhage (1)
- hepatic fibrosis (1)
- hepatic stellate cells (1)
- hepatitis C virus (1)
- hepatocellular cancer (1)
- histone deacetylase 5 (1)
- hospital length of stay (1)
- in vitro models (1)
- incontinence (1)
- insulin resistance (1)
- intensive care admission and mortality (1)
- lactate (1)
- laser-capture microdissection (1)
- leukemia (1)
- lung cancer (1)
- mTOR (1)
- mTOR inhibitor (1)
- management (1)
- marker (1)
- membranous urethra (1)
- metastasis (1)
- metastatic prostate cancer (1)
- miR-142-3p (1)
- miRNA (1)
- mid-term urinary continence (1)
- mortality (1)
- multiparametric magnetic resonance imaging (1)
- multiple trauma (1)
- mutually exclusive mutations (1)
- myocardial fibrosis (1)
- myocyte enhancer factor 2 (1)
- nerve-sparing surgery (1)
- next generation sequencing (1)
- nocardia (1)
- nocardiosis (1)
- oxLDL (1)
- p21-activated kinase 2 (1)
- pad-test (1)
- patient-reported outcomes (1)
- pediatric patients (1)
- pelvic injury (1)
- pelvic ring fracture (1)
- plasma (1)
- polytrauma (1)
- posttraumatic inflammation (1)
- prediction (1)
- prevention (1)
- primary immunodeficiency (PID) (1)
- prognosis (1)
- prostaglandin E2 (1)
- protein kinase D (1)
- proteomics (1)
- pulmonary nocardiosis (1)
- quantitative mass spectrometry (1)
- quark gluon plasma (1)
- re-irradiation (1)
- recurrent mutations (1)
- registry for primary immunodeficiency (1)
- resistant cell lines (1)
- risk group (1)
- risk prediction (1)
- scar (1)
- serum (1)
- solid tumors (1)
- sorafenib (1)
- spectra (1)
- spike-in SILAC (1)
- spine (1)
- squamous cell carcinoma (1)
- stage migration (1)
- steatosis (1)
- stroke (1)
- surgery (1)
- survival (1)
- tivantinib (1)
- traffic accident (1)
- transportation (1)
- traumatic brain injury (1)
- traumatic brain injury (TBI) (1)
- traumaticbraininjury(TBI) (1)
- treatment (1)
- urinary incontinence (1)
- vertebroplasty (1)
- working memory capacity (1)
- x-ray techniques (1)
- Öffentlichkeit (1)
- √sN N = 2.76 TeV (1)
- fibrogenesis (1)
Institute
The genuine event-by-event correlations between three flow amplitudes are measured for the first time in Pb-Pb collisions at sNN−−−√=2.76 TeV by the ALICE Collaboration at the Large Hadron Collider. The results are obtained with recently developed observables, the higher order Symmetric Cumulants (SC), in the midrapidity region |η|<0.8 and the transverse momentum range 0.2<pT<5.0 GeV/c. These higher order observables show the same robustness against systematic biases arising from nonflow effects as the two-harmonic SC. The new results cannot be interpreted in terms of lower order flow measurements, since they are dominated by different patterns of event-by-event flow fluctuations. The results are compared with expectations from initial state models such as TRENTo and next-to-leading order perturbative-QCD+saturation model of initial conditions, followed by iEBE-VISHNU and EKRT viscous hydrodynamic calculations. Model comparisons provide an indication of the development of genuine correlations between the elliptic v2, the triangular v3 and the quadrangular v4 flow amplitudes during the collective evolution of the medium. The comparison with the predictions for the correlations between v2, v3 and the pentagonal flow magnitude v5 illustrate the need for further tuning of model parameterizations. Therefore, these results can provide new and independent constraints for the initial conditions and system properties of nuclear matter created in heavy-ion collisions, complementary to previous flow measurements.
Multiharmonic correlations of different flow amplitudes in Pb-Pb collisions at √sNN = 2.76 TeV
(2021)
The event-by-event correlations between three flow amplitudes are measured for the first time in Pb--Pb collisions, using higher-order Symmetric Cumulants. We find that different three-harmonic correlations develop during the collective evolution of the medium, when compared with correlations that exist in the initial state. These new results cannot be interpreted in terms of previous lower-order flow measurements, since contributions from two-harmonic correlations are explicitly removed in the new observables. Comparison with Monte Carlo simulations provides new and independent constraints for the initial conditions and system properties of nuclear matter created in heavy-ion collisions.
Inclusive photon production at forward rapidities in pp and p–Pb collisions at √sNN = 5.02 TeV
(2023)
A study of multiplicity and pseudorapidity distributions of inclusive photons measured in pp and p−Pb collisions at a center-of-mass energy per nucleon−nucleon collision of sNN−−−√=5.02 TeV using the ALICE detector in the forward pseudorapidity region 2.3<ηlab<3.9 is presented. Measurements in p−Pb collisions are reported for two beam configurations in which the directions of the proton and lead ion beam were reversed. The pseudorapidity distributions in p−Pb collisions are obtained for seven centrality classes which are defined based on different event activity estimators, i.e., the charged-particle multiplicity measured at midrapidity as well as the energy deposited in a calorimeter at beam rapidity. The inclusive photon multiplicity distributions for both pp and p−Pb collisions are described by double negative binomial distributions. The pseudorapidity distributions of inclusive photons are compared to those of charged particles at midrapidity in \pp collisions and for different centrality classes in p−Pb collisions. The results are compared to predictions from various Monte Carlo event generators. None of the generators considered in this paper reproduces the inclusive photon multiplicity distributions in the reported multiplicity range. The pseudorapidity distributions are, however, better described by the same generators.
The first evidence of spin alignment of vector mesons (K∗0 and ϕ) in heavy-ion collisions at the Large Hadron Collider (LHC) is reported. The spin density matrix element ρ00 is measured at midrapidity (|y|< 0.5) in Pb-Pb collisions at a center-of-mass energy (sNN−−−√) of 2.76 TeV with the ALICE detector. ρ00 values are found to be less than 1/3 (1/3 implies no spin alignment) at low transverse momentum (pT< 2 GeV/c) for K∗0 and ϕ at a level of 3σ and 2σ, respectively. No significant spin alignment is observed for the K0S meson (spin = 0) in Pb-Pb collisions and for the vector mesons in pp collisions. The measured spin alignment is unexpectedly large but qualitatively consistent with the expectation from models which attribute it to a polarization of quarks in the presence of angular momentum in heavy-ion collisions and a subsequent hadronization by the process of recombination.
Measurement of spin-orbital angular momentum interactions in relativistic heavy-ion collisions
(2019)
The first measurement of spin alignment of vector mesons (K∗0 and ϕ) in heavy-ion collisions at the Large Hadron Collider (LHC) is reported. The measurements are carried out as a function of transverse momentum (pT ) and collision centrality with the ALICE detector using the particles produced at midrapidity (|y|< 0.5) in Pb-Pb collisions at a center-of-mass energy (sNN−−−√) of 2.76 TeV. The second diagonal spin density matrix element (ρ00 ) is measured from the angular distribution of the decay daughters of the vector meson in the decay rest frame, with respect to the normal of both the event plane and the production plane. The ρ00 values are found to be less than 1/3 (= 1/3 implies no spin alignment) at low pT (< 2 GeV/c) for both vector mesons. The observed deviations from 1/3 are maximal for mid-central collisions at a level of 3σ for K∗0 and 2σ for ϕ mesons. As control measurements, the analysis is also performed using the K0S meson, which has zero spin, and for the vector mesons in pp collisions; in both cases no significant spin alignment is observed. The ρ00 values at low pT with respect to the production plane are closer to 1/3 than for the event plane; they are related to each other through correlations introduced by the elliptic flow in the system. The measured spin alignment is surprisingly large compared to the polarization measured for Λ hyperons, but qualitatively consistent with the expectation from models which attribute the spin alignment to a polarization of quarks in the presence of large initial angular momentum in non-central heavy-ion collisions and a subsequent hadronization by the process of recombination.
The inclusive production of the J/ψ and ψ(2S) charmonium states is studied as a function of centrality in p-Pb collisions at a centre-of-mass energy per nucleon pair sNN−−−√=8.16 TeV at the LHC. The measurement is performed in the dimuon decay channel with the ALICE apparatus in the centre-of-mass rapidity intervals −4.46<ycms<−2.96 (Pb-going direction) and 2.03<ycms<3.53 (p-going direction), down to zero transverse momentum (pT). The J/ψ and ψ(2S) production cross sections are evaluated as a function of the collision centrality, estimated through the energy deposited in the zero degree calorimeter located in the Pb-going direction. The pT-differential J/ψ production cross section is measured at backward and forward rapidity for several centrality classes, together with the corresponding average ⟨pT⟩ and ⟨p2T⟩ values. The nuclear effects affecting the production of both charmonium states are studied using the nuclear modification factor. In the p-going direction, a suppression of the production of both charmonium states is observed, which seems to increase from peripheral to central collisions. In the Pb-going direction, however, the centrality dependence is different for the two states: the nuclear modification factor of the J/ψ increases from below unity in peripheral collisions to above unity in central collisions, while for the ψ(2S) it stays below or consistent with unity for all centralities with no significant centrality dependence. The results are compared with measurements in p-Pb collisions at sNN−−−√=5.02 TeV and no significant dependence on the energy of the collision is observed. Finally, the results are compared with theoretical models implementing various nuclear matter effects.
The multiplicity dependence of the pseudorapidity density of charged particles in proton-proton (pp) collisions at centre-of-mass energies s√ = 5.02, 7 and 13 TeV measured by ALICE is reported. The analysis relies on track segments measured in the midrapidity range (|η|<1.5). Results are presented for inelastic events having at least one charged particle produced in the pseudorapidity interval |η|<1 (INEL>0). The multiplicity dependence of the pseudorapidy density of charged particles is measured with mid and forward rapidity multiplicity estimators, the latter being less affected by autocorrelations. A detailed comparison with predictions from the PYTHIA 8 and EPOS LHC event generators is also presented. Both generators provide a good description of the data.
The multiplicity dependence of the pseudorapidity density of charged particles in proton-proton (pp) collisions at centre-of-mass energies s√ = 5.02, 7 and 13 TeV measured by ALICE is reported. The analysis relies on track segments measured in the midrapidity range (|η|<1.5). Results are presented for inelastic events having at least one charged particle produced in the pseudorapidity interval |η|<1 (INEL>0). The multiplicity dependence of the pseudorapidy density of charged particles is measured with mid and forward rapidity multiplicity estimators, the latter being less affected by autocorrelations. A detailed comparison with predictions from the PYTHIA 8 and EPOS LHC event generators is also presented. Both generators provide a good description of the data.
Measurements of the production of muons from heavy-flavour hadron decays in Pb−Pb collisions at sNN−−−√ = 5.02 and 2.76 TeV using the ALICE detector at the LHC are reported. The nuclear modification factor RAA at sNN−−−√ = 5.02 TeV is measured at forward rapidity (2.5<y<4) as a function of transverse momentum pT in central, semi-central, and peripheral collisions over a wide pT interval, 3<pT<20 GeV/c, in which muons from beauty-hadron decays are expected to take over from charm as the dominant source at high pT (pT>7 GeV/c). The RAA shows an increase of the suppression of the yields of muons from heavy-flavour hadron decays with increasing centrality. A suppression by a factor of about three is observed in the 10% most central collisions. The RAA at sNN−−−√ = 5.02 is similar to that at 2.76 TeV. The precise RAA measurements have the potential to distinguish between model predictions implementing different mechanisms of parton energy loss in the high-density medium formed in heavy-ion collisions. They place important constraints for the understanding of the heavy-quark interaction with the hot and dense QCD medium.
Measurements of the production of muons from heavy-flavour hadron decays in Pb−Pb collisions at sNN−−−√ = 5.02 and 2.76 TeV using the ALICE detector at the LHC are reported. The nuclear modification factor RAA at sNN−−−√ = 5.02 TeV is measured at forward rapidity (2.5<y<4) as a function of transverse momentum pT in central, semi-central, and peripheral collisions over a wide pT interval, 3<pT<20 GeV/c, in which a significant contribution of muons from beauty-hadron decays is expected at high pT. With a significantly improved precision compared to the measurements at lower collision energy, the RAA shows an increase of the suppression of the yields of muons from heavy-flavour hadron decays with increasing centrality. A suppression by a factor of about three is observed in the 10% most central collisions. The RAA at sNN−−−√ = 5.02 is similar to that reported at 2.76 TeV in a broader pT interval and with an improved accuracy with respect to previously published measurements. The precise RAA results have the potential to distinguish between model predictions implementing different mechanisms of parton energy loss in the high-density medium formed in heavy-ion collisions. The results place stringent constraints on the relative energy loss between charm and beauty quarks.
ϒ production and nuclear modification at forward rapidity in Pb–Pb collisions at √sNN = 5.02 TeV
(2021)
The production of Υ mesons in Pb-Pb collisions at a centre-of-mass energy per nucleon pair sNN−−−√ = 5 TeV is measured with the muon spectrometer of the ALICE detector at the LHC. The yields as well as the nuclear modification factors are determined in the forward rapidity region 2.5<y<4.0, as a function of rapidity, transverse momentum and collision centrality. The results show that the production of the Υ(1S) meson is suppressed by a factor of about three with respect to the production in proton-proton collisions. For the first time, a significant signal for the Υ(2S) meson is observed at forward rapidity, indicating a suppression stronger by about a factor 2-3 with respect to the ground state. The measurements are compared with transport, hydrodynamic, comover and statistical hadronisation model calculations.
ϒ production and nuclear modification at forward rapidity in Pb–Pb collisions at √sNN = 5.02 TeV
(2020)
The production of Υ mesons in Pb-Pb collisions at a centre-of-mass energy per nucleon pair sNN−−−√ = 5 TeV is measured with the muon spectrometer of ALICE at the LHC. The yields as well as the nuclear modification factors are determined in the forward rapidity region 2.5<y<4.0, as a function of rapidity, transverse momentum and collision centrality. The results show that the production of Υ(1S) is suppressed by a factor of about three with respect to the production in proton-proton collisions. For the first time, a significant Υ(2S) signal is observed at forward rapidity, indicating a suppression stronger by about a factor 2-3 with respect to the ground state. The measurements are compared with transport, hydrodynamic, comover and statistical hadronisation model calculations.
The first measurements of the production of muons and electrons from heavy-flavour hadron decays in Xe-Xe collisions at sNN−−−√ = 5.44 TeV, using the ALICE detector at the LHC, are reported. The measurement of the nuclear modification factor RAA is performed as a function of transverse momentum pT in several centrality classes at forward rapidity (2.5<y<4) and midrapidity (|y|<0.8) for muons and electrons from heavy-flavour hadron decays, respectively. A suppression by a factor up to about 2.5 compared to the binary-scaled pp reference is observed in central collisions at both central and forward rapidities. The RAA of muons from heavy-flavour hadron decays is compared to previous measurements in Pb-Pb collisions at sNN−−−√ = 5.02 TeV. When the nuclear modification factors are compared in the centrality classes 0-10% for Xe-Xe collisions and 10-20% for Pb-Pb collisions, which have similar charged-particle multiplicity density, a similar suppression, with RAA∼0.4 in the pT interval 4<pT<8 GeV/c, is observed. The comparison of the measured RAA values in the two collision systems brings new insights on the properties of the quark-gluon plasma by investigating the system-size and path-length dependence of medium-induced parton energy loss. The results of muons and electrons from heavy-flavour hadron decays provide new constraints to model calculations.
The first measurements of the production of muons and electrons from heavy-flavour hadron decays in Xe-Xe collisions at sNN−−−√ = 5.44 TeV, using the ALICE detector at the LHC, are reported. The measurement of the nuclear modification factor RAA is performed as a function of transverse momentum pT in several centrality classes at forward rapidity (2.5<y<4) and midrapidity (|y|<0.8) for muons and electrons from heavy-flavour hadron decays, respectively. A suppression by a factor up to about 2.5 compared to the binary-scaled pp reference is observed in central collisions at both central and forward rapidities. The RAA of muons from heavy-flavour hadron decays is compared to previous measurements in Pb-Pb collisions at sNN−−−√ = 5.02 TeV. A similar suppression, with RAA∼0.4 in the pT interval 4<pT<8 GeV/c, is observed in Pb-Pb and Xe-Xe collisions when the nuclear modification factors are compared in event classes with similar charged-particle multiplicity density. The comparison of the measured RAA values in the two collision systems brings new insights on the properties of the quark-gluon plasma by investigating the system-size and path-length dependence of medium-induced parton energy loss. The results of muons and electrons from heavy-flavour hadron decays provide new constraints to model calculations.
Deuteron production in high-energy collisions is sensitive to the space-time evolution of the collision system, and is typically described by a coalescence mechanism. For the first time, we present results on jet-associated deuteron production in \pp\ collisions at s√=13 TeV, providing an opportunity to test the established picture for deuteron production in events with a hard scattering. Using a trigger particle with high transverse-momentum (pT>5 GeV/c) as a proxy for the presence of a jet at midrapidity, we observe a measurable population of deuterons being produced around the jet proxy. The associated deuteron yield measured in a narrow angular range around the trigger particle differs by 2.4-4.8 standard deviations from the uncorrelated background. The data are described by PYTHIA model calculations featuring baryon coalescence.
Deuteron production in high-energy collisions is sensitive to the space-time evolution of the collision system, and is typically described by a coalescence mechanism. For the first time, we present results on jet-associated deuteron production in \pp\ collisions at s√=13 TeV, providing an opportunity to test the established picture for deuteron production in events with a hard scattering. Using a trigger particle with high transverse-momentum (pT>5 GeV/c) as a proxy for the presence of a jet at midrapidity, we observe a measurable population of deuterons being produced around the jet proxy. The associated deuteron yield measured in a narrow angular range around the trigger particle differs by 2.4-4.8 standard deviations from the uncorrelated background. The data are described by PYTHIA model calculations featuring baryon coalescence.
Λ+c production and baryon-to-meson ratios in pp and p–Pb collisions at √sNN = 5.02 TeV at the LHC
(2021)
The prompt production of the charm baryon Λ+c and the Λ+c/D0 production ratios were measured at midrapidity with the ALICE detector in pp and p-Pb collisions at sNN−−−√=5.02TeV. These new measurements show a clear decrease of the Λ+c/D0 ratio with increasing transverse momentum (pT) in both collision systems in the range 2<pT<12 GeV/c, exhibiting similarities with the light-flavour baryon-to-meson ratios p/π and Λ/K0S. At low pT, predictions that include additional colour-reconnection mechanisms beyond the leading-colour approximation; assume the existence of additional higher-mass charm-baryon states; or include hadronisation via coalescence can describe the data, while predictions driven by charm-quark fragmentation processes measured in e+e− and e−p collisions significantly underestimate the data. The results presented in this letter provide significant evidence that the established assumption of universality (colliding-system independence) of parton-to-hadron fragmentation is not sufficient to describe charm-baryon production in hadronic collisions at LHC energies.
Λ+c production and baryon-to-meson ratios in pp and p–Pb collisions at √sNN = 5.02 TeV at the LHC
(2021)
The prompt production of the charm baryon Λ+c and the Λ+c/D0 production ratios were measured at midrapidity with the ALICE detector in pp and p-Pb collisions at sNN−−−√=5.02TeV. These new measurements show a clear decrease of the Λ+c/D0 ratio with increasing transverse momentum (pT) in both collision systems in the range 2<pT<12 GeV/c, exhibiting similarities with the light-flavour baryon-to-meson ratios p/π and Λ/K0S. At low pT, predictions that include additional colour-reconnection mechanisms beyond the leading-colour approximation; assume the existence of additional higher-mass charm-baryon states; or include hadronisation via coalescence can describe the data, while predictions driven by charm-quark fragmentation processes measured in e+e− and e−p collisions significantly underestimate the data. The results presented in this letter provide significant evidence that the established assumption of universality (colliding-system independence) of parton-to-hadron fragmentation is not sufficient to describe charm-baryon production in hadronic collisions at LHC energies.
Λ+c production and baryon-to-meson ratios in pp and p–Pb collisions at √sNN = 5.02 TeV at the LHC
(2021)
The prompt production of the charm baryon Λ+c and the Λ+c/D0 production ratios were measured at midrapidity with the ALICE detector in pp and p-Pb collisions at sNN−−−√=5.02TeV. These new measurements show a clear decrease of the Λ+c/D0 ratio with increasing transverse momentum (pT) in both collision systems in the range 2<pT<12 GeV/c, exhibiting similarities with the light-flavour baryon-to-meson ratios p/π and Λ/K0S. At low pT, predictions that include additional colour-reconnection mechanisms beyond the leading-colour approximation; assume the existence of additional higher-mass charm-baryon states; or include hadronisation via coalescence can describe the data, while predictions driven by charm-quark fragmentation processes measured in e+e− and e−p collisions significantly underestimate the data. The results presented in this letter provide significant evidence that the established assumption of universality (colliding-system independence) of parton-to-hadron fragmentation is not sufficient to describe charm-baryon production in hadronic collisions at LHC energies.
Λ+c production and baryon-to-meson ratios in pp and p–Pb collisions at √sNN = 5.02 TeV at the LHC
(2020)
The prompt production of the charmed baryon Λ+c and the Λ+c/D0 production ratios were measured at midrapidity with the ALICE detector in pp and p-Pb collisions at sNN−−−√=5.02TeV. These new measurements show a clear decrease of the Λ+c/D0 ratio with increasing transverse momentum (pT) in both collision systems in the range 2<pT<12 GeV/c, exhibiting similarities with the light-flavour baryon-to-meson ratios p/π and Λ/K0S. At low pT, predictions that include additional colour-reconnection mechanisms beyond the leading-colour approximation; assume the existence of additional higher-mass charmed-baryon states; or include hadronisation via coalescence can describe the data, while predictions driven by charm-quark fragmentation processes measured in e+e− and e−p collisions significantly underestimate the data. The results presented in this letter provide significant evidence that the established assumption of universality (colliding-system independence) of parton-to-hadron fragmentation is not sufficient to describe charmed-baryon production in hadronic collisions at LHC energies.