Refine
Year of publication
Document Type
- Preprint (740)
- Article (476)
- Conference Proceeding (4)
- Report (3)
- Review (1)
- Working Paper (1)
Has Fulltext
- yes (1225)
Is part of the Bibliography
- no (1225)
Keywords
- Heavy Ion Experiments (21)
- Hadron-Hadron scattering (experiments) (12)
- Hadron-Hadron Scattering (11)
- LHC (9)
- Heavy-ion collision (6)
- Heavy-ion collisions (5)
- ALICE experiment (4)
- Collective Flow (4)
- Jets (4)
- Quark-Gluon Plasma (4)
- ALICE (3)
- Diffraction (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)
- Beam Energy Scan (2)
- Beauty production (2)
- Bipolar disorder (2)
- Bone density (2)
- Charm physics (2)
- Chiral Magnetic Effect (2)
- Collectivity (2)
- Computed tomography (2)
- Correlation (2)
- Diagnostic markers (2)
- Elastic scattering (2)
- Elliptic flow (2)
- Experimental nuclear physics (2)
- Experimental particle physics (2)
- Lepton-Nucleon Scattering (experiments) (2)
- Machine learning (2)
- München (2)
- Oncology (2)
- Osteoporosis (2)
- Particle Correlations and Fluctuations (2)
- Particle and resonance production (2)
- Particle correlations and fluctuations (2)
- Pb–Pb collisions (2)
- QCD (2)
- Seizure (2)
- Shear viscosity (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)
- Anterior cruciate ligament (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 energy scan (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)
- Bone disease (1)
- Bone diseases (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)
- Chiral magnetic effect (1)
- Circadian (1)
- Circular accelerators (1)
- Clinical study (1)
- Coalescence (1)
- Collective Flow, (1)
- Comparison with QCD (1)
- Computerlinguistik (1)
- Conservation (1)
- Conservation biogeography (1)
- Costs (1)
- Critical point (1)
- Deuteron production (1)
- Diagnostic differentiation (1)
- Digitization (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)
- Forward physics (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)
- Groomed jet radius (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)
- Jet substructure (1)
- KRAS (1)
- Knee joint (1)
- Lee-type (1)
- Local therapy (1)
- Lomentospora prolificans (1)
- Low & intermediate-energy accelerators (1)
- Lure sticks (1)
- MRI (1)
- MTOR inhibitor (1)
- Magnetic resonance Imaging (1)
- Malaria (1)
- Material budget (1)
- Medicine (1)
- Metabolic (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)
- Multidetector computed tomography (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)
- Osteoporotic fractures (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)
- Posterior cruciate ligament (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 collisions (1)
- Proton–proton (1)
- Proton–proton collisions (1)
- Prävention (1)
- Pseudarthrosis (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)
- STAR (1)
- SVR (1)
- Scedosporium spp. (1)
- Seasonal variation (1)
- Semantics (1)
- Severe malaria (1)
- Single muons (1)
- Sociodemographic characteristics (1)
- SoftDrop (1)
- Solar insolation (1)
- Splitting function (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)
- UTUC (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)
- adjuvant chemotherapy (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)
- heavy-ion collisions (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)
- nephroureterectomy (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)
- segmental ureteral resection (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)
- upper tract urothelial carcinoma (1)
- ureteroscopy (1)
- urinary incontinence (1)
- vertebroplasty (1)
- working memory capacity (1)
- x-ray techniques (1)
- Öffentlichkeit (1)
- Υ suppression (1)
- √sN N = 2.76 TeV (1)
- fibrogenesis (1)
Institute
- Frankfurt Institute for Advanced Studies (FIAS) (1050)
- Physik (1045)
- Informatik (925)
- Medizin (72)
- Informatik und Mathematik (5)
- ELEMENTS (4)
- Geowissenschaften (4)
- Senckenbergische Naturforschende Gesellschaft (4)
- Biodiversität und Klima Forschungszentrum (BiK-F) (3)
- Biowissenschaften (3)
Neutral pion (π0) and η meson production cross sections were measured up to unprecedentedly high transverse momenta (pT) in p-Pb collisions at sNN−−−√ = 8.16 TeV. The mesons were reconstructed via their two-photon decay channel in the rapidity interval −1.3<y<0.3 in the ranges of 0.4<pT<200 GeV/c and 1.0<pT<50 GeV/c, respectively. The respective nuclear modification factor (RpPb) is presented for pT up to of 200 and 30 GeV/c, where the former was achieved by extending the π0 measurement in pp collisions at s√ = 8 TeV using the merged cluster technique. The values of RpPb are below unity for pT<10 GeV/c, while they are consistent with unity for pT>10 GeV/c, leaving essentially no room for final state energy loss. The new data provide strong constraints for nuclear parton distribution and fragmentation functions over a broad kinematic range and are compared to model predictions as well as previous results at sNN−−−√ = 5.02 TeV.
The coherent photoproduction of J/ψ and ψ′ mesons was measured in ultra-peripheral Pb-Pb collisions at a center-of-mass energy sNN−−−√ = 5.02 TeV with the ALICE detector. Charmonia are detected in the central rapidity region for events where the hadronic interactions are strongly suppressed. The J/ψ is reconstructed using the dilepton (l+l−) and proton-antiproton decay channels, while for the ψ′, the dilepton and the l+l−π+π− decay channels are studied. The analysis is based on an event sample corresponding to an integrated luminosity of about 233 μb−1. The results are compared with theoretical models for coherent J/ψ and ψ′ photoproduction. The coherent cross section is found to be in a good agreement with models incorporating moderate nuclear gluon shadowing of about 0.65 at a Bjorken-x of around 6×10−4, such as the EPS09 parametrization, however none of the models is able to fully describe the rapidity dependence of the coherent J/ψ cross section including ALICE measurements at forward rapidity. The ratio of ψ′ to J/ψ coherent photoproduction cross sections was also measured and found to be consistent with the one for photoproduction off protons.
This Letter presents the first experimental evidence of the attractive strong interaction between a proton and a ϕ meson. The result is obtained from two-particle correlations of combined p-ϕ⊕p¯¯¯-ϕ pairs measured in high-multiplicity pp collisions at s√ = 13 TeV by the ALICE collaboration. The spin-averaged scattering length and effective range of the p-ϕ interaction are extracted from the fully corrected correlation function employing the Lednický-Lyuboshits approach. In particular, the imaginary part of the scattering length vanishes within uncertainties, indicating that inelastic processes do not play a prominent role for the p-ϕ interaction. These data demonstrate that the interaction is dominated by elastic p-ϕ scattering. Furthermore, an analysis employing phenomenological Gaussian- and Yukawa-type potentials is conducted. Under the assumption of the latter, the N-ϕ coupling constant is found to be gN−ϕ=0.14±0.03(stat.)±0.02(syst.). This work provides valuable experimental input to accomplish a self-consistent description of the N-ϕ interaction, which is particularly relevant for the more fundamental studies on partial restoration of chiral symmetry in nuclear medium.
Annihilation dynamics plays a fundamental role in the baryon−antibaryon interaction (B−B¯¯¯¯) at low-energy and its strength and range are crucial in the assessment of possible baryonic bound states. Experimental data on annihilation cross sections are available for the p−p¯¯¯ system but not in the low relative momentum region. Data regarding the B−B¯¯¯¯ interaction with strange degrees of freedom are extremely scarce, hence the modeling of the annihilation contributions is mainly based on nucleon−antinucleon (N−N¯¯¯¯) results, when available. In this letter we present a measurement of the p−p¯¯¯, p−Λ¯¯¯¯⊕p¯¯¯−Λ and Λ−Λ¯¯¯¯ interaction using correlation functions in the relative momentum space in high-multiplicity triggered pp collisions at s√=13 TeV recorded by ALICE at the LHC. In the p−p¯¯¯ system the couplings to the mesonic channels in different partial waves are extracted by adopting a coupled-channel approach with recent χEFT potentials. The inclusion of these inelastic channels provides good agreement with the data, showing a significant presence of the annihilation term down to zero momentum. Predictions obtained using the Lednický−Lyuboshits formula and scattering parameters obtained from heavy-ion collisions, hence mainly sensitive to elastic processes, are compared with the experimental p−Λ¯¯¯¯⊕p¯¯¯−Λ and Λ−Λ¯¯¯¯ correlations. The model describes the Λ−Λ¯¯¯¯ data and underestimates the p−Λ¯¯¯¯⊕p¯¯¯−Λ data in the region of momenta below 200 MeV/c. The observed deviation indicates a different contribution of annihilation channels to the two systems containing strange hadrons.
Recent pT-integrated cross section measurements of the ground-state charm mesons and baryons, D0, D+, D+s, Λ+c, and Ξ0c, are used to evaluate the charm fragmentation fractions and production cross section per unit of rapidity at midrapidity (|y|<0.5), in pp collisions at s√=5.02 TeV at the LHC. The latter is dσcc¯¯¯/dy||y|<0.5 =1165 ±44(stat)+134−101(syst) μb. These measurements were obtained for the first time in hadronic collisions at the LHC including the charm baryon states, recently measured by ALICE at midrapidity. The charm fragmentation fractions differ significantly from the values measured in e+e− and ep collisions, providing evidence of the dependence of the parton-to-hadron fragmentation fractions on the collision system, indicating that the assumption of their universality is not supported by the measured cross sections. An increase of a factor of about 3.3 for the fragmentation fraction for the Λ+c with a significance of 5σ between the values obtained in pp collisions and those obtained in e+e− (ep) collisions is reported. The fragmentation fraction for the Ξ0c was obtained for the first time in any collision system. The measured fragmentation fractions were used to update the cc¯¯ cross sections per unit of rapidity at |y|<0.5 at s√=2.76 and 7 TeV, which are about 40% higher than the previously published results. The data were compared with perturbative-QCD calculations and lie at the upper edge of the theoretical bands.
The pT-differential production cross sections of prompt D0, Λ+c, and Σ0,++c(2455) charmed hadrons are measured at midrapidity (|y|<0.5) in pp collisions at s√=13 TeV. This is the first measurement of Σ0,++c production in hadronic collisions. Assuming the same production yield for the three Σ0,+,++c isospin states, the baryon-to-meson cross-section ratios Σ0,+,++c/D0 and Λ+c/D0 are calculated in the transverse momentum (pT) intervals 2<pT<12 GeV/c and 1<pT<24 GeV/c. Values significantly larger than in e+e− collisions are observed, indicating for the first time that baryon enhancement in hadronic collisions also extends to the Σc. The feed-down contribution to Λ+c production from Σ0,+,++c is also reported and is found to be larger than in e+e− collisions. The data are compared with predictions from event generators and other phenomenological models, providing a sensitive test of the different charm-hadronisation mechanisms implemented in the models.
The pT-differential production cross sections of prompt D0, Λ+c, and Σ0,++c(2455) charmed hadrons are measured at midrapidity (|y|<0.5) in pp collisions at s√=13 TeV. This is the first measurement of Σ0,++c production in hadronic collisions. Assuming the same production yield for the three Σ0,+,++c isospin states, the baryon-to-meson cross section ratios Σ0,+,++c/D0 and Λ+c/D0 are calculated in the transverse momentum (pT) intervals 2<pT<12 GeV/c and 1<pT<24 GeV/c. Values significantly larger than in e+e− collisions are observed, indicating for the first time that baryon enhancement in hadronic collisions also extends to the Σc. The feed-down contribution to Λ+c production from Σ0,+,++c is also reported and is found to be larger than in e+e− collisions. The data are compared with predictions from event generators and other phenomenological models, providing a sensitive test of the different charm-hadronisation mechanisms implemented in the models.
Measurements of the production of electrons from heavy-flavour hadron decays in pp collisions at s√=13 TeV at midrapidity with the ALICE detector are presented down to a transverse momentum (pT) of 0.2 GeV/c and up to pT=35 GeV/c, which is the largest momentum range probed for inclusive electron measurements in ALICE. In p−Pb collisions, the production cross section and the nuclear modification factor of electrons from heavy-flavour hadron decays are measured in the pT range 0.5<pT<26 GeV/c at sNN−−−√=8.16 TeV. The nuclear modification factor is found to be consistent with unity within the statistical and systematic uncertainties. In both collision systems, first measurements of the yields of electrons from heavy-flavour hadron decays in different multiplicity intervals normalised to the multiplicity-integrated yield (self-normalised yield) at midrapidity are reported as a function of the self-normalised charged-particle multiplicity estimated at midrapidity. The self-normalised yields in pp and p−Pb collisions grow faster than linear with the self-normalised multiplicity. A strong pT dependence is observed in pp collisions, where the yield of high-pT electrons increases faster as a function of multiplicity than the one of low-pT electrons. The measurement in p−Pb collisions shows no pT dependence within uncertainties. The self-normalised yields in pp and p−Pb collisions are compared with measurements of other heavy-flavour, light-flavour, and strange particles, and with Monte Carlo simulations.
Multiplicity (Nch) distributions and transverse momentum (pT) spectra of inclusive primary charged particles in the kinematic range of |η|<0.8 and 0.15 GeV/c <pT< 10 GeV/c are reported for pp, p-Pb, Xe-Xe and Pb-Pb collisions at centre-of-mass energies per nucleon pair ranging from sNN−−−√=2.76 TeV up to 13 TeV. A sequential two-dimensional unfolding procedure is used to extract the correlation between the transverse momentum of primary charged particles and the charged-particle multiplicity of the corresponding collision. This correlation sharply characterises important features of the final state of a collision and, therefore, can be used as a stringent test of theoretical models. The multiplicity distributions as well as the mean and standard deviation derived from the pT spectra are compared to state-of-the-art model predictions. Providing these fundamental observables of bulk particle production consistently across a wide range of collision energies and system sizes can serve as an important input for tuning Monte Carlo event generators.
First measurement of 𝚲+c production down to 𝑝T = 0 in pp and p–Pb collisions at √𝑠NN = 5.02 TeV
(2023)
The production of prompt Λ+c baryons has been measured at midrapidity in the transverse momentum interval 0<pT<1 GeV/c for the first time, in pp and p-Pb collisions at a centre-of-mass energy per nucleon-nucleon collision sNN−−−√=5.02 TeV. The measurement was performed in the decay channel Λ+c→pK0S by applying new decay reconstruction techniques using a Kalman-Filter vertexing algorithm and adopting a machine-learning approach for the candidate selection. The pT-integrated Λ+c production cross sections in both collision systems were determined and used along with the measured yields in Pb-Pb collisions to compute the pT-integrated nuclear modification factors RpPb and RAA of Λ+c baryons, which are compared to model calculations that consider nuclear modification of the parton distribution functions. The Λ+c/D0 baryon-to-meson yield ratio is reported for pp and p-Pb collisions. Comparisons with models that include modified hadronisation processes are presented, and the implications of the results on the understanding of charm hadronisation in hadronic collisions are discussed. A significant (3.7σ) modification of the mean transverse momentum of Λ+c baryons is seen in p-Pb collisions with respect to pp collisions, while the pT-integrated Λ+c/D0 yield ratio was found to be consistent between the two collision systems within the uncertainties.
Investigation of K+K− interactions via femtoscopy in Pb-Pb collisions at √sNN = 2.76 TeV at the LHC
(2023)
Femtoscopic correlations of non-identical charged kaons (K+K−) are studied in Pb−Pb collisions at a center-of-mass energy per nucleon−nucleon collision sNN−−−√=2.76 TeV by ALICE at the LHC. One-dimensional K+K− correlation functions are analyzed in three centrality classes and eight intervals of particle-pair transverse momentum. The Lednický and Luboshitz interaction model used in the K+K− analysis includes the final-state Coulomb interactions between kaons and the final-state interaction through a0(980) and f0(980) resonances. The mass of f0(980) and coupling were extracted from the fit to K+K− correlation functions using the femtoscopic technique. The measured mass and width of the f0(980) resonance are consistent with other published measurements. The height of the ϕ(1020) meson peak present in the K+K− correlation function rapidly decreases with increasing source radius, qualitatively in agreement with an inverse volume dependence. A phenomenological fit to this trend suggests that the ϕ(1020) meson yield is dominated by particles produced directly from the hadronization of the system. The small fraction subsequently produced by final-state interactions could not be precisely quantified with data presented in this paper and will be assessed in future work.
This article reports measurements of the angle between differently defined jet axes in pp collisions at s√=5.02 TeV carried out by the ALICE Collaboration. Charged particles at midrapidity are clustered into jets with resolution parameters R=0.2 and 0.4. The jet axis, before and after Soft Drop grooming, is compared to the jet axis from the Winner-Takes-All (WTA) recombination scheme. The angle between these axes, ΔRaxis, probes a wide phase space of the jet formation and evolution, ranging from the initial high-momentum-transfer scattering to the hadronization process. The ΔRaxis observable is presented for 20<pchjetT<100 GeV/c, and compared to predictions from the PYTHIA 8 and Herwig 7 event generators. The distributions can also be calculated analytically with a leading hadronization correction related to the non-perturbative component of the Collins−Soper−Sterman (CSS) evolution kernel. Comparisons to analytical predictions at next-to-leading-logarithmic accuracy with leading hadronization correction implemented from experimental extractions of the CSS kernel in Drell−Yan measurements are presented. The analytical predictions describe the measured data within 20% in the perturbative regime, with surprising agreement in the non-perturbative regime as well. These results are compatible with the universality of the CSS kernel in the context of jet substructure.
The study of the production of nuclei and antinuclei in pp collisions has proven to be a powerful tool to investigate the formation mechanism of loosely bound states in high-energy hadronic collisions. In this paper, the production of protons, deuterons and 3He and their charge conjugates at midrapidity is studied as a function of the charged-particle multiplicity in inelastic pp collisions at s√=5.02 TeV using the ALICE detector. Within the uncertainties, the yields of nuclei in pp collisions at s√=5.02 TeV are compatible with those in pp collisions at different energies and to those in p-Pb collisions when compared at similar multiplicities. The measurements are compared with the expectations of coalescence and Statistical Hadronisation Models. The results suggest a common formation mechanism behind the production of light nuclei in hadronic interactions and confirm that they do not depend on the collision energy but on the number of produced particles.
The study of the production of nuclei and antinuclei in pp collisions has proven to be a powerful tool to investigate the formation mechanism of loosely bound states in high-energy hadronic collisions. In this paper, the production of protons, deuterons and 3He and their charge conjugates at midrapidity is studied as a function of the charged-particle multiplicity in inelastic pp collisions at s√=5.02 TeV using the ALICE detector. Within the uncertainties, the yields of nuclei in pp collisions at s√=5.02 TeV are compatible with those in pp collisions at different energies and to those in p-Pb collisions when compared at similar multiplicities. The measurements are compared with the expectations of coalescence and Statistical Hadronisation Models. The results suggest a common formation mechanism behind the production of light nuclei in hadronic interactions and confirm that they do not depend on the collision energy but on the number of produced particles.
Femtoscopic correlations with the particle pair combinations K0SK0S and K0SK± are studied in pp collisions at s√=5.02 and 13 TeV by the ALICE experiment. At both energies, boson source parameters are extracted for both pair combinations, by fitting models based on Gaussian size distributions of the sources, to the measured two-particle correlation functions. The interaction model used for the K0SK0S analysis includes quantum statistics and strong final-state interactions through the f0(980) and a0(980) resonances. The model used for the K0SK± analysis includes only the final-state interaction through the a0 resonance. Source parameters extracted in the present work are compared with published values from pp collisions at s√= 7 TeV and the different pair combinations are found to be consistent. From the finding that the strength of the K0SK0S correlations is significantly greater than the strength of the K0SK± correlations, the new results are compatible with the a0 resonance being a tetraquark state of the form (q1,q2¯¯¯¯¯,s,s¯¯¯), where q1 and q2 are u or d quarks.
Correlations between mean transverse momentum [pT] and anisotropic flow coefficients v2 or v3 are measured as a function of centrality in Pb−Pb and Xe−Xe collisions at sNN−−−√=5.02 TeV and 5.44 TeV, respectively, with ALICE. In addition, the recently proposed higher-order correlation between [pT], v2, and v3 is measured for the first time, which shows an anticorrelation for the presented centrality ranges. These measurements are compared with hydrodynamic calculations using IP-Glasma and TRENTo initial-state shapes, the former based on the Color Glass Condensate effective theory with gluon saturation, and the latter a parameterized model with nucleons as the relevant degrees of freedom. The data are better described by the IP-Glasma rather than the TRENTo based calculations. In particular, Trajectum and JETSCAPE predictions, both based on the TRENTo initial state model but with different parameter settings, fail to describe the measurements. As the correlations between [pT] and vn are mainly driven by the correlations of the size and the shape of the system in the initial state, these new studies pave a novel way to characterize the initial state and help pin down the uncertainty of the extracted properties of the quark−gluon plasma recreated in relativistic heavy-ion collisions.
Correlations between mean transverse momentum [pT] and anisotropic flow coefficients v2 or v3 are measured as a function of centrality in Pb-Pb and Xe-Xe collisions at sNN−−−√=5.02 TeV and 5.44 TeV, respectively, with ALICE. In addition, the recently proposed higher-order correlation between [pT], v2, and v3 is measured for the first time, which shows an anticorrelation for the presented centrality ranges. These measurements are compared with hydrodynamic calculations using IP-Glasma and TRENTo initial-state shapes, the former based on the Color Glass Condensate effective theory with gluon saturation, and the latter a parameterized model with nucleons as the relevant degrees of freedom. The data are better described by the IP-Glasma rather than the TRENTo based calculations. In particular, Trajectum and JETSCAPE predictions, both based on the TRENTo initial state model but with different parameter settings, fail to describe the measurements. As the correlations between [pT] and vn are mainly driven by the correlations of the size and the shape of the system in the initial state, these new studies pave a novel way to characterize the initial state in relativistic heavy-ion collisions.
Femtoscopic correlations with the particle pair combinations K0SK0S and K0SK± are studied in pp collisions at s√=5.02 and 13 TeV by the ALICE experiment. At both energies, boson source parameters are extracted for both pair combinations, by fitting models based on Gaussian size distributions of the sources, to the measured two-particle correlation functions. The interaction model used for the K0SK0S analysis includes quantum statistics and strong final-state interactions through the f0(980) and a0(980) resonances. The model used for the K0SK± analysis includes only the final-state interaction through the a0 resonance. Source parameters extracted in the present work are compared with published values from pp collisions at s√= 7 TeV and the different pair combinations are found to be consistent. From the observation that the strength of the K0SK0S correlations is significantly greater than the strength of the K0SK± correlations, the new results are compatible with the a0 resonance being a tetraquark state of the form (q1,q2¯¯¯¯¯,s,s¯¯¯), where q1 and q2 are u or d quarks.
The production of prompt D0, D+, and D∗+ mesons was measured at midrapidity (|y|< 0.5) in Pb-Pb collisions at the centre-of-mass energy per nucleon-nucleon pair sNN−−−√ = 5.02 TeV with the ALICE detector at the LHC. The D mesons were reconstructed via their hadronic decay channels and their production yields were measured in central (0-10%) and semicentral (30-50%) collisions. The measurement was performed up to a transverse momentum (pT) of 36 or 50 GeV/c depending on the D meson species and the centrality interval. For the first time in Pb-Pb collisions at the LHC, the yield of D0 mesons was measured down to pT = 0, which allowed a model-independent determination of the pT-integrated yield per unit of rapidity (dN=dy). A maximum suppression by a factor 5 and 2.5 was observed with the nuclear modification factor (RAA) of prompt D mesons at pT = 6-8 GeV/c for the 0-10% and 30-50% centrality classes, respectively. The D-meson RAA is compared with that of charged pions, charged hadrons, and J/ψ mesons as well as with theoretical predictions. The analysis of the agreement between the measured RAA, elliptic (v2) and triangular (v3) flow, and the model predictions allowed us to constrain the charm spatial diffusion coefficient Ds. Furthermore the comparison of RAA and v2 with different implementations of the same models provides an important insight into the role of radiative energy loss as well as charm quark recombination in the hadronisation mechanisms.
Two-particle transverse momentum differential correlators, recently measured in Pb--Pb collisions at energies available at the CERN Large Hadron Collider (LHC), provide an additional tool to gain insights into particle production mechanisms and infer transport properties, such as the ratio of shear viscosity to entropy density, of the medium created in Pb-Pb collisions. The longitudinal long-range correlations and the large azimuthal anisotropy measured at low transverse momenta in small collision systems, namely pp and p-Pb, at LHC energies resemble manifestations of collective behaviour. This suggests that locally equilibrated matter may be produced in these small collision systems, similar to what is observed in Pb-Pb collisions. In this work, the same two-particle transverse momentum differential correlators are exploited in pp and p-Pb collisions at s√=7 TeV and sNN−−−√=5.02 TeV, respectively, to seek evidence for viscous effects. Specifically, the strength and shape of the correlators are studied as a function of the produced particle multiplicity to identify evidence for longitudinal broadening that might reveal the presence of viscous effects in these smaller systems. The measured correlators and their evolution from pp and p--Pb to Pb--Pb collisions are additionally compared to predictions from Monte Carlo event generators, and the potential presence of viscous effects is discussed.