Refine
Year of publication
Document Type
- Preprint (598)
- Article (411)
- Conference Proceeding (2)
Has Fulltext
- yes (1011)
Is part of the Bibliography
- no (1011)
Keywords
- Heavy Ion Experiments (21)
- Hadron-Hadron scattering (experiments) (11)
- Hadron-Hadron Scattering (10)
- BESIII (7)
- Branching fraction (7)
- Heavy-ion collision (5)
- Jets (5)
- Collective Flow (4)
- Quark-Gluon Plasma (4)
- Electroweak interaction (3)
- Experimental nuclear physics (3)
- Experimental particle physics (3)
- Heavy Quark Production (3)
- Jets and Jet Substructure (3)
- Lepton colliders (3)
- Particle and resonance production (3)
- Quarkonium (3)
- Quasi-free scattering (3)
- e +-e − Experiments (3)
- e+-e− Experiments (3)
- Charm Physics (2)
- Charm physics (2)
- Charmed mesons (2)
- Hadronic decays (2)
- Inverse kinematics (2)
- Lepton-Nucleon Scattering (experiments) (2)
- Leptonic, semileptonic & radiative decays (2)
- Particle Correlations and Fluctuations (2)
- Particle and Resonance Production (2)
- Particle correlations and fluctuations (2)
- Particle decays (2)
- QCD (2)
- Quark Gluon Plasma (2)
- Single-particle states (2)
- Spectroscopic factors (2)
- decays (2)
- ALICE detector (1)
- Absolute branching fraction (1)
- Acuris (1)
- Analysis and statistical methods (1)
- Anti-nuclei (1)
- Atmospheric chemistry (1)
- BESIII detector (1)
- Bacterial leakage (1)
- Bhabha (1)
- Biogeochemistry (1)
- Boosted Jets (1)
- Born cross section (1)
- Branching fractions (1)
- CAD/CAM crown (1)
- COVID-19 (1)
- CTLA-4 (1)
- Calorimeters (1)
- Cement gap (1)
- Cerebral cortex (1)
- Charmed baryon (1)
- Collective Flow, (1)
- Conometric connection (1)
- Cross section (1)
- Cross sections (1)
- D meson (1)
- Data processing methods (1)
- Direct nuclear reactions (1)
- Direct reactions (1)
- Effective form factor (1)
- Electromagnetic form factor (1)
- Electromagnetic form factors (1)
- Electron-pion identification (1)
- Erzähltheorie (1)
- Exotics (1)
- Fibre/foam sandwich radiator (1)
- Flavor changing neutral currents (1)
- Flavour Physics (1)
- Form factors (1)
- Hadron-Hadron Scattering Heavy (1)
- Hadron-hadron interactions (1)
- Hard Scattering (1)
- Heavy Ion Experiment (1)
- Heavy Ions (1)
- Heavy-Ion Collision (1)
- Hofmannsthal, Hugo von (1)
- Hyperons (1)
- Inclusive branching fraction (1)
- Initial state radiation (1)
- Ionisation energy loss (1)
- Jet Physics (1)
- Jet Substructure (1)
- K0S (1)
- KIF (1)
- KIF11 (1)
- LHC (1)
- Longitudinal (1)
- Lyrik (1)
- Marginal integrity (1)
- Material budget (1)
- Microgap (1)
- Multi-Parton Interactions (1)
- Multi-wire proportional drift chamber (1)
- NCH93 (1)
- Neural network (1)
- Neutrinos (1)
- Nuclear reactions (1)
- Nuclear structure & decays (1)
- Nucleon induced nuclear reactions (1)
- One-nucleon removal (1)
- PD-1 (1)
- Parkinson's disease (1)
- Particle phenomena (1)
- Pb–Pb collisions (1)
- Performance of High Energy Physics Detectors (1)
- Poetik (1)
- Properties of Hadrons (1)
- Proton (1)
- Quantitative MRI (1)
- Quantum chromodynamics (1)
- Quark Deconfinement (1)
- Quark Production (1)
- Quark gluon plasma (1)
- Rare decays (1)
- Relativistic heavy-ion collisions (1)
- Relaxometry (1)
- SARS-CoV-2 (1)
- Shell model (1)
- Spectroscopic factors & electromagnetic moments (1)
- T1 (1)
- TR (1)
- Techniques Electromagnetic calorimeters (1)
- Threshold effect (1)
- Tracking (1)
- Transition radiation detector (1)
- Trigger (1)
- Vector Boson Production (1)
- Xenon-based gas mixture (1)
- brain imaging (1)
- branching fractions (1)
- center-of-mass energy (1)
- charmed baryon (1)
- dE/dx (1)
- detector (1)
- dimuon (1)
- e+e − annihilation (1)
- e+e⁻ − Experiments (1)
- epilepsy (1)
- experimental results (1)
- hadronic events (1)
- heavy ion experiments (1)
- idiopathic dystonia (1)
- immune checkpoint blockade (1)
- inclusive J/ψ decays (1)
- kinesin (1)
- liver metastasis (1)
- meningioma (1)
- movement disorders (1)
- multiple sclerosis (1)
- neurodegeneration (1)
- neuroimaging (1)
- neutralizing antibodies (1)
- number of J/ψ events (1)
- proton density (1)
- quantitative MRI (1)
- quantitative magnetic resonance imaging (1)
- quark gluon plasma (1)
- relaxometry (1)
- spike protein (1)
- treatment resistance (1)
- trigger efficiency (1)
- uveal melanoma (1)
- variants of concern (1)
- Σ hyperon (1)
- ψ(3686) (1)
Institute
- Physik (998)
- Frankfurt Institute for Advanced Studies (FIAS) (791)
- Informatik (757)
- ELEMENTS (9)
- Medizin (8)
- Informatik und Mathematik (3)
- Geowissenschaften (2)
- Hochschulrechenzentrum (1)
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.
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.
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 +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 center-of-mass energy per nucleon-nucleon collision √sNN = 5.02 TeV. The measurement was performed in the decay channel +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 +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 +c baryons, which are compared to model calculations that consider nuclear modification of the parton distribution functions. The +c /D0 baryon-to-meson yield ratio is reported for pp and p–Pb collisions. Comparisons with models that include modified hadronization processes are presented, and the implications of the results on the understanding of charm hadronization in hadronic collisions are discussed. A significant (3.7σ) modification of the mean transverse momentum of + c baryons is seen in p–Pb collisions with respect to pp collisions, while the pT -integrated +c /D0 yield ratio was found to be consistent between the two collision systems within the uncertainties.
We present the first measurement of event-by-event fluctuations in the kaon sector in Pb – Pb collisions at √sNN = 2.76 TeV with the ALICE detector at the LHC. The robust fluctuation correlator νdyn is used to evaluate the magnitude of fluctuations of the relative yields of neutral and charged kaons, as well as the relative yields of charged kaons, as a function of collision centrality and selected kinematic ranges. While the correlator νdyn[K+,K−] exhibits a scaling approximately in inverse proportion of the charged particle multiplicity, νdyn[K0 S ,K±] features a significant deviation from such scaling. Within uncertainties, the value of νdyn[K0 S ,K±] is independent of the selected transverse momentum interval, while it exhibits a pseudorapidity dependence. The results are compared with HIJING, AMPT and EPOS–LHC predictions, and are further discussed in the context of the possible production of disoriented chiral condensates in central Pb – Pb collisions.
In particle collider experiments, elementary particle interactions with large momentum transfer produce quarks and gluons (known as partons) whose evolution is governed by the strong force, as described by the theory of quantum chromodynamics (QCD)1. These partons subsequently emit further partons in a process that can be described as a parton shower2, which culminates in the formation of detectable hadrons. Studying the pattern of the parton shower is one of the key experimental tools for testing QCD. This pattern is expected to depend on the mass of the initiating parton, through a phenomenon known as the dead-cone effect, which predicts a suppression of the gluon spectrum emitted by a heavy quark of mass mQ and energy E, within a cone of angular size mQ/E around the emitter3. Previously, a direct observation of the dead-cone effect in QCD had not been possible, owing to the challenge of reconstructing the cascading quarks and gluons from the experimentally accessible hadrons. We report the direct observation of the QCD dead cone by using new iterative declustering techniques4,5 to reconstruct the parton shower of charm quarks. This result confirms a fundamental feature of QCD. Furthermore, the measurement of a dead-cone angle constitutes a direct experimental observation of the non-zero mass of the charm quark, which is a fundamental constant in the standard model of particle physics.
The production of J/ψ is measured as a function of charged-particle multiplicity at forward rapidity in proton-proton (pp) collisions at center-of-mass energies s√ = 5.02 and 13 TeV. The J/ψ mesons are reconstructed via their decay into dimuons in the rapidity interval (2.5 < y < 4.0), whereas the charged-particle multiplicity density (dNch/dη) is measured at midrapidity (|η| < 1). The production rate as a function of multiplicity is reported as the ratio of the yield in a given multiplicity interval to the multiplicity-integrated one. This observable shows a linear increase with charged-particle multiplicity normalized to the corresponding average value for inelastic events (dNch/dη/〈dNch/dη〉), at both the colliding energies. Measurements are compared with available ALICE results at midrapidity and theoretical model calculations. First measurement of the mean transverse momentum (〈pT〉) of J/ψ in pp collisions exhibits an increasing trend as a function of dNch/dη/〈dNch/dη〉 showing a saturation towards high charged-particle multiplicities.
The multiplicity dependence of jet production in pp collisions at the centre-of-mass energy of s√=13 TeV is studied for the first time. Jets are reconstructed from charged particles using the anti-kT algorithm with resolution parameters R varying from 0.2 to 0.7. The jets are measured in the pseudorapidity range |ηjet|<0.9−R and in the transverse momentum range 5<pchT,jet<140 GeV/c. The multiplicity intervals are categorised by the ALICE forward detector V0. The pT differential cross section of charged-particle jets are compared to leading order (LO) and next-to-leading order (NLO) perturbative quantum chromodynamics (pQCD) calculations. It is found that the data are better described by the NLO calculation, although the NLO prediction overestimates the jet cross section below 20 GeV/c. The cross section ratios for different R are also measured and compared to model calculations. These measurements provide insights into the angular dependence of jet fragmentation. The jet yield increases with increasing self-normalised charged-particle multiplicity. This increase shows only a weak dependence on jet transverse momentum and resolution parameter at the highest multiplicity. While such behaviour is qualitatively described by the present version of PYTHIA, quantitative description may require implementing new mechanisms for multi-particle production in hadronic collisions.
The energy deposited at very forward rapidities (very forward energy) is a powerful tool for characterising proton fragmentation in pp and p-Pb collisions. The correlation of very forward energy with particle production at midrapidity provides direct insights into the initial stages and the subsequent evolution of the collision. Furthermore, the correlation with the production of particles with large transverse momenta at midrapidity provides information complementary to the measurements of the underlying event, which are usually interpreted in the framework of models implementing centrality-dependent multiple parton interactions.
Results about very forward energy, measured by the ALICE zero degree calorimeters (ZDCs), and its dependence on the activity measured at midrapidity in pp collisions at s√ = 13 TeV and in p-Pb collisions at sNN−−−√ = 8.16 TeV are discussed. The measurements performed in pp collisions are compared with the expectations of three hadronic interaction event generators: PYTHIA 6 (Perugia 2011 tune), PYTHIA 8 (Monash tune), and EPOS LHC. These results provide new constraints on the validity of models in describing the beam remnants at very forward rapidities, where perturbative QCD cannot be used.
Understanding the production mechanism of light (anti)nuclei is one of the key challenges of nuclear physics and has important consequences for astrophysics, since it provides an input for indirect dark-matter searches in space. In this paper, the latest results about the production of light (anti)nuclei in pp collisions at s√ = 13 TeV are presented, focusing on the comparison with the predictions of coalescence and thermal models. For the first time, the coalescence parameters B2 for deuterons and B3 for helions are compared with parameter-free theoretical predictions that are directly constrained by the femtoscopic measurement of the source radius in the same event class. A fair description of the data with a Gaussian wave function is observed for both deuteron and helion, supporting the coalescence mechanism for the production of light (anti)nuclei in pp collisions. This method paves the way for future investigations of the internal structure of more complex nuclear clusters, including the hypertriton.
Two-particle Azimuthal correlations are measured with the ALICE apparatus in pp collisions at s√=13 TeV to explore strangeness- and multiplicity-related effects in the fragmentation of jets and the transition regime between bulk and hard production, probed with the condition that a strange meson (KS0) or baryon (Λ) with transverse momentum pT>3 GeV/c is produced. Azimuthal correlations between kaons or Λ hyperons with other hadrons are presented at midrapidity for a broad range of the trigger (3<ptriggT<20 GeV/c) and associated particle pT (1 GeV/c <passocT<ptriggT), for minimum-bias events and as a function of the event multiplicity. The near- and away-side peak yields are compared for the case of either KS0 or Λ(Λ¯¯¯¯) being the trigger particle with that of inclusive hadrons (a sample dominated by pions). In addition, the measurements are compared with predictions from PYTHIA 8 and EPOS LHC event generators.