Refine
Year of publication
Document Type
- Preprint (532)
- Article (396)
- Working Paper (1)
Language
- English (929)
Has Fulltext
- yes (929)
Is part of the Bibliography
- no (929)
Keywords
- BESIII (17)
- e +-e − Experiments (13)
- Heavy Ion Experiments (12)
- Branching fraction (9)
- Hadron-Hadron Scattering (8)
- Particle and Resonance Production (8)
- Quarkonium (7)
- Hadron-Hadron scattering (experiments) (6)
- Spectroscopy (6)
- Hadronic decays (5)
- Branching fractions (4)
- Charm Physics (4)
- Collective Flow (4)
- Electroweak interaction (4)
- Exotics (4)
- Heavy-ion collisions (4)
- Lepton colliders (4)
- Quark-Gluon Plasma (4)
- Charmed mesons (3)
- Charmonium (3)
- Diffraction (3)
- Elastic scattering (3)
- Experimental nuclear physics (3)
- Experimental particle physics (3)
- Heavy Quark Production (3)
- Heavy-ion collision (3)
- Initial state radiation (3)
- Jets (3)
- Jets and Jet Substructure (3)
- LHC (3)
- Particle and resonance production (3)
- Polarization (3)
- QCD (3)
- e+-e− Experiments (3)
- ALICE experiment (2)
- Beam Energy Scan (2)
- Bhabha (2)
- Charm physics (2)
- Chiral Magnetic Effect (2)
- Collectivity (2)
- Correlation (2)
- Cross section (2)
- Electroweak Interaction (2)
- Hadronic cross section (2)
- Lepton-Nucleon Scattering (experiments) (2)
- Leptonic, semileptonic & radiative decays (2)
- Muon anomaly (2)
- Particle Correlations and Fluctuations (2)
- Particle decays (2)
- Pion form factor (2)
- RHIC (2)
- STAR (2)
- Shear viscosity (2)
- pp collisions (2)
- ALICE (1)
- Absolute branching fraction (1)
- Angular distribution (1)
- Annihilation (1)
- B-slope (1)
- BESIII detector (1)
- Beam energy scan (1)
- Beauty production (1)
- Boosted Jets (1)
- Born cross section measurement (1)
- Bromodomänen (1)
- CP violation (1)
- Charged-particle multiplicity (1)
- Charm quark spatial diffusion coefficient (1)
- Charmonia (1)
- Charmonium (-like) (1)
- Chemische Sonden (1)
- Chiral magnetic effect (1)
- Coalescence (1)
- Cold nuclear matter effects (1)
- Collective Flow, (1)
- Comparison with QCD (1)
- Covariance matrix (1)
- Critical point (1)
- Cross section measurements (1)
- D meson (1)
- D0 and D+ mesons (1)
- DNA barcode (1)
- Dalitz decay (1)
- Dark photon (1)
- Dark sector (1)
- Deuteron production (1)
- Di-hadron correlations (1)
- D⁰ meson (1)
- Electromagnetic amplitude (1)
- Electromagnetic form factor (1)
- Electromagnetic form factors (1)
- Electron-pion identification (1)
- Elliptic flow (1)
- Epigenetik (1)
- FOS: Physical sciences (1)
- Fibre/foam sandwich radiator (1)
- Flavor changing neutral currents (1)
- Flavor symmetries (1)
- Flavour Physics (1)
- Flow (1)
- Form factors (1)
- Forward physics (1)
- Groomed jet radius (1)
- Hadron production (1)
- Hadron-Hadron Scattering Heavy (1)
- Hadron-hadron interactions (1)
- Hadrons (1)
- Hard Scattering (1)
- Heavy Ion Experiment (1)
- Heavy flavor production (1)
- Heavy flavour production (1)
- Heavy ion storage ring (1)
- Heavy-Ion Collision (1)
- Heavy-flavor decay electron (1)
- Heavy-ion (1)
- High Energy Physics - Experiment (hep-ex) (1)
- Higher moments (1)
- Hyperons (1)
- Inclusive branching fraction (1)
- Inclusive spectra (1)
- Interference fragmentation function (1)
- Invisible decays (1)
- Ionisation energy loss (1)
- J/ψ suppression (1)
- Jet Physics (1)
- Jet Substructure (1)
- Jet substructure (1)
- K0S (1)
- Macrothele (1)
- Material budget (1)
- Medizinische Chemie (1)
- Mid-rapidity (1)
- Multi-Parton Interactions (1)
- Multi-strange baryons (1)
- Multi-wire proportional drift chamber (1)
- Multiple parton interactions (1)
- Neural network (1)
- Neutrinos (1)
- New species (1)
- Nonflow (1)
- Orbital electron capture (1)
- Particle correlations and fluctuations (1)
- Particle phenomena (1)
- Phase (1)
- Properties of Hadrons (1)
- Proton (1)
- Proton-proton collisions (1)
- Proton–proton (1)
- Proton–proton collisions (1)
- Quantum chromodynamics (1)
- Quark Deconfinement (1)
- Quark Gluon Plasma (1)
- Quark Production (1)
- R value (1)
- Radiative decay (1)
- Rare decays (1)
- Relativistic heavy-ion collisions (1)
- Semi-leptonic decays (1)
- Single electrons (1)
- Single muons (1)
- Single particle decay spectroscopy (1)
- SoftDrop (1)
- Spin alignment (1)
- Splitting function (1)
- Strong amplitude (1)
- Strukturbasiertes Design (1)
- TR (1)
- Techniques Electromagnetic calorimeters (1)
- Thermal model (1)
- Tracking (1)
- Transition radiation detector (1)
- Transversity (1)
- Trigger (1)
- Triple quarkonia (1)
- Two body weak decay (1)
- Vector Boson Production (1)
- W-exchange (1)
- Xenon-based gas mixture (1)
- Y (4260) (1)
- Y states (1)
- Yunnan (1)
- branching fractions (1)
- bromodomains (1)
- center-of-mass energy (1)
- charmed baryon (1)
- charmonium-like states (1)
- chemical probes (1)
- dE/dx (1)
- decay (1)
- decays (1)
- detector (1)
- dimuon (1)
- diphoton (1)
- e+e − annihilation (1)
- e+e⁻ − Experiments (1)
- e+e− Experiments (1)
- e+e− annihilation (1)
- electron-positron collision (1)
- epigenetics (1)
- experimental results (1)
- hadron spectroscopy (1)
- hadronic events (1)
- heavy-ion collisions (1)
- helicity amplitude analysis (1)
- inclusive J/ψ decays (1)
- luminosity (1)
- medicinal chemistry (1)
- number of J/ψ events (1)
- p+p collisions (1)
- spectra (1)
- structure-based design (1)
- tetraquark (1)
- trigger efficiency (1)
- Λ+c baryon (1)
- Λc⁺ (1)
- Σ hyperon (1)
- Υ suppression (1)
- ψ(3686) (1)
Institute
Multiplicity dependence of inclusive J/ψ production at midrapidity in pp collisions at √s = 13 TeV
(2020)
Measurements of the inclusive J/ψ yield as a function of charged-particle pseudorapidity density dNch/dη in pp collisions at √s = 13 TeV with ALICE at the LHC are reported. The J/ψ meson yield is measured at midrapidity (|y| < 0.9) in the dielectron channel, for events selected based on the charged-particle multiplicity at midrapidity (|η| < 1) and at forward rapidity (−3.7 < η < −1.7 and 2.8 < η < 5.1); both observables are normalized to their corresponding averages in minimum bias events. The increase of the normalized J/ψ yield with normalized dNch/dη is significantly stronger than linear and dependent on the transverse momentum. The data are compared to theoretical predictions, which describe the observed trends well, albeit not always quantitatively.
The measurement of the production of charm jets, identified by the presence of a D0 meson in the jet constituents, is presented in proton–proton collisions at centre-of-mass energies of √s = 5.02 and 13 TeV with the ALICE detector at the CERN LHC. The D0 mesons were reconstructed from their hadronic decay D0 → K−π+ and the respective charge conjugate. Jets were reconstructed from D0-meson candidates and charged particles using the anti-kT algorithm, in the jet transverse momentum range 5 < pT,chjet < 50 GeV/c, pseudorapidity |ηjet| < 0.9 − R, and with the jet resolution parameters R = 0.2, 0.4, 0.6. The distribution of the jet momentum fraction carried by a D0 meson along the jet axis (z ch) was measured in the range 0.4 < z ch < 1.0 in four ranges of the jet transverse momentum. Comparisons of results for different collision energies and jet resolution parameters are also presented. The measurements are compared to predictions from Monte Carlo event generators based on leading-order and next-to-leading-order perturbative quantum chromodynamics calculations. A generally good description of the main features of the data is obtained in spite of a few discrepancies at low pT,chjet. Measurements were also done for R = 0.3 at √s = 5.02 and are shown along with their comparisons to theoretical predictions in an appendix to this paper.
Hadronic resonances are used to probe the hadron gas produced in the late stage of heavy-ion collisions since they decay on the same timescale, of the order of 1 to 10 fm/c, as the decoupling time of the system. In the hadron gas, (pseudo)elastic scatterings among the products of resonances that decayed before the kinetic freeze-out and regeneration processes counteract each other, the net effect depending on the resonance lifetime, the duration of the hadronic phase, and the hadronic cross sections at play. In this context, the Σ(1385)± particle is of particular interest as models predict that regeneration dominates over rescattering despite its relatively short lifetime of about 5.5 fm/c. The first measurement of the Σ(1385)± resonance production at midrapidity in Pb-Pb collisions at sNN−−−√=5.02 TeV with the ALICE detector is presented in this Letter. The resonances are reconstructed via their hadronic decay channel, Λπ, as a function of the transverse momentum (pT) and the collision centrality. The results are discussed in comparison with the measured yield of pions and with expectations from the statistical hadronization model as well as commonly employed event generators, including PYTHIA8/Angantyr and EPOS3 coupled to the UrQMD hadronic cascade afterburner. None of the models can describe the data. For Σ(1385)±, a similar behaviour as K∗(892)0 is observed in data unlike the predictions of EPOS3 with afterburner.
An excess of J/ψ yield at very low transverse momentum (pT<0.3 GeV/c), originating from coherent photoproduction, is observed in peripheral and semicentral hadronic Pb–Pb collisions at a center-of-mass energy per nucleon pair of sNN=5.02 TeV. The measurement is performed with the ALICE detector via the dimuon decay channel at forward rapidity (2.5<y<4). The nuclear modification factor at very low pT and the coherent photoproduction cross section are measured as a function of centrality down to the 10% most central collisions. These results extend the previous study at sNN=2.76 TeV, confirming the clear excess over hadronic production in the pT range 0−0.3 GeV/c and the centrality range 70–90%, and establishing an excess with a significance greater than 5σ also in the 50–70% and 30–50% centrality ranges. The results are compared with earlier measurements at sNN=2.76 TeV and with different theoretical predictions aiming at describing how coherent photoproduction occurs in hadronic interactions with nuclear overlap.
An excess of J/ψ yield at very low transverse momentum (pT<0.3 GeV/c), originating from coherent photoproduction, is observed in peripheral and semicentral hadronic Pb−Pb collisions at a center-of-mass energy per nucleon pair of sNN−−−√=5.02 TeV. The measurement is performed with the ALICE detector via the dimuon decay channel at forward rapidity (2.5<y<4). The nuclear modification factor at very low pT and the coherent photoproduction cross section are measured as a function of centrality down to the 10% most central collisions. These results extend the previous study at sNN−−−√=2.76 TeV, confirming the clear excess over hadronic production in the pT range 0−0.3 GeV/c and the centrality range 70−90%, and establishing an excess with a significance greater than 5σ also in the 50−70% and 30−50% centrality ranges. The results are compared with earlier measurements at sNN−−−√=2.76 TeV and with different theoretical predictions aiming at describing how coherent photoproduction occurs in hadronic interactions with nuclear overlap.
Measurement of anti-3He nuclei absorption in matter and impact on their propagation in the Galaxy
(2022)
In our Galaxy, light antinuclei composed of antiprotons and antineutrons can be produced through high-energy cosmic-ray collisions with the interstellar medium or could also originate from the annihilation of dark-matter particles that have not yet been discovered. On Earth, the only way to produce and study antinuclei with high precision is to create them at high-energy particle accelerators. Although the properties of elementary antiparticles have been studied in detail, the knowledge of the interaction of light antinuclei with matter is limited. We determine the disappearance probability of 3He when it encounters matter particles and annihilates or disintegrates within the ALICE detector at the Large Hadron Collider. We extract the inelastic interaction cross section, which is then used as an input to the calculations of the transparency of our Galaxy to the propagation of 3He stemming from dark-matter annihilation and cosmic-ray interactions within the interstellar medium. For a specifc dark-matter profle, we estimate a transparency of about 50%, whereas it varies with increasing 3He momentum from 25% to 90% for cosmic-ray sources. The results indicate that 3He nuclei can travel long distances in the Galaxy, and can be used to study cosmic-ray interactions and dark-matter annihilation.
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.
W±-boson production in p–Pb collisions at √sNN = 8.16 TeV and Pb–Pb collisions at √sNN = 5.02 TeV
(2023)
The production of the W± bosons measured in p−Pb collisions at a centre-of-mass energy per nucleon−nucleon collision sNN−−−−√=8.16 TeV and Pb−Pb collisions at √sNN=5.02 TeV with ALICE at the LHC is presented. The W± bosons are measured via their muonic decay channel, with the muon reconstructed in the pseudorapidity region −4<ημlab<−2.5 with transverse momentum pμT>10 GeV/c. While in Pb−Pb collisions the measurements are performed in the forward (2.5<yμcms<4) rapidity region, in p−Pb collisions, where the centre-of-mass frame is boosted with respect to the laboratory frame, the measurements are performed in the backward (−4.46<yμcms<−2.96) and forward (2.03<yμcms<3.53) rapidity regions. The W− and W+ production cross sections, lepton-charge asymmetry, and nuclear modification factors are evaluated as a function of the muon rapidity. In order to study the production as a function of the p−Pb collision centrality, the production cross sections of the W− and W+ bosons are combined and normalised to the average number of binary nucleon−nucleon collision ⟨Ncoll⟩. In Pb−Pb collisions, the same measurements are presented as a function of the collision centrality. Study of the binary scaling of the W±-boson cross sections in p−Pb and Pb−Pb collisions is also reported. The results are compared with perturbative QCD (pQCD) calculations, with and without nuclear modifications of the Parton Distribution Functions (PDFs), as well as with available data at the LHC. Significant deviations from the theory expectations are found in the two collision systems, indicating that the measurements can provide additional constraints for the determination of nuclear PDF (nPDFs) and in particular of the light-quark distributions.
In our Galaxy, light antinuclei composed of antiprotons and antineutrons can be produced through high-energy cosmic-ray collisions with the interstellar medium or could also originate from the annihilation of dark-matter particles that have not yet been discovered. On Earth, the only way to produce and study antinuclei with high precision is to create them at high-energy particle accelerators. Although the properties of elementary antiparticles have been studied in detail, the knowledge of the interaction of light antinuclei with matter is limited. We determine the disappearance probability of 3He¯¯¯¯¯¯ when it encounters matter particles and annihilates or disintegrates within the ALICE detector at the Large Hadron Collider. We extract the inelastic interaction cross section, which is then used as input to calculations of the transparency of our Galaxy to the propagation of 3He¯¯¯¯¯¯ stemming from dark-matter annihilation and cosmic-ray interactions within the interstellar medium. For a specific dark-matter profile, we estimate a transparency of about 50%, whereas it varies with increasing 3He¯¯¯¯¯¯ momentum from 25% to 90% for cosmic-ray sources. The results indicate that 3He¯¯¯¯¯¯ nuclei can travel long distances in the Galaxy, and can be used to study cosmic-ray interactions and dark-matter annihilation.
Antimatter particles such as positrons and antiprotons abound in the cosmos. Much less common are light antinuclei, composed of antiprotons and antineutrons, which can be produced in our galaxy via high-energy cosmic-ray collisions with the interstellar medium or could also originate from the annihilation of the still undiscovered dark-matter particles. On Earth, the only way to produce and study antinuclei with high precision is to create them at high-energy particle accelerators like the Large Hadron Collider (LHC). Though the properties of elementary antiparticles have been studied in detail, knowledge of the interaction of light antinuclei with matter is rather limited. This work focuses on the determination of the disappearance probability of \ahe\ when it encounters matter particles and annihilates or disintegrates. The material of the ALICE detector at the LHC serves as a target to extract the inelastic cross section for \ahe\ in the momentum range of 1.17≤p<10 GeV/c. This inelastic cross section is measured for the first time and is used as an essential input to calculations of the transparency of our galaxy to the propagation of 3He¯¯¯¯¯¯ stemming from dark-matter decays and cosmic-ray interactions within the interstellar medium. A transparency of about 50% is estimated using the GALPROP program for a specific dark-matter profile and a standard set of propagation parameters. For cosmic-ray sources, the obtained transparency with the same propagation scheme varies with increasing 3He¯¯¯¯¯¯ momentum from 25% to 90%. The absolute uncertainties associated to the 3He¯¯¯¯¯¯ inelastic cross section measurements are of the order of 10%−15%. The reported results indicate that 3He¯¯¯¯¯¯ nuclei can travel long distances in the galaxy, and can be used to study cosmic-ray interactions and dark-matter decays.