Refine
Year of publication
Document Type
- Preprint (756)
- Article (554)
- Working Paper (1)
Language
- English (1311)
Has Fulltext
- yes (1311)
Is part of the Bibliography
- no (1311)
Keywords
- Heavy Ion Experiments (22)
- BESIII (19)
- e +-e − Experiments (16)
- Branching fraction (12)
- Hadron-Hadron scattering (experiments) (12)
- Hadron-Hadron Scattering (10)
- Particle and Resonance Production (9)
- Quarkonium (9)
- Charm Physics (6)
- Spectroscopy (6)
- Hadronic decays (5)
- Heavy-ion collision (5)
- Jets (5)
- QCD (5)
- Branching fractions (4)
- Charmonium (4)
- Collective Flow (4)
- Electroweak interaction (4)
- Exotics (4)
- Heavy Quark Production (4)
- Heavy-ion collisions (4)
- Lepton colliders (4)
- Quark-Gluon Plasma (4)
- Charmed mesons (3)
- Diffraction (3)
- Elastic scattering (3)
- Experimental nuclear physics (3)
- Experimental particle physics (3)
- Initial state radiation (3)
- Jets and Jet Substructure (3)
- Particle and resonance production (3)
- Polarization (3)
- RHIC (3)
- e+-e− Experiments (3)
- Absolute branching fraction (2)
- Beam Energy Scan (2)
- Bhabha (2)
- Charm physics (2)
- Chiral Magnetic Effect (2)
- Collectivity (2)
- Correlation (2)
- Cross section (2)
- Electroweak Interaction (2)
- Flavour Physics (2)
- Hadronic cross section (2)
- Heavy-Ion Collision (2)
- Lepton-Nucleon Scattering (experiments) (2)
- Leptonic, semileptonic & radiative decays (2)
- Muon anomaly (2)
- Particle Correlations and Fluctuations (2)
- Particle correlations and fluctuations (2)
- Particle decays (2)
- Pion form factor (2)
- Quark Gluon Plasma (2)
- Quark–gluon plasma (2)
- Radiative decay (2)
- STAR (2)
- Shear viscosity (2)
- decays (2)
- 900 GeV (1)
- ALICE (1)
- Acute lymphoblastic leukemia (1)
- Alleles (1)
- Analysis and statistical methods (1)
- Angular distribution (1)
- Annihilation (1)
- Aortic valve (1)
- Apoptosis (1)
- B-slope (1)
- BESIII detector (1)
- Beam energy scan (1)
- Boosted Jets (1)
- Born cross section (1)
- Born cross section measurement (1)
- Branching fraction measurement (1)
- CP violation (1)
- Calorimeters (1)
- Cancer chemotherapy (1)
- Cancer treatment (1)
- Canonical suppression (1)
- Cell proliferation (1)
- Charged-particle multiplicity (1)
- Charm quark spatial diffusion coefficient (1)
- Charm vector (1)
- Charmed baryon (1)
- Charmonia (1)
- Charmonium (-like) (1)
- Chiral magnetic effect (1)
- Chiton (1)
- Coalescence (1)
- Cold nuclear matter effects (1)
- Collective Flow, (1)
- Covariance matrix (1)
- Critical point (1)
- Cross section measurements (1)
- D meson (1)
- D0 and D+ mesons (1)
- Dalitz decay (1)
- Dark photon (1)
- Dark sector (1)
- Data processing methods (1)
- Deuteron (1)
- Deuteron production (1)
- Di-hadron correlations (1)
- D⁰ meson (1)
- Effective form factor (1)
- Electromagnetic amplitude (1)
- Electromagnetic form factor (1)
- Electromagnetic form factors (1)
- Elliptic flow (1)
- Endothelial cells (1)
- FOS: Physical sciences (1)
- Flavor changing neutral currents (1)
- Flavor symmetries (1)
- Flow (1)
- Flow cytometry (1)
- Form factors (1)
- Forward physics (1)
- Groomed jet radius (1)
- Hadron-Hadron Scattering Heavy (1)
- Hadron-hadron interactions (1)
- Hadronization (1)
- Hadrons (1)
- Haematococcus pluvialis (1)
- Hard Scattering (1)
- Heart (1)
- Heavy Ion Experiment (1)
- Heavy flavor (1)
- Heavy ion collisions (1)
- Heavy ion storage ring (1)
- Heavy-flavor decay electron (1)
- Heavy-ion (1)
- Helicity amplitude analysis (1)
- High Energy Physics - Experiment (hep-ex) (1)
- Higher moments (1)
- Homeostasis (1)
- Hyperons (1)
- Immunostaining (1)
- Inclusive branching fraction (1)
- Integrins (1)
- Interference fragmentation function (1)
- Invisible decays (1)
- J/ψ suppression (1)
- Jet Physics (1)
- Jet Substructure (1)
- Jet substructure (1)
- K0S (1)
- Kollision (1)
- Korrelation (1)
- LHC (1)
- Leukemias (1)
- Material budget (1)
- Mollusca (1)
- Mouse models (1)
- Multi-Parton Interactions (1)
- Multiple parton interactions (1)
- Multiple sclerosis (1)
- Net-charge correlations (1)
- Net-charge fluctuations (1)
- Neutrinos (1)
- Nonflow (1)
- Orbital electron capture (1)
- PYTHIA (1)
- Particle phenomena (1)
- Particle production (1)
- Performance of High Energy Physics Detectors (1)
- Phase (1)
- Phylogenomics (1)
- Polyplacophora (1)
- Properties of Hadrons (1)
- Proton (1)
- Proton-proton collisions (1)
- Proton–proton collisions (1)
- Quantum chromodynamics (1)
- Quark Deconfinement (1)
- Quark Production (1)
- R value (1)
- Rare decays (1)
- Relativistic heavy-ion collisions (1)
- Resonances (1)
- Semi-leptonic decays (1)
- Single particle decay spectroscopy (1)
- SoftDrop (1)
- Spin alignment (1)
- Splitting function (1)
- Strangeness enhancement (1)
- Strong amplitude (1)
- Tas2r126 (1)
- Tas2r135 (1)
- Tas2r143 (1)
- Techniques Electromagnetic calorimeters (1)
- Thermal model (1)
- Threshold effect (1)
- Transverse momentum (1)
- Transversity (1)
- Triple quarkonia (1)
- Two body weak decay (1)
- Vector Boson Production (1)
- W-exchange (1)
- Y (4260) (1)
- Y states (1)
- arabidopsis thaliana (1)
- astaxanthin (1)
- b-carotene ketolase (1)
- branching fractions (1)
- carotenoid (1)
- center-of-mass energy (1)
- charmed baryon (1)
- charmonium-like states (1)
- chemosensory cells (1)
- collision (1)
- decay (1)
- detector (1)
- deuteron (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)
- experimental results (1)
- hadron spectroscopy (1)
- hadronic events (1)
- heavy ion experiments (1)
- heavy-ion collisions (1)
- helicity amplitude analysis (1)
- high energie (1)
- hohe Energie (1)
- inclusive J/ψ decays (1)
- luminosity (1)
- number of J/ψ events (1)
- p+p collisions (1)
- quark gluon plasma (1)
- shell eyes (1)
- space-momentum correlation (1)
- tetraquark (1)
- trigger efficiency (1)
- tuft cells (1)
- Λ+c baryon (1)
- Λc⁺ (1)
- Σ hyperon (1)
- Υ suppression (1)
- ψ(3686) (1)
Institute
- Physik (1195)
- Frankfurt Institute for Advanced Studies (FIAS) (816)
- Informatik (682)
- Informatik und Mathematik (3)
- Medizin (3)
- Biowissenschaften (1)
- Center for Financial Studies (CFS) (1)
- ELEMENTS (1)
- House of Finance (HoF) (1)
- Institut für Ökologie, Evolution und Diversität (1)
This article presents new measurements of the fragmentation properties of jets in both proton-proton (pp) and heavy-ion collisions with the ALICE experiment at the LHC. We report distributions of the fraction zr of transverse momentum carried by subjets of radius r within jets of radius R. Charged-particle jets are reconstructed at midrapidity using the anti-kT algorithm with jet radius R=0.4, and subjets are reconstructed by reclustering the jet constituents using the anti-kT algorithm with radii r=0.1 and r=0.2. In pp collisions, we measure both the inclusive and leading subjet distributions. We compare these measurements to perturbative calculations at next-to-leading logarithmic accuracy, which suggest a large impact of threshold resummation and hadronization effects on the zr distribution. In heavy-ion collisions, we measure the leading subjet distributions, which allow access to a region of harder jet fragmentation than has been probed by previous measurements of jet quenching via hadron fragmentation distributions. The zr distributions enable extraction of the parton-to-subjet fragmentation function and allow for tests of the universality of jet fragmentation functions in the quark-gluon plasma (QGP). We find no significant modification of zr distributions in Pb-Pb compared to pp collisions. However, the distributions are also consistent with a hardening trend for zr<0.95, as predicted by several jet quenching models. As zr→1 our results indicate that any such hardening effects cease, exposing qualitatively new possibilities to disentangle competing jet quenching mechanisms. By comparing our results to theoretical calculations based on an independent extraction of the parton-to-jet fragmentation function, we find consistency with the universality of jet fragmentation and no indication of factorization breaking in the QGP.
This article presents new measurements of the fragmentation properties of jets in both proton-proton (pp) and heavy-ion collisions with the ALICE experiment at the LHC. We report distributions of the fraction zr of transverse momentum carried by subjets of radius r within jets of radius R. Charged-particle jets are reconstructed at midrapidity using the anti-kT algorithm with jet radius R=0.4, and subjets are reconstructed by reclustering the jet constituents using the anti-kT algorithm with radii r=0.1 and r=0.2. In pp collisions, we measure both the inclusive and leading subjet distributions. We compare these measurements to perturbative calculations at next-to-leading logarithmic accuracy, which suggest a large impact of threshold resummation and hadronization effects on the zr distribution. In heavy-ion collisions, we measure the leading subjet distributions, which allow access to a region of harder jet fragmentation than has been probed by previous measurements of jet quenching via hadron fragmentation distributions. The zr distributions enable extraction of the parton-to-subjet fragmentation function and allow for tests of the universality of jet fragmentation functions in the quark-gluon plasma (QGP). We find no significant modification of zr distributions in Pb-Pb compared to pp collisions. However, the distributions are also consistent with a hardening trend for zr<0.95, as predicted by several jet quenching models. As zr→1 our results indicate that any such hardening effects cease, exposing qualitatively new possibilities to disentangle competing jet quenching mechanisms. By comparing our results to theoretical calculations based on an independent extraction of the parton-to-jet fragmentation function, we find consistency with the universality of jet fragmentation and no indication of factorization breaking in the QGP.
This letter reports measurements which characterize the underlying event associated with hard scatterings at mid-pseudorapidity (|η|<0.8) in pp, p−Pb and Pb−Pb collisions at centre-of-mass energy per nucleon pair, sNN−−−√=5.02 TeV. The measurements are performed with ALICE at the LHC. Different multiplicity classes are defined based on the event activity measured at forward rapidities. The hard scatterings are identified by the leading particle defined as the charged particle with the largest transverse momentum (pT) in the collision and having 8<pT<15 GeV/c. The pT spectra of associated particles (0.5≤pT<6 GeV/c) are measured in different azimuthal regions defined with respect to the leading particle direction: toward, transverse, and away. The associated charged particle yields in the transverse region are subtracted from those of the away and toward regions. The remaining jet-like yields are reported as a function of the multiplicity measured in the transverse region. The measurements show a suppression of the jet-like yield in the away region and an enhancement of high-pT associated particles in the toward region in central Pb−Pb collisions, as compared to minimum-bias pp collisions. These observations are consistent with previous measurements that used two-particle correlations, and with an interpretation in terms of parton energy loss in a high-density quark gluon plasma. These yield modifications vanish in peripheral Pb−Pb collisions and are not observed in either high-multiplicity pp or p−Pb collisions.
Three-body nuclear forces play an important role in the structure of nuclei and hypernuclei and are also incorporated in models to describe the dynamics of dense baryonic matter, such as in neutron stars. So far, only indirect measurements anchored to the binding energies of nuclei can be used to constrain the three-nucleon force, and if hyperons are considered, the scarce data on hypernuclei impose only weak constraints on the three-body forces. In this work, we present the first direct measurement of the p−p−p and p−p−Λ systems in terms of three-particle mixed moments carried out for pp collisions at s√ = 13 TeV. Three-particle cumulants are extracted from the normalised mixed moments by applying the Kubo formalism, where the three-particle interaction contribution to these moments can be isolated after subtracting the known two-body interaction terms. A negative cumulant is found for the p−p−p system, hinting to the presence of a residual three-body effect while for p−p−Λ the cumulant is consistent with zero. This measurement demonstrates the accessibility of three-baryon correlations at the LHC.
Three-body nuclear forces play an important role in the structure of nuclei and hypernuclei and are also incorporated in models to describe the dynamics of dense baryonic matter, such as in neutron stars. So far, only indirect measurements anchored to the binding energies of nuclei can be used to constrain the three-nucleon force, and if hyperons are considered, the scarce data on hypernuclei impose only weak constraints on the three-body forces. In this work, we present the first direct measurement of the p−p−p and p−p−Λ systems in terms of three-particle correlation functions carried out for pp collisions at s√=13 TeV. Three-particle cumulants are extracted from the correlation functions by applying the Kubo formalism, where the three-particle interaction contribution to these correlations can be isolated after subtracting the known two-body interaction terms. A negative cumulant is found for the p−p−p system, hinting to the presence of a residual three-body effect while for p−p−Λ the cumulant is consistent with zero. This measurement demonstrates the accessibility of three-baryon correlations at the LHC.
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.
Anisotropic flow and flow fluctuations of identified hadrons in Pb–Pb collisions at √sNN = 5.02 TeV
(2023)
The first measurements of elliptic flow of π±, K±, p+p¯¯¯, K0S, Λ+Λ¯¯¯¯, ϕ, Ξ−+Ξ+, and Ω−+Ω+ using multiparticle cumulants in Pb−Pb collisions at sNN−−−√ = 5.02 TeV are presented. Results obtained with two- (v2{2}) and four-particle cumulants (v2{4}) are shown as a function of transverse momentum, pT, for various collision centrality intervals. Combining the data for both v2{2} and v2{4} also allows us to report the first measurements of the mean elliptic flow, elliptic flow fluctuations, and relative elliptic flow fluctuations for various hadron species. These observables probe the event-by-event eccentricity fluctuations in the initial state and the contributions from the dynamic evolution of the expanding quark-gluon plasma. The characteristic features observed in previous pT-differential anisotropic flow measurements for identified hadrons with two-particle correlations, namely the mass ordering at low pT and the approximate scaling with the number of constituent quarks at intermediate pT, are similarly present in the four-particle correlations and the combinations of v2{2} and v2{4}. In addition, a particle species dependence of flow fluctuations is observed that could indicate a significant contribution from final state hadronic interactions. The comparison between experimental measurements and CoLBT model calculations, which combine the various physics processes of hydrodynamics, quark coalescence, and jet fragmentation, illustrates their importance over a wide pT range.
The measurement of the production of f0(980) in inelastic pp collisions at s√=5.02 TeV is presented. This is the first reported measurement of inclusive f0(980) yield at LHC energies. The production is measured at midrapidity, |y|<0.5, in a wide transverse momentum range, 0<pT<16 GeV/c, by reconstructing the resonance in the f0(980)→π+π− hadronic decay channel using the ALICE detector. The pT-differential yields are compared to those of pions, protons and ϕ mesons as well as to predictions from the HERWIG 7.2 QCD-inspired Monte Carlo event generator and calculations from a coalescence model that uses the AMPT model as an input. The ratio of the pT-integrated yield of f0(980) relative to pions is compared to measurements in e+e− and pp collisions at lower energies and predictions from statistical hadronisation models and HERWIG 7.2. A mild collision energy dependence of the f0(980) to pion production is observed in pp collisions from SPS to LHC energies. All considered models underpredict the pT-integrated 2f0(980)/(π++π−) ratio. The prediction from the canonical statistical hadronisation model assuming a zero total strangeness content of f0(980) is consistent with the data within 1.9σ and is the closest to the data. The results provide an essential reference for future measurements of the particle yield and nuclear modification in p−Pb and Pb−Pb collisions, which have been proposed to be instrumental to probe the elusive nature and quark composition of the f0(980) scalar meson.
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 darkmatter 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.
The production of π±, K±, and (p¯¯¯)p is measured in pp collisions at s√=13 TeV in different topological regions. Particle transverse momentum (pT) spectra are measured in the ``toward'', ``transverse'', and ``away'' angular regions defined with respect to the direction of the leading particle in the event. While the toward and away regions contain the fragmentation products of the near-side and away-side jets, respectively, the transverse region is dominated by particles from the Underlying Event (UE). The relative transverse activity classifier, RT=NT/⟨NT⟩, is used to group events according to their UE activity, where NT is the measured charged-particle multiplicity per event in the transverse region and ⟨NT⟩ is the mean value over all the analysed events. The first measurements of identified particle pT spectra as a function of RT in the three topological regions are reported. The yield of high transverse momentum particles relative to the RT-integrated measurement decreases with increasing RT in both the toward and away regions, indicating that the softer UE dominates particle production as RT increases and validating that RT can be used to control the magnitude of the UE. Conversely, the spectral shapes in the transverse region harden significantly with increasing RT. This hardening follows a mass ordering, being more significant for heavier particles. The pT-differential particle ratios (p+p¯¯¯)/(π++π−) and (K++K−)/(π++π−) in the low UE limit (RT→0) approach expectations from Monte Carlo generators such as PYTHIA 8 with Monash 2013 tune and EPOS LHC, where the jet-fragmentation models have been tuned to reproduce e+e− results.