We overview recent jet measurements in pp and Pb-Pb collisions with the ALICE detector. ALICE reconstructs jets at midrapidity using the anti-$k_{\mathrm{T}}$ algorithm, including both charged particle jets from the ALICE tracking detectors, and full jets from the combination of the ALICE electromagnetic calorimeter with the tracking system. We focus on inclusive and semi-inclusive jet measurements as well as jet substructure measurements, including a variety of groomed and ungroomed observables. In pp collisions, these results test pQCD techniques at $p_{\mathrm{T,\;jet}}<140$ GeV$/c$ in a low pileup environment, and can constrain models of non-perturbative effects. In Pb-Pb collisions, these measurements test models of jet quenching in the quark-gluon plasma, and can be used to constrain the properties of high temperature QCD matter.
An overview of the recent results obtained by the ALICE Collaboration from the analysis of the pp, p-Pb and Pb-Pb data samples collected during LHC run I and the first half of run II is presented.
A general overview of the results obtained by the ALICE experiment from the analysis of the $\PbPb$ data sample collected at the end of 2010 during the first heavy-ion run at the LHC is presented.
A selection of recent ALICE results from pp, p--Pb, Pb--Pb and Xe--Xe collisions taken during the Run 1 and Run 2 phases are summarized in this contribution, and the prospects for the upcoming Run 3 phase are outlined.
The results released by the ALICE collaboration at Quark Matter 2014 address topics from identified-particle jet fragmentation functions in pp collisions, to the search for collective signatures in p-Pb collisions to precision measurements of jet quenching with D mesons in Pb-Pb collisions. This paper gives an overview of the contributions (31 parallel talks, 2 flash talks and 80 posters) by the ALICE collaboration at Quark Matter 2014.
The ALICE detector was designed to study the physics of matter under extreme conditions of high energy density. Different results were reported by the experiment using data from the successful run I of the LHC. The goal of the present work is to present an overview of recent ALICE results. This comprises selected results from several analyses of pp, p-pb and Pb-Pb data at the LHC energies.
Ultra-peripheral collisions (UPCs), studied using the ALICE detector, allow us to investigate the low-$x$ behavior of the gluon distribution of the colliding particles. Two new measurements of coherent J/$ψ$ photoproduction cross section from Pb-Pb UPCs at $\sqrt{s_{\rm NN}}=5.02$ TeV are presented: the first measurement of the $|t|$-dependence of the cross section providing a new tool to investigate the transverse gluonic structure at low Bjorken-$x$ and a rapidity-differential measurement at midrapidity allowing us to provide stringent constraints on nuclear gluon shadowing and saturation mo…
One of the key methods used in the study of the Quark-Gluon Plasma (QGP) is femtoscopy, the technique of measuring short-range two-particle correlations as a function of relative momentum. Traditionally, femtoscopy has been utilized to measure the size of the QGP fireball created in relativistic heavy-ion collisions. However, since it is sensitive to the correlations between the particles in the final state, it has been shown recently that the parameters of the strong interaction can be probed as well. This review includes a broad range of ALICE femtoscopy results, including both traditional a…
ALICE is devoted to the study of the properties of the Quark-Gluon Plasma (QGP). This state of matter is created in ultra-relativistic heavy-ion collisions at the LHC. Heavy quarks are considered effective probes of the QGP since, due to their large masses, they are produced in hard scattering processes and experience the full evolution of the hot and dense medium while interacting with its constituents. The heavy-quark measurements provide insights on processes like in-medium energy loss and hadronization. Measurements in proton-proton collisions provide the baseline for interpreting heavy-io…
Recent results from the ALICE experiment are presented with a particular emphasis on particle identification, the nuclear modification factor ($R_{AA}$) and azimuthal anisotropy ($v_2$). Comparison of lead-lead and proton-lead results reveals evidence of collectivity in small systems.
Measurement of short-lived hadronic resonances are used to study different aspects of particle production and collision dynamics in pp, p-A and relativistic heavy-ion collisions. The yields of resonances are sensitive to the competing processes of hadron rescattering and regeneration, thus making these particles unique probes of the properties of the late hadronic phase. Measurements of resonances with different masses and quantum numbers also provide insight into strangeness production and processes that determine the shapes of particle momentum spectra at intermediate transverse momenta, as …
Recent results on the production of light nuclei, including deuterons, tritons, $^3$He, $^4$He and the corresponding antinuclei in Pb-Pb collisions at $\sqrt{s_{\mathrm{NN}}}$ = 5.02 TeV are presented and compared with theoretical predictions to provide insight into their production mechanisms in heavy-ion collisions. The large variety of measurements performed with the ALICE apparatus at different energies and collision systems allows us to constrain the models of the production mechanisms of light flavour baryon clusters, in particular those based on the coalescence and statistical hadronisa…
Selected ALICE results on the global event properties, particle spectra, azimuthal anisotropy, heavy flavour and quarkonium production in Pb-Pb collisions at sqrt(s_NN) = 2.76 TeV are presented. First results on p-Pb collisions at sqrt(s_NN) = 5.02 TeV are briefly reviewed.
Heavy-flavour hadrons, i.e. hadrons containing charm or beauty quarks, are effective probes to test perturbative-QCD (pQCD) calculations, to investigate the different hadronisation mechanisms, and to study the quark-gluon plasma (QGP) produced in relativistic heavy-ion collisions at the LHC. Measurements performed in pp and p-Pb collisions have recently revealed unexpected features not in line with the expectations based on previous measurements from $\rm{e^+e^-}$ and ep collisions, showing that charm fragmentation fractions are not universal. The investigation of initial-state effects such as…
The ALICE experiment at LHC is mainly dedicated to heavy-ion physics. An overview of its performances, some predictions related to its first measurements and QGP observable measurements will be given.
In this paper selected results obtained by the ALICE experiment at the LHC will be presented. Data collected during the pp runs taken at sqrt(s)=0.9, 2.76 and 7 TeV and Pb-Pb runs at sqrt(s_NN)=2.76 TeV allowed interesting studies on the properties of the hadronic and nuclear matter: proton runs gave us the possibility to explore the ordinary matter at very high energy and up to very low pt, while Pb-Pb runs provided spectacular events where several thousands of particles produced in the interaction revealed how a very dense medium behaves, providing a deeper picture on the quark gluon plasma(…
ALICE is a general purpose experiment designed to investigate nucleus-nucleus collisions at the Large Hadron Collider (LHC), located at CERN. The ALICE detector is optimized for the reconstruction of quarkonia through the dimuon decay channel at foward rapidity as well as the dielectron decay channel at midrapidity. In this contribution, quarkonium measurements performed by the ALICE collaboration at both midrapidity and forward rapidity for various energies and colliding systems (pp, p-Pb and Pb-Pb), will be discussed and compared to theory.
The ALICE detector is dedicated to studying the properties of hot and dense matter created in heavy-ion collisions. Among the probes used to investigate these properties are high-momentum particles, which originate in hard-scatterings occurring before the fireball creation. The fragments of hard scatterings interact with the hot and dense matter and via this interaction their spectra and azimuthal distributions are modified. This is probed by the measurement of the nuclear modification factor, where the $p_{\mathrm{T}}$ spectra obtained in Pb-Pb collisions are compared to a pp baseline. A stro…
The ALICE experiment explores the properties of strongly interacting QCD matter at extremely high temperatures created in Pb-Pb collisions at LHC and provides further insight into small-system physics in (high-multiplicity) pp and p-Pb collisions. The ALICE collaboration presented 27 parallel talks, 50 posters, and 1 flash talk at Quark Matter 2015 and covered various topics including collective dynamics, correlations and fluctuations, heavy flavors, quarkonia, jets and high $p_{\rm T}$ hadrons, electromagnetic probes, small system physics, and the upgrade program. This paper highlights some o…
Azimuthal correlations are a powerful tool to probe the properties and the evolution of the collision system. In this proceedings, we will review the recent azimuthal correlation measurements from ALICE at the LHC. The comparison to other experimental measurements and various theoretical calculations will be discussed as well.
Highly energetic jets and photons are complementary probes for the kinematics and the topology of nuclear collisions. Jets are collimated sprays of charged and neutral particles, which are produced in the fragmentation of hard scattered partons in an early stage of the collision. While traversing the medium formed in nuclear collisions, they lose energy and therefore carry information about the interaction of partons with the medium. The jet substructure is particularly interesting to learn about in-medium modification of the jets and several observables exists to probe it. In contrast to jets…
An overview of the latest results on the hard probes from the PHENIX experiment at RHIC is given. The results on the measurements of high $p_{T}$ hadrons, hadron-hadron correlations, open heavy flavor and quarkonia, and direct photons from large (Au+Au) to small collision systems ($p$+Al and $p/d/^3$He+Au) provided a deeper insight on the medium created in the large systems and the possible onset of QGP-nization in transition from small to large systems.
An overview is presented of the recent heavy ion results from the ALICE experiment at the Large Hadron Collider. These new results are placed in perspective with those from the Relativistic Heavy Ion Collider experiments.
The ALICE detector is well suited to measure heavy-flavour (charm and beauty) production via hadronic and semi-leptonic decay channels of heavy-flavour particles. Here an overview of heavy-flavour measurements made with the ALICE detector during Run 1 in pp and p--Pb collisions is presented and discussed.
We discuss the latest results from jet fragmentation and jet substructure measurements performed with the ALICE experiment in proton-proton and heavy-ion collisions in a wide range of jet transverse momentum. The jet production cross sections and cross section ratios for different jet resolution parameters will be shown in a wide range of $p_{\textrm{T}}$. Results will be compared to next-to-leading order pQCD calculations.
We report recent results from the ALICE experiment at the LHC for minimum bias pp collisions. This overview includes results on inelastic cross section, with analysis of single and double diffractive events; the study of hadron production mechanisms, both for inclusive and identified particles; Bose-Einstein correlations; and fluctuations in $<p_T>$
The ALICE experiment at the LHC has collected data in proton-proton (pp) collisions at $\sqrt{s}$ = 0.9, 2.76, 7 and 8 TeV, in lead-lead (Pb--Pb) collisions at $\sqrt{s_{\rm NN}}$ = 2.76 TeV and in proton-lead (p-Pb) collisions at $\sqrt{s_{\rm NN}}$ = 5.02 TeV. A summary overview of recent experimental physics results obtained by ALICE is presented in this paper with a selection of few representative measurements.
We present the latest results on the ALICE performance for heavy-quark production and quenching measurements, focusing in particular on charm particles.
An overview of recent ALICE results aimed to understand collective phenomena in Pb-Pb collisions at the LHC is presented. These include the centrality dependence of the transverse momentum ($p_{\rm T}$) distributions of charged pions, kaons, and protons as well as results on anisotropic flow using data from Pb-Pb collisions at $\sqrt{s_{\mathrm{NN}}} = 5.02$ TeV. In addition, comparisons between data and model predictions are presented.
Long-range correlations between particles separated by a pseudorapidity gap are a powerful tool to explore the initial stages and evolution of the medium created in hadron-hadron collisions. An overview of the long-range correlations measured by the ALICE detector in pp, p-Pb and Pb-Pb will be presented. This includes analyses of forward-backward, two- and multi-particle correlations with the use of the central barrel and forward detectors.
The ALICE experiment at the Large Hadron Collider (LHC) at CERN is optimized for recording events in the very large particle multiplicity environment of heavy-ion collisions at LHC energies. The ALICE collaboration has taken data in Pb-Pb collisions in Run I and Run II at nucleon-nucleon center-of-mass energies $\sqrt{s_{\text{NN}}}$ = 2.76 and \mbox{5.02 TeV}, respectively, and in pp collisions at center-of-mass energies $\sqrt{s}$ = 0.9, 2.76, 5.02, 7, 8 and 13 TeV. The asymmetric system p-Pb was measured at a center-of-mass energy $\sqrt{s_{\text{NN}}}$ = 5.02 TeV. Selected physics results …
In this paper, an overview of recent $\mathrm D^{0}$, $\mathrm D^{+}$ and $\mathrm D^{*+}$ measurements, performed by ALICE in proton--proton collisions at $\sqrt{s}~=~2.76$, 5, 7, 8 and 13 TeV, is reported. The minimum-bias production cross sections, as well as their energy and species dependences, are compared to perturbative QCD calculations. The evolution of the D-meson yields with the event multiplicity is compared to phenomenological models.
Angular correlations are a sensitive probe of the transport properties of the system produced in nucleus-nucleus collisions. Similar studies performed in p-Pb collisions have recently revealed intriguing features as well. In this article, we review the latest results on charged and identified particle correlations obtained with the ALICE detector at the LHC in both Pb-Pb and p-Pb events.
Hadronic resonances are a valuable tool to study the properties of the medium formed in heavy-ion collisions. In particular, they can provide information on particle-formation mechanisms and on the properties of the medium at chemical freeze-out. Furthermore they contribute to the systematic study of parton energy loss and quark recombination. Measurements of resonances in pp and in p-Pb collisions provide a necessary baseline for heavy-ion data and help to disentangle initial-state effects from medium-induced effects. In this paper the latest ALICE results on mid-rapidity K*(892)^0 and ϕ(1020…
ALICE at the LHC has a unique potential to study proton-proton collisions with the goal to probe Quantum ChromoDynamics (QCD). The apparatus was designed to reconstruct particles over a large range in transverse momentum and rapidity. In particular, quarkonia are very interesting probes of QCD, because their production mechanisms are governed by both perturbative and non-perturbative QCD processes. In ALICE, quarkonia are reconstructed via their dilepton decay channel down to zero transverse momentum. This contribution gives a short overview of quarkonium production results in proton-proton co…
An overview of recent ${\rm D^+}$, ${\rm D^0}$, ${\rm D^{*+}}$ and ${\rm D_s^+}$ measurements performed by ALICE at central rapidity in proton-proton collisions at $\sqrt{s}=7$ and 8 TeV, as well as lead-lead collisions at $\sqrt{s_\mathrm{NN}}=2.76$ TeV, is presented. An emphasis is put on the discussion of theoretical predictions with respect to the LHC Run I data.
Latest results on open heavy favour measurements in pp collisions at 7 TeV and Pb-Pb collisions at sqrt(s_NN) = 2.76 TeV with the ALICE experiment are presented. The results of the single lepton analyses (electrons at central rapidity, muons at forward rapidity) and D meson reconstruction will be discussed.
At the LHC collision energies, multiple parton interactions (MPI) are a key ingredient for particle production models including hard scale processes like heavy-quark production (charm and beauty). Quarkonium measurements in high-multiplicity proton-proton (pp) collisions can shed light on the role of MPI at such hard momentum scales, as well as on the interplay between hard and soft particle production mechanisms. In addition, quarkonium production measurements in minimum bias pp collisions, besides serving as a reference for heavy-ion collisions collected at the same center-of-mass energy, re…
Heavy quarks, produced in hard parton scatterings in the early stage of ultra-relativistic heavy-ion collisions, are ideal probes to investigate the properties of the Quark--Gluon Plasma (QGP) produced in such collisions. Measurements of heavy-flavour jets can provide constraints on energy-loss models. In particular, they add information on how the radiated energy is dissipated in the medium. Studies of angular correlations between heavy-flavour and charged particles allow us to characterize the heavy-quark fragmentation process and its possible modification in a hot nuclear matter environment…
We present an overview of the ALICE measurements on the production of $\mathrm{J/}ψ$ in Pb-Pb collisions at a centre-of-mass energy per nucleon pair of $\sqrt{s_\mathrm{NN}} = 2.76\,\mathrm{TeV}$ and p-Pb collisions at $\sqrt{s_\mathrm{NN}}= 5.02\,\mathrm{TeV}$ at mid-rapidity ($|y_\mathrm{lab} | < 0.8$) down to zero transverse momentum. The cold nuclear matter effects estimated from the p-Pb measurements and their impact on the interpretation of Pb-Pb results are discussed, based on comparison of data to model calculations.
In this contribution, the latest ALICE results on charmed baryon production are presented. In particular the measurements of $Λ_{\rm c}^{+}$-baryon production in pp collisions at ${\sqrt{\rm s}}$ = 5.02 TeV and in p-Pb collisions at $\sqrt{\rm s_{NN}}$ = 5.02 TeV are shown and compared with previous measurements performed using pp and p-Pb data samples collected during LHC Run 1. At mid-rapidity charmed baryons are reconstructed via their hadronic decay and semileptonic decay channels, exploiting the high precision tracking, excellent vertexing and particle identification capabilities offered …
The ALICE experiment at the Large Hadron Collider LHC is presented, and an overview of its physics program is given. A few specific observables are discussed in order to illustrate the physics potential of ALICE.
Measurement of heavy-flavour production in small systems can be used to test the Quantum ChromoDynamic (QCD) models. In this manuscript, the production cross section of D mesons at midrapidity and open heavy-flavour decay muons (HFM) measured at forward rapidity in pp collisions at $\sqrt{s}$ = 5.02 TeV, and open heavy-flavour decay electrons (HFE) measured at midrapidity in pp collisions at $\sqrt{s}$ = 13 TeV with ALICE detector will be presented. The self-normalized yield of open heavy-flavour decay electrons and muons as a function of multiplicity in pp and p$-$Pb collisions will be presen…
Charmonia, bound states of charm and anti-charm quarks, represent an interesting probe for the study of Quantum Chromodynamics (QCD) since their production involves both hard and soft energy scales. Several effective models are available to describe the production of charmonia, but so far none have been able to describe all experimental observables simultaneously. ALICE has studied the production of charmonia in different collision systems at all available LHC energies at both mid- and forward-rapidity down to zero transverse momentum. In this contribution, different measurements performed in …
In this work we present a summary of the most relevant results on heavy-ion and astroparticle physics in ALICE. The summary includes a brief overview of the current status on the characterization of the hot and dense QCD medium created in the heavy-ion collisions produced at the LHC, as well as the intriguing finding of collective-like phenomena in small collision systems.
Hadrons containing heavy quarks, i.e. charm or beauty, are unique probes of the properties of the hot and dense QCD medium produced in heavy-ion collisions. Due to their large masses, heavy quarks are produced at the initial stage of the collision, almost exclusively via hard partonic scattering processes. Therefore, they are expected to experience the full collision history propagating through the QCD medium losing energy via elastic and inelastic collisions with the medium constituents. The ALICE collaboration has measured the production of open heavy-flavour hadrons via their hadronic and s…
The event-by-event fluctuations of identified particles in ultrarelativistic nucleus-nucleus collisions give information about the state of matter created in these collisions as well as the phase diagram of nuclear matter. In this proceedings, we present the latest results from ALICE on the centrality and pseudorapidity dependence of net-proton fluctuations, which are closely related to net-baryon fluctuations, as well as net-kaon and net-pion fluctuations. The effects of volume fluctuations and global baryon conservation on these observables are discussed. Furthermore, the correlated fluctuat…
ALICE is the general purpose heavy-ion detector at the CERN LHC. Its goal is to investigate the properties of the strongly interacting matter under the extreme conditions of density and temperature reached in Pb{Pb collisions, with the aim to characterize the Quark-Gluon Plasma (QGP). In this scenario, the upgrade of the ALICE inner tracker targets physics topics in which ALICE can bring a unique contribution to the QGP characterization via the heavy avour probes. We present an overview of the inner tracker upgrade and the expected physics performance for heavy avour measurements.
The measurement of jets recoiling from a trigger hadron in heavy-ion collisions can be used to understand the properties of the Quark Gluon Plasma. Jet-medium interactions cause jets to lose energy in the medium and may modify the jet structure. Jet deflection towards large angles due to scattering off of quasi-particles in the Quark-Gluon Plasma may also occur, which can be studied through a measurement of the hadron-jet acoplanarity. These phenomena can be studied through the semi-inclusive distribution of track-based jets recoiling from a trigger hadron. This contribution presents the lates…
We give an overview of photon physics which will be studied by the ALICE experiment in proton-proton and heavy ion collisions at LHC. We compare properties of ALICE photon detectors and estimate their ability to measure neutral meson and direct photon spectra as well as gamma-hadron and gamma-jet correlations in pp and Pb+Pb collisions.
Bottomonium production is a powerful tool to investigate hadron collisions and the properties of the medium created in heavy-ion collisions. According to the color-screening model, these mesons give important information about the deconfined medium called Quark-Gluon Plasma (QGP) produced in ultrarelativistic heavy-ion collisions. Cold nuclear matter (CNM) effects can modify the bottomonium production even in absence of deconfined matter: the study of proton-nucleus collisions is therefore essential to disentangle these effects from the hot ones. Last but not least, measurement in pp collision…
The ALICE experiment at the LHC has collected wealthy data in proton-proton and lead-lead collisions. An overview of recent ALICE results is given in this paper. Hadron spectra measured in pp collisions at $\sqrt{s}=0.9$, 2.76 and 7 TeV are discussed. Properties of hot nuclear matter produced in Pb-Pb collisions at $\sqrt{s_{NN}}=2.76$ TeV, revealed via many observables measured with the ALICE experiment, are shown.
Heavy-flavour production measurements in pp collisions are important tools to test theoretical models based on perturbative quantum chromodymanics (pQCD) and to investigate the heavy-quark hadronization mechanisms. In ALICE, heavy quarks are measured via the hadronic and electronic decay channels at central rapidity (-0.9 $<$ $\textit{y}$ $<$ 0.9) and via the muon decay channels at forward rapidity (-4 $<$ $\textit{y}$ $<$ -2.5). In this contribution, the production cross-section measurements via the leptonic decay of heavy-flavour hadrons are presented and compared to pQCD theoretical calcula…
In this contribution the latest measurements of real and virtual photons in Pb-Pb collisions at $\sqrt{s_{\rm NN}} = 5.02$ TeV from the ALICE Collaboration are presented. The extracted photon spectra are compared to predictions from state-of-the-art models that explicitly include the whole evolution of the heavy-ion collision as well as measurements at lower energies. Experimental developments that in the future will help to extend the range and procession of the measurements are introduced before concluding with an outlook to possible future measurements at the LHC.
The ALICE experiment has measured the production of a rich set of hadronic resonances, such as $ρ(770)^{0}$, ${\rm K}^{\ast}(892)^{0}$, $ϕ$(1020), $Σ^{\pm}$(1385), $Λ(1520)$ and $Ξ^{\ast 0}$ in pp, p-Pb and Pb-Pb collisions at various energies at the LHC. A comprehensive overview and the latest results are presented in this paper. Special focus is given to the role of hadronic resonances for the study of final-state effects in high-energy collisions. In particular, the measurement of resonance production in heavy-ion collisions has the capability to provide insight into the existence of a prol…
ALICE is an experiment mainly dedicated to the study of the quark-gluon plasma (QGP), a state of nuclear matter where quarks and gluons are deconfined, due to high temperature and density. The production of quarkonia, bound states of either a charm and anti-charm quark pair for charmonia or a bottom and anti-bottom quark pair for bottomonia, is a very useful probe of this state of matter. Indeed, the presence of the QGP modifies their production yields, due to a competition between medium-induced suppression and, at least for charmonia, a recombination mechanism in medium or at hadronization. …
The open heavy-flavour hadron measurements in proton--proton and proton--lead collisions give insight into the charm production and hadronization mechanisms. In this contribution, the latest measurements of the production cross section of prompt $Λ^+_{\rm c}$ and its charge conjugate performed with the ALICE detector at midrapidity in pp, and the new measurement of $Λ_\mathrm{c}^+ \to \mathrm{p} \mathrm{K}_\mathrm{S}^0$ performed down to $p_{\rm T}=0$ in p--Pb collisions at $\sqrt{s_{\rm NN}}$ = 5.02 TeV are presented. We also present the first ALICE measurement of the baryon-to-meson ratio $Λ…
