Highly energetic jets are sensitive 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 the early stage of the collision. The measurement of nuclear modification of charged jet spectra in p-Pb collisions provides an important way of quantifying the effects of cold nuclear matter in the initial state on jet production, fragmentation, and hadronization. Unlike in Pb-Pb collisions, modifications of jet production due to hot nuclear matter effects are not expected to occur in p-Pb collisions. Therefore, measurements of nuclear modifications in charged jet spectra in p-Pb collisions (commonly known as $R_\mathrm{pPb}$) can be used to isolate and quantify cold nuclear matter effects. Potential nuclear effects are expected to be more pronounced in more central p-Pb collisions due to a higher probability of an interaction between the proton and the lead-nucleus. To measure the centrality dependence of charged jet spectra, it is crucial to use a reliable definition of event centrality, which ALICE developed utilizing the Zero-Degree Calorimeter (ZDC).
We present the current status of the measurement of jets that contain a D meson (D-tagged jets) with ALICE. D-meson candidates, identified via their hadronic decay channels, were combined with the other charged tracks reconstructed with the central tracking system, using the anti-$k_{\rm T}$ jet-finding algorithm. The yield of D-tagged jets was extracted through an invariant mass analysis of the D-meson candidates. A Monte Carlo simulation was used to determine the detector performance and validate the signal extraction techniques.
A Monte Carlo study of two jet observables that can be used to obtain jet samples enhanced in quark or gluon content is presented. We compare the performance of one of these methods on pure Monte Carlo events with that after the transport of events through the full simulation of the ALICE experiment. It is shown that the performance of the method is not deteriorated by experimental effects like resolution and inefficiency.
ALICE measured transverse momentum spectra of pi0 and eta mesons via the two photon decay in pp collisions at sqrt(s)=0.9, 2.76 and 7 TeV and Pb-Pb collisions at sqrt(sNN)=2.76 TeV. NLO pQCD calculations agree with p-p measurements at 0.9 TeV, but overestimate the data at 2.76 and 7 TeV. The nuclear modification factor for neutral pions shows a strong suppression of high-pt particle production in central Pb-Pb collisions. Raw spectra of charged particle jets have been measured in Pb-Pb collisions. Detailed studies of background fluctuations have been performed and will allow us to unfold the s…
We present the measurements of D0, D+, D*+ meson v_2 as well as D0 R_{AA} in different directions with respect to the estimated reaction plane in Pb-Pb collisions at sqrt(s_{NN)) = 2.76 TeV with the ALICE detector at the LHC.
We present the measurement of the D+s production in pp collisions at sqrt{s} = 7 TeV and in Pb Pb collisions at sqrt{s_NN} =2.76 TeV performed with the ALICE detector at central rapidity through the reconstruction of the hadronic decay channel D+s-> K+K-pi+. The preliminary results of the D+s nuclear modification factor will be presented.
Electron spectra measured with ALICE at mid-rapidity are used to study the production of hadrons carrying a charm or a beauty quark. The production cross section of electrons from heavy-flavour hadron decays is measured in pp collisions at $\sqrt{s}$=7 TeV. Electrons from the beauty decays are identified via the displacement from the interaction vertex. From the electron spectra measured in Pb--Pb collisions, we determine the nuclear modification factor, which is sensitive to the heavy-quark energy loss in a hot strongly interacting medium.
Jets and direct photons are used to probe the formation and the properties of the Quark-Gluon Plasma (QGP) by the ALICE Collaboration. The results shown here will present the measurements obtained from Pb$-$Pb and p$-$Pb collisions. It is observed that in Pb$-$Pb collisions jets are collimated and hadron yields ($π^{0}$ and $η$) at high transverse momentum undergo strong suppression due to the interaction of the patrons with the QGP. On the other hand, photons do not show any suppression in this region, and, in addition, an excess attributed to a thermal emission is observed at low transverse …
We present new results for the nuclear modification factor \RAA of \jpsi mesons as a function of centrality and transverse momentum at mid-rapidity. The measurement is carried out with the ALICE central barrel detectors in the acceptance range $|y|$ < 0.9 and \pt > 0 in the dielectron decay channel.
Measurements of jet yields in heavy-ion collisions can be used to constrain jet energy loss models, and in turn provide information about the physical properties of deconfined QCD matter. ALICE reconstructs charged particle jets ($\textit{charged jets}$) with high-precision tracking of charged particles down to $p_{\mathrm{T}}^{\mathrm{track}} = 150$ MeV/$c$, and jets ($\textit{full jets}$) with the addition of particle information from the electromagnetic calorimeter down to $E_{\mathrm{cluster}} = 300$ MeV. By including low momentum jet constituents, ALICE is uniquely positioned at the LHC t…
Jet quenching, a standard signature of quark--gluon plasma (QGP) formation in which jets lose energy by traversing the medium, comprises a well-studied set of observables in heavy-ion collisions. Significant questions remain, however, concerning the mechanisms driving this phenomenon. Theoretical work that attempts to address these open questions offers the path-length dependence of jet energy loss as one way to better understand the underlying mechanisms of jet quenching. It has proven challenging, however, to derive explicit values for the path-length dependence from experimental data. These…
We present ALICE results on strange and multi-strange hadron production as a function of centrality in Pb-Pb collisions at $\sqrt{s_{\rm{NN}}}$ = 2.76 TeV at the LHC. Their transverse momentum spectra, yields and particle ratios are compared to the corresponding measurements in pp collisions to address strangeness enhancement and high $p_{\rm T}$ particle suppression. The results are also compared to measurements at RHIC and SPS energies.
We report the measurements of elliptic flow $v_{2}$, as well as higher harmonics triangular flow $v_{3}$ and quadrangular flow $v_{4}$, in $\sqrt{s_{_{NN}}} =$ 2.76 TeV Pb--Pb collisions, measured with the ALICE detector. We show that the measured elliptic and triangular flow can be understood from the initial spatial anisotropy and its event--by--event fluctuations. The resulting fluctuations of $v_{2}$ and $v_{3}$ are also discussed.
This paper discusses the measurement of I_CP and I_AA,Pythia with ALICE (A Large Ion Collider Experiment). An away-side suppression is found expected from in-medium energy loss. Further, and unexpected, a near-side enhancement is seen which has not been reported by previous experiments at lower energies.
We present the ALICE results on the nuclear modification factor and elliptic flow of electrons and muons from open heavy-flavour hadron decays at mid-rapidity and forward rapidity in Pb--Pb collisions at $\sqrt{s_{\rm NN}}$ = 2.76 and 5.02 TeV for different centrality intervals. The results are compared to model calculations that include interactions of heavy quarks with the medium.
The large statistics accumulated during the LHC Run-1 and Run-2 have provided the unique opportunity to study the properties of the Quark-Gluon Plasma using rare hard probes. The ALICE Collaboration has presented new results on the jet shape observables in p--Pb and Pb--Pb collision. Using data from Run-2, the elliptic flow of open and hidden charm mesons have been measured with much better precision, confirming that charm quarks participate in the collective dynamic expansion with the medium. In p--Pb collisions the absence of jet quenching correlated with high event activity has been confirm…
The measurements of charged-particle multiplicity and transverse energy at mid-rapidity in Pb-Pb collisions at sqrt(sNN) = 2.76 TeV are reported as a function of centrality. The fraction of the inelastic cross section recorded by the ALICE detector is estimated using a Glauber model. The results scaled by the number of participating nucleons are compared with pp collisions at the same collision energy, to similar results obtained at significantly lower energies, and with models based on different mechanisms for particle production in nuclear collisions.
Charged particle directed flow at midrapidity, |eta|<0.8, and forward rapidity, 1.7 < |eta|<5.1, is measured in Pb-Pb collisions at sqrt{s_NN} = 2.76 TeV with ALICE at the LHC. Directed flow is reported as a function of collision centrality, charged particle transverse momentum, and pseudo-rapidity. Results are compared to measurements at RHIC and recent model calculations for LHC energies.
We present the elliptic flow of inclusive J/$ψ$ measured in the $μ^{+}μ^{-}$ channel at forward rapidity ($2.5<y<4.0$), down to zero transverse momentum, in Pb-Pb collisions at $\sqrt{s_{_{\mathrm{NN}}}}=2.76$ TeV with the ALICE muon spectrometer. The $p_{\mathrm T}$ dependence of J/$ψ$ $v_2$ in non-central (20%-60%) Pb-Pb collisions at $\sqrt{s_{_{\mathrm{NN}}}}=2.76$ TeV is compared with existing measurements at RHIC and theoretical calculations. The centrality dependence of the $p_{\mathrm{T}}$-integrated elliptic flow, as well as the $p_{\mathrm{T}}$ dependence in several finer centrality …
We present results on inclusive electrons for 1.5 $ < p_{\rm T} < $ 6 GeV/$c$ in {Pb-Pb} collisions at $\sqrt{s_{\rm NN}}$ = 2.76 TeV measured with ALICE at the LHC and compare these to a cocktail of background electron sources. The excess of electrons beyond the cocktail at high momenta ({$p_{\rm T} >$ 3.5 GeV/$c$}) is attributed to electrons from heavy-flavour decays. The corresponding nuclear modification factor indicates heavy-flavour suppression by a factor of 1.5-4.
Vector mesons are key probes of the hot and dense state of strongly interacting matter produced in heavy ion collisions. Their dileptonic decay channel is particularly suitable for these studies, since dileptons have negligible final state interactions in hadronic matter. A preliminary measurement of the $ϕ$ and $ω$ differential cross sections was performed by the ALICE experiment in pp collisions at $\sqrt{s}=7$ TeV, through their decay in muon pairs. The $p_{\rm T}$ and rapidity regions covered in this analysis are $p_{\rm T}>1$ GeV$/c$ and $2.5 < y < 4$.
Mixed harmonic charge dependent azimuthal correlations at mid-rapidity in Pb-Pb collisions at $\sqrt{s_{NN}}$ = 2.76 TeV were measured with the ALICE detector at the LHC. A clear charge dependence for a series of correlations is observed both via the multi-particle cumulant and the event plane methods. Implications from these measurements for the possible effects of the local parity violation in QCD and for models which incorporate the azimuthal anisotropic flow and the local charge conservation on the kinetic freeze-out surface are discussed.
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…
A Large Ion Collider Experiment (ALICE) is one of the four large experiments at the Large Hadron Collider (LHC), and it is dedicated to the study of ultra-relativistic heavy-ion collisions, with the goal of investigating the properties of the high-density state of QCD matter produced in these collisions. The study of D meson production azimuthal anisotropy and the measurement of their elliptic flow (v2) can provide insight on the degree of thermalisation of charm quarks in the medium and on the charm hadronization mechanism. We present the measurement of the D+ and D0 meson v2 in Pb-Pb collisi…
Jets correlated with isolated photons are a promising channel to study jet quenching in heavy-ion collisions, as photons do not interact strongly and therefore constrain the $Q^2$ of the initial hard scattering. We present the isolated photon-jet correlations measured in Pb--Pb collisions at $\sqrt{s_{\text{NN}}}$ = 5.02 TeV by the ALICE collaboration. We study correlations of isolated photons above 20 GeV/$c$ with charged-particle jets above 10 GeV/$c$, reconstructed with the anti-$k_\text{T}$ algorithm. The correlations probe the lowest jet $p_\text{T}$ range ever measured at LHC energies, a…
Highly energetic jets are sensitive 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. The measurement of jet spectra in p-Pb collisions provides an important way of quantifying the effects of cold nuclear matter in the initial state on jet production, fragmentation, and hadronization. Unlike in Pb-Pb collisions, strong hot nuclear matter effects - e.g. from quark-gluon plasma formation - are not expected to occur in p…
We present a measurement of the nuclear modification factor of electrons from heavy- flavour hadron decays at midrapidity in Pb-Pb collisions at {\surd}sNN = 2.76 TeV. Electrons are identified in the pt range 1.5 GeV/c < pt < 6 GeV/c. A suppression is seen for pt larger than 3.5 GeV/c in the most central collisions.
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.
These proceedings report on measurements of the jet spectrum and nuclear modification factor for inclusive full jets (containing both charged and neutral constituents) in Pb-Pb and pp collisions at $\sqrt{s_{\rm NN}} = 5.02$ TeV recorded with the ALICE detector. These measurements use a machine learning based background correction, which reduces residual fluctuations. This method allows for measurements to lower transverse momenta and larger jet resolution parameter (R) than previously possible in ALICE. In this method, machine learning techniques are used to correct the jet transverse momentu…
The status of the analysis of electron-positron pairs measured by ALICE in pp collisions at $\sqrt{s} = 7$ TeV and central Pb-Pb collisions at $\sqrt{s_\mathrm{NN}}=2.76$ TeV is presented. Key questions and the main challenges of the analysis are discussed on the basis of first raw invariant mass spectra for both collision systems.
An observable that can be used to better constrain the mechanism responsible for the parton energy loss is the elliptic azimuthal event anisotropy, $v_2$. We report on measurements of $v_2$ for inclusive and identified charged particles in Pb-Pb collisions at $\sqrt{s_{NN}} = 2.76$ TeV recorded by the ALICE experiment at the LHC. $v_2$ is presented for a wide range of particle transverse momentum up to $p_T=20$ GeV/c. The particle $v_2$ is finite, positive and approximately constant for $p_T>8$ GeV/c. The proton $v_2$ is higher than that of the pion up to about $p_T=8$ GeV/c. The results are c…
We present the first results from the ALICE experiment on the nuclear modification factors for heavy-flavour hadron production in Pb-Pb collisions at sqrt{s_NN}=2.76 TeV. Using proton-proton and lead-lead collision samples at sqrt{s}=7 TeV and sqrt{s_NN}=2.76 TeV, respectively, nuclear modification factors R_AA(pt) were measured for D mesons at central rapidity (via displaced decay vertex reconstruction), and for electrons and muons, at central and forward rapidity, respectively.
Measurements of high-pT particle production in heavy-ion collisions at RHIC have shown that medium-induced energy loss affects the partons produced in the early stage of a heavy-ion col- lision. The increased initial production cross section for partons at LHC energies makes fully reconstructed jets available in a wide kinematic range, which allows for a more differential in- vestigation of parton energy loss. Partonic energy loss allows us to access key observables of the hot deconfined nuclear matter produced in heavy-ion collisions. The inclusive cross-section of reconstructed jets using th…
We present the analysis of the semi-inclusive distribution of reconstructed charged particle jets recoiling from a high pT hadron trigger in central Pb Pb collisions at $\sqrt{s_{NN}}=2.76$ TeV. We measure, subtract and unfold the large underlying event background in such collisions, utilizing a novel technique that does not impose fragmentation bias on the measured jet population. The Pb Pb measurements are compared to a pp PYTHIA reference distribution generated at the same $\sqrt{s}$. Modification of jet structure due to quenching is explored by varying the cone radius $R$ (0.2, 0.4) and th…
The ALICE Collaboration measured dielectron production as a function of the invariant mass ($m_{\rm ee}$), the pair transverse momentum ($p_{\rm T,ee}$) and the pair distance of closest approach ($\rm DCA_{ee}$) in pp collisions at $\sqrt{s} = 7$ TeV. Prompt and non-prompt dielectron sources can be separated with the $\rm DCA_{ee}$, which will give the opportunity in heavy-ion collisions to identify thermal radiation from the medium in the intermediate-mass range dominated by contributions from open-charm and beauty hadron decays. The charm and beauty total cross sections are extracted from th…
Highly energetic jets are sensitive probes for the kinematics and the topology of nuclear collisions. Jets are produced in an early stage of the collision from hard-scattered partons, which fragment into a spray of charged and neutral particles. The measurement of jet spectra in p-Pb collisions provides an important way to quantify the effects of cold nuclear matter on jet production, fragmentation and hadronization. This is possible because the hot, dense medium produced in Pb-Pb collisions is not expected to form. Proton-Lead collisions also provide an important constraint for the nuclear pa…
We present the results on elliptic flow with multi-strange baryons produced in Pb-Pb collisions at \sqrt{s_{NN}} = 2.76 TeV. The analysis is performed with the ALICE detector at LHC. Multi-strange baryons are reconstructed via their decay topologies and the v_2 values are analyzed with the two-particle scalar product method. The p_T differential v_2 values are compared to the VISH2+1 model calculation and to the STAR measurements at 200 GeV in Au+Au collisions. We found that the model describes Ξand Ωv_2 measurements within experimental uncertainties. The differential flow of Ξand Ωis similar …
Measurements of anisotropic flow in heavy-ion collisions provide evidence for the creation of strongly interacting matter which appears to behave as an almost ideal fluid. Anisotropic flow signals the presence of multiple interactions and is very sensitive to the initial spatial anisotropy of the overlap region in non-central heavy-ion collisions. In this article we report measurements of elliptic $v_2$, triangular $v_3$, quadrangular $v_4$ and pentagonal $v_5$ flow. These measurements have been performed with 2- and multi-particle correlation techniques.
Measurements of the suppression of high-pT particles and the away-side jets from heavy-ion collisions at RHIC have shown that medium-induced energy loss affects partons produced in the early stage of a heavy-ion collision. At LHC energies the initial production cross-section is much higher, which allows jets to be reconstructed with a wide kinematic range. Measuring fully reconstructed jets by taking advantage of the ALICE Electromagnetic Calorimeter allows for a more differential investigation of the parton energy loss. Parton energy loss will allow us to access key observables of the hot, de…
We report a measurement of transverse momentum spectra of jets detected with the ALICE detector in Pb-Pb collisions at sqrt(sNN)=2.76 TeV. Jets are reconstructed from charged particles using the anti-kt jet algorithm. The background from soft particle production is determined for each event and subtracted. The remaining influence of underlying event fluctuations is quantified by embedding different probes into heavy-ion data. The reconstructed transverse momentum spectrum is corrected for background fluctuations by unfolding. We compare the inclusive jet spectra reconstructed with R=0.2 and R=…
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.
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.
In 2013, inclusive J/psi measurements in p-Pb collisions were performed at the LHC at sqrt(sNN) = 5.02 TeV, in order to measure the effects related to the cold nuclear matter on the J/psi production. Their evaluation is important in order to be able to disentangle hot and cold nuclear matter effects in Pb-Pb collisions. In this contribution, results on the inclusive J/psi production in p-Pb collisions, in the dimuon decay channel at forward and backward rapidity, down to zero transverse momentum, are presented and compared to theoretical models.
The study of inclusive charged-particle production in heavy-ion collisions provides insights into the density of the medium and the energy-loss mechanisms. The observed suppression of high-$\textit{p}_\text{T}$ yield is generally attributed to energy loss of partons as they propagate through a deconfined state of quarks and gluons - Quark-Gluon Plasma (QGP) - predicted by QCD. Such measurements allow the characterization of the QGP by comparison with models. In these proceedings, results on high-$\textit{p}_\text{T}$ particle production measured by ALICE in Pb-Pb collisions at $ \sqrt{\text{s}…
We report on the first measurement of the charged hadron composition in charged jets from pp collisions. The ALICE detector at the LHC was used to study charged pion, kaon and (anti-)proton production in jets. The results were extracted from $2 \times 10^8$ minimum bias events at a centre-of-mass energy of $\sqrt{s} = 7$ TeV. We present the transverse momentum ($p_{\mathrm{T}}$) spectra and reduced momentum spectra ($z^{\mathrm{ch}} \equiv p_{\mathrm{T}}^{\mathrm{track}} / p_{\mathrm{T, jet}}^{\mathrm{ch}}$) of $π$, K and p in charged jets with $p_{\mathrm{T, jet}}^{\mathrm{ch}}$ between 5 and…
Reconstruction of jets in high-energy heavy-ion collisions is challenging due to the large and fluctuating background coming from the underlying event. We report results on full jet reconstruction, obtained from data collected in 2011 by the ALICE detector at LHC for Pb-Pb collisions at $\sqrt{s_{\mathrm{NN}}}=2.76~\mathrm{TeV}$. The analysis makes use of the tracking system and the electromagnetic calorimeter. Signal jets, which come from hard scattered partons, are reconstructed using the anti-$k_{\mathrm{T}}$ jet finder algorithm. The average background is subtracted on a jet-by-jet basis t…
The ALICE collaboration has studied inclusive J/$ψ$ and $ψ$(2S) production at forward rapidities in pp collisions at $\sqrt{s} = 7$ TeV with the ALICE Muon Spectrometer. The analysis has been carried out on a data sample corresponding to an integrated luminosity $\mathcal{L}_{\rm int}$ = 1.35 pb$^{-1}$. The production cross-sections of J/$ψ$ and $ψ$(2S), integrated over \pt\ (0 $<$ \pt\ $<$ 20 GeV/$c$) and \y\ (2.5 $<$ \y\ $<$ 4), have been measured. The J/$ψ$ and $ψ$(2S) differential cross-sections, in transverse momentum and rapidity, have also been measured. The results have been compared w…
We report the first measurement of charged pion, kaon and (anti-)proton production in jets from hadron colliders. The measurement was carried out with the ALICE detector using $2\times10^8$ minimum bias pp collisions at a centre-of-mass energy of $\sqrt{s}=7$ TeV at the LHC. We present the $π$, K and p transverse momentum ($p_\textrm{T}$) spectra, as well as the spectra of the reduced momentum (${z^\textrm{ch}\equiv p_\textrm{T}^\textrm{track}/p_\textrm{T, jet}^\textrm{ch}}$), in charged jets of $p_\textrm{T}$ between 5--20 $\textrm{GeV}/c$. The measurement is compared to Monte Carlo calculati…
We present preliminary results from di-hadron correlations in azimuth (phi) and pseudo-rapidity (eta) induced by hadronic di-jets produced in Pb-Pb collisions at sqrt(s_NN) = 2.76 TeV. The jet-like near-side peak has been isolated from eta-independent collective flow correlations using an eta-gap method and its shape has been characterized by rms and excess kurtosis. These quantities have been studied as a function of centrality as well as of trigger (associated) particle transverse momentum ranging from 2-8 GeV (1-3 GeV). We observe that the rms in Deta increases with the centrality of the co…
Measurements of spectra of identified particles produced in jets represent an important tool for understanding the interplay of various hadronisation mechanisms which contribute to particle production in the hot and dense medium created in ultra-relativistic heavy-ion collisions. In this contribution, we present the measurements of the pT spectra of Λ baryons and K0S mesons produced in charged jets in Pb--Pb collisions at sqrt(sNN) = 2.76 TeV and in p--Pb collisions at sqrt(sNN) = 5.02 TeV. The results are obtained with the ALICE detector at the LHC, exploiting the excellent particle identific…
This contribution summarises the results on heavy-flavour correlations and jets measured with ALICE detector. Studies of D$^{0}$-tagged jets are presented in various collision systems and energies. The measurement of the fraction of jet momentum carried by the D$^{0}$ meson in the direction of the jet axis ($z_{\rm ||}^{\rm ch,jet}$) in pp collisions at $\sqrt{s}$ = 5.02 and 13 TeV as well as the nuclear modification factor in p--Pb and Pb--Pb collisions are presented. The measurements of the production of jets tagged by electrons from heavy-flavour decays in pp and p--Pb are compared to expec…
ALICE is the dedicated heavy-ion experiment at the LHC. Its main physics goal is to study the properties of strongly-interacting matter at conditions of high energy density and high temperature expected to be reached in central Pb--Pb collisions. Charm and beauty quarks are well-suited tools to investigate this state of matter since they are produced in initial hard scatterings and are therefore generated early in the system evolution and probe its hottest, densest stage. ALICE recorded pp data at $\rm \sqrt{s}$ = 7 TeV and 2.76 TeV and Pb--Pb data at $\rm \sqrt{s}_{\rm NN}$=2.76 TeV in 2010 a…
We study the production of ${\rm K}_{\rm S}^{0}$ mesons and $Λ$ baryons in jets in p--Pb collisions at $\sqrt{s_{\rm NN}}=5.02$ TeV with ALICE at the LHC. The $p_{\rm T}$-differential density of the particles produced in jets is compared to the inclusive distributions and the $Λ/{\rm K}_{\rm S}^{0}$ ratio is reported in bins of multiplicity of the collisions. The hard scatterings are selected on an event-by-event basis using the anti-$k_{\rm T}$ clustering algorithm with resolution parameter $R=0.2,~0.3$ and $0.4$, reconstructed from charged particles with a minimum $p_{\rm T,jet}$ of $10$ (or…
The production of charmonium states, J/$ψ$ and $ψ$(2S), in heavy-ion collisions, is an important probe to investigate the formation of a plasma of quarks and gluons (QGP). In a hot and deconfined medium, quarkonium production is, indeed, expected to be significantly modified, with respect to the pp yields, due to a balance of color screening and charm-quark recombination mechanisms. The ALICE Collaboration at the LHC has measured charmonium production in Pb-Pb collisions at $\sqrt{s}_{\rm NN} =$ 2.76 and 5.02 TeV. The nuclear modification factor of inclusive J/$ψ$, evaluated at forward ($-4<η<…
The D meson yields as a function of charged-particle multiplicity in pp collisions at $\sqrt{s}=7$ TeV and in p-Pb collisions at $\sqrt{s_{\mathrm{NN}}}=5.02$ TeV are presented. The measurement of the yields of electrons from heavy-flavour hadron decays as a function of charged-particle multiplicity in p-Pb collisions at $\sqrt{s_{\mathrm{NN}}}=5.02$ TeV are shown as well. The measurement of azimuthal correlations of prompt D mesons and charged hadrons in pp collisions at $\sqrt{s}=7$ TeV and in p-Pb collisions at $\sqrt{s_{\mathrm{NN}}}=5.02$ TeV are also presented. The results are compared w…
Jets are generated in hard interactions in high-energy nuclear collisions. Jets propagate through the quark-gluon plasma (QGP) as the jet shower evolves; their interaction with the QGP, known as jet quenching, generates observable phenomena that provide incisive probes of the structure and dynamics of the QGP. For instance, medium-induced modification of jet substructure probes color coherence, and may be sensitive to differences in quark and gluon energy loss due to their different Casimir factors. Jet grooming can be used to focus on specific regions of phase space, isolating medium-induced …
Two-particle azimuthal correlations allow one to study high-$p_{\rm T}$ parton fragmentation without full jet reconstruction. Enhancements of the azimuthal correlations are seen at $Δφ\approx 0$ and $Δφ\approx π$, resulting from back-to-back jet fragmentation in the parton center-of-mass system. We present the current status of the study of correlations between charged trigger particles and associated strange baryons ($Λ$) and mesons (K$_{S}^{0}$) in pp collisions at $\sqrt{s}$ = 7 TeV. A data-driven feeddown correction for $Λ$ is also presented, which could allow a more accurate calculation o…
Dielectrons probe a wide range of phenomena in heavy-ion collisions. These include light- and heavy-flavour meson production, thermal radiation and coherent photo-production. The latter process is distinguished by dielectron production at low transverse-pair momentum ($ \it{p}_{\textrm{T,ee}}$). Transverse momentum spectra of dielectrons in central and peripheral Pb-Pb collisions are extracted and compared to the corresponding expectations. In central collisions the data fit the expected spectrum, which is dominated by semi-leptonic decays of correlated heavy-flavour hadrons. In peripheral col…
Two-particle correlations at small relative momenta give insight into the size of the emitting source. Of particular interest is the test of hydrodynamic models which predict a universal, apparent decrease of the extent of the system with increasing transverse mass mT as a consequence of the strong radial flow in heavy-ion collisions at LHC energies. This contribution presents a study of correlations for protons and Λ particles in Pb-Pb collisions at sqrt(sNN) = 2.76 TeV measured with ALICE. The investigated particle species expand the experimental reach in mT due to their high rest mass. Resi…
The $π^{0}$ and $η$ meson production in Pb-Pb collisions at $\sqrt{s_{NN}}$ = 2.76 TeV is studied with the ALICE experiment at the LHC. The $π^{0}$ invariant yields and nuclear modification factor $R_{\mbox{AA}}$ are presented here in six centrality classes. The results are a combined measurement using the Photon Conversion Method (PCM) and the PHOS detector, in the transverse momentum range 0.4 $< p_{\mbox{T}} <$ 12 GeV/$c$. The $π^{0}$ $R_{\mbox{AA}}$ is studied in different centrality classes and compared with results from experiments at lower energies, both as a function of transverse mome…
