1,722,732 research outputs found
Production of identified and unidentified charged hadrons in Pb--Pb collisions at \sqrts_\rm NN~5.02~TeV
No full textIn late 2015, the ALICE collaboration recorded data from Pb--Pb collisions at
the unprecedented energy of \sqrts_\rm NN~5.02~TeV. The transverse-momentum
(p_\rm T) spectra of pions, kaons and protons are presented. The evolution
of the particle ratios as a function of collision energy and centrality is
discussed. The ratio between p_\rm T-integrated particle yields are
measured and compared to different collision energies as well as smaller
collision systems. For the study of energy loss mechanisms in the QCD medium at
high transverse momenta, the nuclear modification factors () are
computed and compared with results obtained at lower energy
Measurement of charm production at central rapidity in proton-proton collisions at sqrt(s) = 2.76 TeV
No full textCoherent J/psi photoproduction at forward rapidity in ultra-peripheral Pb-Pb collisions at root s(NN)=5.02 TeV
Get PDFThe ALICE collaboration performed the first rapidity-differential measurement of coherent J/psi photoproduction in ultra-peripheral Pb-Pbcollisions at a center-of-mass energy root s(NN) = 5.02TeV. The J/psi is detected via its dimuon decay in the forward rapidity region (-4.0 <y <-2.5) for events where the hadronic activity is required to be minimal. The analysis is based on an event sample corresponding to an integrated luminosity of about 750 mu b(-1). The cross section for coherent J/psi production is presented in six rapidity bins. The results are compared with theoretical models for coherent J/psi photoproduction. These comparisons indicate that gluon shadowing effects play a role in the photoproduction process. The ratio of psi' to J/psi coherent photoproduction cross sections was measured and found to be consistent with that measured for photoproduction off protons. (C) 2019 The Author. Published by Elsevier B.V.Peer reviewe
Demographics of the ALICE Collaboration
No full textThe ALICE Collaboration at the LHC is made up of around 1900 people from 39 countries. These proceedings discuss the composition of the Collaboration in terms of gender and career status. The distribution of responsibilities among various demographic groups will also be presented, and the time evolution of these statistics will be explored
Highlights from the ALICE collaboration
No full textSignificant advances in heavy-ion physics have come about as almost ten years have passed since the beginning of the heavy-ion programme at the LHC. In thisdocument, we review some key results from the ALICE collaboration on a variety of topics, from properties of the quark-gluon plasma (QGP) to basic QCD, and discuss how theseset the stage for further measurements in the next decade
Operations and Performance of the Silicon Drift and Silicon Strip Detectors of the ALICE experiment.
Get PDFThe calibration and performance of the Silicon Drift and Silicon Strip Detectors of the ALICE experiment is presented. In particular the monitoring of the noise, bad channels and drift velocity, the monitoring and quality assurance, along with the charge calibration with cosmic muons and pp collisions are shown
The pixel module for the Inner Tracking System upgrade of ALICE at LHC
No full textThe ALICE (A Large Ion Collider Experiment) detector at the CERN LHC collider was designed to address
the physics of strongly interacting matter, and in particular the properties of the Quark-Gluon
Plasma (QGP) using proton-proton, proton-nucleus, and nucleus-nucleus collisions. Even if with
this physics goal a lot of important results were already reached, there are still several fundamental
measurements to be finalized, like high precision measurements of rare probes (D, B mesons and
Lambda barions decays) over a broad range of transverse momenta. In order to achieve these new
results, a wide upgrade plan was approved that combined with a significant increase of luminosity
will enhance the ALICE physics capabilities enormously.
The ALICE Inner Tracking System (ITS) upgrade is one of the major improvements of the experimental
set-up that will take place in 2019-2020 where the whole ITS sub-detector will be replaced with
a new one realized using a innovative CMOS Monolithic Active Pixel silicon Sensor (MAPS), called
ALPIDE. This new upgraded ITS will be realized using more than twenty-four thousand ALPIDE
chips organized in seven different cylindrical layers surrounding the ALICE interaction point along
the beam-line, for a total surface of about ten square meters. The main features of the future ALICE
ITS are a low material budget, high granularity and low power consumption. All these peculiar capabilities
will allow for full reconstruction of rare heavy flavor decays and the achievement of the
physics goals.
In this talk after a description of new ALIPIDE pixel chip and the whole ITS upgrade project, will be
presented the construction procedure of the basic building block of the detector, namely the module,
and the laboratory characterization of this element
Validation of the 65 nm TPSCo CMOS imaging technology for the ALICE ITS3
Get PDFDuring the next Long Shutdown (LS3) of the LHC, planned for 2026, the innermost three
layers of the ALICE Inner Tracking System will be replaced by a new vertex detector composed of curved ultra-thin monolithic silicon sensors. The R&D initiative on monolithic sensors of the CERN Experimental Physics Department, in cooperation with the ALICE ITS3 upgrade project, prepared the first submission of chip designs in the TPSCo 65 nm technology, called MLR1 (Multi Layer Reticle). It contains four different test structures with different process splits and pixel designs. These proceedings illustrate the first validation of the technology in terms of pixel performance and radiation hardness
Results on flow from the ALICE Collaboration
No full textThis short overview includes recent results from the ALICE Collaboration on anisotropic flow of charged and identified particles in sqrt(sNN) = 2.76 TeV Pb-Pb collisions. We also discuss charge dependent and event plane dependent azimuthal correlations that are important in tests of the chiral magnetic effect, as well as understanding the dynamics of the system evolution and hadronization process. Lastly, we present ALICE results obtained with a new technique, the event shape engineering, which allows to perform a physical analysis on events with very large or small flow.This short overview includes recent results from the ALICE Collaboration on anisotropic flow of charged and identified particles in =2.76TeV Pb-Pb collisions. We also discuss charge dependent and event plane dependent azimuthal correlations that are important in tests of the chiral magnetic effect, as well as understanding the dynamics of the system evolution and hadronization process. Lastly, we present ALICE results obtained with a new technique, the event shape engineering, which allows to perform a physical analysis on events with very large or small flow.This short overview includes recent results from the ALICE Collaboration on anisotropic flow of charged and identified particles in sNN=2.76TeV Pb–Pb collisions. We also discuss charge dependent and event plane dependent azimuthal correlations that are important in tests of the chiral magnetic effect, as well as understanding the dynamics of the system evolution and hadronization process. Lastly, we present ALICE results obtained with a new technique, the event shape engineering, which allows to perform a physical analysis on events with very large or small flow.This short overview includes recent results from the ALICE Collaboration on anisotropic flow of charged and identified particles in sqrt(sNN) = 2.76 TeV Pb-Pb collisions. We also discuss charge dependent and event plane dependent azimuthal correlations that are important in tests of the chiral magnetic effect, as well as understanding the dynamics of the system evolution and hadronization process. Lastly, we present ALICE results obtained with a new technique, the event shape engineering, which allows to perform a physical analysis on events with very large or small flow
Exploration of jet substructure using iterative declustering in pp and Pb-Pb collisions at LHC energies
Get PDFThe ALICE collaboration at the CERN LHC reports novel measurements of jet substructure in pp collisions at root s = 7 TeV and central Pb-Pb collisions at root s(NN) = 2.76 TeV. Jet substructure of track-based jets is explored via iterative declustering and grooming techniques. We present the measurement of the momentum sharing of two-prong substructure exposed via grooming, the z(g), and its dependence on the opening angle, in both pp and Pb-Pb collisions. We also present the measurement of the distribution of the number of branches obtained in the iterative declustering of the jet, which is interpreted as the number of its hard splittings. In Pb-Pb collisions, we observe a suppression of symmetric splittings at large opening angles and an enhancement of splittings at small opening angles relative to pp collisions, with no significant modification of the number of splittings. The results are compared to predictions from various Monte Carlo event generators to test the role of important concepts in the evolution of the jet in the medium such as colour coherence. (C) 2020 The Author(s). Published by Elsevier B.V.Peer reviewe
- …
