Soft Physics in ALICE

ALICE is the dedicated experiment for relativistic heavy-ion physics at LHC. Following some considerations on the main characteristics of heavy-ion physics expected at the LHC energies, a review of the performance of the ALICE detector in the soft physics domain is discussed. In particular, global event characterization, measurement of identified particle spectra, detection of hadronic short-lived resonances, anisotropic flow determination and HBT correlation studies are discusse

Hadronic resonance production in pp and Pb–Pb collisions at LHC with the ALICE experiment

Resonances, with their lifetimes comparable to that of the fireball, can be used to estimate the time span and hadronic interaction cross section in the phase between chemical and kinetic freeze-out. In pp collisions, measurements of resonances provide an important baseline for heavy-ion data and allow for the tuning of QCD-inspired particle production models. The ALICE collaboration measured K*(892) and (1020) production, both in pp collisions at TeV and in Pb–Pb collisions at TeV. The inelastic yield of Σ(1385)± in pp collision at TeV was also measured. Transverse momentum spectra, ratios to stable particles and a comparison between central and peripheral production are shown

Performance of prototypes for the ALICE electromagnetic calorimeter

The performance of prototypes for the ALICE electromagnetic sampling calorimeter has been studied in test beam measurements at FNAL and CERN. A $4\times4$ array of final design modules showed an energy resolution of about 11% /$\sqrt{E(\mathrm{GeV})}$ $\oplus$ 1.7 % with a uniformity of the response to electrons of 1% and a good linearity in the energy range from 10 to 100 GeV. The electromagnetic shower position resolution was found to be described by 1.5 mm $\oplus$ 5.3 mm /$\sqrt{E \mathrm{(GeV)}}$. For an electron identification efficiency of 90% a hadron rejection factor of $>600$ was obtained.Comment: 10 pages, 10 figure

Strange hadrons and resonances at LHC energies with the ALICE detector

The study of (multi)strange hadrons and resonance production allows in heavyion collisions to gather information on the early partonic phase of the fireball and its evolution. The ALICE collaboration has measured the production of K*(892)0, φ(1020) resonances and KS0, Λ, Ξ−, Ω− hadrons and their anti-particles at mid-rapidity in Pb–Pb collisions at √sNN = 2.76 TeV. This contribution presents results on strangeness enhancement, baryon to meson ratios (Λ/KS0 and Ω−/φ) and on resonance to stable particle ratio (φ/K and K*/K). The nuclear modification factor RAA of the φ(1020) will be also discussed

Hadronic resonance production measured by the ALICE detector at LHC energies

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 particleformation mechanisms and on the properties of the medium at freeze-out, and furthermore they contribute to the systematic study of energy loss and 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 proceedings the latest ALICE results on hadronic resonance production in pp, p-Pb and Pb-Pb collisions at LHC energies will be presented. In particular, the production of the K*(892)^0 and o/(1020) resonances at mid-rapidity has been studied in different collision systems at LHC energies, reconstructing the resonances via their hadronic decay in a wide momentum range. The resonance transverse momentum spectra, mean transverse momenta, ratio to stable particles and nuclear modification factor will be discussed

Subthreshold production of pions in coincidence with light particles

International audienc

Production of deuterons, tritons, He 3 nuclei, and their antinuclei in pp collisions at s =0.9, 2.76, and 7 TeV

Invariant differential yields of deuterons and antideuterons in pp collisions at s = 0.9, 2.76 and 7 TeV and the yields of tritons, He3 nuclei, and their antinuclei at s = 7 TeV have been measured with the ALICE detector at the CERN Large Hadron Collider. The measurements cover a wide transverse momentum (pT) range in the rapidity interval |y|<0.5, extending both the energy and the pT reach of previous measurements up to 3 GeV/c for A=2 and 6 GeV/c for A=3. The coalescence parameters of (anti)deuterons and Hē3 nuclei exhibit an increasing trend with pT and are found to be compatible with measurements in pA collisions at low pT and lower energies. The integrated yields decrease by a factor of about 1000 for each increase of the mass number with one (anti)nucleon. Furthermore, the deuteron-to-proton ratio is reported as a function of the average charged particle multiplicity at different center-of-mass energies

Production of deuterons, tritons, He 3 nuclei, and their antinuclei in pp collisions at s =0.9, 2.76, and 7 TeV

Invariant differential yields of deuterons and antideuterons in pp collisions at s = 0.9, 2.76 and 7 TeV and the yields of tritons, He3 nuclei, and their antinuclei at s = 7 TeV have been measured with the ALICE detector at the CERN Large Hadron Collider. The measurements cover a wide transverse momentum (pT) range in the rapidity interval |y|<0.5, extending both the energy and the pT reach of previous measurements up to 3 GeV/c for A=2 and 6 GeV/c for A=3. The coalescence parameters of (anti)deuterons and Hē3 nuclei exhibit an increasing trend with pT and are found to be compatible with measurements in pA collisions at low pT and lower energies. The integrated yields decrease by a factor of about 1000 for each increase of the mass number with one (anti)nucleon. Furthermore, the deuteron-to-proton ratio is reported as a function of the average charged particle multiplicity at different center-of-mass energies