The ratio of the yields of antiprotons to protons in pp collisions has been measured by the ALICE experiment at {radical}(s)=0.9 and 7 TeV during the initial running periods of the Large Hadron ...Collider. The measurement covers the transverse momentum interval 0.45<p{sub t}<1.05 GeV/c and rapidity |y|<0.5. The ratio is measured to be R{sub |y|<0.5}=0.957{+-}0.006(stat){+-}0.014(syst) at 0.9 TeV and R{sub |y|<0.5}=0.991{+-}0.005(stat){+-}0.014(syst) at 7 TeV and it is independent of both rapidity and transverse momentum. The results are consistent with the conventional model of baryon-number transport and set stringent limits on any additional contributions to baryon-number transfer over very large rapidity intervals in pp collisions.
Dielectrons produced in ultra-relativistic heavy-ion collisions provide a unique probe of the whole system evolution as they are unperturbed by final-state interactions. The dielectron continuum is ...extremely rich in physics sources: thermal radiation is of particular interest as it carries information about the temperature of the hot and dense system created in such collisions. The dielectron invariant mass distribution is sensitive to medium modifications of the spectral function of vector mesons that are linked to the potential restoration of chiral symmetry. Correlated electron pairs from semi-leptonic charm and beauty decays provide information about the heavy-quark energy loss.
A summary of the LHC Run-1 preliminary results in all three collisions systems (pp, p-Pb and Pb-Pb) is presented. Furthermore, the status of the ongoing Run-2 analyses is discussed with a focus on pp collisions collected with a high charged-particle multiplicity trigger, on new analysis methods to separate prompt from non-prompt sources, and on the usage of machine learning methods for background rejection.
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