Dielectron measurements in pp and Pb–Pb colllisions with ALICE at the LHC

The production of low-mass dielectrons is one of the most promising tools for the investigation of chiral symmetry restoration and thermal radiation from the QGP created in heavy-ion collisions. To single out the signal characteristics of the QGP, it is crucial to understand the primordial $e^{+}e^{-}$ pair production in vacuum, i.e. in inelastic proton-proton (pp) collisions. Low-mass dielectrons have been measured with ALICE at the LHC in pp collisions at $\sqrt{s}= 7$, and in Pb–Pb collisions at $\sqrt{^{s}NN}= 2.76$ TeV. An overview of the results on dielectron production is presented, together with their implications for the direct-photon and heavy-quark production