Associated production of weak bosons at LHC with the ATLAS detector

The study of the associated production of weak vector bosons at LHC allows to search for New Physics through the measurement of possible deviations of the weak boson self-couplings from the expectation within the Standard Model. The sensitivity of the ATLAS experiment to Standard Model diboson (W+W-, W± Z, Z Z, W± gamma, and Z gamma ) production in pp collisions at sqrt(s) = 14 TeV, using final states containing electrons, muons and photons, is presented. These studies use Monte Carlo data sets (with full detector simulation) from the ATLAS Computer System Commissioning, which furthermore include detailled trigger information as well as effects of detector calibration and alignment corrections. The influuence of backgrounds on diboson detection is assessed using further dedicated large samples of fully simulated background events. The sensitivity of the ATLAS experiment to anomalous triple gauge boson couplings is determined. Even for small integrated luminosities (about 0.1 fb-1) the sensitivity to anomalous triple gauge boson couplings at the LHC can be significantly improved by ATLAS, when comparing to results from Tevatron that use 1.0 fb$^{-1}$ of data.