Yulia Rodina

Search for high-mass new phenomena in the dilepton final state using proton–proton collisions at s=13TeV with the ATLAS detector

A search is conducted for both resonant and non-resonant hig h-mass new phenomena in dielectron and dimuon final states. The search uses 3.2 fb −1 o proton–proton collision data, collected at √ s= 13 TeV by the ATLAS experiment at the LHC in 2015. The dilepton invariant mass is used as the discriminating variable. No significa t deviation from the Standard Model prediction is observed; therefore limits are set on th e signal model parameters of interest at 95% credibility level. Upper limits are set on the c ross-section times branching ratio for resonances decaying to dileptons, and the limits are con verted into lower limits on the resonance mass, ranging between 2.74 TeV and 3.36 TeV, depen ing on the model. Lower limits on thellqq contact interaction scale are set between 16.7 TeV and 25.2 T eV, also depending on the model. c

Measurement of the

A bstractA measurement of the ZZ production cross section in the ℓ−ℓ+ℓ′ −ℓ′ + and ℓ−ℓ+νν¯

production cross section in

{\ell}^{-}{\ell}^{+}\nu \overline{\nu}

collisions at

channels (ℓ = e, μ) in proton-proton collisions at s=8

= 8 TeV using the

\sqrt{s}=8

and

TeV at the Large Hadron Collider at CERN, using data corresponding to an integrated luminosity of 20.3 fb−1 collected by the ATLAS experiment in 2012 is presented. The fiducial cross sections for ZZ → ℓ−ℓ+ℓ′ −ℓ′ + and ZZ→ℓ−ℓ+νν¯