The talk will give an overview of recent $B$-physics measurements at the ATLAS experiment, with a focus on the $CP$ violation in $B^0_s \rightarrow J/\psi(\mu^+\mu^−)\phi(K^+K^−)$ decay channel. In the Standard Model $CP$ violation is described by a phase in the CKM matrix. One of the manifestations of this complex phase is a phase shift between direct and mixing-mediated $B_s$ decays...
Complex phase in the CKM matrix describing quark mixing causes CP violation and can be studied in the decay $B^0_s \rightarrow J/\psi + \phi$. The determination of the initial flavour of neutral $B$ mesons can be inferred using information from the $B$ meson containing other pair-produced b-quark, reffered as opposite-side tagging. To study and calibrate the opposite-side tagging method,...
Last year, the D0 experiment announced the observation of narrow structure X(5568) in decay of B_s + \pi with almost 5 \sigma significance. This structure is investigated by the B-Physics Working group based on a data sample recorded with the ATLAS detector corresponding to 4.9 \fb^{-1} of pp collision data at 7 TeV and 19.5 \fb^{-1} at 8 TeV.
Evidence of the vector boson scattering (VBS) phenomena was discovered in Run 1
of the ATLAS detector at the LHC in the same sign WW production channel. Since
the detector acquire more and more data in Run 2, the phenomena starts to be
accessible also in the ZZ channel. This channel is very clean because of the
small background other than comming from QCD and provides a good opportunity...
Currently large $t\bar{t}$ production at the LHC allows detail study of the top quark, $t\bar{t}$quark pairs. The talk will instrodude the results of the analysis interested with the measurement of differential cross-section of high boosted $t$ quark and $t \bar{t}$ pairs as a function of various kinematic observables. Study is performed on the full datasets collected by the ATLAS detector at...