The Standard Model, although very successful in describing all

experimental results in particle physics, is not able to explain the

apparent asymmetry between matter and antimatter in the Universe.

Additional CP violation effects, produced by the new physics

contribution beyond the Standard Model, are required to explain this

asymmetry, and one of the main task of the current and future

experiments is to identify and study them. The DØ experiment at

Fermilab performs the search for these new CP violation effects in the

decays of B mesons. In this talk I present the latest results of the

DØ experiment in this subject, with the main emphasis on the new

measurement of the CP violation phase in the BS mixing, obtained from the study of BS → J/ψ φ decay. We obtain the most precise value of this phase: ϕS = −0.57 +0.24 −0.30(stat)  +0.07 −0.02 (syst).

Slides (pdf)