New Physics in the B-physics studies at ATLAS

Slides for the Joint Theory-Experiment Workshop “Searches for New Physics via Heavy Quark Physics at Hadron Colliders” University of Washington, Seattle February 6th - 10th, 2012 This presentation will discuss recent results of the B-physics studies with the ATLAS experiment. Relying mainly on decays with di-muon final states, ATLAS has observed different decays of neutral B0d and B0s mesons, the B+ -> J/psi K+ decay, the Lamba_b -> J/psi Lambda decay and a new Chi_b state. The B meson lifetimes have been measured in the decay modes B0d -> J/psi K0* and B0s -> J/psi phi as well as in inclusive B -> J/psi X decays. The ATLAS B-physics program includes the search for New Physics in (very) rare decays of B mesons like Bs->mu+mu- and possible CP violation in the decay B0s -> J/psi phi. The measurement of the cross section of b-jets produced in association with a Z or W boson provides important tests for pertubative QCD predictions. Furthermore, the search for prompt like-sign muon pairs and derived constraints on New Physics models and the cross section for microscopic black holes will be presented.