HEP - ASTRO SEMINAR | Particle-Antiparticle Oscillation and CP Violation in D⁰ -> Kp and B_s -> D_s pi Decays

Particle-antiparticle oscillation (also called mixing) and CP violation are sensitive to Beyond the Standard Model (BSM) amplitudes as well as Standard Model amplitudes. Studies of mixing in the D and B_s systems probe mass scales much higher than the Higgs mass and complement direct searches for BSM physics at the LHC. This talk will provide a general introduction to the phenomenology of particle-antiparticle mixing and CP violation, followed by discussions of specific measurements. The primary focus will be the study of D⁰ -> D⁰ and D⁰ -> D⁰ oscillations using ~ 2.3 × 10⁵ “wrong-sign” (WS) Kp and approximately 230 times more “right sign” (RS) decays. The differences of the D⁰ and D⁰ WS/RS ratios as functions of decay time are sensitive to both direct CP violation and indirect CP violation. I will discuss the results themselves and bounds on CP violation when they are combined with other measurements. In addition, I will discuss LHCb's recent measurement of the B_s oscillation frequency using B_s -> D_s pi decays.