[ x’² = (5.5 ± 4.9)x10^-5 ; y’ = (4.8 ± 1.0)x10^-3 ]
[ A_Γ(KK) = (-0.35 ± 0.62 ± 0.12)x10^-3 A_Γ(ππ) = (0.33 ± 1.06 ± 0.14)x10^-3 ]

The LHCb Collaboration has reported recently new important results on charm physics.

(1) Ten months ago, the LHCb Collaboration presented the first observation of the D⁰–D⁰ oscillations in which the D⁰ matter mesons turn into their antimatter partners. Contrary to the B⁰–B⁰ and B⁰_s–B⁰_s oscillations in which the mesons turn into their antimatter partners many times during their lifetime, the D⁰–D⁰ oscillations are very slow, over one hundred times the average lifetime (see 7 November 2012 news for introduction). LHCb has now updated this result using the full 2011 and 2012 data set of 3 fb^-1. The new result is 2.5 times more precise. The values parameterizing the oscillations, the so-called mixing parameters y’ and x’², are shown above.

By now, CP violation, differences in the behaviour of matter and antimatter, has been observed in all oscillating neutral-meson (K⁰, B⁰, B⁰_s) systems apart from the charm system. First evidence for charm CP violation (see 14 November 2011 news) has not been unambiguously confirmed to date (see 12 March 2013 news). The D⁰ mesons are the only mesons containing up-type quarks which undergo matter anti-matter oscillations (called also mixing) and therefore provide unique access to effects from physics beyond the Standard Model.

As part of the new analysis, LHCb has investigated whether there is a CP violating contribution to the oscillations, in contrast to the Standard Model expectation. This is done by investigating whether the oscillation parameters for mesons produced as D⁰ and D⁰ differ. Studying the D⁰ and D⁰ decays separately shows no evidence for CP violation and provides the most stringent bounds on the parameters (A_D and