B Physics in the LHC Era

Abstract

In the last few years there has been great experimental progress in quark flavour physics. The validity of the Standard Model (SM) has been strongly reinforced by a series of challenging experimental tests in B, D and K decays. All the relevant SM parameters controlling quark-flavour dynamics (the quark masses and the angles of the Cabibbo-Kobayashi-Maskawa matrix [1,2]) have been determined with good accuracy. More importantly, several suppressed observables (such as ΔmBd , ΔmBs , ACPKΨ, B → Xsγ, K , . . . ) that are potentially sensitive to physics beyond the SM have been measured with good accuracy and show no deviations from the SM. The situation is somewhat similar to the flavour-conserving electroweak precision observables after LEP: the SM works very well and genuine one-loop electroweak effects have been tested with relative accuracy in the 10%–30% range. As in the case of electroweak observables, non-standard effects in the quark flavour sector can only appear as small corrections to the leading SM contribution.