First evidence for direct CP violation

First Evidence of Direct CP Violation in Charmless Two-Body Decays of Bs Mesons

Using a data sample corresponding to an integrated luminosity of 0:35 fb 1 collected by LHCb in 2011, we report the first evidence of CP violation in the decays of Bs mesons to K pairs, ACPðBs ! K Þ 1⁄4 0:27 0:08ðstatÞ 0:02ðsystÞ, with a significance of 3:3 . Furthermore, we report the most precise measurement of CP violation in the decays of B mesons to K pairs, ACPðB ! K Þ 1⁄4 0:088 0:011ðsta...

The search for direct CP violation

The formalism necessary to understand the phenomenon of CP nonconservation as observed in the neutral-kaon system is presented. The distinction between indirect CP violation and direct CP violation is made, and the level of understanding of the phenomenon in the standard model is reviewed. Attention is placed on new experimental efforts that could definitely establish a first-order or direct ef...

Direct CP Violation in B Decays

We discuss several aspects of direct CP asymmetries in B decays, which are very useful in spite of hadronic uncertainties in asymmetry calculations. 1) Asymmetries in decays to D(∗)K(∗), π+π−, ρ+ρ−, providing precision tests for the CKM phase γ. 2) Null tests in B+ → J/ψK+, π+π0, where a nonzero asymmetry provides evidence for New Physics. 3) Isospin and broken flavor SU(3) relations among CP a...

New Measurements of Direct Cp Violation

Large Direct CP Violation in B →

We present a novel method to search for a new CP -violating phase in the b → ss̄ss̄s transition using B → φφXs decays, where Xs represents a final state with a specific strange flavor such as K, K or Kπ. Direct CP violation can be enhanced due to an interference between an amplitude beyond the standard model (SM) and the SM decay amplitude through the ηc resonance. We find that the CP asymmetry c...