DeterminingγusingB±→DK±with multibodyDdecays

Abstract

We propose a method for determining ␥ using B Ϯ →DK Ϯ decays followed by a multibody D decay, such as D→K S Ϫ ϩ , D→K S K Ϫ K ϩ , and D→K S Ϫ ϩ 0 . The main advantages of the method are that it uses only Cabibbo allowed D decays, and that large strong phases are expected due to the presence of resonances. Since no knowledge about the resonance structure is needed, ␥ can be extracted without any hadronic uncertainty.

B-Physics at the LHC

“…The ADS [17] strategy combines colour-suppressed B decays with colour-favoured D decays (and vice versa), thus increasing the interference effects. The GGSZ [18] strategy uses a Dalitz analysis of D 0 → K S ππ decays to extract γ together with the strong phases in the D 0 decay. The sensitivity to γ in this case comes from the differences in the Dalitz plot for B + and B − decays as can be seen in Figure 11.…”

LHCb strategies for γ from

“…This method for determining γ was proposed in [10]. It makes use of the decay B ± → DK ± followed by a multibody D decay into a CP eigenstate Here we explain the basic idea using D → K 0 S π + π − as an example.…”

“…This error is expected to reduce significantly through exploitation of the coherently produced D mesons available at CLEOc [14] and BES [15]. A discussion of how these data may be used in a model independent analysis can be found in [10,16]. Similar techniques can be used for the four-body decay mode, where LHCb also expects large numbers of flavour-tagged D decays for use in model calibration.…”

CKM Fits: What the Data Say (Focused on B Physics)

“…Several variants were proposed to measure γ which can be grouped by the choice of the D decays: CP eigenstate, e.g., K 0 S π 0 (GLW) [38], flavor-specific state, e.g., K − π + (ADS) [39] and the many-body final state (interference in the Dalitz plot), e.g., K 0 S π + π − (GGSZ) [40]. All methods fit simultaneously γ, the strong phases δ and the ratio of the suppressed-to-dominated amplitudes r B (γ is common to all final states whereas δ and r B depend on the final states).…”