Cp Violating Anomalous Trilinear Gauge Couplings From

We study the contributions of the CP violating anomalous WWγ interactions to b → sll. We obtain cutoff independent results on κ̃ and λ̃, by constructing an asymmetry for the process B → Kll, where the B and B̄ events are added. We show that a sample of 10 B → Kee events can yield a bound, |κ̃| < 0.42 at 90% C.L., which is much tighter than the recent constraint from D0. PACS number: 12.60Cn, 13.20.He, 11.30.Er Typeset using REVTEX e-mail: nita,[email protected] 1 Two of the aspects of the Standard Model(SM) which remain to be further explored are the gauge nature of the W, Z bosons and CP violation. The vector boson self interactions are uniquely fixed by the SU(2)L × U(1) gauge structure of the SM. However, new physics as well as higher order corrections will modify these self interactions. While tests of trilinear gauge couplings are now being done at present colliders, only weak bounds on them exist [1,2]. CP violation on the other hand is only parameterized in the SM via the CKM matrix, and has been seen only in the neutral K mesons. Much effort is now being put into studying CP violation in the B mesons. Large number of B mesons are expected to be produced in the near future, at the new asymmetric colliders and upgraded Tevatron, which would enable study of its rare decay modes. Rare decays of B mesons, occur in the SM only through loops and are thus expected to be very sensitive to new physics. In particular the mode b → sll has been extensively studied [3–5] for possible contributions from new physics. New physics that affects the gauge nature of the W, Z bosons, can be parameterized in terms of CP conserving as well as CP violating anomalous trilinear gauge boson couplings. The CP conserving couplings have been considered in the rare modes b → sγ, b → sll [6–8]. Since, the origin of CP violation is not understood, any potential source of CP violation should be pursued. Here we focus attention on the CP violating anomalous couplings, by studying the mode B → Kll. The couplings of W bosons to the photon and Z can be described by an effective Lagrangian, the most general form of which may be written down with the minimum requirements– that of Lorentz invariance, global SU(2) and local U(1) symmetry [9] as: Leff = − gV [