Supersymmetric contribution to [formula omitted] and [formula omitted] decays in SCET

Gaber Faisel,David Delepine,M Shalaby

doi:10.1016/j.physletb.2011.10.041

Abstract

We analyze the supersymmetric contributions to the direct CP asymmetries of the decays B→πK⁎ and B→ρK within Soft Collinear Effective Theory. We extend the Standard Model analysis of these asymmetries to include the next leading order QCD corrections. We find that, even with QCD correction, the Standard Model predictions cannot accommodate the direct CP asymmetries in these decay modes. Using Mass Insertion Approximation (MIA), we show that non-minimal flavor SUSY contributions mediated by gluino exchange can enhance the CP asymmetries significantly and thus can accommodate the experimental results.

Highlights

In the standard model (SM), Charge conjugation Parity (CP) violation and flavour transition arise from the complex Yukawa couplings in the Cabibbo Kobayashi Maskawa (CKM) matrix
The expected CP asymmetries in some decay channels for B meson are in contradiction with the experimental measurements carried by Babar and Belle B-factories and proton antiproton collider as Tevatron, with its experiments CDF and D0
The largest discrepancy has been observed in the decay B → Kπ where the world averages for the CP asymmetries of B0 → K±π∓ and B± → K±π0 are given by[1]: ACP (B0 → K±π∓) = −0.098 ± 0.012, (1)

Summary

INTRODUCTION

In the standard model (SM), Charge conjugation Parity (CP) violation and flavour transition arise from the complex Yukawa couplings in the Cabibbo Kobayashi Maskawa (CKM) matrix. The decay modes B → πK∗ and B → ρK are generated at the quark level in the same way as B → Kπ and it is interesting to explore hints of New Physics (NP) in these decays These decay modes are studied within SM in framework of QCDF [2], PQCD [3,4,5,6] and Soft Collinear Effective Theory (SCET) [7]. SCET is an effective field theory describing the dynamics of highly energetic particles moving close to the light-cone interacting with a background field of soft quanta[16] It provides a systematic and rigorous way to deal with the decays of the heavy hadrons that involve different energy scales. In the following we give a brief account for each amplitude

Leading order amplitude

Chirally enhanced penguins amplitude

Annihilation amplitudes

Long distance charm penguin amplitude

CONCLUSION