Abstract
We study the forward-backward asymmetry (AFB) and the differential branching ratio (DBR) in B → K * μ + μ − in the presence of new physics (NP) with different Lorentz structures. We consider NP contributions from vector-axial vector (VA), scalarpseudoscalar (SP), and tensor (T) operators, as well as their combinations. We calculate the effects of these new Lorentz structures in the low-q 2 and high-q 2 regions, and explain their features through analytic approximations. We find two mechanisms that can give a significant deviation from the standard-model predictions, in the direction indicated by the recent measurement of AFB by the Belle experiment. They involve the addition of the following NP operators: (i) VA, or (ii) a combination of SP and T (slightly better than T alone). These two mechanisms can be distinguished through measurements of DBR in B → K * μ + μ − and AFB in B → Kμ + μ −.
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Kumar Alok, A., Dighe, A., Ghosh, D. et al. New-physics contributions to the forward-backward asymmetry in B → K * μ + μ − . J. High Energ. Phys. 2010, 53 (2010). https://doi.org/10.1007/JHEP02(2010)053
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DOI: https://doi.org/10.1007/JHEP02(2010)053