New-physics contributions to the forward-backward asymmetry in B → K*μ +μ -

Ashutosh Kumar Alok, Amol Dighe, Diptimoy Ghosh, David London, Joaquim Matias, Makiko Nagashima, Alejandro Szynkmana

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62 Citations (Scopus)


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 -. © 2010 SISSA.
Original languageEnglish
Article number053
JournalJournal of High Energy Physics
Issue number2
Publication statusPublished - 30 Jul 2010


  • B-Physics
  • Beyond standard model


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