  We propose a supersymmetric explanation for the anomalously high forward
backward asymmetry in top pair production measured by CDF and D0. We suppose
that it is due to the t-channel exchange of a right-handed sbottom which
couples to d_R and t_R, as is present in the R-parity violating minimal
supersymmetric standard model. We show that all Tevatron and LHC experiments' t
tbar constraints may be respected for a sbottom mass between 300 and 1200 GeV,
and a large Yukawa coupling >2.2, yielding A_{FB} up to 0.18. The non Standard
Model contribution to the LHC charge asymmetry parameter is Delta
A_C^y=0.017-0.045, small enough to be consistent with current measurements but
non-zero and positive, allowing for LHC confirmation in the future within 20
fb^-1. A small additional contribution to the LHC t tbar production
cross-section is also predicted, allowing a further test. We estimate that 10
fb^-1 of LHC luminosity would be sufficient to rule out the proposal to 95%
confidence level, if the measurements of the t tbar cross-section turn out to
be centred on the Standard Model prediction.
