Impact of squark generation mixing on the search for squarks decaying into fermions at LHC

We study the effect of squark generation mixing on squark production and decays at LHC in the Minimal Supersymmetric Standard Model (MSSM). We show that the effect can be very large despite the very strong constraints on quark flavour violation (QFV) from experimental data on B mesons. We find that the two lightest up-type squarks su_{1,2} can have large branching ratios for the decays into c-quark + neutralino_1 and t-quark + neutralino_1 at the same time due to squark generation mixing, leading to QFV signals pp -> c bar{t} (t bar{c}) + missing-E_T + X with a significant rate. The observation of this remarkable signature would provide a powerful test of supersymmetric QFV at LHC. This could have a significant impact on the search for squarks and the determination of the underlying MSSM parameters.