Flavoured naturalness

We show that a large mixing between the right-handed charm and top squarks (i) is allowed by low-energy flavour constraints; (ii) reduces the experimental bound on the stop mass; (iii) has a mild, but beneficial, effect on fine-tuning; (iv) leads to interesting signatures at the LHC not presently investigated by experiments. We estimate the current bound on the stop mass, in presence of flavour mixing, and discuss the new collider signatures. The signal in the t (c) over bar (c (t) over bar) + is not an element of(T) channel is large enough that it can be immediately searched for experimentally, while the signature with same-sign tops and is not an element of(T) requires a luminosity upgrade of the LHC.