  A search for pair production of third-generation scalar leptoquarks decaying
to top quark and tau lepton pairs is presented using proton-proton collision
data at a center-of-mass energy of sqrt(s) = 8 TeV collected with the CMS
detector at the LHC and corresponding to an integrated luminosity of 19.7
inverse femtobarns. The search is performed using events that contain an
electron or a muon, a hadronically decaying tau lepton, and two or more jets.
The observations are found to be consistent with the standard model
predictions. Assuming that all leptoquarks decay to a top quark and a tau
lepton, the existence of pair produced, charge -1/3, third-generation
leptoquarks up to a mass of 685 GeV is excluded at 95% confidence level. This
result constitutes the first direct limit for leptoquarks decaying into a top
quark and a tau lepton, and may also be applied directly to the pair production
of bottom squarks decaying predominantly via the R-parity violating coupling
lambda'[333].
