  Single top quark events produced in the t channel are used to set limits on
anomalous Wtb couplings and to search for top quark flavour-changing neutral
current (FCNC) interactions. The data taken with the CMS detector at the LHC in
proton-proton collisions at sqrt(s) = 7 and 8 TeV correspond to integrated
luminosities of 5.0 and 19.7 inverse femtobarns, respectively. The analysis is
performed using events with one muon and two or three jets. A Bayesian neural
network technique is used to discriminate between the signal and backgrounds,
which are observed to be consistent with the standard model prediction. The 95%
confidence level (CL) exclusion limits on anomalous right-handed vector, and
left- and right-handed tensor Wtb couplings are measured to be |f[V]^R| < 0.16,
|f[T]^L| < 0.057, and -0.049 < f[T]^R < 0.048, respectively. For the FCNC
couplings kappa[tug] and kappa[tcg], the 95% CL upper limits on coupling
strengths are |kappa[tug]|/Lambda < 4.1E-3 TeV-1 and |kappa[tcg]|/Lambda <
1.8E-2 TeV-1, where Lambda is the scale for new physics, and correspond to
upper limits on the branching fractions of 2.0E-5 and 4.1E-4 for the decays t
to ug and t to cg, respectively.
