  The result of a search for flavor changing neutral currents (FCNC) through
single top quark production in association with a photon is presented. The
study is based on proton-proton collisions at a center-of-mass energy of 8 TeV
using data collected with the CMS detector at the LHC, corresponding to an
integrated luminosity of 19.8 inverse femtobarns. The search for t gamma events
where t to Wb and W to mu nu is conducted in final states with a muon, a
photon, at least one hadronic jet with at most one being consistent with
originating from a bottom quark, and missing transverse momentum. No evidence
of single top quark production in association with a photon through a FCNC is
observed. Upper limits at the 95% confidence level are set on the tu gamma and
tc gamma anomalous couplings and translated into upper limits on the branching
fraction of the FCNC top quark decays: B(t to u gamma) < 1.3E-4 and B(t to c
gamma) < 1.7E-3. Upper limits are also set on the cross section of associated t
gamma production in a restricted phase-space region. These are the most
stringent limits currently available.
