  The key result of the present work is the theoretical prediction and
observation of the formation of a new type of transport barrier in fusion
plasmas, called F-ATB (fast ion-induced anomalous transport barrier). As
demonstrated through state-of-the-art global electrostatic and electromagnetic
simulations, the F-ATB is characterized by a full suppression of the turbulent
transport - caused by strongly sheared, axisymmetric $E \times B$ flows - and
an increase of the neoclassical counterpart, albeit keeping the overall fluxes
at significantly reduced levels. The trigger mechanism is shown to be a mainly
electrostatic resonant interaction between supra-thermal particles, generated
via ion-cyclotron-resonance heating, and plasma micro-turbulence. These
findings are obtained by realistic simulations of the ASDEX Upgrade discharge
$\#36637$ - properly designed to maximized the beneficial role of the
wave-particle resonance interaction - which exhibits the expected properties of
improved confinement produced by energetic particles.
