Antipin, O

Resizing the conformal window: A {beta}-function ansatz

We propose an ansatz for the nonperturbative beta-function of a generic nonsupersymmetric Yang-Mills theory with or without fermions in an arbitrary representation of the gauge group. While our construction is similar to the recently proposed Ryttov-Sannino all-order beta-function, the essential difference is that it allows for the existence of an unstable ultraviolet fixed point in addition to the predicted Banks-Zaks-like infrared stable fixed point. Our beta-function preserves all of the tested features with respect to the nonsupersymmetric Yang-Mills theories. We predict the conformal window identifying the lower end of it as a merger of the infrared and ultraviolet fixed points.