UCLA

Accommodating scalar fields in local QFT, without BSM physics, has been a persistent problem. The quantum triviality problem means that no matter the initial choice of coupling constants, after renormalization, the theory becomes the free one. The lack of evidence for BSM physics, specifically supersymmetry or compositeness, that may address such issues has led us to consider other possible options. Here we consider one such solution to this problem: nonlocal fields. After choosing a suitable nonlocal kernel that satisfies constraints including Lorentz invariance, unitarity, and UV finiteness, the delocalization is applied to a pure phi^4 theory. We show that the beta function mimics a UV FP near the scale of locality, defined as M in momentum space. Then an additional interaction vertex is added to understand how the presence of higher-order interactions affects this result. More matter content is also investigated, in a theory involving a Dirac fermion coupled to a scalar field via a Yukawa interaction. Finally, an Abelian gauge theory is discussed, which have thusfar eluded delocalization due to the difficulty of preserving the gauge symmetry and avoiding the introduction of singularities from the nonlocal kernel. In all cases, we find that above the locality scale, the beta functions are exponentially suppressed, mimicking the presence of a UV FP.