2013/05/29 by Sergei Dubovsky, Victor Gorbenko, Mehrdad Mirbabayi · 1 voice · 3 citations
Physics and Astronomy · Social Sciences · #Particle physics theoretical and experimental studies #International Science and Diplomacy #Quantum and Classical Electrodynamics
paper · pdf · doi:10.1007/jhep09(2013)045
The cosmological constant problem and the absence of new natural physics at the electroweak scale, if confirmed by the LHC, may either indicate that the nature is fine-tuned or that a refined notion of naturalness is required. We construct a family of toy UV complete quantum theories providing a proof of concept for the second possibility. Low energy physics is described by a tuned effective field theory, which exhibits relevant interactions not protected by any symmetries and separated by an arbitrary large mass gap from the new "gravitational" physics, represented by a set of irrelevant operators. Nevertheless, the only available language to describe dynamics at all energy scales does not require any fine-tuning. The interesting novel feature of this construction is that UV physics is not described by a fixed point, but rather exhibits asymptotic fragility. Observation of additional unprotected scalars at the LHC would be a smoking gun for this scenario. Natural tuning also favors TeV scale unification.