February 28, 2018 to March 2, 2018
Europe/Zurich timezone

Naturalness, Wilsonian Renormalization, and ‘Fundamental Parameters’ in Quantum Field Theory

Mar 1, 2018, 9:00 AM


Joshua Rosaler


Increasingly strong indications from the LHC that the Standard Model
violates the naturalness principle raise several possibilities: 1)
failure of naturalness is a genuinely problematic feature of the
Standard Model that we should seek to correct in the search for deeper
theories, 2) failure of naturalness is problematic, but a contingent
fact of nature that we must simply accept, 3) failure of naturalness is
unproblematic, and the naturalness principle should be
abandoned. Exploring the third possibility, we closely examine one
influential and inter-connected set of justifications for imposing
naturalness in the particular senses that prohibit fine-tuning of the
bare Higgs mass and delicate sensitivity to slight variations in bare
parameters at the Standard Model's physical high-energy cutoff. We
highlight the dependence of these justifications on the physical
interpretation of these bare parameters as "fundamental parameters,"
which draws heavily on the well-known analogy between elementary
particle physics and condensed matter theory. We argue that while
failure of naturalness in these senses is legitimately regarded as
problematic on this interpretation, there remains a viable alternative
physical interpretation of these parameters that is under-recognized
within the literature on naturalness, according to which there is
nothing problematic or "unnatural" about the fine tunings or
sensitivities in question. On this interpretation, all bare parameters,
including those at an effective field theory's physical cutoff, are
unphysical "auxiliary" parameters. We argue that this interpretation
may be more appropriate to the context of elementary particle physics,
implying that, despite the strong mathematical analogies between the
quantum field theoretic formalisms of condensed matter theory and elementary particle physics, the particular forms of naturalness-based
reasoning discussed here are undermined by strong disanalogies
of physical interpretation of the formalism in these different contexts.

Primary authors

Robert Valentin Harlander (Rheinisch Westfaelische Tech. Hoch. (DE)) Joshua Rosaler

Presentation materials