On the scaling behavior of the cosmological constant and the possible existence of new forces and new light degrees of freedom

TL;DR

This paper explores how the cosmological constant's value varies across energy scales due to Standard Model interactions, suggesting potential new light forces and particles like a Cosmon-like dilaton.

Contribution

It investigates the scale dependence of the cosmological constant within the Standard Model, proposing the existence of new light degrees of freedom and forces.

Findings

The observable CC varies with energy scale, becoming nonzero near the neutrino mass scale.

The sign of the CC at this scale is negative, conflicting with supernova observations.

A new light scalar, possibly a Cosmon-like dilaton, may mediate macroscopic forces.

Abstract

A large value of the cosmological constant (CC) is induced in the Standard Model (SM) of Elementary Particle Physics because of Spontaneous Symmetry Breaking. To provide a small value of the observable CC one has to introduce the vacuum term which cancels the induced one at some point in the very far infrared cosmic scale. Starting from this point we investigate whether the cancellation is preserved at different energy scales. We find that the running of the Higgs mass, couplings and the vacuum term inevitably result in a scaling dependence of the observable CC value. As a consequence one meets a nonzero CC at an energy scale comparable to the typical electron neutrino mass suggested by some experiments, and the order of magnitude of this constant is roughly the one derived from recent supernovae observations. However the sign of it is negative -- opposite to what is suggested by these observations. This discrepancy may be a hint of the existence of an extra very light scalar, perhaps a Cosmon-like dilaton, which should essentially decouple from the SM Lagrangian, but that it nevertheless could mediate new macroscopic forces in the submillimeter range.