Abstract
We investigate asymptotic safety of a toy model of a singlet-scalar extension of the Higgs sector including two real scalar fields under the impact of quantum-gravity fluctuations. Employing functional renormalization group techniques, we search for fixed points of the system which provide a tentative ultraviolet completion of the system. We find that in a particular regime of the gravitational parameter space the canonically marginal and relevant couplings in the scalar sector -- including the mass parameters -- become irrelevant at the ultraviolet fixed point. The infrared potential for the two scalars that can be reached from that fixed point is fully predicted and features no free parameters. In the remainder of the gravitational parameter space, the values of the quartic couplings in our model are predicted. In light of these results, we discuss whether the singlet-scalar could be a dark-matter candidate. Furthermore, we highlight how "classical scale invariance" in the sense of a flat potential of the scalar sector at the Planck scale could arise as a consequence of asymptotic safety.
Highlights
Compelling astrophysical and cosmological evidence points to the existence of dark matter
We find a Gaussian-matter fixed point in agreement with general arguments on the fixed-point structure based on global symmetries [62]
The Higgs portal coupling stays irrelevant for all Λ Ã. If these results persist beyond our truncation and under the inclusion of additional standard model (SM) degrees of freedom, they hint that a simple scalar dark matter candidate does not couple to the SM through a finite momentumindependent Higgs portal coupling
Summary
Compelling astrophysical and cosmological evidence points to the existence of dark matter. In its simplest form, dark matter might be just an additional scalar field. To stabilize the additional field and prevent it from decaying, a Z2 reflection symmetry can be used. A dimension 4 operator exists that is compatible with the symmetries and couples the dark scalar to the standard model (SM) Higgs. The Higgs portal coupling is an additional marginal coupling and expected to play an important role in a general effective field theory setup. It is attractive, because in addition to providing a portal into the dark sector that enables direct and indirect experimental searches [14,15], it could contribute to stabilizing the Higgs potential [16–24]
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Free) 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
