Abstract. We show that both the baryon asymmetry of the Universe and the dark matter abundance can be explained within a single framework that makes use of maximally helical hypermagnetic fields produced during pseudoscalar inflation and the chiral anomaly in the Standard Model. We consider a minimal asymmetric dark matter model free from anomalies and constraints. We find that the observed baryon and the dark matter abundances are achieved for a wide range of inflationary parameters, and the dark matter mass ranges between 7-15 GeV. The novelty of our mechanism stems from the fact that the same source of CP violation occurring during inflation explains both baryonic and dark matter in the Universe with two inflationary parameters, hence addressing all the initial condition problems in an economical way.
We show that the baryon asymmetry of the universe can be explained in models
where the Higgs couples to the Chern-Simons term of the hypercharge group
and is away from the late-time minimum of its potential during inflation. The Higgs then relaxes toward this minimum once inflation ends which leads to the production of (hyper)magnetic helicity. We discuss the conditions under which this helicity can be approximately conserved during its joint evolution with the thermal plasma. At the electroweak phase transition the helicity is then converted into a baryon asymmetry by virtue of the chiral anomaly in the standard model. We propose a simple model which realizes this mechanism and show that the observed baryon asymmetry of the universe can be reproduced.
We study a modification of the Higgs inflation scenario where we introduce an extra scalar φ, with mass m, coupled to the Ricci scalar as gφ 2 R, and mixed with the Higgs field h by means of the Lagrangian term µφh 2 . Both fields participate in the inflation process in a unitary theory that predicts values of the cosmological observables in agreement with the results from the Planck/BICEP/Keck collaborations. In addition, by means of a CP odd effective operator that couples φ to the Chern-Simons term of the hypercharge gauge group as f −1 φ φ Y µν Ỹ µν , maximally helical magnetic fields are produced during the last e-folds of inflation.We found a window in the coupling f φ where these fields survive all constraints until the electroweak phase transition, and source the baryon asymmetry of the Universe through the Standard Model chiral anomaly. From a phenomenological perspective, the model can solve the Standard Model instability problem at the scale Q I 10 11 GeV, provided that µ m Q I , and for m O(few) TeV, the φ-h mixing becomes sizable while the theory turns natural. The latter thus predicts modifications of the trilinear and quartic couplings that could be explored at the HE-LHC, as well as at future colliders, and allows for direct φ production at the LHC followed by decay into hh. Present results from ATLAS and CMS already put (mild) bounds on the mass of the heavy scalar as m 0.55 TeV at 95% CL.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.