2018/05/31 by Nayara Fonseca, Enrico Morgante, Geraldine Servant +1 · 3 citations
Physics and Astronomy · #Cosmology and Gravitation Theories #Dark Matter and Cosmic Phenomena #Dark matter #Electroweak interaction #Electroweak scale #Gauge (firearms) #Gauge boson #Gauge theory #Higgs boson #Higgs field #Higgs sector #Inflation (cosmology) #Particle physics #Particle physics theoretical and experimental studies #Physics #Standard Model (mathematical formulation) #Theoretical physics #Vacuum expectation value #hep-ph
paper · pdf · doi:10.1007/jhep10(2018)020
51 pages, 16 figures. v3: Minor revisions, version published in JHEP
openalex created_date 2018/05/17 · arxiv created 2018/09/30 · openalex publication_date 2018/10/01 · arxiv updated 2018/11/14 · openalex updated_date 2026/08/05
A bstract We show that the mechanism of cosmological relaxation of the electroweak scale can take place independently of the inflation mechanism, thus relieving burdens from the original relaxion proposal. What eventually stops the (fast-rolling) relaxion field during its cosmological evolution is the production of particles whose mass is controlled by the Higgs vacuum expectation value. We first show that Higgs particle production does not work for that purpose as the Higgs field does not track the minimum of its potential in the regime where Higgs particles get efficiently produced through their coupling to the relaxion. We then focus on gauge boson production. We provide a detailed analysis of the scanning and stopping mechanism and determine the parameter space for which the relaxion mechanism can take place after inflation, while being compatible with cosmological constraints, such as the relaxion dark matter overabundance and Big Bang Nucleosynthesis. We find that the cutoff scale can be as high as two hundreds of TeV. In this approach, the relaxion sector is responsible for reheating the visible sector. The stopping barriers of the periodic potential are large and Higgs-independent, facilitating model-building. The allowed relaxion mass ranges from 200 MeV up to the weak scale. In this scenario, the relaxion field excursion is subplanckian, and is thus many orders of magnitude smaller than in the original relaxion proposal.