English   español  
Please use this identifier to cite or link to this item: http://hdl.handle.net/10261/194605
Share/Impact:
Statistics
logo share SHARE logo core CORE   Add this article to your Mendeley library MendeleyBASE

Visualizar otros formatos: MARC | Dublin Core | RDF | ORE | MODS | METS | DIDL | DATACITE
Exportar a otros formatos:

Title

Cosmology with a very light Lμ − Lτ gauge boson

AuthorsEscudero Abenza, Miguel; Hooper Dan; Krnjaic, Gordan; Pierre, Mathias
Issue DateMar-2019
PublisherInstitute of Physics Publishing
CitationJournal of High Energy Physics 2019: 71 (2019)
AbstractIn this paper, we explore in detail the cosmological implications of an abelian L − L gauge extension of the Standard Model featuring a light and weakly coupled Z′. Such a scenario is motivated by the longstanding ∼ 4σ discrepancy between the measured and predicted values of the muon’s anomalous magnetic moment, (g − 2) , as well as the tension between late and early time determinations of the Hubble constant. If sufficiently light, the Z′ population will decay to neutrinos, increasing the overall energy density of radiation and altering the expansion history of the early universe. We identify two distinct regions of parameter space in this model in which the Hubble tension can be significantly relaxed. The first of these is the previously identified region in which a ∼ 10 − 20 MeV Z′ reaches equilibrium in the early universe and then decays, heating the neutrino population and delaying the process of neutrino decoupling. For a coupling of g ≃ (3 − 8) × 10 , such a particle can also explain the observed (g − 2) anomaly. In the second region, the Z′ is very light (mZ′ ∼ 1eV to MeV) and very weakly coupled (g ∼ 10 to 10 ). In this case, the Z′ population is produced through freeze-in, and decays to neutrinos after neutrino decoupling. Across large regions of parameter space, we predict a contribution to the energy density of radiation that can appreciably relax the reported Hubble tension, ΔN ≃ 0.2.
URIhttp://hdl.handle.net/10261/194605
DOIhttp://dx.doi.org/10.1007/JHEP03(2019)071
Identifiersdoi: 10.1007/JHEP03(2019)071
issn: 1029-8479
Appears in Collections:(IFIC) Artículos
Files in This Item:
File Description SizeFormat 
33_Escudero_CosmologyWithAVeryLightLμLτGau.pdf1,02 MBAdobe PDFThumbnail
View/Open
Show full item record
Review this work
 


WARNING: Items in Digital.CSIC are protected by copyright, with all rights reserved, unless otherwise indicated.