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Indications for a Nonzero Lepton Asymmetry from Extremely Metal-Poor Galaxies
- Source :
- Physical Review Letters
- Publication Year :
- 2023
- Publisher :
- American Physical Society (APS), 2023.
-
Abstract
- The recent measurement of helium-4 from the near-infrared spectroscopy of extremely metal-poor galaxies (EMPGs) by the Subaru Survey may point to a new puzzle in the Early Universe. We exploit this new helium measurement together with the percent-level determination of primordial deuterium, to assess indications for a non-vanishing lepton asymmetry during the Big Bang Nucleosynthesis (BBN) era, paying particular attention to the role of uncertainties in the nuclear reaction network. A cutting-edge Bayesian analysis focused on the role of the newly measured EMPGs, jointly with information from the Cosmic Microwave Background, suggests the existence of a nonzero lepton asymmetry at around the $2 \sigma$ level, providing a hint for cosmology beyond $\Lambda$CDM. We discuss conditions for a large total lepton asymmetry to be consistently realized in the Early Universe.<br />Comment: Analysis updated with Astrophys.J. 941 (2022) 2, 167. 95% joint probability distribution now shown in Fig.1. Minor modifications of the text, conclusions unchanged. Version matches publication in Physical Review Letters
- Subjects :
- High Energy Physics - Phenomenology
High Energy Physics - Phenomenology (hep-ph)
Cosmology and Nongalactic Astrophysics (astro-ph.CO)
FOS: Physical sciences
General Physics and Astronomy
Astrophysics::Cosmology and Extragalactic Astrophysics
Astrophysics - Cosmology and Nongalactic Astrophysics
Subjects
Details
- ISSN :
- 10797114 and 00319007
- Volume :
- 130
- Database :
- OpenAIRE
- Journal :
- Physical Review Letters
- Accession number :
- edsair.doi.dedup.....5a5f7727220c13ae9e10950018d2f461