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Relic neutrino decay solution to the excess radio background

Relic neutrino decay solution to the excess radio background
Relic neutrino decay solution to the excess radio background
The excess radio background detected by ARCADE 2 represents a puzzle within the standard cosmological model. There is no clear viable astrophysical solution and, therefore, it might indicate the presence of new physics. Radiative decays of a relic neutrino νi into a sterile neutrino νs, assumed to be quasi-degenerate, provide a solution that currently evades all constraints posed by different cosmological observations and reproduces very well the ARCADE 2 data. We find a very good fit to the ARCADE 2 data with best fit values τi=1.46×1021s and Δmi=4.0×10−5eV, where τi is the lifetime and Δmi is the mass difference between the decaying active neutrino and the sterile neutrino. On the other hand, if relic neutrino decays do not explain ARCADE 2 data, then these place a stringent constraint $\D m_i^{3/2} \tau_i \gtrsim 2 \times 10^{14}\,{\rm eV}^{3/2}\,{\rm s}$ in the range $1.4 \times 10^{-5} \, {\rm eV} < \D m_i < 2.5 \times 10^{-4}\,{\rm eV}$. The solution also predicts a stronger 21 cm absorption global signal than the predicted one from the ŁCDM model, with a contrast brightness temperature T21=−238+21−20mK (99% C.L.) at redshift z≃17. This is in mild tension with the even stronger signal found by the EDGES collaboration, T21=−500+200−500mK, suggesting that this might have been overestimated, maybe receiving a contribution from some unidentified foreground source.
hep-ph, astro-ph.CO, hep-th
arXiv
Dev, P.S. Bhupal
c48d060a-ccb4-4df3-aaae-2fc2571d1cab
Bari, Pasquale Di
3fe21e59-0eff-41bc-8faa-fdd817146418
Martínez-Soler, Ivan
8992db44-49bd-4073-b54b-74b88a6a118b
Roshan, Rishav
8b76c007-f9b6-4568-8a45-741931b06bb5
Dev, P.S. Bhupal
c48d060a-ccb4-4df3-aaae-2fc2571d1cab
Bari, Pasquale Di
3fe21e59-0eff-41bc-8faa-fdd817146418
Martínez-Soler, Ivan
8992db44-49bd-4073-b54b-74b88a6a118b
Roshan, Rishav
8b76c007-f9b6-4568-8a45-741931b06bb5

[Unknown type: UNSPECIFIED]

Record type: UNSPECIFIED

Abstract

The excess radio background detected by ARCADE 2 represents a puzzle within the standard cosmological model. There is no clear viable astrophysical solution and, therefore, it might indicate the presence of new physics. Radiative decays of a relic neutrino νi into a sterile neutrino νs, assumed to be quasi-degenerate, provide a solution that currently evades all constraints posed by different cosmological observations and reproduces very well the ARCADE 2 data. We find a very good fit to the ARCADE 2 data with best fit values τi=1.46×1021s and Δmi=4.0×10−5eV, where τi is the lifetime and Δmi is the mass difference between the decaying active neutrino and the sterile neutrino. On the other hand, if relic neutrino decays do not explain ARCADE 2 data, then these place a stringent constraint $\D m_i^{3/2} \tau_i \gtrsim 2 \times 10^{14}\,{\rm eV}^{3/2}\,{\rm s}$ in the range $1.4 \times 10^{-5} \, {\rm eV} < \D m_i < 2.5 \times 10^{-4}\,{\rm eV}$. The solution also predicts a stronger 21 cm absorption global signal than the predicted one from the ŁCDM model, with a contrast brightness temperature T21=−238+21−20mK (99% C.L.) at redshift z≃17. This is in mild tension with the even stronger signal found by the EDGES collaboration, T21=−500+200−500mK, suggesting that this might have been overestimated, maybe receiving a contribution from some unidentified foreground source.

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2312.03082v1 - Author's Original
Available under License Creative Commons Attribution.
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More information

Accepted/In Press date: 5 December 2023
Additional Information: 3 figures, 2 tables
Keywords: hep-ph, astro-ph.CO, hep-th

Identifiers

Local EPrints ID: 486086
URI: http://eprints.soton.ac.uk/id/eprint/486086
PURE UUID: 8c74c588-5e00-4066-9144-d6b1f392cf29

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Date deposited: 09 Jan 2024 17:33
Last modified: 17 Mar 2024 06:44

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Contributors

Author: P.S. Bhupal Dev
Author: Ivan Martínez-Soler
Author: Rishav Roshan

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