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30 May 2022 to 4 June 2022
Virtual Seoul
Asia/Seoul timezone

Pseudoscalar sterile neutrino self-interactions in light of Planck, SPT and ACT data

Not scheduled
5m
Virtual Seoul

Virtual Seoul

Poster Neutrinos and cosmology Poster

Speaker

Dr Mattia Atzori Corona (aDipartimento di Fisica, Universit`a degli Studi di Cagliari, Complesso Universitario di Monserrato; University of Cagliari - INFN Cagliari)

Description

In this poster I would like to discuss our recent results on the pseudoscalar sterile neutrino self-interactions model.
In particular, we reassess the viability of a cosmological model including a fourth additional sterile neutrino species that self-interacts through a new pseudoscalar degree of freedom.
To that end, we perform a series of extensive analyses fitting various combinations of Cosmic Microwave Background data from Planck, the Atacama Cosmology Telescope and the South Pole Telescope, both alone and in combination with Baryon Acoustic Oscillation and Supernova Ia observations.
We show that the scenario under study, although capable to resolve the Hubble tension without worsening the $S_8$ tension, is severely constrained by high-multipole polarization data from both Planck and SPT.
Intriguingly, when trading Planck TE-EE data for those from ACT, we find a $> 3 \sigma$ preference for a non-zero sterile neutrino mass, $m_s=3.6^{+1.1}_{-0.6}$ eV (68 % C.L.), compatible with the range suggested by longstanding short-baseline (SBL) anomalies in neutrino oscillation experiments.
The preference is mostly driven by ACT favouring a higher value for the primordial spectral index $n_s$ with respect to Planck and SPT. The pseudoscalar model appears indeed to provide a better fit to ACT data with respect to $\Lambda$CDM ($\Delta\chi^2 \simeq -5$).
In particular, we show that the mild tension between Planck and ACT is due to the different pattern in the TE and EE power spectra on multipoles between $350 < \ell < 1000$.

Primary authors

Dr Mattia Atzori Corona (aDipartimento di Fisica, Universit`a degli Studi di Cagliari, Complesso Universitario di Monserrato; University of Cagliari - INFN Cagliari) Dr Riccardo Murgia (LUPM – Laboratoire Univers & Particules de Montpellier, CNRS & Universit´e de Montpellier (UMR-5299)) Prof. Matteo Cadeddu (INFN – Istituto Nazionale di Fisica Nucleare, Sezione di Cagliari) Prof. Maria Archidiacono (Universit`a degli Studi di Milano; INFN – Istituto Nazionale di Fisica Nucleare, Sezione di Milano) Dr Stefano Gariazzo (INFN – Istituto Nazionale di Fisica Nucleare, Sezione di Torino) Prof. Carlo Giunti (INFN – Istituto Nazionale di Fisica Nucleare, Sezione di Torino) Prof. Steen Hannestad (Department of Physics and Astronomy, Aarhus University)

Presentation materials