When feebly interacting massive particles decay into neutrinos: The N-eff story
Publikation: Bidrag til tidsskrift › Tidsskriftartikel › Forskning › fagfællebedømt
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When feebly interacting massive particles decay into neutrinos : The N-eff story. / Boyarsky, Alexey; Ovchynnikov, Maksym; Sabti, Nashwan; Syvolap, Vsevolod.
I: Physical Review D, Bind 104, Nr. 3, 035006, 10.08.2021.Publikation: Bidrag til tidsskrift › Tidsskriftartikel › Forskning › fagfællebedømt
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TY - JOUR
T1 - When feebly interacting massive particles decay into neutrinos
T2 - The N-eff story
AU - Boyarsky, Alexey
AU - Ovchynnikov, Maksym
AU - Sabti, Nashwan
AU - Syvolap, Vsevolod
PY - 2021/8/10
Y1 - 2021/8/10
N2 - The existence of feebly interacting massive particles (FIMPs) could have significant implications on the effective number of relativistic species N-eff in the early Universe. In this work, we investigate in detail how short-lived FIMPs that can decay into neutrinos affect N-eff and highlight the relevant effects that govern its evolution. We show that even if unstable FIMPs inject most of their energy into neutrinos, they may still decrease N-eff, and identify neutrino spectral distortions as the driving power behind this effect. As a case study, we consider heavy neutral leptons (HNLs) and indicate which regions of their parameter space increase or decrease Neff. Moreover, we derive bounds on the HNL lifetime from the cosmic microwave background and comment on the possible role that HNLs could play in alleviating the Hubble tension.
AB - The existence of feebly interacting massive particles (FIMPs) could have significant implications on the effective number of relativistic species N-eff in the early Universe. In this work, we investigate in detail how short-lived FIMPs that can decay into neutrinos affect N-eff and highlight the relevant effects that govern its evolution. We show that even if unstable FIMPs inject most of their energy into neutrinos, they may still decrease N-eff, and identify neutrino spectral distortions as the driving power behind this effect. As a case study, we consider heavy neutral leptons (HNLs) and indicate which regions of their parameter space increase or decrease Neff. Moreover, we derive bounds on the HNL lifetime from the cosmic microwave background and comment on the possible role that HNLs could play in alleviating the Hubble tension.
KW - BIG-BANG NUCLEOSYNTHESIS
KW - DARK-MATTER
KW - STERILE NEUTRINO
KW - BOUNDS
KW - VMSM
U2 - 10.1103/PhysRevD.104.035006
DO - 10.1103/PhysRevD.104.035006
M3 - Journal article
VL - 104
JO - Physical Review D
JF - Physical Review D
SN - 2470-0010
IS - 3
M1 - 035006
ER -
ID: 276377577