Article
Astronomy & Astrophysics
Vedran Brdar, Admir Greljo, Joachim Kopp, Toby Opferkuch
Summary: This study focuses on the physics of neutrino magnetic moments, particularly in scenarios where right-handed or sterile neutrinos are heavier than left-handed Standard Model neutrinos. Strong exclusion limits on the active-to-sterile neutrino transition magnetic moment are derived based on data from various sources and experiments. Complementary constraints from astrophysics and cosmology are also investigated, along with a thorough analysis of Big Bang nucleosynthesis.
JOURNAL OF COSMOLOGY AND ASTROPARTICLE PHYSICS
(2021)
Article
Astronomy & Astrophysics
Mariana Carrillo Gonzalez, Qiuyue Liang, Jeremy Sakstein, Mark Trodden
Summary: The tension between measurements of the Hubble constant at different redshifts may indicate new physics at play in the early universe, potentially involving early dark energy and scalar field interactions with standard model neutrinos. A neutrino-assisted early dark energy model is proposed to explain the coincidence between different epochs, with detailed analysis and constraints needed for validation. This scenario opens up new avenues for testing using cosmological data sets.
JOURNAL OF COSMOLOGY AND ASTROPARTICLE PHYSICS
(2021)
Article
Astronomy & Astrophysics
Mattia Atzori Corona, Riccardo Murgia, Matteo Cadeddu, Maria Archidiacono, Stefano Gariazzo, Carlo Giunti, Steen Hannestad
Summary: This study reassesses a cosmological model with an additional sterile neutrino species and investigates its viability using various cosmic microwave background data. The model is found to resolve the Hubble tension but is constrained by high-multipole polarization data. Interestingly, when using ACT data, there is a possibility of a non-zero sterile neutrino mass, consistent with anomalies observed in short-baseline neutrino oscillation experiments. However, the combined analysis with Planck still favors the ACDM model.
JOURNAL OF COSMOLOGY AND ASTROPARTICLE PHYSICS
(2022)
Article
Physics, Particles & Fields
Yong Du, Jiang-Hao Yu
Summary: The study precisely calculates the number of relativistic species, N-eff, in the standard model and predicts it will be measured to the percent level by CMB-S4 in the future. Neutral-current non-standard interactions are found to impact neutrino decoupling in the early Universe, subsequently modifying N-eff. The results provide a comprehensive analysis of the dimension-7 parameterized operators in effective field theory framework and offer a stringent constraint on the dimension-6 vector-type neutrino-electron operator's scale.
JOURNAL OF HIGH ENERGY PHYSICS
(2021)
Article
Astronomy & Astrophysics
Ananya Tapadar, Sougata Ganguly, Sourov Roy
Summary: In this paper, the non-adiabatic evolution of dark sector is studied in the framework of a U(1)(L mu)-( L tau )circle times U(1)(x) extension of the standard model. The connection between the visible and dark sectors is established through a portal coupling. The temperature evolution and various non-equilibrium stages of the dark sector are analyzed. Constraints on the model parameters from laboratory and astrophysical searches are investigated. The parameter space for the non-adiabatic evolution of the dark sector is significantly constrained for certain values of mass and coupling, while other constraints depend on the mass ratio.
JOURNAL OF COSMOLOGY AND ASTROPARTICLE PHYSICS
(2022)
Article
Astronomy & Astrophysics
Sougata Ganguly, Sourov Roy, Ananya Tapadar
Summary: The lack of information before BBN allows for the presence of a new species 0 with a specific energy density redshift. This non-standard cosmological setup enables a larger coupling between the dark and visible sectors, even without thermal equilibrium. By considering the U(1)Lmu-LT 0 U(1)X gauge extension of the SM, different cosmological phases of the thermally decoupled dark sector are studied. It is shown that the dark matter relic density and muon (g - 2) anomaly can be reconciled within this scenario, satisfying various constraints.
JOURNAL OF COSMOLOGY AND ASTROPARTICLE PHYSICS
(2023)
Article
Physics, Particles & Fields
David Dunsky, Lawrence J. Hall, Keisuke Harigaya
Summary: The study investigates SU(2)_L x SU(2)_R x U(1)_(B-L) theories that incorporate the Higgs Parity mechanism, solving the strong CP problem and predicting three right-handed neutrinos. It introduces cosmologies where right-handed neutrinos are produced via different mechanisms and explores the parameter space where the lightest right-handed neutrino is dark matter and contributes to baryon asymmetry via leptogenesis. A theory of flavor is constructed to explain the lightness and stability of right-handed neutrino dark matter, while maintaining sufficient baryon asymmetry. The allowed parameter space can be probed by future colliders, lattice computations, and measurements of the neutrino mass hierarchy.
JOURNAL OF HIGH ENERGY PHYSICS
(2021)
Article
Astronomy & Astrophysics
Alberto Salvio
Summary: The article investigates the general effective field theory describing the interactions of a massless dark photon with all Standard Model particles. The thermal production rate, cosmological yield, and contribution to the effective number of neutrinos of the dark photon are calculated. These predictions meet current observational bounds and will be tested in future measurements.
JOURNAL OF COSMOLOGY AND ASTROPARTICLE PHYSICS
(2023)
Article
Astronomy & Astrophysics
B. Fu, S. F. King
Summary: We study the extension of the Standard Model with scalar leptoquarks in different SU(2) representations. By coupling leptoquarks with the SM Higgs field, the electroweak phase transition (EWPT) can turn into first-order, generating gravitational wave signals. We calculate the necessary leptoquark-Higgs coupling for first-order EWPT and discuss the constraints from Higgs phenomenology. Using benchmarks, we compare the strength of gravitational waves produced during leptoquark-induced first-order EWPT to detector sensitivities, finding that the SU(2) representations of leptoquarks can be differentiated by gravitational waves in the parameter space where first-order EWPT can occur as a function of the Higgs portal coupling.
JOURNAL OF COSMOLOGY AND ASTROPARTICLE PHYSICS
(2023)
Article
Astronomy & Astrophysics
Graciela B. Gelmini, Alexander Kusenko, Volodymyr Takhistov
Summary: Observations in the local Universe have found a discrepancy in the value of the Hubble constant H-0 compared to early Universe measurements, which can potentially be alleviated by the additional radiation from an unstable sterile neutrino with a mass of O(10) MeV before the Big Bang Nucleosynthesis. The necessary masses and couplings of the sterile neutrino, assumed to primarily mix with ν(τ) and/or ν(μ) neutrinos, are within reach of experiments like Super-Kamiokande, NA62, and DUNE.
JOURNAL OF COSMOLOGY AND ASTROPARTICLE PHYSICS
(2021)
Article
Physics, Particles & Fields
Roberto A. Lineros, Mathias Pierre
Summary: The model explores the connection between Dark Matter and neutrinos by introducing new electroweakly charged states and imposing a discrete symmetry, generating a stable Dark Matter candidate. Numerical analysis shows that the model can reproduce neutrino masses, correct dark matter density, and viable dark matter masses. Direct and indirect detection signatures are explored, showing promising detection prospects with CTA, Darwin, and KM3Net, highlighting the complementarity between these observables.
JOURNAL OF HIGH ENERGY PHYSICS
(2021)
Article
Physics, Particles & Fields
Rupert Coy, Thomas Hambye
Summary: The text discusses the stability of dark matter particles and the potential for decay induced by seesaw physics, showing that this could lead to neutrino lines of intensity comparable to current neutrino telescope sensitivity. Models involving gauge bosons of abelian or non-abelian gauge symmetries are used to illustrate this possibility.
JOURNAL OF HIGH ENERGY PHYSICS
(2021)
Article
Astronomy & Astrophysics
Manuel Drees, Bardia Najjari
Summary: In this study, we focus on the spectrum of energetic particles originating from the decay of massive progenitors during thermalization, considering factors such as background temperature, IR cutoff, and the LPM effect. By solving the resulting integral equation numerically and constructing an accurate analytical fit of the solutions, we obtain precise results.
JOURNAL OF COSMOLOGY AND ASTROPARTICLE PHYSICS
(2021)
Article
Physics, Particles & Fields
Maira Dutra, Vinicius Oliveira, C. A. de S. Pires, Farinaldo S. Queiroz
Summary: In this model, a mixed warm and hot keV neutrino dark matter is naturally produced by arranging active and sterile neutrinos in the same SU(3)(L) multiplet, with the lightest sterile neutrino serving as dark matter. The heavy sterile neutrinos also play a role in diluting the dark matter density and affecting the population through their out-of-equilibrium decay, which helps to address the issue of overproduction in keV neutrino dark matter. Potential implications for Big Bang Nucleosynthesis and the number of relativistic degrees of freedom are explored in this study.
JOURNAL OF HIGH ENERGY PHYSICS
(2021)
Article
Astronomy & Astrophysics
Thomas Biekoetter, Sven Heinemeyer, Jose Miguel No, Maria Olalla Olea, Georg Weiglein
Summary: Extensions of the Higgs sector of the Standard Model can lead to a rich cosmological history around the electroweak scale, with the possibility of various phenomena such as non-restoration of electroweak symmetry or vacuum trapping. By focusing on the N2HDM of type II and considering theoretical and experimental constraints, scenarios of electroweak symmetry non-restoration, vacuum trapping, and first-order phase transition in the thermal history of the Universe are identified. Despite the presence of a global electroweak minimum in the scalar potential at zero temperature, the physical viability of the N2HDM parameter space is not guaranteed, emphasizing the importance of analyzing tunneling probability for reliable predictions of the Universe's thermal history.
JOURNAL OF COSMOLOGY AND ASTROPARTICLE PHYSICS
(2021)