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Related papers: Dirac neutrinos and $N_{{\rm eff}}$

200 papers

It is shown on the ground of a simple 6\times 6 neutrino mixing model that one of three conventional sterile (righthanded) neutrinos, if light enough, may be consistently used for explaining a {\it small} LSND effect. Then, it is still…

High Energy Physics - Phenomenology · Physics 2007-05-23 Wojciech Krolikowski

The simplest model that can accomodate a viable nonbaryonic dark matter candidate is the standard electroweak theory with the addition of right-handed or sterile neutrinos. We reexamine this model and find that the sterile neutrinos can be…

High Energy Physics - Phenomenology · Physics 2008-11-26 Scott Dodelson , Lawrence M. Widrow

The observed flavor oscillations of solar and atmospheric neutrinos determine several elements of the leptonic mixing matrix, but leave open the small mixing angle Theta_13, a possible CP-violating phase, the mass ordering, the absolute…

Astrophysics · Physics 2017-08-23 G. G. Raffelt

The equilibration of the right-helicity states $\nu_+$ of light Dirac-neutrinos is discussed. I point out that the $\nu_+$ production rate is enhanced by weak gauge boson pole effects so that the right-helicity component of $\nu_\tau$ is…

High Energy Physics - Phenomenology · Physics 2007-05-23 Kari Enqvist

Since future, precise theory of neutrino oscillations should include the understanding of the neutrino mass generation and a precise, relativistic description of hadrons, and observing that such a future theory may require Dirac's FF of…

High Energy Physics - Phenomenology · Physics 2013-01-09 Stanisław D. Głazek , Arkadiusz P. Trawiński

Assuming all three known neutrinos are Dirac fermions, $U(1)_{B-L}$ can be an exact symmetry. We show that, if the condition of charge quantization is relaxed, the anomaly-free $B-L$ charges of two out of three right-handed neutrinos can be…

High Energy Physics - Phenomenology · Physics 2026-01-22 Xiyuan Gao , Amir N. Khan

The absolute mass of neutrinos and their nature are presently unknown. Aggregate matter has a coherent weak charge leading to a repulsive interaction mediated by a neutrino pair. Near its range at micron distances the virtual neutrinos are…

Atomic Physics · Physics 2024-04-11 José Bernabeu , Dylan O. Sabulsky , Federico Sánchez , Alejandro Segarra

Dark matter (DM) and neutrinos are the two most compelling pieces of evidence of new physics beyond the Standard Model of Particle Physics but these are often treated as belonging to two different sectors. Yet DM-neutrino interactions are…

High Energy Physics - Phenomenology · Physics 2017-05-12 Celine Boehm , Andres Olivares-Del Campo , Sergio Palomares-Ruiz , Silvia Pascoli

Massive neutrinos are guaranteed to have nonzero electromagnetic moments and, since there are at least three neutrino species, these dipole moments define a matrix. Here, we estimate the current upper bounds on all independent neutrino…

High Energy Physics - Phenomenology · Physics 2022-09-09 André de Gouvêa , Giancarlo Jusino Sánchez , Pedro A. N. Machado , Zahra Tabrizi

The characteristic scale of neutral current, provided by an extension of Standard Model with a local group over the right-handed fermions, determines the smallness of neutrino masses of Dirac kind. The experimental observation of neutrino…

High Energy Physics - Phenomenology · Physics 2007-05-23 V. V. Kiselev

We propose a gauged $U(1)_{B-L}$ version of the light Dirac neutrino portal dark matter. The $U(1)_{B-L}$ symmetry provides a UV completion by naturally accommodating three right handed neutrinos from anomaly cancellation requirements…

High Energy Physics - Phenomenology · Physics 2024-04-10 Nayan Das , Debasish Borah

Neutrino oscillation experiments have provided direct evidence for the existence of neutrino masses. The seesaw mechanism explains the smallness of these masses through the introduction of heavy right-handed neutrino (RHN) states. The RHN…

High Energy Physics - Phenomenology · Physics 2024-09-18 Manimala Mitra , Subham Saha , Michael Spannowsky , Michihisa Takeuchi

The possibility of direct detection of light fermionic dark matter in neutrino detectors is explored from a model-independent standpoint. We consider all operators of dimension six or lower which can contribute to the interaction $\bar{f} p…

High Energy Physics - Phenomenology · Physics 2010-01-07 Jennifer Kile , Amarjit Soni

The possibility of the existence of right-handed neutrinos remains one of the most important open questions in particle physics, as they can help elucidate the problems of neutrino masses, matter-antimatter asymmetry, and dark matter.…

High Energy Physics - Experiment · Physics 2017-04-28 P. Mermod

We point out that the minimal seesaw model can provide a natural framework to accommodate tiny neutrino masses, while its experimental testability and notable predictiveness are still maintained. This possibility is based on the observation…

High Energy Physics - Phenomenology · Physics 2010-05-12 He Zhang , Shun Zhou

We present a scenario of neutrino masses and mixing angles. Each generation includes a sterile right handed neutrino in addition to the usual left handed one. We assume a hierarchy in their Dirac masses similar to, but much larger than the…

High Energy Physics - Phenomenology · Physics 2016-08-24 D. Ring

We explore scenarios where the $R(D^{(*)})$ anomalies arise from semitauonic decays to a right-handed sterile neutrino. We perform an EFT study of all five simplified models capable of generating at tree-level the lowest dimension…

High Energy Physics - Phenomenology · Physics 2019-03-27 Dean J. Robinson , Bibhushan Shakya , Jure Zupan

The measured $B$-meson semi-leptonic branching ratios $R_{D}$ and $R_{D^*}$ have long-standing deviations between theory and experiment. We introduce a model which explains both anomalies through a single interaction by introducing a…

High Energy Physics - Phenomenology · Physics 2019-01-09 Pouya Asadi , Matthew R. Buckley , David Shih

We derive general expressions for the neutrino dispersion relation in a magnetized plasma with a wide range of temperatures, chemical potentials, and magnetic field strengths. If the electron and proton chemical potentials vanish, as in the…

High Energy Physics - Phenomenology · Physics 2009-10-28 Per Elmfors , Dario Grasso , Georg Raffelt

We point out that, for Dirac neutrinos, in addition to the standard thermal cosmic neutrino background (C$\nu$B) there could also exist a non-thermal neutrino background with comparable number density. As the right-handed components are…

High Energy Physics - Phenomenology · Physics 2016-01-08 Mu-Chun Chen , Michael Ratz , Andreas Trautner