A scalar-field proposal connects neutrino masses and dark-matter interactions

The preprint by Manoranjan Dutta explores a model that ties together two questions in particle physics: how neutrinos acquire mass, and whether dark-matter particles interact with one another. Its central ingredient is a scalar field that plays a role in both parts of the proposal. The abstract describes a theoretical calculation, not an observation of the new particles or field.

In the model, the scalar’s vacuum expectation value—its value in the lowest-energy state—breaks lepton number at the mega-electronvolt (MeV) scale. Neutrino masses arise through an inverse seesaw, a framework that introduces additional particles and can produce light neutrino masses. The same scalar is proposed as a light mediator: a particle that carries a force between dark-matter particles.

The dark matter is a pseudo-Dirac fermion, meaning it consists of two closely related states with a small mass difference. The abstract says that this splitting arises from the scalar’s vacuum expectation value and is proportional to that value multiplied by the self-interaction coupling. In this model, a strong central interaction between the dark states requires a sizable splitting.

To test whether the model can match astrophysical inferences, the author fixes the dark-matter coupling using the relic abundance—the amount of dark matter left over from the early universe—and calculates scattering using exact partial-wave cross sections. The abstract reports that the predicted interaction varies with particle speed in a way that can reproduce the pattern inferred from dwarf galaxies to clusters, along a narrow band of model parameters. It gives a best-fit example with a dark-matter mass of about 7.6 GeV and a mediator mass of about 15 MeV. At higher masses, the abstract reports resonant regions, or “islands,” with comparable fit quality.

According to the abstract, cluster data set an upper bound on the dark-matter mass within this analysis. The allowed masses extend from about 3 to 70 GeV at 95% confidence, with correlated mediator masses of 6–28 MeV. These ranges describe the model’s allowed parameter space under the authors’ analysis; they are not measurements of dark-matter particles.

The proposal also links the scalar to neutrinos in a way that may be testable. Its decay into neutrinos is predicted to have a rate fixed by neutrino masses and independent of the scalar’s mixing with the Higgs boson. Combining constraints from the effective number of neutrino species, SN 1987A, and direct-detection searches, the author reports that the lepton-number-breaking scale is confined to a window of a few hundred MeV. The abstract also reports a strong preference for normal neutrino mass ordering. It identifies future measurements of the effective number of neutrino species, low-threshold direct detection, and neutrino mass ordering as possible tests of the remaining parameter space.

The results need to be read as conditional theoretical findings. The evidence available here is the preprint abstract, rather than the full paper. That means the detailed data choices, statistical methods, assumptions, and robustness of the fit cannot be assessed from the supplied material. The abstract does not establish that this model is preferred over alternatives, or that the proposed particles exist. Its reported mass ranges and fit describe what the model can accommodate, not a discovery.

The model’s distinctive idea is that a single scalar connects neutrino-mass generation with interactions among separate dark-matter particles. Whether nature follows this proposal remains open. The suggested observations could help test it, but further scrutiny of the full work and independent evidence would be needed to assess the claims.