Dark Matter as Screened Ordinary Matter

We look at our since long studied model for dark matter as being pearls of a speculated new vacuum containing highly compressed ordinary matter, with so much ordinary in it that the content of ordinary matter in the dark matter pearls dominate. Most dark matter models have the dark matter consisting mainly of new-physics-matter such as WIMPs being supersymmetric partners of possibly known particles or, as in Maxim Khlopovs model, a doubly negatively charged new-physics-particle with a helium nucleus attached. But usually the new-physics matter makes up weight-wise the major content. It is only in our model that the ordinary matter content in the dark matter dominates. We here expose some weak phenomenological evidence that, in truth, dark matter should be of the type with a dominant component of ordinary matter (weight-wise), thus favoring as the typical example our previously so much studied vacuum type 2 model. The main such evidence is that we manage a fit to data in which the 3.5 keV X-rays, presumed to result from dark matter, come both from collisions of dark matter with dark matter and from dark matter with ordinary matter! Both mechanisms are of so similar an order of magnitude that they are both seen, indicating that their similarity is due to a significant similarity between dark with ordinary matter. The fact that the amounts of ordinary and dark matter only deviate by a factor 6 points in the same direction. Using the information obtained from this fitting, we develop our speculation that the main content weight-wise of dark matter is ordinary matter to the very DAMA experiment. Actually we found three spots on the sky in which we fit the observed production of 3.5 keV X-rays with ordinary plus dark scattering.

💡 Research Summary

The authors propose a highly unconventional picture of dark matter: instead of being composed primarily of new particles such as WIMPs or axions, dark matter consists of macroscopic “pearls” that contain ordinary nuclei and electrons trapped inside a new vacuum phase (referred to as vacuum type 2). Within each pearl the ordinary matter is assumed to be strongly electrically screened by a dense electron cloud, so that the nuclei interact only weakly with external charged particles. Consequently, although the pearls are made of ordinary matter, the bulk of the dark‑matter mass is claimed to be ordinary (the ordinary‑to‑dark mass ratio is roughly 6 : 1).

The paper builds its case on four observational pillars:

1. 3.5 keV X‑ray line – The authors fit data from various astrophysical environments and claim that the observed 3.5 keV line can be produced both by dark‑matter–dark‑matter (DM‑DM) collisions and by dark‑matter–ordinary‑matter (DM‑OM) collisions. The two mechanisms apparently give comparable contributions, which the authors interpret as evidence that the two components have similar effective cross‑section‑to‑mass ratios (σ′′/m).

2. Self‑interaction from dwarf galaxies – Using results from Camilla Correa’s analysis of dwarf‑galaxy dynamics, they extract an effective σ′′/m ≈ 0.1 m² kg⁻¹. They argue that this matches the expected DM‑DM scattering of screened nuclei (scnu) inside the pearls, especially after accounting for a quantum‑interference enhancement proportional to the square of the number of constituent nuclei (n²).

3. DAMA/LIBRA annual modulation – The authors suggest that the seasonal signal observed by DAMA/LIBRA arises because pearls are stopped at a depth of about 1400 m in the Earth’s crust. By equating the stopping length L ≈ 1/(σ′′ ρ) with the known depth and a typical rock density (ρ≈3000 kg m⁻³), they infer σ′′ ≈ 2.4 × 10⁶ kg m⁻², which they claim is consistent with the number of screened nuclei per pearl.

4. Energy‑conversion efficiency – Assuming that essentially all kinetic energy of an incoming pearl is converted into 3.5 keV photons, they estimate an efficiency of ~2 × 10⁻⁹. To reconcile this with the observed DAMA rate they argue that elastic DM‑OM scattering must be about 10⁹ times larger than the inelastic (photon‑producing) channel.

Throughout the manuscript the authors use the quantity σ′′/m as a proxy for stopping power, assuming that each screened nucleus scatters independently. They further posit that quantum interference among the many nuclei inside a pearl can amplify the effective cross‑section by factors of n or n², depending on the process.

Despite its originality, the paper suffers from several serious shortcomings:

• Lack of a concrete theoretical framework – The existence of a new vacuum phase with a lower nucleon potential is postulated without any underlying field‑theoretic model, lattice QCD evidence, or cosmological phase‑transition analysis. The required domain‑wall tension (∼MeV³) and its stability are not demonstrated.

• Screening physics is hand‑waved – No quantitative calculation shows how the dense electron cloud suppresses nuclear electromagnetic interactions to the level needed for the pearls to be effectively “dark”. Strong nuclear forces would still dominate intra‑pearl dynamics, potentially leading to observable self‑interaction signatures that conflict with structure‑formation constraints.

• Over‑interpretation of the 3.5 keV line – The claim that DM‑DM and DM‑OM collisions contribute equally is based on a fit with large systematic uncertainties. Current observations do not robustly separate the two channels, and alternative astrophysical explanations (e.g., potassium decay) remain viable.

• Simplistic DAMA stopping‑length argument – Equating the stopping length to the detector depth ignores the distribution of pearl velocities, angular incidence, and the stochastic nature of energy loss. Moreover, existing direct‑detection experiments (XENON, LUX, PandaX) have placed stringent limits on any sizable elastic scattering cross‑section, which the model does not address.

• Missing consistency checks – If pearls contain ordinary nuclei, they should contribute to baryon‑to‑photon ratios, Big‑Bang Nucleosynthesis, and CMB acoustic peaks. The paper does not discuss how the proposed mass fraction (≈85 % ordinary) can be reconciled with these well‑measured cosmological parameters.

In summary, the manuscript introduces an imaginative scenario where dark matter is essentially screened ordinary matter confined in macroscopic objects. While the idea is intriguing and the authors attempt to connect it to several disparate observations, the work lacks a rigorous microscopic description, quantitative predictions, and thorough confrontation with existing astrophysical and laboratory constraints. Future progress would require a solid field‑theoretic model of the new vacuum, detailed calculations of screening and scattering, and a systematic comparison with the full suite of dark‑matter data.