[Paper Review] Seven (and a half) reasons to believe in Mirror Matter: From neutrino puzzles to the inferred Dark matter in the Universe

R. Foot|ArXiv.org|Feb 16, 2001

Dark Matter and Cosmic Phenomena3 citations

TL;DR

This paper proposes that mirror matter—hypothetical particles symmetric to ordinary matter under parity—could resolve multiple unresolved puzzles in particle physics and cosmology. It argues that mirror matter explains dark matter, neutrino oscillations, orthopositronium lifetime anomalies, and anomalous meteor events, with four key testable predictions, including 50% reduced Higgs decay rates if the Higgs sector mixes with its mirror counterpart.

ABSTRACT

Parity and time reversal are obvious and plausible candidates for fundamental symmetries of nature. Hypothesising that these symmetries exist implies the existence of a new form of matter, called mirror matter. The mirror matter theory (or exact parity model) makes four main predictions: 1) Dark matter in the form of mirror matter should exist in the Universe (i.e. mirror galaxies, stars, planets, meteoroids...), 2) Maximal ordinary neutrino - mirror neutrino oscillations if neutrinos have mass, 3) Orthopositronium should have a shorter effective lifetime than predicted by QED (in "vacuum" experiments) because of the effects of photon-mirror photon mixing and 4) Higgs production and decay rate should be 50% lower than in the standard model due to Higgs mirror - Higgs mixing (assuming that the seperation of the Higgs masses is larger than their decay widths). At the present time there is strong experimental/observational evidence supporting the first three of these predictions, while the fourth one is not tested yet because the Higgs boson, predicted in the standard model of particle physics, is yet to be found. This experimental/observational evidence is rich and varied ranging from the atmospheric and solar neutrino deficits, MACHO gravitational microlensing events, strange properties of extra-solar planets, the existence of "isolated" planets, orthopositronium lifetime anomaly, Tunguska and other strange "meteor" events including perhaps, the origin of the moon. The purpose of this article is to provide a not too technical review of these ideas along with some new results.

Motivation & Objective

• To propose mirror matter as a solution to unresolved issues in particle physics and cosmology, including neutrino oscillations and dark matter.
• To argue that parity and time reversal symmetries, though broken in observed interactions, may be fundamental if mirror matter exists.
• To unify disparate phenomena—neutrino deficits, microlensing, anomalous meteors, and orthopositronium decay—under a single theoretical framework.
• To present testable predictions of the mirror matter theory, particularly regarding Higgs physics and neutrino mixing.
• To motivate experimental and observational searches for mirror matter through accumulated indirect evidence.

Proposed method

• Postulate a parity-invariant extension of the Standard Model with a doubled gauge group: $G \otimes G$, where $G = SU(3) \otimes SU(2)_L \otimes U(1)_Y$.
• Introduce mirror fermions and mirror gauge bosons that are singlets under the ordinary gauge group, ensuring weakly coupled interactions with ordinary matter.
• Implement photon-mirror photon kinetic mixing to explain deviations in orthopositronium lifetime.
• Model Higgs-mirror Higgs mixing to predict a 50% reduction in Higgs production and decay rates compared to the Standard Model.
• Use maximal ordinary-mirror neutrino oscillations as a prediction if neutrinos are massive and non-degenerate.
• Analyze observational data—such as MACHO microlensing, Tunguska-like events, and exoplanet anomalies—within the mirror matter framework.

Experimental results

Research questions

• RQ1 Can mirror matter explain the observed atmospheric and solar neutrino deficits through maximal oscillations between ordinary and mirror neutrinos?
• RQ2 Does the anomalous shortening of orthopositronium’s effective lifetime in vacuum experiments provide evidence for photon-mirror photon mixing?
• RQ3 Can mirror matter account for the dark matter inferred from gravitational microlensing and galactic rotation curves?
• RQ4 Is the 50% reduction in Higgs production and decay rates a viable prediction of Higgs-mirror Higgs mixing, and how can it be tested?
• RQ5 Can mirror matter explain the absence of impact craters in events like the Tunguska explosion and the existence of isolated or 'disappearing' meteors?

Key findings

• Mirror matter provides a natural explanation for dark matter, with mirror galaxies, stars, and planets potentially existing undetected due to weak coupling to ordinary matter.
• If neutrinos have mass and are non-degenerate, maximal oscillations between ordinary and mirror neutrinos are predicted, consistent with solar and atmospheric neutrino data.
• Orthopositronium’s effective lifetime is predicted to be shorter than in QED due to photon-mirror photon kinetic mixing, offering a testable signature.
• Higgs production and decay rates are predicted to be 50% lower than in the Standard Model due to Higgs-mirror Higgs mixing, though this remains untested due to the Higgs boson’s non-discovery at the time.
• Anomalous meteor events, such as the Tunguska explosion, may result from collisions with mirror matter bodies that do not leave craters or fragments.
• The origin of the Moon may be explained by a mirror matter impact, which would leave no detectable chemical signature, resolving the compositional similarity between Earth’s mantle and the Moon.