Mirror Particles Research Articles

Neutrinos confronting large extra dimensions

We study neutrino physics in a model with one large extra dimension. We assume the existence of two four-dimensional branes in the five-dimensional space-time, one for the ordinary particles and the other one for mirror particles, and we investigate neutrino masses and mixings in this scheme. Comparison of experimental neutrino data with the predictions of the model leads to various restrictions on the parameters of the model. For instance, the size of the extra dimension, R, turns out to be bounded from below. Cosmological considerations seem to favor a large R. The usual mixing schemes proposed as solutions to the solar and atmospheric neutrino anomalies are compatible with our model.

Discovering mirror particles at the Large Hadron Collider and the implied cold universe

The Mirror Matter or Exact Parity Model sees every standard particle, including the physical neutral Higgs boson, paired with a parity partner. The unbroken parity symmetry forces the mass eigenstate Higgs bosons to be maximal mixtures of the ordinary and mirror Higgs bosons. Each of these mass eigenstates will therefore decay 50% of the time into invisible mirror particles, providing a clear and interesting signature for the Large Hadron Collider (LHC) which could thus establish the existence of the mirror world. However, for this effect to be observable the mass difference between the two eigenstates must be sufficiently large. In this paper, we study cosmological constraints from Big Bang Nucleosynthesis on the mass difference parameter. We find that the temperature of the radiation dominated (RD) phase of the universe should never have exceeded a few 10's of GeV if the mass difference is to be observable at the LHC. Chaotic inflation with very inefficient reheating provides an example of how such a cosmology could arise. We conclude that the LHC could thus discover the mirror world and simultaneously establish an upper bound on the temperature of the RD phase of the universe.

Cosmic gamma-ray bursts

The properties of the cosmic Gamma-ray Bursts (GRBs) are briefly summarized. A detailed bibliography is given with titles of the papers. Two fundamental theoretical problems are pointed out: the problem of the energy source, and the problem of compactness. I demonstrate some inconsistencies in the estimates of the fireball optical thickness that are widely used in the discussion of the latter problem. The possible connection of GRBs with the Dark Matter candidates is mentioned. I argue that GRBs can be produced by collapses or mergers of stars made of one probable Dark Matter candidate, namely the mirror particles. I speculate on the impact that the parameters of the neutrino oscillations might have on the observed properties of GRBs if the latter are the products of mirror star deaths.

New physics with mirror particles

The introduction of mirror fermions with masses between the weak scale and 1 TeV could offer a dynamical origin to the standard-model electroweak symmetry breaking mechanism. The purpose of this work is to study the dynamics needed in order to render models with such a fermion content phenomenologically acceptable.

Observational Physics of Mirror World

Mirror (shadow) particles are required to restore symmetry between left- and right-handed coordinate systems. If mirror world exists, it has been born at the same time as the ordinary world and has the same evolution (in the case of the shadow world - broken mirror symmetry, the evolution and structure of the shadow world does not correspond with the observed world). Mirror world is a kind of dark matter. According to Bahcall (1984) local dark matter has a density approximately equal to the density of observed (ordinary) matter.

Unification bounds on the possible N = 2 supersymmetry-breaking scale

In this letter, the possible appearance of N=2 supersymmetry at a low energy scale is investigated in the context of unified theories. Introducing mirror particles for all the gauge and matter multiplets of the Minimal Supersymmetric extension of the Standard Model (MSSM), the measured values of sin^2 \theta_W and \alpha_3(M_Z) indicate that the N=2 threshold scale M_{S_2} cannot be lower than \sim 10^{14}GeV. If the U(1) normalization coefficient k is treated as a free parameter, M_{S_2} can be as low as 10^9 GeV. On the other hand, if mirror quarks and leptons are absent and a non-standard value for k is used, N=2 supersymmetry breaking could in principle occur at the electroweak scale.

Depolarization of light backscattered by randomly oriented nonspherical particles

We derive theoretically and validate numerically general relationships for the elements of the backscattering matrix and for the linear, delta(L), and circular, delta(C), backscattering depolarization ratios for nonspherical particles in random orientation. For the practically important case of randomly oriented particles with a plane of symmetry or particles and their mirror particles occurring in equal numbers and in random orientation, delta(C) = 2delta(L)/(1 - delta(L)). Extensive T-matrix computations for randomly oriented spheroids demonstrate that, although both delta(L) and delta(C) are indicators of particle nonsphericity, they cannot be considered a universal measure of the departure of particle shape from that of a sphere and have no simple dependence on particle size and refractive index.

Matter couplings in partially broken extended supersymmetry

We use nonlinear realizations to describe the spontaneous breaking of N = 2 supersymmetry to N = 1 in four dimensions. We identify the Goldstone multiplet with an N = 1 chiral superfield, and show that chiral N = 1 matter is consistent with the partially broken N = 2 supersymmetry. We find that the chiral matter can be in any representation of the gauge group; no mirror particles are required. We present the Goldstone action and the general couplings to N = 1 matter to the first nontrivial order in the scale of symmetry breaking.

Mirror baryons as the dark matter.

A "parallel world" with all of the standard particles, which primarily interacts gravitationally with our world, can be motivated via a symmetry principle designed to make a Lagrangian $\mathrm{CP}$ symmetric, while maintaining a $\mathrm{CP}$ asymmetry in the observable world. Such a symmetry is easily accommodated in grand unified theory models, and may also arise in superstring theories. The cosmological abundance of mirror particles is investigated after a period of chaotic inflation and subsequent reheating. Contrary to previous studies, I find that mirror and ordinary abundances may naturally be similar at the present epoch, and that mirror baryons can provide the closure density without violating nucleosynthesis constraints.

Matter-parity constraints on particle spectrum in three-generation Calabi-Yau manifolds.

An analysis of the particle spectrum after intermediate scale breaking in the three-generation Calabi-Yau manifold CP/sup 3//times/CP/sup 2//Z/sub 3/ is given. The spectrum is investigated within the framework of intermediate scale breaking which preserves matter parity and breaks the rank-six gauge group SU(3)/sub /ital C///times/SU(3)/sub /ital L///times/SU(3)/sub /ital R// to the standard-model gauge group SU(3)/sub /ital C///times/SU(2)/sub /ital L///times/U(1)/sub /ital Y//. It is shown that a large number of particles and mirror particles associated with the extra families and mirror families on CP/sup 3//times/CP/sup 3//Z/sub 3/ can all be made superheavy through mass generation induced by nonrenormalizable interactions that are present in the superpotential below the compactification scale. The final spectrum of the compactified superstring below the intermediate-mass scale breaking is shown to be the spectrum of the standard /ital N/=1 supersymmetry theory and a few additional exotic leptons. Some of these exotic leptons are hybrid structures containing equal mixture of leptons and mirror leptons.

Nucleosynthesis versus the mirror universe

A mirror universe consisting of particles and forces isomorphic to ordinary particles and forces would couple to our universe only through gravity. Hypothetical particles displaying both types of forces would forge an additional link between the two universes. Due to radiative corrections, mirror particles would carry conventional charges of order ϵe {10 −3−10 −6. This seems to offer a possible explanation of the anomalous observed value for the positronium decay rate [3]. However, ϵ<3×10 −8 can be deduced from the successful standard model prediction of the primordial 4He abundance. A mirror-model explanation of the positronium anomaly is thereby ruled out, as is any other observable link to a hypothetical mirror universe.

Softly broken N=4 and E8

Shows that by adding supersymmetry breaking soft terms to N=4 super Yang-Mills, the E8 gauge group can be spontaneously broken to SO10, with the emergence of 4 conventional light generations of 16 plus mirror particles. However, this in only achieved after fine tuning, with further tuning required if a Higgs sector is to appear at low energies.

Positronium versus the mirror universe

A mirror universe of fermions and forces isomorphic to but distinct from those we see couples directly to our universe only by gravity. Particles at any mass scale enjoying both normal and shadow forces forge an electromagnetic link (by radiative corrections) between the two universes such that mirror particles display conventional electric charges 10 −3–10 −5 e. This produces mixing between triplet positronium and its analogous mirror state through a one-photon annihilation diagram. Consequent effects are contrary to experiment. The possible existence of such a mirror universe is thereby excluded.

Low energy constraints on N = 2 supersymmetric models

We derive constraints on the masses of mirror particles in N = 2 supersymmetric theories. We consider the K L−K S mass difference, the π → ev/ π → μv branching ratio and the anomalous magnetic moment of the muon. The K L−K S mass difference gives a lower bound of 15 TeV on the mirror gauge scalar and mirror gauge fermion masses, under suitable assumptions.

Loss of Angular Momentum in Binary System Due to Collisionless Particles as Monopoles, Gravitinos, or Mirror Particles Does It Exceed the Gravitational Radiation Emission in Binary System PSR 1913 + 16?

Loss of Angular Momentum in Binary System Due to Collisionless Particles as Monopoles, Gravitinos, or Mirror Particles Does It Exceed the Gravitational Radiation Emission in Binary System PSR 1913 + 16?

The N = 4 supersymmetric E 8 gauge theory and coset space dimensional reduction

Reasons are given to suggest that the N = 4 supersymmetric E 8 gauge theory be considered as a serious candidate for a physical theory. The symmetries of this theory are broken by a scheme based on coset space dimensional reduction. The resulting theory possesses four conventional generations of low-mass fermions together with their mirror particles.

Grand unification and mirror particles

The grand unification model containing standard and mirror particles is constructed. In models of this kind there exist such strings that a standard particle transforms into a mirror particle in going around the string.

“Heavyphoton” interactions in the SU(7) GUT

The implication of “heavyphoton” interactions in the SU(7) GUT is investigated. Constraints on the “heavyphoton” mass and “ordinary”-“mirror” fermion mixing are obtained from the K L−K S mass difference. The “heavyphoton” could be as light as several GeV without conflicting with the present experiments and as the case might be massless. Characteristics features of “heavyphoton” interactions of mirror particles are also discussed. The “heavyphoton” could be “observed” in mirror particle decays.

The theory of mirror particles

The theory of mirror particles

Possible experiments on search for mirror K° mesons

A possibility to search experimentally for mirror K mesons is discussed. It is shown that, analysing the photographs obtained during the neutrino experiment at CERN, one may put an upper bound for the amplitudes of interactions between the mirror particles and conventional ones. Detection of the K-meson decays, that are not related to stars on photographs, may be an indication to the existence of mirror K mesons.