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In recent years it has become clear that despite the great success of
describing a wide range of the currently known elementary particles, the
standard model requires further clarification considering the discovery of
symmetry breaking effects of time (
T
) reversal at small distances. Thereby,
the theory predicts that the phason rest mass must be different from
zero. Thus, the conclusion is made about existence of the elementary
particles with extremely small but finite rest mass [8–11]. Axions can
be the examples of such particles [1]. The axion rest mass is expected
to correspond to the energy range of 0.001. . . of 1.0 meV, i.e., it must be
considerably less than the rest mass of all known elementary particles.
Axions are pseudo-scalar particles, i.e. their wave function changes the
sign under inversion and mirror reflections of space.
The current trend in modern physics is also associated with predicting
the presence of the dark matter in the Universe (total share is 0.23) and the
dark energy (total share is 0.73).
Recently a hypothesis has been put forward based on astrophysical
data [12–17] that the axions, which are pseudo-scalar particles with the
extremely low rest mass and relativistic law of dispersion, can be contenders
for the role of dark matter particles.
“Cold” (slow) axions are nonrelativistic (Newtonian) particles. They
can turn into the state of Bose-Einstein condensate in case of having
a density high enough to perform it. “Hot” (fast) axions are relativistic
particles and move at speeds close to the speed of light. An important
property of these particles is their hyperweak interaction with the material
media, this property being similar to neutrino’s. According to the estimates
based on astrophysical data, the equilibrium concentration of axions in our
part of the Galaxy is about
10
−
24
g/сm
3
. With this concentration, due to the
extremely low rest mass of axions, the Bose-Einstein condensation must
occur, even at room temperature.
Some papers discussed the problem of detecting and generating axions
in the laboratory [12–17]. The possibilities of realization of photon-
axion conversion processes are being analyzed along with the inverse
processes that are allowed by the selection rules in the presence of a strong
external magnetic field. The two effects are being studied: 1) generation of
“hot” axions during the photon conversion of the laser or x-ray radiation
into the axions of the same energy; 2) detection of “cold” (Newtonian)
axions in their conversion into microwave range photons. Only the first
experimental results have recently been obtained in these areas that
require optimization of the observation conditions and finding ways to
strengthen the effectiveness of the processes being discussed to find a
reliable interpretation of the obtained experimental results.
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ISSN 1812-3368. Herald of the BMSTU. Series “Natural Sciences”. 2014. No. 6