Physicists have found a way to detect parity violation in molecules

Scientists have developed a method that enables you to record the effects of the violation of spatial parity in molecules. Theoretical calculation and simulation experiment showed that for such measurements with enough sensitivity of existing devices. Work published in the journal Physical Review Research.

According to modern concepts, three of the four fundamental interactions have a spatial symmetry of the equations that describe the system under the action of the forces do not change when changing the signs of all spatial coordinates on the opposite. In other words, if in the first experiment, to follow the reflection of the real system in the mirror, and the second to really display the position of all its parts and to follow the new system, the observations will not differ. This kind of symmetry corresponds to a conservation law of the special values of the spatial parity.

At the same time, the fourth, the weak interaction has the opposite property: the real system is mapped under the action of weak forces is not developing as it makes the reflection of the source system — that is, the parity is not preserved. To understand the mechanisms that underlie such phenomena, experimental data allowing to test theoretical predictions and to build a new model. In particular, great interest parity-violation effects in molecules — large (in comparison with the characteristic radius of action of weak forces) systems that often have a complex set of energy States. Physicists have developed a theoretical description of such phenomena, but to register the parity violation at the molecular level in the experiment still failed.

Physicists from Germany, USA and under the leadership of John Blanchard (John Blanchard) of the German center for the study of heavy ions Helmholtz analyzed one of the possible manifestations of parity-violation in molecules and proposed a method of recording this effect. In the considered scenario, the spatial asymmetry affects the interaction between a pair of atomic nuclei, which is caused by the mutual orientation of their spins. The latter, in turn, are connected with the magnetic properties of matter — thanks to this you can register the desired effect on the characteristic changes in the magnetic field.

Based on theoretical considerations, scientists have determined how the orientation of the two spins under the influence of an alternating electric field. The authors then conducted a computer simulation to connect the 1H,19F, assuming that the scope of such field is polarized sample (with artificially created orderliness in the orientation of the magnetic moments of the nuclei) of the substance.

It turned out that within a certain range of frequencies of the external field the spins of the nuclei in the sample are arranged so that it starts to generate a weak magnetic field. This is due to two processes, only one of which is associated with the parity violation. When this occurs the component of the magnetic field, which corresponds to the mechanism with parity violation, a hundred thousand times weaker components caused by a different phenomenon (10-16 to 10-11 Tesla). This circumstance in the real experiment could lead to the fact that the measured magnetic disturbance will be visible on the background side, however, the authors found a way to avoid the problem. They found that the desired signal will vary with the phase of the oscillations of the electric field — if you change the latter’s direction, change the direction of the weak components of the magnetic field, while the heavy component will remain the same. Thus, a second experiment with the opposite direction of the electric field can effectively separate the weak signal from interference.

Computationally, the researchers found that the registration of the parity-violation effects quite available today, the sensitivity of the magnetometers. The necessary duration of such an experiment is a few hours — during this time the level of accumulated signal must exceed the noise level that will allow you to witness the discovery of the effect. In addition, the proposed method is not only applicable to diatomic molecules like 1H19F same approach can be used to explore more complex connections. However, the authors warn that the real experience will need to consider the possibility of many systematic errors that are associated with the initial magnetization of the sample, adjustment of frequency of the electric field and the direction along which the magnetic field is measured.

Today, physicists are actively searching and other non-standard effects in systems of atoms. Only last month we spoke about the implementation of two similar experiments, scientists were able to create a controlled quantum entanglement between the atom and the molecule and to carry out laser spectroscopy of short-lived radioactive compounds.

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