What are the differences between the effects of gravity on matter and antimatter? Physicists at the University of California (Riverside city) intend to answer this question. If successful, this would explain why there is no antimatter in the universe and why it is expanding at an ever-increasing rate.
In the laboratory, researchers have taken the first step towards measuring the free fall of "positronium" which consists of a positron and an electron. Positron - is antimaterial version of the electron. It has identical electron mass, but is charged positively. When a positron and electron encounter each other, it is their mutual annihilation with the release of two gamma rays.
Physicists David Cassidy and Allen Mills was the first to separate from the electron and positron create one positronium, the existence of which is sufficient to measure the effect of gravity on it.
"Using lasers we increase the energy of positronium to the Rydberg state, which is characterized by the weakening of bonds of the atom, the electron and positron move away from each other," - said Cassidy. "This prevents their mutual destruction at some period of time during which they can be to conduct experiments."
Rydberg atoms - are atoms in a highly excited state. They are interesting to physicists because many of the properties of atoms in this state are beginning to appear brighter.
In this state, the duration of the existence of positronium become 10-100 times more.
"But this is not enough to achieve our goals," - said Cassidy. "In the near future, we will apply the technique, which gives a high angular momentum Rydberg atoms. Through this, they will be less susceptible to decay and can be up to 10 milliseconds, or 10 000 times longer. This will become acquainted with them."
They will create a beam of these over-excited atoms to study the effect of gravity on it.
"We will study the deflection of the beam as a function of flight time to find out whether its gravity bends" - said Cassidy. "If we find that the behavior of antimatter differs from matter, it is shocking to the physics world. Currently, it is believed that matter and antimatter behave in the same way, except for a few properties such as charge. This premise was the basis of the theory that during the Big Bang formed an equal amount of matter and antimatter. But physicists do not watch a lot of antimatter in the universe, which forced them to seek the differences in their behavior in order to explain this phenomenon. "
Cassidy and Mills will continue to conduct experiments with gravity this summer.