One possible answer to be tested at CERN would be a tiny deviation of antimatter from the mirror-image behavior asserted by standard theory. Antihydrogen is particularly suitable for this test because a certain property of the hydrogen atom is extremely well known.
In the hydrogen atom, an electron revolves around a proton. According to quantum mechanics, the electron can not move on arbitrary orbits around the proton, but only has specific orbits to choose from. The frequency with which the electron changes from the lowest to the highest level under certain conditions is known to within a trillionth of a percent.
The CERN physicists want to compare this frequency with the corresponding frequency in the antihydrogen atom. The accuracy of this comparison should be one to a trillion (a one with 18 zeros). To achieve this accuracy, the temperature of the antihydrogen must be close to absolute zero at minus 273 degrees Celsius. Because you can not just cool antihydrogen for obvious reasons? the electrons and protons of the atoms of the cooling medium would immediately destroy themselves together with the corresponding antiparticles of the antihydrogen? physicists produce antihydrogen even at this low temperature. display
Another experiment planned with antihydrogen is the general relativity test. One wants to know if antihydrogen atoms fall as fast as hydrogen atoms under the influence of gravity. With individual elementary particles such as electrons or positrons, such a test is difficult to carry out because these particles are deflected by the smallest electromagnetic fields due to their electric charge. On the other hand, the (anti) hydrogen atom is neutral to these fields.Axel Tilleman