Andrei Linde o perspektywach eksperymentów w fizyce wysokich energii: ... (@Clermont)

Andrei Linde o perspektywach eksperymentów w fizyce wysokich energii:

Cosmology has likewise turned out to be an important source of information for elementary particle theory. The recent rapid development of the latter has resulted in a somewhat unusual situation in that branch of theoretical physics. The reason is that typical elementary particle energies required for a direct test of grand unified theories are of the order of 10^15 GeV, and direct tests of supergravity, Kaluza–Klein theories, and superstring theory require energies of the order of 10^19 GeV. On the other hand, currently planned accelerators will only produce particle beams with energies of about 10^4 GeV. Experts estimate that the largest accelerator that could be built on earth (which has a radius of about 6000 km) would enable us to study particle interactions at energies of the order of 10^7 GeV, which is typically the highest (center-of-mass) energy encountered in cosmic ray experiments. Yet this is twelve orders of magnitude lower than the Planck energy EP ∼ MP ∼ 10^19 GeV.

The difficulties involved in studying interactions at superhigh energies can be highlighted by noting that 10^15 GeV is the kinetic energy of a small car, and 10^19 GeV is the kinetic energy of a medium-sized airplane. Estimates indicate that accelerating particles to energies of the order of 10^15 GeV using present-day technology would require an accelerator approximately one light-year long.

It would be wrong to think, though, that the elementary particle theories currently being developed are totally without experimental foundation — witness the experiments on a huge scale which are under way to detect the decay of the proton, as predicted by grand unified theories. It is also possible that accelerators will enable us to detect some of the lighter particles (with mass m ∼ 10^2 –10^3 GeV) predicted by certain versions of supergravity and superstring theories.

#fizyka #ligamozgow #liganauki #gruparatowaniapoziomu #nauka