Prospects for ElementaryParticle Physics
The
October 25, 2006
1 Present Status of ElementaryParticle Physics
In the second half of the twentieth century, remarkable progress was made in particle physics
both experimentally and theoretically, which led to the development of the Standard Model of
elementary particles. According to the Standard Model, quarks and leptons are the fundamental
constituents of matter. They interact with each other by four kinds of fundamental forces; three
of them are governed by the gauge principle in the Standard Model. The Standard Model has
been tested by many experiments with high precision, and its success has become increasingly
firm. Nonetheless, the Higgs particle, which is the origin of the mechanism to generate particle
masses, has not been discovered yet. Thus one of the pillars of the Standard Model is still missing
and awaits experimental confirmation.
In addition, the Standard Model does not unify the three forces mentioned above, and does
not even include gravity. Furthermore, it cannot explain why there are three generations and
twelve kinds of quarks and leptons, why they have different masses, and why mixing between
different generations occurs. We are thus convinced that the Standard Model is not the ultimate
theory of particle physics. We now face the challenge of finding a new direction in particle physics
beyond the Standard Model.
Turning to astrophysical observations, we now confront the astonishing fact that known
particles, which form ordinary matter, account for only 4% of the total energy density of the
Universe. All the rest consists of dark matter (23%) and dark energy (73%), which are not yet
identified in terms of particle physics. It is likely that dark matter consists of weakly interacting
particles that were created in the early Universe and survived until now. These particles were
attracted toward each other by gravity and became seed galaxies. Dark energy is carried by
the vacuum and is responsible for the accelerating expansion of the Universe. Dark energy
corresponds to the cosmological constant that was introduced by Einstein into the fundamental
equation of general relativity. Both dark matter and dark energy should be explained in terms
of particle physics in the future.
ادامه مطلب
In the center of our research work is located the theoretical investigation of the characteristics (e.g. masses, couplings, discrete symmetry characteristics, total and partial decay widths etc..) of elementary particles and their connection conditions (e.g. Positronium, corpse, D and b-b-Mesonen, Charmonium, Bottomonium etc..) as well as their reciprocal effects during impact processes with high energies (e.g. electron positron destruction, lepton nucleon -, nucleon nucleon and photon photon dispersion etc..) in the context of the standard model and its extensions (e.g. fourth fermion generation, supersymmetry, models with Majorananeutrinos or other exotic leptons, scenarios without Higgsbosonen, effective theories with abnormal couplings etc.). The high accuracy of final, current and planned experiments of particle physics makes the inclusion of quantum corrections indispensable in many cases into the theoretical forecasts.
ادامه مطلب
Elementary Particles, in physics, particles that cannot be broken down into any other particles. The term elementary particles also is used more loosely to include some subatomic particles that are composed of other particles. Particles that cannot be broken further are sometimes called fundamental particles to avoid confusion. These fundamental particles provide the basic units that make up all matter and energy in the universe.
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