فيزياء الجسيمات الاولية

The four fundamental forces of nature are the electromagnetic force, the strong force, the weak force and the gravitational force. The non-gravitational forces are described by quantum Yang-Mills field theories on a flat Minkowski four dimensional spacetime and they are unified in the standard model of particle physics.

Particle physics also called high energy physics is a major branch of physics which studies elementary constituent of matter and their interactions. Here we mean by elementary particles those particles which are not bound states of other more elementary particles such as the electron and the photon. The proton for example is not an elementary particle but a bound state of more elementary particles known as quarks.

Matter within the standard model is described by spinorial fields with the exception of the scalar Higgs particle which is not discovered yet. Forces (corresponding to radiations) are described by vector gauge fields. They are mediated by gauge bosons which are the photon (electromagnetic), the gluons (strong) and the W^+,W^- and Z^0 (weak). Electromagnetic and weak interactions are unified within the electroweak theory with the symmetry between them  only spontaneously broken via the Higgs. The strong force is described by quantum chromodynamics or QCD. The unification of the electroweak theory and QCD is the standard model.

Gravity can be unified with the other  forces only within the context of string theory which is not a field theory. Classical gravitation is described by general relativity. Modern cosmology is based on the combination of the principles of general relativity and particle physics and is sumarized in the so-called standard model of cosmology. The most important problems of cosmology are dark matter and dark energy. The fundamental solutions of these problems  will lie at the end within the theory of quantum gravity. The only known successful theory of quantum gravity is again given by string theory under the name of M-theory. This is supposed/claimed to be a theory of everything.

Some of the ingredients of string theory are supersymmetry (which the LHC particle accelerator is  currently aiming  at discovering with the Higgs particle of the standard model), Kaluza-Klein extra dimensions, conformal field theory, Yang-Mills gauge theories and Riemann surfaces together with a lot of pure mathematics. I can safely claim that this is the most challenging subject that one can study in theoretical physics at this current point of history.

1 comment:

  1. هل من الممكن د باديس الحصول على تكميم للجاذبية عند طاقات عالية جدا فى المسرعات هل هذا احد تنبؤات نظرية الأتار ؟