mercoledì 14 settembre 2011

Standard Model and Fundamental Forces: Look at the recoil !

Since the eighties of the twentieth century, many theorists have focused on defining a quantum theory which would reconcile quantum mechanics and general relativity and explain clearly the existence of four families of particles, intermediate bosons and gravity.
In the Standard Model there are three types of bosons: photons, gluons and so-called "weak bosons", namely the W and Z bosons (also called more precisely "intermediate vector bosons W and Z"). These three types of bosons are responsible, respectively, for the electromagnetic force, the strong nuclear force and the weak nuclear force. Photons are Gauge bosons of electromagnetic interactions (electromagnetic force), the gluons those ones of the strong interaction (strong force), and W and Z are the bosons of weak interactions (weak force). In particle physics, the Gauge bosons are elementary particles that have the task of transporting the fundamental forces of nature. In particular, the elementary particles whose interactions are described by Gauge theories exert forces on each other particle through the exchange of Gauge bosons.The theory of general relativity by Albert Einstein described the gravitational field in geometric terms (using the notion of spacetime curvature). However, it does not tell us anything about the particle mediating the gravitational force, the so-called gravitons.The quantum gravity is that field of theoretical physics that attempts to unify the field theory (relativistic quantum mechanics), which describes three of the fundamental forces of nature (electromagnetic, weak and strong), with the theory of general relativity, on the fourth fundamental interaction that is gravity. At a theoretical level, all the simple Gauge bosons must be massless and the forces that they describe must be a long haul. The contradiction between this theory and experimental evidence, regarding the short range of weak interactions, require further theoretical and at present a justification of this comes from the Higgs mechanism. This process leads to massive Gauge bosons from initially massless particles..The ultimate goal of some theories in this field (such as string theory), is also to get a unique structure for all four fundamental forces and then to build a theory of everything.

But a theory that do arise the fundamental forces between elementary particles by the exchange of massive bosons, although formally correct from the mathematical point of view, is itself inconsistent from the physical point of view because it clearly violates the principle of conservation of momentum that at quantum scales, is a physical law experimentally evident.

For example, the Mössbauer spectroscopy is a spectroscopic technique based on the absorption and emission of resonant gamma rays in solids.With gamma rays, unlike other less energetic photons, there is usually a problem: the atom emitting a photon recoils in a non-negligible way, thus absorbing a slice of energy from the same photon which, consequently, doesen’t have the same frequency as before and is not able to make similar resonance with another atom. As the first solution to this problem was obtained by placing the substance emitting over an high speed rotating cylinder so as to compensate the before mentioned recoil.But then the resonant absorption and emission were observed for the first time by Rudolf Mössbauer in 1957 on materials that had a crystalline structure such as to distribute the same recoil on many more atoms thus reducing loss of the photon energy range: this phenomenon has been precisely known as “Mössbauer effect”.
The above is to reaffirm the notion that, until proven otherwise, the law of conservation of momentum is valid and working among the elementary particles of the Standard Model.

Structure of the proton : Strong nuclear force.


Each quark has a color charge moving constantly changing gluons to other quarks. Such sharing of gluons generates attractive field which opposes the electrodynamic repulsion forces.

It remains then to understand how can be stable this kind of structure, or how can develop attractive forces between elementary particles that are exchanged massive particles (the gluons in this case).

Is the particle mass mediators, in fact, to determine the range of interaction, with which is compared to a ratio of inverse proportionality (see Yukawa theory), range that, in the case of the strong force is extremely short. So if the rest mass of gluons be void, as in the case of the photon and the graviton (mediators, respectively, of electromagnetic force and gravitation), the radius of action of the force would be infinite.

Then, "confinement" of quarks is physically possible only assuming that they are "relocated" as matter waves, according to Loise De Broglie's hypotesis, the interaction with mediators replacing that of a quantum field in turn consists of matter waves in which the quarks are "immersed" acting also from the outside.

This is why the creator of the MT, Marius, believes that only by replacing a model wave-particle of matter to that proposed by the Standard Model could be explained the attractive forces (including, of course, the gravity force) as well as repulsive.

Stefano Gusman

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