The standard model contains all the secure knowledge in particle physics. It describes the building blocks of matter and the rules that they obey. All matter is composed of quarks and leptons (the electron also belongs to these). The four elementary forces acting between the particles is transmitted from the mediating particles (which are the graviton for gravity, the photon to the electromagnetic force, W and Z bosons for the weak force, the gluon for the strong force). All these particles are 'point', hence the term just means that, even in experiments with the highest resolution, it is not possible to measure effects related to their extension.
The intensity of each of the four fundamental forces is determined by properties of the particles that can be described as generalized charges. In the case of electromagnetism this property is the well-known electrical charge, while in the case of gravitation is the mass. The forces, weak and strong are not part of our daily experience: the concepts of "weak charge" and "color charge" introduced by physicists for these properties are therefore a bit abstract.
These different positions are measured in different units: for example the mass in grams and the electric charge in coulombs. In order to compare the forces, particle physicists use, however, in lieu of charges, dimensionless coupling constants. The larger this constant, the more intense the radiation of the carrier particle, and thus the greater the force.
Is the particle mass mediators to determine essentially how the force depends on the distance (see Yukawa theory): if the mass is zero, as in the case of the photon and the graviton (remember to be the mediating particles, respectively, the electromagnetic force and gravitation), the radius of action of the force is infinite, so we know these forces also by our macroscopic world in everyday life. The so-called W and Z bosons, mediators of the weak force,have a mass one hundred times greater than that of the proton, so the range of the weak force is limited to one hundredth of the diameter of the proton, ie 2x10 ^ -18 meters.
The situation is completely different in the case of the strong force. Though its mediating particles - gluons - are massless, its range is equal only to the radius of the proton (about 10 ^ -15 meters). The value of strong coupling constants is therefore so small that only for distances much less than the radius of the proton, we can use the image of individual particles and solve the equations of quantum chromodynamics (QCD) in the same way already used in QED. For longer distances, the coupling constant, as a result of the interactions with the gluons, carrying the color charge, becomes so great that it is impossible, for example, separate from the others, one of the three quarks that make up the proton. You fail to include the methods of calculation of QCD, and so far have not been able to find satisfactory answers to theoretical questions about the structure of the proton or the confinement of quarks and gluons in the proton. In order to go further we must rely primarily on experimental research, such as those that are conducted in the Hera collider.
"Why quarks and gluons are imprisoned inside the proton?".
The Author:ROBERT KLANNER is a professor of experimental physics at the University of Hamburg in December 1999 and is director of research of Deutsches Elektronen-Synchrotron (DESY) in the same city. At the center of his interests are the development of particle detectors and the investigation of the strong interaction and the structure of hadrons. Before moving to Hamburg in 1984, had already worked with several large accelerators: a Serpuchov (Russia), at Fermilab, near Chicago, and the European Laboratory for Particle Physics (CERN) in Geneva.
Maianni Luciano, La fisica delle particelle, «Le Scienze quaderni» nr. 103, settembre 1998
Rith Klaus e Schäfer Andreas, Il mistero dello spin dei nucleoni, in «Le Scienze» nr. 173, settembre 1999
OPHERA because the title to this post? Because according to the MT the incredible results of the “Opera” experiment conducted by equipe of Professor Antonio Ereditato between CERN and the Gran Sasso underground laboratories are closely related to those obtained in HERA such as in the previous article that ends with the question:”Why do quarks and gluons inside the proton are imprisoned? ".A structure such as a proton, composed of localized particles (quarks) that exchange mass bosons (gluons) can not be stable, because it does not respect the law of conservation of momentum that even at quantum scale is valid and active (see Moessbauer effect). Now three quarks exchanging gluons should not only recoil, but also absorb the momentum of the gluons received and the proton would explode unless an external pressing force, exerted by a physical "material" space, confines quarks. But this kind of action is conceivable, beyond the standard model which provides estimates of point particles, only by adopting a model in which the particles are unlocalized matter waves, such as Louis De Broglie hypothesized."Almost particles" as solitons or dromions (Attilio Maccari: http://www.ejtp.com/articles/ejtpv3i10p39.pdf) that make up perturbations of the same fields whose they belong constituting also the surrounding space. The change in frequency of the waves determines the modulation of the thrust and counter thrust being able to maintain the balance between internal and external. So, for example, when a quark is "ripped" to a proton, internal matter quickly “repairs” itself and restore balance. So neutrinos, rather than exceed the speed of light, could have simply underpass geodesics impressed by gravity to the space-time digging a tunnel through such that kind of space ; in other words, light geodesic wouldn’t minimum distance lines between points. In place of the space - time there would be a normal three-dimensional euclidean space that can be traversed in a tendential straight line which is not to bend space - time, but electromagnetic radiation. On the other hand, excluding statistical and systematic errors, or neutrinos were faster than light (with all the theoretical consequences of the case) or have taken a "shortcut". This would make safe goats (experiment) and cabbage (insuperability of c).But this "short cut", like a tunnel, needs "something real" to be "dug".The Alice experiment conducted at the Large Hadron Collider (LHC) could detect a continuous spectrum of emission/absorption of collisions between protons as a "calling card" of these waves of matter formed by the "almost particles".Taking, then, that until now, the Atlas experiment, also conducted at the LHC, has ruled out the existence of the Higgs boson in a wide range of mass/energy, it can be assumed that, even for the same name field, on the detectors may have a distribution of statistical data more and more 'homogeneous with reduction of the"peaks" with increasing energy, to indicate the presence of mass/energy unlocalized, in place of localized massive vector bosons.