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Fundamental particle with electric charge. fundamental particle
ON UNDERSTANDING THE MOVEMENT OF MATTER, ITS ABILITY FOR SELF-DEVELOPMENT, AS WELL AS CONNECTION AND INTERACTION OF MATERIAL OBJECTS IN MODERN NATURAL SCIENCE Tsyupka V.P. Federal State Autonomous Educational Institution of Higher Professional Education "Belgorod State National Research University" (NRU "BelSU")
1. Movement of matter
“An integral property of matter is movement” 1 , which is a form of existence of matter and manifests itself in any of its changes. From the indestructibility and indestructibility of matter and its attributes, including motion, it follows that the motion of matter exists forever and is infinitely diverse in the form of its manifestations. The existence of any material object is manifested in its movement, i.e., in any change that occurs with it. In the course of change, some properties of a material object always change. Since the totality of all the properties of a material object, which characterizes its certainty, individuality, feature at a particular moment in time, corresponds to its state, it turns out that the movement of a material object is accompanied by a change in its states. Changing properties can go so far that one material object can become another material object. “But a material object can never turn into a property” (for example, mass, energy), and “property - into a material object” 2, because only moving matter can be a changing substance. In natural science, the movement of matter is also called a natural phenomenon (natural phenomenon). It is known that “without motion there is no matter” 3 as well as without matter there can be no motion. The motion of matter can be expressed quantitatively. The universal quantitative measure of the motion of matter, as well as of any material object, is energy, which expresses the own activity of matter and any material object. Hence, energy is one of the properties of moving matter, and energy cannot be outside matter, separate from it. Energy is in an equivalent relationship with mass. Therefore, the mass can characterize not only the amount of a substance, but also the degree of its activity. From the fact that the motion of matter exists forever and is infinitely diverse in the form of its manifestations, it inexorably follows that the energy characterizing the motion of matter quantitatively also exists eternally (uncreated and indestructible) and infinitely diverse in the form of its manifestations. "Thus, energy never disappears and does not appear again, it only changes from one form to another" 1 in accordance with the change in the types of movement. Various types (forms) of motion of matter are observed. They can be classified taking into account changes in the properties of material objects and the characteristics of their impact on each other. The movement of the physical vacuum (free fundamental fields in the normal state) is reduced to the fact that it all the time slightly deviates in different directions from its equilibrium, as if “trembling”. As a result of such spontaneous low-energy excitations (deviations, perturbations, fluctuations), virtual particles are formed, which immediately dissolve in the physical vacuum. This is the lowest (basic) energy state of the moving physical vacuum, its energy is close to zero. But the physical vacuum can for some time in some place go into an excited state, characterized by a certain excess of energy. With such significant, high-energy excitations (deviations, perturbations, fluctuations) of the physical vacuum, virtual particles can complete their appearance and then real fundamental particles of various types break out of the physical vacuum, and, as a rule, in pairs (having an electric charge in the form of a particle and an antiparticle with electric charges of opposite signs, for example, in the form of an electron-positron pair). Single quantum excitations of various free fundamental fields are fundamental particles. Fermionic (spinor) fundamental fields can give rise to 24 fermions (6 quarks and 6 antiquarks, as well as 6 leptons and 6 antileptons), which are divided into three generations (families). In the first generation, up and down quarks (and antiquarks), as well as leptons, an electron and an electron neutrino (and a positron with an electron antineutrino), form ordinary matter (and rarely found antimatter). In the second generation, the charmed and strange quarks (and antiquarks), as well as leptons, the muon and the muon neutrino (and the antimuon with the muon antineutrino), have a greater mass (greater gravitational charge). In the third generation, true and lovely quarks (and antiquarks), as well as leptons taon and taon neutrino (and antitaon with taon antineutrino). Fermions of the second and third generations do not participate in the formation of ordinary matter, are unstable and decay with the formation of first generation fermions. Bosonic (gauge) fundamental fields can generate 18 types of bosons: gravitational field - gravitons, electromagnetic field - photons, weak interaction field - 3 types of "vions" 1 , gluon field - 8 types of gluons, Higgs field - 5 types of Higgs bosons. The physical vacuum in a sufficiently high-energy (excited) state is capable of generating many fundamental particles with significant energy, in the form of a mini-universe. For the substance of the microcosm, the movement is reduced: to distribution, collision and transformation into each other of elementary particles; the formation of atomic nuclei from protons and neutrons, their movement, collision and change; the formation of atoms from atomic nuclei and electrons, their movement, collision and change, including the jumping of electrons from one atomic orbital to another and their separation from atoms, the addition of excess electrons; the formation of molecules from atoms, their movement, collision and change, including the addition of new atoms, the release of atoms, the replacement of one atom by another, a change in the arrangement of atoms relative to each other in a molecule.
For the substance of the macrocosm and the megaworld, movement is reduced to displacement, collision, deformation, destruction, unification of various bodies, as well as to their most diverse changes. If the movement of a material object (a quantized field or a material object) is accompanied by a change only in its physical properties, for example, frequency or wavelength for a quantized field, instantaneous speed, temperature, electric charge for a material object, then such movement is referred to as a physical form. If the movement of a material object is accompanied by a change in its chemical properties, for example, solubility, combustibility, acidity, then such movement is referred to as a chemical form. If the movement concerns the change of objects of the mega-world (cosmic objects), then such movement is referred to as an astronomical form. If the movement concerns a change in the objects of the deep earth shells (earth interior), then such movement is referred to as a geological form. If the movement concerns a change in the objects of the geographical shell that unites all surface earthly shells, then such movement is referred to as a geographical form. The movement of living bodies and their systems in the form of their various vital manifestations is referred to as a biological form. The movement of material objects, accompanied by a change in socially significant properties with the obligatory participation of a person, for example, the extraction of iron ore and the production of iron and steel, the cultivation of sugar beets and the production of sugar, is referred to as a socially determined form of movement. The movement of any material object cannot always be attributed to any one form. It is complex and varied. Even the physical movement inherent in material objects from a quantized field to bodies can include several forms. For example, the elastic collision (collision) of two solid bodies in the form of billiard balls includes both the change in the position of the balls over time relative to each other and the table, and the rotation of the balls, and the friction of the balls on the surface of the table and air, and the movement of the particles of each ball, and practically reversible change in the shape of the balls during elastic collision, and the exchange of kinetic energy with its partial conversion into the internal energy of the balls during elastic collision, and the transfer of heat between the balls, air and the surface of the table, and the possible radioactive decay of the nuclei contained in the balls of unstable isotopes, and the penetration of neutrinos cosmic rays through balls, etc. With the development of matter and the emergence of chemical, astronomical, geological, geographical, biological and socially conditioned material objects, the forms of motion become more complex and more diverse. Thus, in chemical motion one can see both physical forms of motion and qualitatively new, not reducible to physical, chemical forms. In the movement of astronomical, geological, geographical, biological and socially conditioned objects, one can see both physical and chemical forms of movement, as well as qualitatively new, not reducible to physical and chemical, respectively astronomical, geological, geographical, biological or socially conditioned forms of movement. At the same time, the lower forms of the motion of matter do not differ in material objects of varying degrees of complexity. For example, the physical movement of elementary particles, atomic nuclei and atoms does not differ in astronomical, geological, geographical, biological or socially conditioned material objects. In the study of complex forms of movement, two extremes must be avoided. First, the study of a complex form of movement cannot be reduced to simple forms of movement; a complex form of movement cannot be derived from simple ones. For example, biological motion cannot be derived solely from the physical and chemical forms of motion, while ignoring the biological forms of motion themselves. And secondly, one cannot limit oneself to studying only complex forms of movement, ignoring simple ones. For example, the study of biological movement is a good complement to the study of the physical and chemical forms of movement that are manifested in this case.
2. The ability of matter to self-development
As is known, self-development of matter, and matter is capable of self-development, is characterized by spontaneous, directed and irreversible gradual complication of the forms of moving matter. The spontaneous self-development of matter means that the process of gradual complication of the forms of moving matter occurs by itself, naturally, without the participation of any unnatural or supernatural forces, the Creator, due to internal, natural causes. The direction of the self-development of matter means a kind of canalization of the process of gradual complication of the forms of moving matter from one of its forms that existed earlier to another form that appeared later: for any new form of moving matter, you can find the previous form of moving matter, which gave it a start, and vice versa, for any previous form of moving matter, you can find a new form of moving matter that has arisen from it. At the same time, the previous form of moving matter always existed before the new form of moving matter that arose from it, the previous form is always older than the new form that arose from it. Due to the canalization of the self-development of moving matter, peculiar series of gradual complication of its forms arise, showing in which direction, and also through which intermediate (transitional) forms, the historical development of one or another form of moving matter proceeded. The irreversibility of the self-development of matter means that the process of gradual complication of the forms of moving matter cannot go in the opposite direction, backwards: a new form of moving matter cannot give rise to the form of moving matter that preceded it, from which it arose, but it can become the previous form for new forms. And if suddenly some new form of moving matter turns out to be very similar to one of the forms that preceded it, then this will not mean that the moving matter began to self-develop in the opposite direction: the previous form of moving matter appeared much earlier, and the new form of moving matter, even and very similar to it, appeared much later and is, although similar, but a fundamentally different form of moving matter.
3. Communication and interaction of material objects
The integral properties of matter are communication and interaction, which are the cause of its movement. Since connection and interaction are the cause of the movement of matter, therefore connection and interaction, like movement, are universal, i.e. inherent in all material objects, regardless of their nature, origin and complexity. All phenomena in the material world are determined (in the sense of being conditioned) by natural material connections and interactions, as well as by objective laws of nature, reflecting the laws of connection and interaction. “In this sense, there is nothing supernatural and absolutely opposed to matter in the world.” 1 Interaction, like movement, is a form of being (existence) of matter. The existence of all material objects manifests itself in interaction. For any material “object, to exist means to somehow manifest itself in relation to other material objects, interacting with them, being in objective connections and relations with them. If a hypothetical material “object that would not manifest itself in any way in relation to some other material objects, would not be associated with them in any way, would not interact with them, then it would not exist for these other material objects. “But our assumption about him also could not be based on anything, since due to the lack of interaction we would have zero information about him.” 2 Interaction is a process of mutual influence of some material objects on others with the exchange of energy. The interaction of real objects can be direct, for example, in the form of a collision (collision) of two rigid bodies. And it can happen at a distance. In this case, the interaction of real objects is provided by the bosonic (gauge) fundamental fields associated with them. A change in one material object causes excitation (deviation, perturbation, fluctuation) of the corresponding bosonic (gauge) fundamental field associated with it, and this excitation propagates in the form of a wave with a finite speed not exceeding the speed of light in vacuum (almost 300 thousand km / With). The interaction of real objects at a distance, according to the quantum-field mechanism of interaction transfer, is of an exchange nature, since the interaction is transferred by carrier particles in the form of quanta of the corresponding bosonic (gauge) fundamental field. Different bosons as interaction carrier particles are excitations (deviations, perturbations, fluctuations) of the corresponding bosonic (gauge) fundamental fields: during the emission and absorption of a material object, they are real, and during propagation they are virtual. It turns out that in any case, the interaction of material objects, even at a distance, is a short-range action, since it is carried out without any gaps, voids. The interaction of a particle with an antiparticle of matter is accompanied by their annihilation, i.e., their transformation into the corresponding fermionic (spinor) fundamental field. In this case, their mass (gravitational energy) is converted into the energy of the corresponding fermionic (spinor) fundamental field. Virtual particles of the excited (deflecting, perturbing, "trembling") physical vacuum can interact with real particles, as if enveloping them, accompanying them in the form of the so-called quantum foam. For example, as a result of the interaction of the electrons of an atom with virtual particles of the physical vacuum, a certain shift of their energy levels in atoms occurs, while the electrons themselves perform oscillatory motions with a small amplitude. There are four types of fundamental interactions: gravitational, electromagnetic, weak and strong. "The gravitational interaction is manifested in the mutual attraction ... of material objects having a mass" 1 of rest, i.e., material objects, at any large distances. It is assumed that the excited physical vacuum, which generates many fundamental particles, is capable of manifestation of gravitational repulsion. The gravitational interaction is carried by the gravitons of the gravitational field. The gravitational field connects bodies and particles with rest mass. No medium is required for the propagation of a gravitational field in the form of gravitational waves (virtual gravitons). The gravitational interaction is the weakest in its strength, therefore it is insignificant in the microcosm due to the insignificance of the masses of particles, in the macrocosm its manifestation is noticeable and it causes, for example, the fall of bodies to the Earth, and in the megaworld it plays a leading role due to the huge masses of the bodies of the megaworld and it provides, for example, the rotation of the Moon and artificial satellites around the Earth; the formation and movement of planets, planetoids, comets and other bodies in the solar system and its integrity; the formation and movement of stars in galaxies - giant star systems, including up to hundreds of billions of stars, connected by mutual gravitation and a common origin, as well as their integrity; the integrity of clusters of galaxies - systems of relatively closely spaced galaxies connected by gravitational forces; the integrity of the Metagalaxy - a system of all known clusters of galaxies, connected by gravitational forces, as a studied part of the Universe, the integrity of the entire Universe. The gravitational interaction determines the concentration of matter scattered in the Universe and its inclusion in new cycles of development. "Electromagnetic interaction is due to electric charges and is transmitted" 1 by photons of the electromagnetic field over any large distances. An electromagnetic field connects bodies and particles that have electric charges. Moreover, stationary electric charges are connected only by the electric component of the electromagnetic field in the form of an electric field, and mobile electric charges are connected by both the electric and magnetic components of the electromagnetic field. For the propagation of an electromagnetic field in the form of electromagnetic waves, no additional medium is required, since "a changing magnetic field generates an alternating electric field, which, in turn, is a source of an alternating magnetic field" 2 . “Electromagnetic interaction can manifest itself both as attraction (between opposite charges) and as repulsion (between” 3 similar charges). The electromagnetic interaction is much stronger than the gravitational one. It manifests itself both in the microcosm, and in the macrocosm and megaworld, but the leading role belongs to it in the macrocosm. Electromagnetic interaction ensures the interaction of electrons with nuclei. Interatomic and intermolecular interaction is electromagnetic, thanks to it, for example, there are molecules and the chemical form of the movement of matter is carried out, bodies exist and their states of aggregation, elasticity, friction, surface tension of a liquid are determined, vision functions. Thus, electromagnetic interaction ensures the stability of atoms, molecules and macroscopic bodies. The weak interaction involves elementary particles having a rest mass, it is carried by "vions" of 4 gauge fields. Fields of weak interaction bind various elementary particles with a rest mass. The weak interaction is much weaker than the electromagnetic one, but stronger than the gravitational one. Due to its short action, it manifests itself only in the microcosm, causing, for example, most of the self-decays of elementary particles (for example, a free neutron self-decays with the participation of a negatively charged gauge boson into a proton, an electron and an electron antineutrino, sometimes another photon is formed), the interaction of a neutrino with the rest of the substance. Strong interaction manifests itself in the mutual attraction of hadrons, which include quark structures, for example, two-quark mesons and three-quark nucleons. It is transmitted by gluons of gluon fields. Gluon fields bind hadrons. This is the strongest interaction, but due to its short action it manifests itself only in the microcosm, providing, for example, the bonding of quarks in nucleons, the bonding of nucleons in atomic nuclei, ensuring their stability. The strong interaction is 1000 times stronger than the electromagnetic one and does not allow like-charged protons united in the nucleus to scatter. Thermonuclear reactions, in which several nuclei combine into one, are also possible due to the strong interaction. Natural thermonuclear reactors are stars that create all chemical elements heavier than hydrogen. Heavy multinucleon nuclei become unstable and fission, because their dimensions already exceed the distance at which the strong interaction manifests itself. "As a result of experimental studies of the interactions of elementary particles ... it was found that at high proton collision energies - about 100 GeV - ... the weak and electromagnetic interactions do not differ - they can be considered as a single electroweak interaction." 1 It is assumed that “at an energy of 10 15 GeV, a strong interaction joins them, and at” 2 even “higher interaction energies of particles (up to 10 19 GeV) or at an extremely high temperature of matter, all four fundamental interactions are characterized by the same strength, i.e. represent one interaction” 3 in the form of a “superpower”. Perhaps such high-energy conditions existed at the beginning of the development of the Universe that emerged from the physical vacuum. In the process of further expansion of the Universe, accompanied by a rapid cooling of the formed matter, the integral interaction was first divided into electroweak, gravitational and strong, and then the electroweak interaction was divided into electromagnetic and weak, i.e., into four interactions fundamentally different from each other.
BIBLIOGRAPHY:
Karpenkov, S.Kh. Basic concepts of natural science [Text]: textbook. allowance for universities / S. Kh. Karpenkov. - 2nd ed., revised. and additional - M. : Academic Project, 2002. - 368 p. Concepts of modern natural science [Text]: textbook. for universities / Ed. V. N. Lavrinenko, V. P. Ratnikova. - 3rd ed., revised. and additional - M. : UNITI-DANA, 2005. - 317 p. Philosophical problems of natural science [Text]: textbook. allowance for graduate students and students of philosophy. and natures. fak. un-tov / Ed. S. T. Melyukhina. - M. : Higher School, 1985. - 400 p. Tsyupka, V.P. Natural science picture of the world: concepts of modern natural science [Text]: textbook. allowance / V. P. Tsyupka. - Belgorod: IPK NRU "BelGU", 2012. - 144 p. Tsyupka, V.P. Concepts of modern physics, constituting the modern physical picture of the world [Electronic resource] // Scientific electronic archive of the Russian Academy of Natural Sciences: correspondence courses. electron. scientific conf. "Concepts of modern natural science or natural science picture of the world" URL: http://site/article/6315(posted: 10/31/2011) Yandex. Dictionaries. [Electronic resource] URL: http://slovari.yandex.ru/ 1Karpenkov S. Kh. Basic concepts of natural science. M. Academic Project. 2002, p. 60. 2Philosophical problems of natural science. M. Higher school. 1985. S. 181. 3Karpenkov S. Kh. Basic concepts of natural science ... S. 60. 1Karpenkov S. Kh. Basic concepts of natural science ... S. 79. 1Karpenkov S. Kh. 1Philosophical problems of natural science ... S. 178. 2Ibid. S. 191. 1Karpenkov S. Kh. Basic concepts of natural science ... S. 67. 1Karpenkov S. Kh. Basic concepts of natural science ... S. 68. 3Philosophical problems of natural science ... S. 195. 4Karpenkov S. Kh. Basic concepts of natural science ... S. 69. 1Karpenkov S. Kh. Basic concepts of natural science ... S. 70. 2Concepts of modern natural science. M. UNITY-DANA. 2005. S. 119. 3Karpenkov S. Kh. Basic concepts of natural science ... S. 71.
Tsyupka V.P. ON UNDERSTANDING THE MOVEMENT OF MATTER, ITS ABILITY FOR SELF-DEVELOPMENT, AS WELL AS COMMUNICATION AND INTERACTION OF MATERIAL OBJECTS IN MODERN NATURAL SCIENCE // Scientific electronic archive.
URL: (date of access: 03/17/2020).
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4200±70 |
see also
Write a review on the article "Fundamental particle"
Notes
Links
- S. A. Slavatinsky// Moscow Institute of Physics and Technology (Dolgoprudny, Moscow region)
- Slavatinsky S.A. // SOZH, 2001, No 2, p. 62–68 archive web.archive.org/web/20060116134302/journal.issep.rssi.ru/annot.php?id=S1176
- // nuclphys.sinp.msu.ru
- // second-physics.ru
- // physics.ru
- // nature.web.ru
- // nature.web.ru
- // nature.web.ru
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An excerpt characterizing the Fundamental particle
The next day he woke up late. Resuming the impressions of the past, he remembered, first of all, that today he had to introduce himself to Emperor Franz, remembered the Minister of War, the courteous Austrian adjutant's wing, Bilibin, and the conversation of the previous evening. Dressing in full dress uniform, which he had not worn for a long time, for a trip to the palace, he, fresh, lively and handsome, with a bandaged hand, entered Bilibin's office. There were four gentlemen of the diplomatic corps in the office. With Prince Ippolit Kuragin, who was the secretary of the embassy, Bolkonsky was familiar; Bilibin introduced him to others.
The gentlemen who visited Bilibin, secular, young, rich and cheerful people, made up a separate circle both in Vienna and here, which Bilibin, who was the head of this circle, called ours, les nеtres. This circle, which consisted almost exclusively of diplomats, apparently had its own interests of high society, relations with certain women, and the clerical side of the service, which had nothing to do with war and politics. These gentlemen, apparently, willingly, as their own (an honor that they did to a few), accepted Prince Andrei into their circle. Out of courtesy, and as a subject for entering into conversation, several questions were put to him about the army and the battle, and the conversation again crumbled into inconsistent, merry jokes and gossip.
“But it’s especially good,” one said, describing the failure of a fellow diplomat, “it’s especially good that the chancellor told him directly that his appointment to London was a promotion, and that he should look at it that way. Do you see his figure at the same time? ...
"But what's worse, gentlemen, I betray Kuragin to you: a man is in misfortune, and this Don Juan, this terrible man, is taking advantage of this!"
Prince Hippolyte was lying in a Voltaire chair, with his legs over the handle. He laughed.
- Parlez moi de ca, [Well, well, well,] - he said.
Oh, Don Juan! Oh snake! voices were heard.
“You don’t know, Bolkonsky,” Bilibin turned to Prince Andrei, “that all the horrors of the French army (I almost said the Russian army) are nothing compared to what this man did between women.
- La femme est la compagne de l "homme, [A woman is a man's friend,] - said Prince Hippolyte and began to look at his raised legs through a lorgnette.
Bilibin and ours burst out laughing, looking into Ippolit's eyes. Prince Andrei saw that this Ippolit, whom he (he had to confess) was almost jealous of his wife, was a jester in this society.
“No, I have to treat you with Kuragins,” Bilibin said quietly to Bolkonsky. - He is charming when he talks about politics, you need to see this importance.
He sat down next to Hippolyte and, gathering his folds on his forehead, started a conversation with him about politics. Prince Andrei and others surrounded them both.
- Le cabinet de Berlin ne peut pas exprimer un sentiment d "alliance," Hippolyte began, looking around significantly at everyone, "sans exprimer ... comme dans sa derieniere note ... vous comprenez ... vous comprenez ... et puis si sa Majeste l "Empereur ne deroge pas au principe de notre alliance… [The Berlin cabinet cannot express its opinion on the alliance without expressing… as in its last note… you understand… you understand… however, if His Majesty the Emperor does not change the essence of our alliance…]
- Attendez, je n "ai pas fini ... - he said to Prince Andrei, grabbing his hand. - Je suppose que l" intervention sera plus forte que la non intervention. Et…” He paused. - On ne pourra pas imputer a la fin de non recevoir notre depeche du 28 Novembre. Voila comment tout cela finira. [Wait, I didn't finish. I think that intervention will be stronger than non-intervention. And ... It is impossible to consider the case as completed by the non-acceptance of our dispatch of November 28th. How will this all end?]
And he let go of Bolkonsky's hand, showing by the fact that now he had completely finished.
- Demosthenes, je te reconnais au caillou que tu as cache dans ta bouche d "or! [Demosthenes, I recognize you by the pebble that you hide in your golden lips!] - said Bilibin, whose hat of hair moved on his head with pleasure .
Everyone laughed. Hippolyte laughed the loudest. He was apparently suffering, suffocating, but he could not help laughing wildly, stretching his always motionless face.
- Well, gentlemen, - said Bilibin, - Bolkonsky is my guest in the house and here in Brunn, and I want to treat him as much as I can with all the joys of life here. If we were in Brunn, it would be easy; but here, dans ce vilain trou morave [in that nasty Moravian hole], it is more difficult, and I ask you all for help. Il faut lui faire les honneurs de Brunn. [I need to show him Brunn.] You take over the theatre, I take over society, you, Hippolyte, of course, take over the women.
- We must show him Amelie, lovely! one of ours said, kissing the tips of his fingers.
“In general, this bloodthirsty soldier,” Bilibin said, “should be turned to more philanthropic views.
“I can hardly take advantage of your hospitality, gentlemen, and now it’s time for me to go,” Bolkonsky said, looking at his watch.
- Where?
- To the emperor.
- ABOUT! O! O!
- Well, goodbye, Bolkonsky! Goodbye, prince; come to dinner earlier, - voices followed. - We take care of you.
“Try as much as possible to praise the order in the delivery of provisions and routes when you speak with the emperor,” said Bilibin, escorting Bolkonsky to the front.
“And I would like to praise, but I can’t, as far as I know,” answered Bolkonsky smiling.
Well, talk as much as you can. His passion is audiences; but he does not like to speak and does not know how, as you will see. | Z0 |
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texvc not found; See math/README for setup help.): u / \, \overline(u)
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from 1.5 to 3 |
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d-quark (down-quark) / anti-d-quark |
Unable to parse expression (executable file texvc not found; See math/README for setup help.): d / \, \overline(d)
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4.79±0.07 |
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c-quark (charm-quark) / anti-c-quark |
Unable to parse expression (executable file texvc not found; See math/README for setup help.): c / \, \overline(c)
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1250±90 |
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s-quark (strange quark) / anti-s-quark |
Unable to parse expression (executable file texvc not found; See math/README for setup help.): s / \, \overline(s)
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95±25 |
| 3
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t-quark (top-quark) / anti-t-quark |
Unable to parse expression (executable file texvc not found; See math/README for setup help.): t / \, \overline(t)
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174 200 ± 3300 |
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b-quark (bottom-quark) / anti-b-quark |
Unable to parse expression (executable file texvc not found; See math/README for setup help.): b / \, \overline(b)
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4200±70 |
see also
Write a review on the article "Fundamental particle"
Notes
Links
- S. A. Slavatinsky// Moscow Institute of Physics and Technology (Dolgoprudny, Moscow region)
- Slavatinsky S.A. // SOZH, 2001, No 2, p. 62–68 archive http://web.archive.org/web/20060116134302/http://journal.issep.rssi.ru/annot.php?id=S1176
- // nuclphys.sinp.msu.ru
- // second-physics.ru
- // physics.ru
- // nature.web.ru
- // nature.web.ru
- // nature.web.ru
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I couldn't stand it any longer...
"And how do you know where we're going?" – ruffled like a frozen sparrow, I grumbled offendedly.
So everything is written on your face, - grandmother smiled.
Of course, this was not written on my face, but I would give a lot to find out how she always knew everything so confidently when it came to me?
A few minutes later we were already stomping together towards the forest, enthusiastically chatting about the most diverse and incredible stories, which she, of course, knew much more than I did, and this was one of the reasons why I loved walking with her so much.
We were just the two of us, and there was no need to be afraid that someone would overhear and someone might not like what we were talking about.
Grandmother very easily accepted all my oddities, and was never afraid of anything; and sometimes, if she saw that I was completely “lost” in something, she gave me advice that helped me get out of this or that undesirable situation, but most often she simply watched how I react to life difficulties that have already become permanent, without the end that came across on my "spiky" path. Recently, it began to seem to me that my grandmother was just waiting for something new to come across to see if I had matured at least a heel, or if I was still “boiling” in my “happy childhood”, not wanting to get out of the short nursery shirts. But even for her “cruel” behavior, I loved her very much and tried to use every convenient moment to spend time together with her as often as possible.
The forest greeted us with the friendly rustle of golden autumn foliage. The weather was excellent, and one could hope that my new acquaintance, by "lucky chance", would also be there.
I picked a small bouquet of some modest autumn flowers that still remained, and in a few minutes we were already near the cemetery, at the gates of which ... the same miniature sweet old woman was sitting in the same place ...
“And I thought I couldn’t wait for you!” she happily greeted.
I literally “jaw dropped” from such a surprise, and at that moment I apparently looked rather stupid, as the old woman, laughing merrily, came up to us and gently patted me on the cheek.
- Well, you go, dear, Stella has already been waiting for you. And we'll sit here for a while...
I didn’t even have time to ask how I would get to the same Stella, how everything disappeared somewhere again, and I found myself in the already familiar, sparkling and iridescent world of exuberant Stella’s fantasy, and, not having had time to look around better, right there heard an enthusiastic voice:
“Oh, it’s good that you came! And I was waiting, waiting!
The girl flew up to me like a whirlwind and slapped me right on my hands... a little red "dragon"... I recoiled in surprise, but immediately laughed merrily, because it was the most amusing and funny creature in the world!...
The "dragon", if you can call it that, bulged its tender pink belly and hissed at me menacingly, apparently hoping to scare me in this way. But, when I saw that no one was going to be scared here, he calmly sat down on my lap and began to snore peacefully, showing how good he is and how much you need to love him ...
I asked Stela what his name was and how long ago she created it.
Oh, I haven't even thought of a name yet! And he showed up right now! Do you really like him? the girl chirped cheerfully, and I felt that she was pleased to see me again.
- This is for you! she suddenly said. He will live with you.
The little dragon stretched out its spiky muzzle funny, apparently deciding to see if I had something interesting ... And suddenly licked me right on the nose! Stella squealed with delight and was obviously very pleased with her work.
“Well, okay,” I agreed, “as long as I'm here, he can be with me.
"Won't you take him with you?" Stella was surprised.
And then I realized that she, apparently, does not know at all that we are “different”, and that we no longer live in the same world. Most likely, the grandmother, in order to feel sorry for her, did not tell the girl the whole truth, and she sincerely thought that this was exactly the same world in which she had lived before, with the only difference being that now she could still create her world herself .. .
I knew for sure that I didn't want to be the one to tell this trusting little girl what her life is really like today. She was satisfied and happy in this “her own” fantastic reality, and I mentally swore to myself that I would never and never be the one who would destroy this fairy-tale world of hers. I just couldn’t understand how my grandmother explained the sudden disappearance of her entire family and, in general, everything in which she now lived? ..
“You see,” I said with a slight hesitation, smiling, “where I live, dragons are not very popular ....
So no one will see him! - the little girl chirped cheerfully.
It was like a mountain off my shoulders! .. I hated to lie or get out, and especially in front of such a clean little man as Stella was. It turned out that she perfectly understood everything and somehow managed to combine the joy of creation and sadness from the loss of her relatives.
“I finally found a friend here!” the little girl declared triumphantly. |
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Until relatively recently, several hundred particles and antiparticles were considered elementary. A detailed study of their properties and interactions with other particles and the development of the theory showed that most of them are in fact not elementary, since they themselves consist of the simplest or, as they say now, fundamental particles. Fundamental particles themselves no longer consist of anything. Numerous experiments have shown that all fundamental particles behave like dimensionless point objects that do not have an internal structure, at least up to the smallest distances studied now ~10 -16 cm.
Introduction
Among the countless and varied processes of interaction between particles, there are four basic or fundamental interactions: strong (nuclear), electromagnetic, and gravitational. In the world of particles, the gravitational interaction is very weak, its role is still unclear, and we will not talk about it further.
In nature, there are two groups of particles: hadrons, which participate in all fundamental interactions, and leptons, which do not participate only in the strong interaction.
According to modern concepts, interactions between particles are carried out through the emission and subsequent absorption of quanta of the corresponding field (strong, weak, electromagnetic) surrounding the particle. Such quanta are gauge bosons, which are also fundamental particles. Bosons have their own angular momentum, called spin, equal to the integer value of Planck's constant $h = 1.05 \cdot 10^(-27) erg \cdot c$. The quanta of the field and, accordingly, the carriers of the strong interaction are gluons, denoted by the symbol g, the quanta of the electromagnetic field are the well-known quanta of light - photons, denoted by $\gamma $, and the quanta of the weak field and, accordingly, the carriers of weak interactions are W± (double ve) - and Z 0 (zet zero)-bosons.
Unlike bosons, all other fundamental particles are fermions, that is, particles that have a half-integer spin equal to h/2.
In table. 1 shows the symbols of fundamental fermions - leptons and quarks.
Each particle given in table. 1 corresponds to an antiparticle, which differs from a particle only in the signs of the electric charge and other quantum numbers (see Table 2) and in the direction of the spin relative to the direction of the particle's momentum. We will denote antiparticles with the same symbols as particles, but with a wavy line above the symbol.
Particles in the table. 1 are denoted by Greek and Latin letters, namely: letter $\nu$ - three different neutrinos, letters e - electron, $\mu$ - muon, $\tau$ - taon, letters u, c, t, d, s, b denotes quarks; their names and characteristics are given in table. 2.
Particles in the table. 1 are grouped into three generations I, II and III according to the structure of modern theory. Our Universe is built of particles of the first generation - leptons and quarks and gauge bosons, but, as modern science of the development of the Universe shows, at the initial stage of its development particles of all three generations played an important role.
| Leptons |
Quarks |
| I |
II |
III |
$\nu_e$
e
|
$\nu_(\mu)$
$\mu$ |
$\nu_(\tau)$
$\tau$ |
|
|
Leptons
Let us first consider the properties of leptons in more detail. In the top line of the table 1 contains three different neutrinos: electron $\nu_e$, muon $\nu_m$ and tau neutrino $\nu_t$. Their mass has not yet been accurately measured, but its upper limit has been determined, for example, for ne equal to 10 -5 of the electron mass (that is, $\leq 10^(-32)$ g).
Looking at Table. 1 involuntarily raises the question of why nature needed the creation of three different neutrinos. There is no answer to this question yet, because such a comprehensive theory of fundamental particles has not been created, which would indicate the necessity and sufficiency of all such particles and would describe their main properties. Perhaps this problem will be solved in the 21st century (or later).
The bottom line of the table. 1 begins with the particle we have studied the most - the electron. The electron was discovered at the end of the last century by the English physicist J. Thomson. The role of electrons in our world is enormous. They are those negatively charged particles that, together with atomic nuclei, form all the atoms of the elements of the Periodic Table known to us. In each atom, the number of electrons is exactly equal to the number of protons in the atomic nucleus, which makes the atom electrically neutral.
The electron is stable, the main possibility of destroying an electron is its death in a collision with an antiparticle - a positron e + . This process is called annihilation:
$$e^- + e^+ \to \gamma + \gamma .$$
As a result of annihilation, two gamma quanta are formed (as high-energy photons are called), which carry away both the rest energies e + and e - and their kinetic energies. At high energies e + and e - hadrons and quark pairs are formed (see, for example, (5) and Fig. 4).
Reaction (1) clearly illustrates the validity of A. Einstein's famous formula about the equivalence of mass and energy: E = mc 2 .
Indeed, during the annihilation of a positron stopped in a substance and an electron at rest, the entire mass of their rest (equal to 1.22 MeV) passes into the energy of $\gamma$-quanta, which have no rest mass.
In the second generation of the bottom row of Table. 1 is located > muon - a particle, which in all its properties is an analogue of an electron, but with an anomalously large mass. The mass of the muon is 207 times the mass of the electron. Unlike the electron, the muon is unstable. The time of his life t= 2.2 10 -6 s. The muon mainly decays into an electron and two neutrinos according to the scheme
$$\mu^- \to e^- + \tilde \nu_e +\nu_(\mu)$$
An even heavier analog of the electron is the $\tau$-lepton (taon). Its mass is more than 3 thousand times greater than the mass of an electron ($m_(\tau) = 1777$ MeV/c 2), that is, the taon is heavier than the proton and neutron. Its lifetime is 2.9 10 -13 s, and out of more than a hundred different schemes (channels) of its decay, the following are possible:
$$\tau^-\left\langle\begin(matrix) \to e^- + \tilde \nu_e +\nu_(\tau)\\ \to \mu^- + \tilde \nu_\mu +\nu_ (\tau)\end(matrix)\right.$$
Speaking of leptons, it is interesting to compare the weak and electromagnetic forces at some specific distance, for example R\u003d 10 -13 cm. At such a distance, electromagnetic forces are almost 10 billion times greater than weak forces. But this does not mean at all that the role of weak forces in nature is small. Far from it.
It is weak forces that are responsible for many mutual transformations of various particles into other particles, as, for example, in reactions (2), (3), and such mutual transformations are one of the most characteristic features of particle physics. In contrast to reactions (2), (3), electromagnetic forces act in reaction (1).
Speaking of leptons, it must be added that the modern theory describes the electromagnetic and weak interactions with the help of a unified electroweak theory. It was developed by S. Weinberg, A. Salam and S. Glashow in 1967.
Quarks
The very idea of quarks arose as a result of a brilliant attempt to classify a large number of particles participating in strong interactions and called hadrons. M. Gell-Man and G. Zweig suggested that all hadrons consist of a corresponding set of fundamental particles - quarks, their antiquarks and carriers of the strong interaction - gluons.
The total number of hadrons currently observed is over a hundred particles (and the same number of antiparticles). Many dozens of particles have not yet been registered. All hadrons are subdivided into heavy particles called baryons, and averages named mesons.
Baryons are characterized by the baryon number b= 1 for particles and b = -1 for antibaryons. Their birth and destruction always occur in pairs: a baryon and an antibaryon. Mesons have a baryon charge b = 0. According to the idea of Gell-Mann and Zweig, all baryons consist of three quarks, antibaryons - of three antiquarks. Therefore, each quark was assigned a baryon number of 1/3, so that in total the baryon would have b= 1 (or -1 for an antibaryon consisting of three antiquarks). Mesons have a baryon number b= 0, so they can be composed of any combination of pairs of any quark and any antiquark. In addition to the quantum numbers that are the same for all quarks - spin and baryon number, there are other important characteristics of them, such as the magnitude of their rest mass m, the magnitude of the electric charge Q/e(in fractions of electron charge e\u003d 1.6 · 10 -19 coulomb) and a certain set of quantum numbers characterizing the so-called quark flavor. These include:
1) the value of the isotopic spin I and the magnitude of its third projection, that is I 3 . So, u-quark and d-quark form an isotopic doublet, they are assigned a full isotopic spin I= 1/2 with projections I 3 = +1/2 corresponding u-quark, and I 3 = -1/2 corresponding d-quark. Both components of the doublet have similar masses and are identical in all other properties, except for the electric charge;
2) quantum number S- strangeness characterizes the strange behavior of some particles that have an anomalously long lifetime (~10 -8 - 10 -13 s) compared to the characteristic nuclear time (~10 -23 s). The particles themselves have been called strange, containing one or more strange quarks and strange antiquarks. The creation or disappearance of strange particles due to strong interactions occurs in pairs, that is, in any nuclear reaction, the sum of $\Sigma$S before the reaction must be equal to $\Sigma$S after the reaction. However, in weak interactions the law of conservation of strangeness does not hold.
In experiments on accelerators, particles were observed that could not be described using u-, d- And s-quarks. By analogy with strangeness, it was necessary to introduce three more new quarks with new quantum numbers WITH = +1, IN= -1 and T= +1. Particles composed of these quarks have a much larger mass (> 2 GeV/c2). They have a wide variety of decay schemes with a lifetime of ~10 -13 s. A summary of the characteristics of all quarks is given in Table. 2.
Each quark in Table. 2 corresponds to its antiquark. For antiquarks, all quantum numbers have a sign opposite to that indicated for a quark. The following must be said about the magnitude of the mass of quarks. Given in table. 2 values correspond to the masses of bare quarks, that is, the quarks themselves without taking into account the gluons surrounding them. The mass of dressed quarks due to the energy carried by gluons is greater. This is especially noticeable for the lightest u- And d-quarks, the gluon coat of which has an energy of about 300 MeV.
Quarks that determine the basic physical properties of particles are called valence quarks. In addition to valence quarks, hadrons contain virtual pairs of particles - quarks and antiquarks, which are emitted and absorbed by gluons for a very short time.
(Where E is the energy of a virtual pair), which occurs with a violation of the law of conservation of energy in accordance with the Heisenberg uncertainty relation. Virtual pairs of quarks are called sea quarks or sea quarks. Thus, the structure of hadrons includes valence and sea quarks and gluons.
The main feature of all quarks is that they are the owners of the corresponding strong charges. Strong field charges have three equal varieties (instead of one electric charge in the theory of electric forces). In historical terminology, these three types of charge are called the colors of quarks, namely: conditionally red, green and blue. Thus, each quark in Table. 1 and 2 can be in three forms and is a colored particle. Mixing all three colors, just as it takes place in optics, gives a white color, that is, it bleaches the particle. All observed hadrons are colorless.
| Quarks |
u(up) |
d(down) |
s(strange) |
c(charm) |
b(bottom) |
t(top) |
| Mass m0 |
(1.5-5) MeV/s 2 |
(3-9) MeV/s 2 |
(60-170) MeV/s 2 |
(1.1-4.4) GeV/c 2 |
(4.1-4.4) GeV/c 2 |
174 GeV/s 2 |
| Isospin I
|
+1/2
|
+1/2
|
0
|
0
|
0
|
0
|
| Projection I 3
|
+1/2
|
-1/2
|
0
|
0
|
0
|
0
|
| Electric charge Q/e
|
+2/3
|
-1/3
|
-1/3
|
+2/3
|
-1/3
|
+2/3
|
| Weirdness S
|
0
|
0
|
-1
|
0
|
0
|
0
|
| Charm C
|
0
|
0
|
0
|
+1
|
0
|
0
|
| Bottom B
|
0
|
0
|
0
|
0
|
-1
|
0
|
| Top T
|
0
|
0
|
0
|
0
|
0
|
+1
|
Quark interactions are carried out by eight different gluons. The term "gluon" means glue in translation from English, that is, these field quanta are particles that, as it were, glue quarks together. Like quarks, gluons are colored particles, but since each gluon changes the colors of two quarks at once (the quark that emits the gluon and the quark that absorbed the gluon), the gluon is colored twice, carrying a color and an anticolor, usually different from the color .
The rest mass of gluons, like that of a photon, is zero. In addition, gluons are electrically neutral and do not have a weak charge.
Hadrons are also usually divided into stable particles and resonances: baryon and meson.
Resonances are characterized by an extremely short lifetime (~10 -20 -10 -24 s), since their decay is due to strong interaction.
Dozens of such particles were discovered by the American physicist L.V. Alvarez. Since the path of such particles to decay is so short that they cannot be observed in detectors that record traces of particles (such as a bubble chamber, etc.), they were all detected indirectly, by the presence of peaks in the dependence of the probability of interaction of various particles with each other on energy. Figure 1 explains what has been said. The figure shows the dependence of the interaction cross section (proportional to the probability value) of a positive pion $\pi^+$ with a proton p from the kinetic energy of the pion. At an energy of about 200 MeV, a peak is seen in the course of the cross section. Its width is $\Gamma = 110$ MeV, and the total particle mass $\Delta^(++)$ is equal to $T^(")_(max)+M_p c^2+M_\pi c^2=1232$ MeV /с 2 , where $T^(")_(max)$ is the kinetic energy of particle collision in the system of their center of mass. Most resonances can be thought of as an excited state of stable particles, since they have the same quark composition as their stable counterparts, although the mass of the resonances is greater due to the excitation energy.
Quark model of hadrons
We will begin to describe the quark model of hadrons from the drawing of field lines emanating from a source - a quark with a color charge and ending at an antiquark (Fig. 2, b). For comparison, in Fig. 2, and we show that in the case of electromagnetic interaction, the lines of force diverge from their source - an electric charge like a fan, because virtual photons emitted simultaneously by the source do not interact with each other. The result is Coulomb's law.
In contrast to this picture, gluons themselves have color charges and interact strongly with each other. As a result, instead of a fan of lines of force, we have a bundle, shown in Fig. 2, b. The rope is stretched between the quark and the antiquark, but the most surprising thing is that the gluons themselves, having colored charges, become sources of new gluons, the number of which increases as they move away from the quark.
Such a pattern of interaction corresponds to the dependence of the potential energy of interaction between quarks on the distance between them, shown in Fig. 3. Namely: up to a distance R> 10 -13 cm, the dependence U(R) has a funnel-shaped character, and the strength of the color charge in this range of distances is relatively small, so that quarks at R> 10 -15 cm in the first approximation can be considered as free, non-interacting particles. This phenomenon has the special name of the asymptotic freedom of quarks at small R. However, when R more than some critical value $R_(cr) \approx 10^(-13)$ cm U(R) becomes directly proportional to the value R. It follows directly from this that the force F = -dU/dR= const, that is, does not depend on distance. No other interactions that physicists have previously studied have had such an unusual property.
Calculations show that the forces acting between a quark and an antiquark, indeed, starting from $R_(cr) \approx 10_(-13)$ cm, cease to depend on the distance, remaining at a level of a huge value close to 20 tons. At a distance R~ 10 -12 cm (equal to the radius of average atomic nuclei) color forces are more than 100 thousand times greater than electromagnetic forces. If we compare the color force with the nuclear forces between a proton and a neutron inside an atomic nucleus, it turns out that the color force is thousands of times greater! Thus, a new grandiose picture of colored forces in nature has opened before physicists, many orders of magnitude greater than the currently known nuclear forces. Of course, the question immediately arises as to whether such forces can be made to work as a source of energy. Unfortunately, the answer to this question is no.
Naturally, another question arises: to what distances R between quarks, the potential energy increases linearly with increasing R?
The answer is simple: at large distances, the bundle of field lines breaks, since it is energetically more profitable to form a break with the birth of a quark-antiquark pair of particles. This occurs when the potential energy at the break is greater than the rest mass of the quark and antiquark. The process of breaking the bundle of force lines of the gluon field is shown in fig. 2, V.
Such qualitative ideas about the birth of a quark-antiquark make it possible to understand why single quarks are not observed at all and cannot be observed in nature. Quarks are forever trapped inside hadrons. This phenomenon of non-ejection of quarks is called confinement. At high energies, it may be more advantageous for the bundle to break in many places at once, forming a set of $q \tilde q$-pairs. In this way we have approached the problem of multiple births. quark-antiquark pairs and the formation of hard quark jets.
Let us first consider the structure of light hadrons, that is, mesons. They consist, as we have already said, of one quark and one antiquark.
It is extremely important that both partners of the pair have the same color charge and the same anti-charge (for example, a blue quark and an anti-blue antiquark), so that their pair, regardless of the quark flavors, has no color (and we observe only colorless particles).
All quarks and antiquarks have spin (in fractions of h) equal to 1/2. Therefore, the total spin of the combination of a quark with an antiquark is either 0 when the spins are antiparallel, or 1 when the spins are parallel to each other. But the spin of a particle can be greater than 1 if the quarks themselves rotate along some orbits inside the particle.
In table. Figure 3 shows some paired and more complex combinations of quarks with an indication of which previously known hadrons this combination of quarks corresponds to.
| Quarks |
Mesons |
|
Quarks |
baryons |
| J=0
|
J=1
|
J=1/2
|
J=3/2
|
| particles |
resonances |
particles |
resonances |
|
|
$\pi^+$
|
$\rho^+$
|
uuu
|
|
$\Delta^(++)$
|
| $\tilde u d$ |
$\pi^-$
|
$\rho^-$
|
uud
|
p
|
$\Delta^+$
|
| $u \tilde u - d \tilde d$ |
$\pi^0$
|
$\rho^0$
|
udd
|
n
(neutron) |
\Delta^0
(delta0) |
| $u \tilde u + d \tilde d$ |
$\eta$
|
$\omega$
|
ddd
|
|
$\Delta^-$
|
| $d \tilde s$ |
$k^0$
|
$k^0*$
|
uus
|
$\Sigma^+$
|
$\Sigma^+*$
|
| $u \tilde s$ |
$k^+$
|
$k^+*$
|
uds
|
$\Lambda^0$
|
$\Sigma^0*$
|
| $\tilde u s$ |
$k^-$
|
$k^-*$
|
dds
|
$\Sigma^-$
|
$\Sigma^-*$
|
| $c \tilde d$ |
$D^+$
|
$D^+*$
|
uss
|
$\Xi^0$
|
$\Xi^0*$
|
| $c \tilde s$ |
$D^+_s$
|
$D^+_s*$
|
dss
|
$\Xi^-$
|
$\Xi^-*$
|
| $c \tilde c$ |
Charmonium |
$J/\psi$
|
sss
|
$\Omega^-$
|
|
| $b \tilde b$ |
Bottonium |
Upsilon |
udc
|
$\Lambda^+_c$
(lambda-ce+) |
|
| $c \tilde u$ |
$D^0$
|
$D^0*$
|
uuc
|
$\Sigma^(++)_c$
|
|
| $b \tilde u$ |
$B^-$
|
$B*$
|
udb
|
$\Lambda_b$
|
|
Of the currently best studied mesons and meson resonances, the largest group is made up of light non-aromatic particles, whose quantum numbers S = C = B= 0. This group includes about 40 particles. Table 3 begins with pions $\pi$ ±,0 discovered by the English physicist S.F. Powell in 1949. Charged pions live for about 10 -8 s, decaying into leptons according to the following schemes:
$\pi^+ \to \mu + \nu_(\mu)$ and $\pi^- \to \mu^- + \tilde \nu_(\mu)$.
Their "relatives" in Table. 3 - resonances $\rho$ ±,0 (rho mesons) unlike pions have a spin J= 1, they are unstable and live only about 10 -23 s. The reason for the $\rho$ ±,0 decay is the strong interaction.
The reason for the decay of charged pions is due to the weak interaction, namely, the fact that the quarks that make up the particle are able to emit and absorb as a result of the weak interaction for a short time. t in accordance with relation (4), virtual gauge bosons: $u \to d + W^+$ or $d \to u + W^-$, and, unlike leptons, there are also transitions of a quark of one generation to a quark of another generation, for example $u \to b + W^+$ or $u \to s + W^+$, etc., although such transitions are much rarer than transitions within one generation. At the same time, during all such transformations, the electric charge in the reaction is conserved.
The study of mesons, including s- And c-quarks, led to the discovery of several dozen strange and charmed particles. Their research is now being carried out in many scientific centers of the world.
The study of mesons, including b- And t-quarks, began intensively at accelerators, and we will not talk about them in more detail for the time being.
Let's move on to the consideration of heavy hadrons, that is, baryons. They are all made up of three quarks, but those that have all three kinds of color, since, like mesons, all baryons are colorless. Quarks inside baryons can have orbital motion. In this case, the total spin of the particle will exceed the total spin of the quarks, equal to 1/2 or 3/2 (if the spins of all three quarks are parallel to each other).
The baryon with the minimum mass is the proton p(see Table 3). It is from protons and neutrons that all atomic nuclei of chemical elements consist. The number of protons in the nucleus determines its total electric charge Z.
The other main particle in atomic nuclei is the neutron. n. The neutron is slightly heavier than the proton, it is unstable and in the free state with a lifetime of about 900 s decays into a proton, an electron and a neutrino. In table. 3 shows the quark state of the proton uud and neutron udd. But with the spin of this combination of quarks J= 3/2, the resonances $\Delta^+$ and $D^0$ are formed, respectively. All other baryons composed of heavier quarks s, b, t, and have a much larger mass. Among them, of particular interest was W- -hyperon, consisting of three strange quarks. It was first discovered on paper, that is, by calculation, using the ideas of the quark structure of baryons. All the main properties of this particle were predicted and then confirmed by experiments.
Many experimentally observed facts now speak convincingly of the existence of quarks. In particular, we are talking about the discovery of a new process in the reaction of collision of electrons and positrons, leading to the formation of quark-antiquark jets. The scheme of this process is shown in fig. 4. The experiment was carried out on colliders in Germany and the USA. The arrows show the directions of the beams in the figure e+ and e- , and a quark is emitted from the point of their collision q and an antiquark $\tilde q$ at a zenith angle $\Theta$ to the direction of flight e+ and e- . This $q+\tilde q$ pair is produced in the reaction
$$e^+ + e^- \to \gamma_(virt) \to q + \tilde q$$
As we have already said, a tourniquet of lines of force (more often they say a string) breaks into its components with a sufficiently large tension.
At high energies of the quark and antiquark, as mentioned earlier, the string breaks in many places, as a result of which two narrow beams of secondary colorless particles are formed in both directions along the line of flight of the q quark and antiquark, as shown in Fig. 4. Such particle beams are called jets. The formation of three, four or more jets of particles simultaneously is observed quite often in the experiment.
In experiments that were carried out at superacceleration energies in cosmic rays, in which the author of this article also took part, photographs of the process of formation of many jets were obtained, as it were. The fact is that a rope or a string is one-dimensional and therefore the centers of formation of three, four or more jets are also located along a straight line.
The theory describing strong interactions is called quantum chromodynamics or abbreviated QCD. It is much more complicated than the theory of electroweak interactions. QCD is especially successful in describing the so-called hard processes, that is, the processes of particle interaction with a large momentum transfer between particles. Although the creation of the theory has not yet been completed, many theoretical physicists are already busy creating the "grand unification" - the unification of quantum chromodynamics and the theory of the electroweak interaction into a single theory.
In conclusion, let us briefly dwell on whether six leptons and 18 multicolored quarks (and their antiparticles), as well as quanta of fundamental fields, exhaust the photon, W ± -, Z 0 -bosons, eight gluons and, finally, quanta of the gravitational field - gravitons - the whole arsenal of truly elementary, more precisely, fundamental particles. Apparently not. Most likely, the described pictures of particles and fields are only a reflection of our current knowledge. It is not for nothing that there are already many theoretical ideas in which a large group of so-called supersymmetric particles, an octet of superheavy quarks, and much more are introduced.
Obviously, modern physics is still far from constructing a complete theory of particles. Perhaps the great physicist Albert Einstein was right, believing that only taking into account gravity, despite its now seeming small role in the microcosm, would allow building a rigorous theory of particles. But all this is already in the 21st century or even later.
Literature
1. Okun L.B. Physics of elementary particles. Moscow: Nauka, 1988.
2. Kobzarev I.Yu. Laureates of the Nobel Prize in 1979: S. Weinberg, S. Glashow, A. Salam // Priroda. 1980. N 1. S. 84.
3. Zeldovich Ya.B. Classification of elementary particles and quarks in the presentation for pedestrians // Uspekhi nat. Sciences. 1965. T. 8. S. 303.
4. Krainov V.P. Uncertainty relation for energy and time // Soros Educational Journal. 1998. N 5. S. 77-82.
5. I. Nambu, “Why there are no free quarks,” Usp. Phys. Sciences. 1978. V. 124. S. 146.
6. Zhdanov G.B., Maksimenko V.M., Slavatinsky S.A. Experiment "Pamir" // Nature. 1984. No. 11. S. 24
Article reviewer L.I. Sarychev
S. A. Slavatinsky Moscow Institute of Physics and Technology, Dolgoprudny, Moscow Region
Structures of the microworld
Previously, elementary particles were called particles that make up the atom and are indecomposable into more elementary components, namely electrons and nuclei.
Later it was found that the nuclei are composed of simpler particles - nucleons(protons and neutrons), which in turn are made up of other particles. That's why elementary particles began to be considered the smallest particles of matter
, excluding atoms and their nuclei
.
To date, hundreds of elementary particles have been discovered, which requires their classification:
– by types of interactions
- by time of life
- the size of the back
Elementary particles are divided into the following groups:
Composite and fundamental (structureless) particles
Composite particles
Hadrons (heavy)– particles participating in all types of fundamental interactions. They consist of quarks and are subdivided, in turn, into: mesons- hadrons with integer spin, that is, being bosons; baryons- hadrons with half-integer spin, that is, fermions. These include, in particular, the particles that make up the nucleus of an atom - the proton and neutron, i.e. nucleons.
Fundamental (structureless) particles
Leptons (light)- fermions, which have the form of point particles (that is, they do not consist of anything) up to scales of the order of 10 − 18 m. They do not participate in strong interactions. Participation in electromagnetic interactions was experimentally observed only for charged leptons (electrons, muons, tau-leptons) and was not observed for neutrinos.
Quarks are fractionally charged particles that make up hadrons. They were not observed in the free state.
Gauge bosons- particles through the exchange of which interactions are carried out:
– photon – a particle carrying electromagnetic interaction;
- eight gluons - particles that carry the strong interaction;
are three intermediate vector bosons W + , W− and Z 0 , carrying weak interaction;
– graviton is a hypothetical particle carrying gravitational interaction. The existence of gravitons, although not yet experimentally proven due to the weakness of the gravitational interaction, is considered quite probable; however, the graviton is not included in the Standard Model of elementary particles.
According to modern concepts, fundamental particles (or “true” elementary particles) that do not have an internal structure and finite sizes include:
Quarks and leptons
Particles providing fundamental interactions: gravitons, photons, vector bosons, gluons.
Classification of elementary particles by lifetime:
- stable:
particles whose lifetime is very long (it tends to infinity in the limit). These include electrons
, protons
, neutrino
. Neutrons are also stable inside nuclei, but they are unstable outside the nucleus.
- unstable
(quasi-stable): elementary particles are particles that decay due to electromagnetic and weak interactions, and whose lifetime is more than 10–20 sec. These particles include free neutron
(i.e. a neutron outside the nucleus of an atom)
- resonances
(unstable, short lived). Resonances include elementary particles that decay due to strong interaction. The lifetime for them is less than 10 -20 sec.
Classification of particles by participation in interactions:
- leptons
: Neutrons are also among them. All of them do not participate in the whirlpool of intranuclear interactions, i.e. not subject to strong interaction. They participate in the weak interaction, and having an electric charge participate in the electromagnetic interaction.
- hadrons
: particles that exist inside the atomic nucleus and participate in the strong interaction. The most famous of them are proton
And neutron
.
Currently known six leptons
:
Muons and tau particles, which are similar to the electron but more massive, belong to the same family as the electron. Muons and tau particles are unstable and eventually decay into several other particles, including an electron.
Three electrically neutral particles with zero (or close to zero, scientists have not yet decided on this matter) mass, called neutrino
. Each of the three neutrinos (electron neutrino, muon neutrino, tau neutrino) is paired with one of the three types of particles of the electron family.
The most famous hadrons
, protons and neutrinos, there are hundreds of relatives, which are born in many and immediately decay in the process of various nuclear reactions. With the exception of the proton, they are all unstable and can be classified according to the composition of the particles they decay into:
If there is a proton among the final decay products of particles, then it is called baryon
If there is no proton among the decay products, then the particle is called meson
.
The chaotic picture of the subatomic world, which became more complicated with the discovery of each new hadron, gave way to a new picture, with the advent of the concept of quarks. According to the quark model, all hadrons (but not leptons) consist of even more elementary particles - quarks. So baryons
(particularly the proton) are made up of three quarks, and mesons
from a quark-antiquark pair.
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