The word atom means "indivisible". It was introduced by the Greek philosophers to denote the smallest particles of which, according to their idea, matter consists.

Physicists and chemists of the nineteenth century adopted the term for the smallest particles known to them. Although we have been able to “split” atoms for a long time and the indivisible has ceased to be indivisible, nevertheless this term has been preserved. According to our present idea, the atom consists of the smallest particles, which we call elementary particles. There are also other elementary particles that are not actually integral part atoms. They are usually produced using powerful cyclotrons, synchrotrons, and other particle accelerators specially designed to study these particles. They also arise when cosmic rays pass through the atmosphere. These elementary particles decay after a few millionths of a second, and often in an even shorter period of time after their appearance. As a result of decay, they either change, turning into other elementary particles, or release energy in the form of radiation.

The study of elementary particles focuses on the ever-increasing number of short-lived elementary particles. Although this problem is of great importance, in particular, because it is connected with the most fundamental laws of physics, nevertheless, the study of particles is currently carried out almost in isolation from other branches of physics. For this reason, we will confine ourselves to considering only those particles that are permanent components of the most common materials, as well as some particles that are very close to them. The first of the elementary particles discovered at the end of the nineteenth century was the electron, which then became an extremely useful servant. In radio tubes, the flow of electrons moves in a vacuum; and it is by adjusting this flow that incoming radio signals are amplified and converted into sound or noise. In a television set, the electron beam serves as a pen that instantaneously and accurately replicates on the receiver screen what the transmitter's camera sees. In both these cases, the electrons move in a vacuum so that, if possible, nothing interferes with their movement. Another useful property is their ability, passing through the gas, to make it glow. Thus, by allowing electrons to pass through a glass tube filled with gas at a certain pressure, we use this phenomenon to produce neon light, which is used at night to illuminate major cities. And here is another meeting with electrons: lightning flashed, and myriads of electrons, breaking through the thickness of the air, create a rolling sound of thunder.

However, under terrestrial conditions there is relatively no big number electrons that can move freely, as we saw in the previous examples. Most of them are securely bound in atoms. Since the nucleus of an atom is positively charged, it attracts negatively charged electrons to itself, forcing them to stay in orbits that are relatively close to the nucleus. An atom usually consists of a nucleus and a number of electrons. If an electron leaves an atom, it is usually immediately replaced by another electron, which the atomic nucleus attracts with great force from its immediate environment.

What does this wonderful electron look like? No one has seen him and will never see him; and yet we know its properties so well that we can predict in great detail how it will behave in the most varied situations. We know its mass (its "weight") and its electric charge. We know that most of the time he behaves as if he is facing a very small particle, in other cases it reveals the properties waves. An extremely abstract, but at the same time very precise theory of the electron was proposed in its final form several decades ago by the English physicist Dirac. This theory gives us the opportunity to determine under what circumstances the electron will be more like a particle, and under what circumstances its wave character will prevail. This dual nature - particle and wave - makes it difficult to give a clear picture of the electron; therefore, a theory that takes into account both of these concepts and yet gives a complete description of the electron must be very abstract. But it would be unreasonable to limit the description of such a remarkable phenomenon as the electron to such earthly images as peas and waves.

One of the premises of Dirac's theory of the electron was that there must be an elementary particle that has the same properties as the electron, except that it is positively charged and not negatively charged. Indeed, such an electron twin was discovered and named positron. It is part of cosmic rays, and also occurs as a result of the decay of certain radioactive substances. Under terrestrial conditions, the life of a positron is short. As soon as it is in the neighborhood of an electron, and this happens in all substances, the electron and positron "exterminate" each other; the positive electric charge of the positron neutralizes negative charge electron. Since, according to the theory of relativity, mass is a form of energy, and since energy is "indestructible", the energy represented by the combined masses of the electron and positron must somehow be stored. This task is performed by a photon (quantum of light), or usually two photons, which are emitted as a result of this fatal collision; their energy is equal to the total energy of the electron and positron.

We also know that the reverse process is also taking place, a Photon can, under certain conditions, for example, flying close to the nucleus of an atom, create an electron and a positron “out of nothing”. For such a creation, he must have an energy of at least equal energy, corresponding to the total mass of the electron and positron.

Therefore, elementary particles are not eternal or permanent. Both electrons and positrons can come and go; however, energy and the resulting electrical charges are conserved.

With the exception of the electron, the elementary particle known to us much earlier than any other particle is not the positron, which is relatively rare, but proton is the nucleus of the hydrogen atom. Like the positron, it is positively charged, but its mass is about two thousand times greater than the mass of the positron or electron. Like these particles, the proton sometimes exhibits wave properties, but only under exceptionally special conditions. That its wave nature is less pronounced is in fact a direct consequence of its much larger mass. The wave nature, which is characteristic of all matter, does not become of great importance to us until we begin to work with exceptionally light particles, such as electrons.

The proton is a very common particle. The hydrogen atom consists of a proton, which is its nucleus, and an electron, which orbits around it. The proton is also part of all other atomic nuclei.

Theoretical physicists predicted that the proton, like the electron, has an antiparticle. Opening negative proton or antiproton, which has the same properties as the proton but is negatively charged, confirmed this prediction. The collision of an antiproton with a proton "exterminates" them both in the same way as in the case of a collision of an electron and a positron.

Another elementary particle neutron, has almost the same mass as a proton, but is electrically neutral (without electric charge generally). Its discovery in the thirties of our century - approximately simultaneously with the discovery of the positron - was extremely important for nuclear physics. The neutron is part of all atomic nuclei (with the exception, of course, of the ordinary nucleus of the hydrogen atom, which is simply a free proton); When an atomic nucleus breaks down, it releases one (or more) neutrons. Explosion atomic bomb occurs due to neutrons released from the nuclei of uranium or plutonium.

Since protons and neutrons together form atomic nuclei, both are called nucleons. After some time, a free neutron turns into a proton and an electron.

We are familiar with another particle called antineutron, which, like the neutron, is electrically neutral. It has many of the properties of a neutron, but one of the fundamental differences is that an antineutron decays into an antiproton and an electron. Colliding, neutron and antineutron destroy each other,

Photon, or light quantum, an extremely interesting elementary particle. Wanting to read a book, we turn on the light bulb. So, the included light bulb generates a huge number of photons that rush to the book, as well as to all other corners of the room, at the speed of light. Some of them, hitting the walls, die immediately, others again and again hit and bounce off the walls of other objects, but after less than one millionth of a second from the moment they appear, they all die, with the exception of a few who manage to escape through the window and slip into space. The energy needed to generate photons is supplied by electrons flowing through a light bulb that is on; dying, photons give this energy to a book or other object, heating it, or to the eye, causing stimulation of the optic nerves.

The energy of a photon, and hence its mass, does not remain unchanged: there are very light photons along with very heavy ones. The photons that produce ordinary light are very light, their mass is only a few millionths of the mass of an electron. Other photons have a mass about the same as the mass of an electron, and even much more. Examples of heavy photons are x-rays and gamma rays.

Here general rule: the lighter the elementary particle, the more expressive its wave nature. The heaviest elementary particles - protons - reveal relatively weak wave characteristics; they are somewhat stronger for electrons; the strongest are those of photons. Indeed, the wave nature of light was discovered much earlier than its corpuscular characteristics. We have known that light is nothing more than the movement of electromagnetic waves since Maxwell demonstrated it during the second half of the last century, but it was Planck and Einstein at the dawn of the twentieth century who discovered that light also has corpuscular characteristics, that it sometimes emitted in the form of separate "quanta", or, in other words, in the form of a stream of photons. It cannot be denied that it is difficult to unite and merge together in our minds these two apparently dissimilar conceptions of the nature of light; but we may say that, like the "dual nature" of the electron, our conception of such an elusive phenomenon as light must be very abstract. And only when we want to express our idea in crude terms, we must sometimes liken light to a stream of particles, photons, or wave motion of an electromagnetic nature.

There is a relationship between the corpuscular nature of the phenomenon and its "wave" properties. The heavier the particle, the shorter its corresponding wavelength; the longer the wavelength, the lighter the corresponding particle. X-rays, consisting of very heavy photons, have correspondingly very short wavelengths. Red light, which has a longer wavelength than blue light, is made up of lighter photons than blue light photons. The longest electromagnetic waves in existence - radio waves - are made up of tiny photons. These waves do not exhibit the properties of particles in the slightest, their wave nature being entirely the predominant characteristic.

And finally, the smallest of all small elementary particles is neutrino. It is devoid of electric charge, and if it has any mass, then it is close to zero. With some exaggeration, we can say that the neutrino is simply devoid of properties.

Our knowledge of elementary particles is the modern frontier of physics. The atom was discovered in the nineteenth century, and scientists of the time discovered an increasing number of various kinds atoms; similarly today we find more and more elementary particles. And although it has been proven that atoms are composed of elementary particles, we cannot expect that, by analogy, it will be found, something elementary particles are made up of even smaller particles. The problem we face today is quite different, and there is not the slightest sign that we can split elementary particles. Rather, it should be hoped that it will be shown that all elementary particles are manifestations of one even more fundamental phenomenon. And if it were possible to establish this, we would be able to understand all the properties of elementary particles; could calculate their masses and how they interact. Many attempts have been made to approach this problem, which is one of the most important issues physics.

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There is no clear definition of the concept of "elementary particle"; usually only a certain set of values ​​is specified physical quantities characterizing these particles, and some of their very important distinctive properties. Elementary particles have:

1) electric charge

2) proper angular momentum or spin

3) magnetic moment

4) own mass - "rest mass"

In the future, other quantities characterizing particles may be found, so this list of the basic properties of elementary particles should not be considered complete.

However, not all elementary particles (a list of them is given below) have a complete set of the above properties. Some of them have only an electric charge and mass, but do not have a spin (charged pions and kaons); other particles have mass, spin and magnetic moment, but no electric charge (neutron, lambda hyperon); others have only mass (neutral pions and kaons) or only spin (photons, neutrinos). Mandatory for elementary particles is the presence of at least one of the properties listed above. Note that the most important particles of matter - runs and electrons - are characterized by a complete set of these properties. It must be emphasized that electric charge and spin are fundamental properties of particles of matter, i.e., their numerical values ​​remain constant under all conditions.

PARTICLES AND ANTIPARTICLES

Each elementary particle has its opposite - "antiparticle". The mass, spin and magnetic moment of the particle and antiparticle are the same, but if the particle has an electric charge, then its antiparticle has a charge of the opposite sign. The proton, positron and antineutron have the same magnetic moments and spins, while the electron, neutron and antiproton have opposite orientations.

The interaction of a particle with its antiparticle differs significantly from the interaction with other particles. This difference is expressed in the fact that a particle and its antiparticle are capable of annihilation, i.e., a process in which they disappear and other particles appear instead. So, for example, as a result of the annihilation of an electron and a positron, photons, protons and antiproton-pions, etc. appear.

LIFETIME

Stability is not a mandatory feature of elementary particles. Only the electron, proton, neutrino and their antiparticles, as well as photons, are stable. The rest of the particles are transformed into stable ones either directly, as happens, for example, with a neutron, or through a chain of successive transformations; for example, an unstable negative pion first turns into a muon and a neutrino, and then the muon turns into an electron and another neutrino:

Symbols denote "muon" neutrinos and antineutrinos, which are different from "electronic" neutrinos and antineutrinos.

The instability of particles is estimated by the duration of their existence from the moment of "birth" to the moment of decay; both of these points in time are marked by particle tracks in the measuring setups. In the presence of a large number of observations of particles of a given “sort”, either the “average lifetime” or the half-period of decay is calculated.

you can calculate the average lifetime (during which the number of particles decreases by a factor) and the half-life

(during which this number is halved).

It is interesting to note that:

1) all uncharged particles, except for neutrinos and photons, are unstable (neutrinos and photons stand out among other elementary particles in that they do not have their own rest mass);

2) of the charged particles, only the electron and proton (and their antiparticles) are stable.

Here is a list of the most important particles (their number continues to increase at the present time) with indication of designations and main

properties; electric charge is usually given in elementary units mass - in units of electron mass spin - in units

(see scan)

CLASSIFICATION OF PARTICLES

The study of elementary particles showed that their grouping according to the values ​​of the main properties (charge, mass, spin) is insufficient. It turned out to be necessary to divide these particles into essentially different "families":

1) photons, 2) leptons, 3) mesons, 4) baryons

and introduce new characteristics of particles that would show that a given particle belongs to one of these families. These characteristics are conventionally called "charges" or "numbers". There are three types of charges:

1) lepton-electronic charge;

2) lepton-muon charge

3) baryon charge

Numerical values ​​are given to these charges: and -1 (particles have a plus sign, antiparticles have a minus sign; photons and mesons have zero charges).

Elementary particles obey the following two rules:

each elementary particle belongs to only one family and is characterized by only one of the above charges (numbers).

For example:

However, a certain set of different particles may belong to one family of elementary particles; for example, the group of baryons includes the proton, the neutron, and a large number of hyperons. We present the division of elementary particles into families:

leptons "electronic": These include the electron positron electron neutrino and electron antineutrino

"muon" leptons: These include muons with negative and positive electric charge and muon neutrinos and antineutrinos. These include the proton, neutron, hyperons and all their antiparticles.

The existence or absence of an electric charge is not associated with belonging to any of the listed families. It is noted that all particles whose spin is equal to 1/2 necessarily have one of the above charges. Photons (having a spin equal to unity), mesons - pions and kaons (whose spin is equal to zero) have neither lepton nor baryon charges.

In all physical phenomena, in which elementary particles participate - in decay processes; birth, annihilation and mutual transformations, - the second rule is observed:

the algebraic sums of numbers for each type of charge separately are always kept constant.

This rule is equivalent to three conservation laws:

These laws also mean that mutual transformations between particles belonging to different families are prohibited.

For some particles - kaons and hyperons - it turned out to be necessary to additionally introduce one more characteristic, called strangeness and denoted by Kaons have lambda and sigma hyperons - xi-hyperons - (upper sign for particles, lower sign for antiparticles). In processes in which the appearance (birth) of particles with strangeness is observed, the following rule is observed:

The law of conservation of strangeness. This means that the appearance of one strange particle must necessarily be accompanied by the appearance of one or more strange antiparticles, so that the algebraic sum of numbers before and after

the birth process remained constant. It has also been noted that the law of conservation of strangeness is not observed in the decay of strange particles, i.e., this law is valid only in the processes of production of strange particles. Thus, for strange particles, the processes of creation and decay are irreversible. For example, a lambda hyperon (strangeness equals decays into a proton and a negative pion:

In this reaction, the strangeness conservation law is not observed, since the proton and pion obtained after the reaction have strangenesses equal to zero. However, in the reverse reaction, when a negative pion collides with a proton, a single lambda hyperon does not appear; the reaction proceeds with the formation of two particles with oddities of opposite signs:

Consequently, in the lambda-hyperon birth reaction, the law of conservation of strangeness is observed: before and after the reaction, the algebraic sum of "strange" numbers is equal to zero. Only one decay reaction is known in which the constancy of the sum of strange numbers is satisfied - this is the decay of a neutral sigma hyperon into a lambda hyperon and a photon:

Another feature of strange particles is the sharp difference between the duration of the production processes (on the order of ) and the average time of their existence (about ); for other (not strange) particles, these times are of the same order.

Note that the necessity of introducing lepton and baryon numbers or charges and the existence of the above conservation laws make us assume that these charges express a qualitative difference between particles of different types, as well as between particles and antiparticles. The fact that it is necessary to assign charges of opposite signs to particles and antiparticles indicates the impossibility of mutual transformations between them.

The attention of physicists and philosophers is now riveted to the question of elementary particles. What are elementary particles? The Soviet physicist V. S. Barashenkov, when asked what object is called "elementary", answers: "This is a particle that cannot be built from other particles so that the mass defect in this case would be compared with the mass of this particle or the masses of component particles so small that it could be neglected" (31.1965.9.87). Somewhat later, together with D. I. Blokhintsev, they wrote: “At present, the group of elementary particles includes all particles, any possible decays of which, both real and virtual, occur with a mass defect comparable in magnitude with the mass of the original particle or with the masses decay particles" (74, 181).

In our opinion, elementary particles are such qualitatively unique types of matter that interact discretely as a single whole in all known processes. It should be said that the name "elementary" is clearly unfortunate. “The term “elementary” rather refers to the level of our knowledge,” wrote the famous Italian physicist E. Fermi. “In general, we can say that at each stage in the development of science, we call elementary those particles whose structures we do not know and which we consider as point” (151 , 9). But in reality, based on the most general considerations and experimental data, it can be shown that any elementary particle must have a structure. This statement follows from the analysis of various processes in which elementary particles participate. At present, a large number of reactions of dispersion, generation, transformations, formations of some elementary particles from others are already known. These experimental data give grounds for asserting that elementary particles have an internal structure. The structure of elementary particles is one of the reflections of endless internal and external connections in nature, a reflection of the motion of matter. Each of the micro-objects not only causes certain natural phenomena, but is itself conditioned and, therefore, has a structure, a structure. The presence of a structure in elementary particles is already indicated by the fact that elementary particles are not one or two, but many.

It should be noted that almost all elementary particles have corresponding antiparticles. We list some of them: electron- a stable particle with a mass equal to 9.108 * 10 -28 g and a negative elementary electric charge. Electrons play the most important role in the structure of matter, being an integral part of all atoms.

Photon, or quantum electromagnetic radiation arbitrary frequency (a concept introduced by A. Einstein in his theory of the photoelectric effect). A distinctive feature of a photon in comparison with other elementary particles is that it always moves at a constant speed - C = 3*10 10 cm/s (in vacuum). It has no rest mass, and its stop is nothing but absorption, i.e., the end of its existence as a photon.

It should also be said about proton- a positively charged hydrogen nucleus, an elementary particle, the mass of which is 1836 times greater than the mass of an electron. It is an integral part of the nuclei of all elements.

In 1932 was opened neutron- a particle devoid of an electric charge with a mass of 1838 electron masses. Neutrons, along with protons, are part of atomic nuclei.

In the same year, it opened positron, which is the antiparticle of the electron. The mass of the positron is equal to the mass of the electron, its electric charge is positive and equal to elementary charge(electron charge).

An extremely interesting elementary particle, devoid of an electric charge, is neutrino. As for its rest mass, this question still remains open: it is either zero or very small. Fine and detailed measurements of the tritium decay spectrum carried out at the Institute of Theoretical and Experimental Physics (ITEP) of the USSR Academy of Sciences by a group consisting of V. A. Lyubimov, E. G. Novikov, V. Z. Nozika, E. F. Tretyakova, and V. S. Kozik (283, 301) indicate that the neutrino has a rest mass. It is known that work on the discovery of the rest mass of neutrinos has been going on for a long time. Back in 1949, the work of G. Khan and B. Pontecorvo was published, in which the question of the limit of the neutrino mass was considered. By 1972, K. Berquist (207, 317) refined the desired limit, which was close to 55 eV. Since 1973, this work has been started by the aforementioned group of Soviet physicists. The neutrino rest mass measured by them turned out to be very small - between 14 and 16 eV. However, under the conditions of the Universe, the presence of even such a small rest mass in neutrinos leads to very large consequences, to a change in our ideas about the structure and evolution of the Universe.

If we proceed from the modern model of the hot Universe, then in it now there are ~ 500 relic neutrinos in one cubic centimeter. Calculation taking into account their mass shows that 90-99% of the entire mass of the Universe is the mass of neutrinos. As Academician Ya. B. Zel'dovich wrote, this means that we live in a neutrino Universe. The mass of neutrinos affects the age of the Universe (it is shrinking), heavy neutrinos will stop its expansion, and ~ in 20-30*10 9 years, as a result of compression, a grandiose collapse of the Universe will occur. The presence of a rest mass for neutrinos makes it possible to discover new properties of already known elementary particles. The very light neutrino, for example, can serve as an indication of the existence of a world of superheavy particles 1 . The theoretically predicted neutrino lifetime (10 29 years) is approximately 19 orders of magnitude longer than the age of the Universe (10 10 years). The discovery of a finite mass in neutrinos (if the above data is confirmed) will be one of the major discoveries in modern physics.

1 (This physical foresight lies in line with the dialectical-materialist principle of the unity of opposites.)

Having no electric charge, rest mass, magnetic moment, neutrinos interact extremely weakly with other particles and are very penetrating. The neutrino differs from the antineutrino in its "spirality", figuratively speaking, the direction of the spin in relation to the direction of motion.

It should be noted that part of the solar energy is carried away into space in the form of antineutrinos emitted when nuclear reactions in the depths of the sun.

Developing the theory of elementary particles, Soviet physicists, and above all M. A. Markov and B. M. Pontecorvo, predicted the existence in nature of two types of neutrinos. At present, three types of neutrinos are already known: v e , v μ , v τ and their corresponding antineutrinos.

Studies of cosmic rays (primary cosmic rays consist mainly of protons and α-particles), as well as experiments on powerful accelerators, led to the discovery of a number of new particles; among them particles with an intermediate mass between the mass of an electron and the mass of a proton - mesons. In 1937, μ ± mesons with a mass of 206.7 electron masses, with a lifetime of 2.22 * 10 -6 s were discovered. In addition, π +, π-, π 0 mesons and K-mesons are now known , a large group of elementary particles called hyperons, whose mass exceeds the mass of a proton. So, for example, Ξ - minus hyperon (cascade hyperon) has a mass of ~2586 electron masses. AT last years discovered a number of short-lived particles combined common name reasons 1 .

1 (In the next paragraph of this chapter, where we will talk about the classification of particles, we will continue their list.)

Knowing that the atoms of all chemical elements, occurring in nature, "consist" of electrons, protons, neutrons and virtual n-mesons, one could come to the conclusion that other particles do not play a role in the structure of atoms or their nuclei, but arise only during various reactions in cosmic rays or laboratory conditions. However, this is not the case. Along with the indicated types of particles, there are many other particles actually present in atoms, and there are also fields that ensure the interaction of particles.

Indeed, the electron is attracted to the nuclei mainly due to electrostatic forces (magnetic and electromagnetic forces play an insignificant role). The quanta of this field are emitted by atoms in the form of photons during the transition of electrons from a higher energy level to a lower one or in collisions of an atom with other atoms.

The electromagnetic field is also present in an implicit, non-radiated state in the nuclei, causing the electrostatic repulsion of protons and the magnetic interaction of protons and neutrons (since both types of nucleons have magnetic moments), as well as other minor additional forces. This has been known for a long time, and only various quantum, in some cases very subtle and difficult to calculate and difficult to observe corrections have been established until recently.

In addition to the electromagnetic field, there are also special fields in the nuclei of atoms associated with nuclear forces that restrain protons and neutrons in the nuclei and are neither gravitational nor magnetic.

The field of nuclear forces, which have tremendous intensity, is of a specific nature. It is due to particles that have mass. This was found primarily in theoretical works V. Heisenberg, I. Tamm, D. Ivanenko and the Japanese physicist G. Yukawa. It turned out to be very difficult to make the atom radiate, i.e., tear the nuclear field away from the nucleons; It is not for nothing that this bond is the "strong" one, the largest of all known between particles. The quanta of the nuclear field, emitted by the nuclei of atoms, in the collisions of protons or neutrons turned out to be particles, average in mass between electrons and nucleons. In close agreement with theoretical predictions, they have an integer, more precisely, vanishing spin S = 0. These particles were called π- mesons, or " peonies". Their existence was predicted theoretically.

The field of pions inside nuclei provides the nuclear forces, just as the electric field between protons and electrons is provided by their charges. Nuclear forces between nucleons arise due to the fact that one nucleon emits a virtual pion, and the other absorbs it. The theory of the interaction of nucleons and pions and the corresponding experiments have made great progress, and we now understand many aspects of the scattering of pions and their production. The theory of nuclear, mainly n-meson, forces was also able to explain many significant aspects of the interaction between nucleons, in particular, their short-range, charge-independent, non-central nature and the form of the spin dependence.

So, we have established the composition of atoms together with the nucleus: electrons, protons, neutrons plus the electromagnetic and meson field (π-meson). It would seem that the study of the composition of matter can now be considered complete. However, a number of new elementary particles have been discovered in recent decades. First, it turned out that neutrons and pions are unstable particles: they spontaneously decay, giving rise to new particles that do not directly play a role in the structure of substances. Charged n-mesons with the need, on average, after 2 * 10 -8 s decay into a neutrino or, respectively, an antineutrino plus a new particle of the meson type, the so-called (μ-meson, or "muon":

neutral muons are unknown. The neutral pion extremely quickly, after a time of approximately 10 -16 s, decays into two γ-photons:

A free neutron necessarily decays, having lived on average for about 12 minutes, into a proton, an electron and a neutrino (more precisely, an antineutrino):

Decay nuclear neutrons depends on the stability of the entire nucleus: the electrons generated in this case are called beta particles (β).

Secondly, in the collision of already known particles (π, ρ, n, μ, etc.) of high energy, various new particles are generated, in particular, superheavy hyperons, exceeding the mass of nucleons (protons and neutrons), and new K-mesons , heavier than peonies. In this case, various "antiparticles" or charge-conjugated particles are also generated, which are "mirror" images of ordinary particles. For example, during the passage of photons with an energy of over 1 million electron volts, a pair can appear near the nucleus: an electron + a positron.

Every elementary particle has a variety of properties, and this confirms the Marxist-Leninist position on the inexhaustibility of matter. Any kind of matter discovered by science in the process of infinite knowledge of nature has a large variety of properties that depend on the structure of the material objects themselves and on an infinite number of connections between them.

Marxist-Leninist philosophy draws attention to the fact that every phenomenon, every body has its own essence, which is manifested in these phenomena and objects. An elementary particle, or, more precisely, a micro-object, has its own essence. But this essence is largely undiscovered, not known, is a "thing in itself." The presence of essence in a micro-object testifies to the structure, the existence of complex internal connections, i.e., connections and interactions between the elements of matter that make up this micro-object, which are manifested in its various properties.

Dialectical materialism shows that all objects and phenomena in nature are in mutual connection and conditionality. Any phenomenon can be understood correctly only in connection with the surrounding world. Therefore, in the study of the properties of micro-objects, the study of external relations, interactions of a given micro-object with other bodies and fields plays an important role.

Thus, if internal connections determine the structure of a micro-object, then its structure manifests itself in external connections.

The division of links into external and internal is relative. But, on the other hand, the division of links into internal and external is very important, since it allows you to highlight the qualitative characteristics of the object that determine this particular object.

What allows us to separate connections into internal and external? Where is the criterion for this division? ST Melyukhin believes that "the division into internal and external is very relative and is determined mainly by the spatial configuration of bodies" (94, 202).

From this, he draws the following conclusion: “For macroscopic objects with relatively sharp spatial boundaries, the division of bonds into internal and external in most cases does not present particular difficulties. However, this division is sometimes very difficult to carry out for microobjects. The fact is that elementary particles one cannot attribute sharp geometric boundaries, because they are not some kind of microscopic balls, but they also have wave properties"(94, 202). We think that such a division is possible as a result of the presence of a qualitative certainty in an object. In any interaction with external bodies, both internal and external connections are manifested. But in some cases, internal connections play a decisive role, in others - external. Undoubtedly, the spatial configuration plays a certain role in this. But there is no reason to believe that it is of such a categorical character. For example, in the case of an atom, we can quite accurately make such a relative division of bonds into internal and external. In the case of elementary particles, this at the present time it is really difficult to make, since they are still very poorly studied, but there is a possibility that after the creation of the theory of elementary particles such a subdivision can be made.

Thus, the term "elementary particles", on the one hand, reflects a certain level of our knowledge, but, on the other hand, it also has a certain objective content. V. I. Lenin wrote: “Logical concepts are subjective as long as they remain “abstract”, in their abstract form, but at the same time they express things in themselves. Nature is both concrete and abstract, and the phenomenon and essence, and the moment and relation. Human concepts are subjective in their abstractness, isolation, but objective in general, in the process, as a result, in the trend, in the source" (2, 29, 190). How is the objective content reflected in the concept of "elementary particle"? It lies in the fact that the concept of "elementary particle" reflects the qualitative indivisibility of the corresponding types of matter, many of whose properties will be revealed by science in the future.

Consider some of the properties that microparticles (elementary particles) have.

One of the most important properties of microobjects is that they have masses.

Let us pay attention to the fact that micro-objects with rest mass can move at any speed (from zero to almost the speed of light in vacuum), while particles without rest mass always move at the speed of light. Apparently, further study of the microworld will make it possible to explain what interactions and between what types of matter manifest such peculiar properties of microobjects.

It can be argued that the mass is determined mainly by internal connections and is one of the characteristics of the qualitative certainty of the subject.

Another important property of microparticles is electric charge, which characterizes the connection of particles with electromagnetic field. It is still unclear what causes the presence of the same absolute charge in different particles and the absence of an electric charge in some particles. But it is quite obvious that this is a manifestation of some deep internal, not yet discovered regularity, a manifestation of some commonality in the structure of particles.

Spin is another important property of microparticles.

Particle spin is a special fundamental property of elementary particles, inherent only to them. We can speak of the spin as a particle's own "rotation" only by analogy with the rotation in the macrocosm. The spin of an elementary particle cannot be increased or decreased. Spin is measured in units of h. The proton, neutron and electron have spin S = 1 / 2, and the spin of the photon is 1. The fact that the spin is a very important characteristic associated with the very essence of an elementary particle and indicating the presence of unity between a number of particles is indicated by the existence of two types of statistics ( Bose - Einstein and Fermi - Dirac), i.e., regularities that reflect both the general and the special for all known elementary particles. Particles with half-integer spin obey the Fermi-Dirac statistics and are called fermions, and particles with integer spin obey Bose-Einstein statistics and are called bosons. It is known that no more than one fermion can be in the same state, i.e., fermions behave as "individualists"; this rule does not apply to bosons, and they behave like "collectivists". The internal nature of these features in the behavior of elementary particles is still far from being established, although the connection of these properties with the properties of symmetry and asymmetry has already been established.

Spin is considered as a manifestation of the internal degree of freedom in the motion of an electron or other elementary particle, which, therefore, is characterized by four degrees of freedom: three external, expressing spatial displacement, and the fourth internal, spin. The presence of a spin also indicates the existence of a complex structure and a certain type of internal bonds in microparticles.

Another important property of elementary particles is magnetic moment. It is possessed by both charged and neutral particles. It is assumed that some part of the magnetic moment of charged particles is due to their spatial displacement. Thus, it is believed that the currents of meson clouds around protons and neutrons determine their magnetic moments.