Are there permanent particles in nature? Elementary particles. Classification of elementary particles
Lesson topic: "Stages in the development of elementary particle physics." In this lesson, we will cover the following questions:
- The history of the development of ideas that the world consists of elementary particles What are elementary particles? How can one obtain a separate elementary particle and is it possible? Typology of particles.
Our lesson will be held mainly in the form of a lecture, and if during the lecture you guys have questions or additions, I will be glad to listen to them.
The notion that the world is made up of fundamental particles has a long history. To date, there are three stages in the development of elementary particle physics.
Let's open the textbook on page , pr. Let's get acquainted with the names of the stages and the time frame.
Stage 1.
Elementary, that is, the simplest, indivisible further, this is how the well-known ancient Greek scientist Democritus imagined the atom. Let me remind you that the word "atom" in translation means "indivisible". For the first time, the idea of the existence of the smallest, invisible particles that make up all the surrounding objects was expressed by Democritus 400 years before our era. Science began to use the concept of atoms only at the beginning of the 19th century, when it was possible to explain a number of chemical phenomena on this basis. And at the end of this century, the complex structure of the atom was discovered. In 1911, the atomic nucleus was discovered (E. Rutherford) and it was finally proved that atoms have a complex structure.
Let's remember the guys: what particles are part of the atom and briefly characterize them?
Guys, maybe some of you remember: by whom and in what years were the electron, proton and neutron discovered?
After the discovery of the proton and neutron, it became clear that the nuclei of atoms, like the atoms themselves, have a complex structure. The proton-neutron theory of the structure of nuclei arose (D. D. Ivanenko and V. Heisenberg).
In the 30s of the 19th century, in the theory of electrolysis developed by M. Faraday, the concept of an ion appeared and the elementary charge was measured. The end of the XIX century - in addition to the discovery of the electron, was marked by the discovery of the phenomenon of radioactivity (A. Becquerel, 1896). In 1905, in physics, an idea arose about the quanta of the electromagnetic field - photons (A. Einstein).
Recall: what is called a photon?
Open particles were considered indivisible and unchanging original essences, the basic building blocks of the universe.
Stage 2.
However, this opinion did not last long.
In the 1930s, the mutual transformations of protons and neutrons were discovered and studied, and it became clear that these particles are not the same elementary "bricks" of nature either.
Currently, about 400 subnuclear particles are known (particles of which atoms are composed, which are commonly called elementary. The vast majority of these particles are unstable (elementary particles turn into each other).
The only exceptions are the photon, electron, proton and neutrino.
Photon, electron, proton and neutrino are stable particles (particles that can exist in a free state for an unlimited time), but each of them, when interacting with other particles, can turn into other particles.
All other particles at certain intervals experience spontaneous transformations into other particles and this is the main fact of their existence.
I mentioned another particle - the neutrino. What are the main characteristics of this particle? By whom and when was it discovered?
Unstable elementary particles strongly differ from each other in lifetimes.
The longest lived particle is the neutron.. The lifetime of a neutron of the order 15 minutes.
Other particles "live" for a much shorter time.
There are several tens of particles with a lifetime exceeding 10–17 s. In terms of the scale of the microcosm, this is a significant time. Such particles are called relatively stable.
Majority short lived elementary particles have lifetimes of the order of 10–22–10–23 s.
The ability for mutual transformations is the most important property of all elementary particles.
Elementary particles are capable of being born and destroyed (emitted and absorbed). This also applies to stable particles, with the only difference that transformations of stable particles do not occur spontaneously, but when interacting with other particles.
An example is the annihilation (ie, disappearance) of an electron and a positron, accompanied by the production of photons of high energy.
Positron- (electron antiparticle) a positively charged particle that has the same mass and the same (modulo) charge as the electron. We will talk about its characteristics in more detail in the next lesson. Let's just say that the existence of the positron was predicted by P. Dirac in 1928, and K. Anderson discovered it in 1932 in cosmic rays.
In 1937, particles with a mass of 207 electron masses, called muons (μ-mesons), were discovered in cosmic rays. The average lifetime of a μ meson is
Then, in 1947–1950, pions (that is, π mesons) were discovered. The average lifetime of a neutral π meson is 0.87 10–16 s.
In subsequent years, the number of newly discovered particles began to grow rapidly. This was facilitated by the study of cosmic rays, the development of accelerator technology, and the study of nuclear reactions.
Modern accelerators necessary for the implementation of the process of the birth of new particles and the study of the properties of elementary particles. The initial particles are accelerated in the accelerator to high energies “on a collision course” and collide with each other in a certain place. If the energy of the particles is high, then in the course of the collision many new particles are born, usually unstable. These particles, flying away from the point of collision, break up into more stable particles, which are registered by the detectors. For each such act of collision (physicists say: for each event) - and they are recorded in thousands per second! -experimenters as a result determine the kinematic variables: the values of the momenta and energies of the "caught" particles, as well as their trajectories (see the figure in the textbook or Appendix No. 1). Having collected many events of the same type and having studied the distributions of these kinematic quantities, physicists restore how the interaction proceeded and what type of particles the resulting particles can be attributed to.
Stage 3.
Elementary particles are combined into three groups: photons, leptons and hadrons (Appendix No. 2 - table).
Guys, list me the particles belonging to different groups.
The next group consists of light lepton particles.
Leptons also include a number of particles not listed in the table.
The third large group is made up of heavy particles called hadrons. This group is divided into two subgroups. Lighter particles make up a subgroup of mesons.
The second subgroup - baryons - includes heavier particles. It is the most extensive.
They are followed by the so-called hyperons. The omega-minus-hyperon, discovered in 1964, closes the table.
The abundance of discovered and newly discovered hadrons led scientists to the idea that they are all built from some other more fundamental particles.
In 1964, the American physicist M. Gell-Man put forward a hypothesis, confirmed by subsequent studies, that all heavy fundamental particles - hadrons - are built from more fundamental particles called quarks.
From a structural point of view, elementary particles that make up atomic nuclei ( nucleons), and in general all heavy particles - hadrons (baryons and mesons) - consist of even simpler particles, which are usually called fundamental. In this role, the truly fundamental primary elements of matter are quarks, whose electric charge is equal to +2/3 or –1/3 of the unit positive charge of the proton.
The most common and lightest quarks are called top and lower and denote, respectively, u(from English up) and d(down). Sometimes they are called proton and neutron quark due to the fact that the proton consists of a combination uud, and the neutron udd. The top quark has a charge of +2/3; lower - negative charge -1/3. Since the proton consists of two up and one down quarks, and the neutron consists of one up and two down quarks, you can see for yourself that the total charge of the proton and neutron is strictly equal to 1 and 0.
The other two pairs of quarks are part of more exotic particles. Quarks from the second pair are called enchanted - c(from charmed) and strange - s(from strange).
The third pair is true - t(from truth, or in English. traditions top) and beautiful - b(from beauty, or in English. traditions bottom) quarks.
Almost all particles consisting of various combinations of quarks have already been discovered experimentally.
With the acceptance of the quark hypothesis, it was possible to create a coherent system of elementary particles. Numerous searches for quarks in the free state, carried out in high-energy accelerators and in cosmic rays, turned out to be unsuccessful. Scientists believe that one of the reasons for the non-observability of free quarks is, perhaps, their very large masses. This prevents the creation of quarks at the energies that are achieved at modern accelerators.
The experiment to extract free quarks was born about 10 years ago, and will be launched next year. Now the elements of the largest experimental facility in the world are being prepared - this is the Large Hadron Collider in Switzerland.
And this experiment, which will be launched next year, will answer many questions and, in fact, will push physics to develop further.
Presentation on the topic "Elementary particles" in physics in powerpoint format. This presentation for 11th grade students explains elementary particle physics and systematizes knowledge on the topic. The purpose of the work is to develop abstract, ecological and scientific thinking of students based on ideas about elementary particles and their interactions. Presentation author: Popova I.A., teacher of physics.
Fragments from the presentation
How many elements are in the periodic table?
- Only 92.
- How? Is there more?
- True, but all the rest are artificially obtained, they do not occur in nature.
- So - 92 atoms. Molecules can also be made from them, i.e. substances!
- But the fact that all substances are made up of atoms was argued by Democritus (400 BC).
- He was a great traveler, and his favorite saying was:
- "There is nothing but atoms and pure space, everything else is a view"
Timeline of particle physics
- Theoretical physicists faced the most difficult task of ordering the entire discovered "zoo" of particles and trying to reduce the number of fundamental particles to a minimum, proving that other particles consist of fundamental particles.
- All these particles were unstable; decayed into particles with smaller masses, eventually turning into a stable proton, electron, photon and neutrino (and their antiparticles).
- The third one. M. Gell-Mann and independently J. Zweig Proposed a model for the structure of strongly interacting particles from fundamental particles - quarks
- This model has now turned into a coherent theory of all known types of particle interactions.
How to detect an elementary particle?
Usually, traces (trajectories or tracks) left by particles are studied and analyzed from photographs.
Classification of elementary particles
All particles are divided into two classes:
- Fermions, which make up matter;
- Bosons through which the interaction is carried out.
Quarks
- Quarks participate in strong interactions, as well as in weak and electromagnetic ones.
- Gell-Mann and Georg Zweig proposed the quark model in 1964.
- Pauli principle: in one system of interconnected particles there never exist at least two particles with identical parameters if these particles have a half-integer spin.
What is spin?
- Spin demonstrates that there is a state space that has nothing to do with the movement of a particle in ordinary space;
- Spin (from English to spin - to spin) is often compared with the angular momentum of a "quickly rotating top" - this is not true!
- Spin is an intrinsic quantum characteristic of a particle that has no analogue in classical mechanics;
- Spin (from the English spin - rotate [-sya], rotation) - the intrinsic angular momentum of elementary particles, which has a quantum nature and is not associated with the movement of the particle as a whole
Four types of physical interactions
- gravity,
- electromagnetic,
- weak,
- strong.
- Weak interaction- changes the internal nature of the particles.
- Strong interactions- cause various nuclear reactions, as well as the emergence of forces that bind neutrons and protons in nuclei.
Properties of quarks
- Quarks have a property called color charge.
- There are three types of color charge, conventionally denoted as
- blue,
- green
- Red.
- Each color has an addition in the form of its anti-color - anti-blue, anti-green and anti-red.
- Unlike quarks, antiquarks do not have color, but anticolor, that is, the opposite color charge.
Properties of quarks: mass
- Quarks have two main types of masses that do not match in magnitude:
- the mass of the current quark, estimated in processes with significant 4-momentum squared transfer, and
- structural mass (block, constituent mass); also includes the mass of the gluon field around the quark and is estimated from the mass of hadrons and their quark composition.
Properties of quarks: flavor
- Each flavor (kind) of a quark is characterized by such quantum numbers as
- isospin Iz,
- oddity S,
- charm C,
- beauty (bottominess, beauty) B′,
- truth (topness) T.
Tasks
- What energy is released during the annihilation of an electron and a positron?
- What energy is released during the annihilation of a proton and an antiproton?
- What nuclear processes produce neutrinos?
- A. With α - decay.
- B. With β - decay.
- B. With the radiation of γ - quanta.
- What nuclear processes produce antineutrinos?
- A. With α - decay.
- B. With β - decay.
- B. With the radiation of γ - quanta.
- D. With any nuclear transformations
- The proton is...
- BUT. . . .neutron, positron and neutrino.
- B. . . .mesons.
- AT. . . .quarks.
- G. Proton has no constituent parts.
- The neutron is...
- BUT. . . .proton, electron and neutrino.
- B. . . .mesons.
- AT. . . . quarks.
- G. The neutron has no constituent parts.
- What was proved by the experiments of Davisson and Germer?
- A. Quantum character of energy absorption by atoms.
- B. Quantum nature of radiation of energy by atoms.
- B. Wave properties of light.
- D. Wave properties of electrons.
- Which of the following formulas determines the de Broglie wavelength for an electron (m and v are the mass and speed of the electron)?
Test
- What physical systems are formed from elementary particles as a result of electromagnetic interaction? A. Electrons, protons. B. The nuclei of atoms. B. Atoms, molecules of matter and antiparticles.
- From the point of view of interaction, all particles are divided into three types: A. Mesons, photons and leptons. B. Photons, leptons and baryons. B. Photons, leptons and hadrons.
- What is the main factor in the existence of elementary particles? A. Mutual transformation. B. Stability. B. Interaction of particles with each other.
- What interactions determine the stability of nuclei in atoms? A. Gravity. B. Electromagnetic. B. Nuclear. D. Weak.
- Are there permanent particles in nature? A. There are. B. Do not exist.
- The reality of the transformation of matter into an electromagnetic field: A. Confirmed by the experience of annihilation of an electron and a positron. B. Confirmed by the experience of the annihilation of an electron and a proton.
- The reaction of the transformation of matter in the field: A. e + 2γ → e + B. e + 2γ → e- C. e + + e- \u003d 2γ.
- What interaction is responsible for the transformation of elementary particles into each other? A. Strong interaction. B. Gravitational. C. Weak interaction D. Strong, weak, electromagnetic.
Municipal budgetary non-standard educational institution "Gymnasium No. 1 named after Tasirov G.Kh. of the city of Belovo" Elementary particles Presentation for a physics lesson in grade 11 (profile level) Completed by: Popova I.A., teacher of physics Belovo, 2012 PURPOSE: Familiarization with elementary particle physics and systematization of knowledge on the topic. The development of abstract, ecological and scientific thinking of students based on ideas about elementary particles and their interactions How many elements are in the periodic table? Only 92. How? Is there more? True, but all the rest are artificially obtained, they do not occur in nature. So - 92 atoms. Molecules can also be made from them, i.e. substances! But the fact that all substances are made up of atoms was argued by Democritus (400 BC). He was a great traveler, and his favorite saying was: "There is nothing but atoms and pure space, everything else is a view" Chronology of particle physics Democritus Atom Date Scientist's surname Discovery (hypothesis) 400 BC. Early XX 1910 1928 1928 1929 Thomson Electron An antiparticle is a particle having the same mass and spin as E. Rutherford, but Dirac and the discovery of the positron have opposite Anderson charges of all types; A. Einstein Photon P. Dirac Prediction of the existence 1931 Pauli Discovery of the neutrino and antineutrino 1932 J. Chadwick 1932 1930 1935 antiparticles For any neutron of an elementary particle there is its own antiparticle - positron e + V. Pauli antiparticle Prediction of the existence of Yukawa neutrino n Discovery of the meson Chronology of particle physics Date Discovery (hypothesis) Theoretical physicists faced the second stage of the most difficult task throughout 1947. hundreds of new lows, others 1960s. consist of elementary particles having particle masses of fundamental particles in the range from 140 MeV to 2 GeV. All these particles were unstable; decayed into particles with smaller masses, eventually turning into a stable proton, electron, photon and neutrino (and their antiparticles). Chronology of particle physics Date Name of the scientist Discovery (hypothesis) Third stage 1962 M. Gell-Mann Proposed a model and independently structures of strongly interacting particles J. Zweig from fundamental particles of quarks 1995 a coherent theory of all known types of particle interactions. quark How to detect an elementary particle? Usually, traces (trajectories or tracks) left by particles are studied and analyzed from photographs. Classification of elementary particles All particles are divided into two classes: 1. Fermions, which make up matter; 2. Bosons through which the interaction is carried out. Classification of elementary Quarks participate in strong interactions, and particles also in weak and electromagnetic ones. Fermions are subdivided into leptons and quarks. Quarks Gell-Mann and Georg Zweig proposed the quark model in 1964. Pauli's principle: in the same system of interconnected particles there never exist at least two particles with identical parameters if these particles have half-integer spin. M. Gell-Mann at the conference in 2007 What is spin? Spin demonstrates that there is a Spin (from the English. spin - rotate [-sya], state space, in no way connected with rotation) - the proper movement of a particle in an ordinary moment in space; the momentum of elementary particles, Spin (from the English quantum to spin - to spin) is often compared with the angular momentum "quickly associated with the movement of a particle of a rotating top" - this is not true! as a whole, Spin is an internal quantum characteristic of a particle, which has no analogue in classical mechanics; Spins of some microparticles Spin 0 Common name for particles π-mesons, K-mesons, Higgs boson, atoms and scalar particles of the 4He nucleus, even-even nuclei, parapositronium 1/2 spinor particles 1 vector particles 3/2 spin-vector particles 2 Examples electron , quarks, proton, neutron, atoms and nuclei 3He photon, gluon, vector mesons, orthopositronium Δ-isobars tensor particles graviton, tensor mesons Quarks Quarks participate in strong interactions, as well as in weak and electromagnetic ones. Fractional charges of quarks - from -1/3e to +2/3e (e is the electron charge). Quarks in today's Universe exist only in bound states - only as part of hadrons. For example, a proton is uud, a neutron is udd. Four types of physical interactions are gravitational, electromagnetic, weak, nuclear strong. There is only one mechanism: Weak interaction - interactions change the internal nature of particles due to the exchange. particles Strong interactionsothers - cause various nuclear reactions, and carriers also the emergence of forces that bind interaction neutrons. and protons in nuclei. Four kinds of physical interactions Electromagnetic And photons, and Interaction Radius of action Const. mutual interaction: the carrier of gravitons is not a photon. have masses Gravitational -39 Gravitational Infinitely large 6.10 interaction: carriers - (rest masses) and gravitational field quanta always move gravitons. Electromagnetic Infinitely large 1/137 with speed Weak interactions: light. carriers are vector bosons. Weak Does not exceed 10-16 cm 10-14 Significant difference Carriers of strong carriers of weak interactions: gluons (from -13 interaction from a photon Strong Do not glue exceeds 10 cm 1 of the English word - glue), and graviton is their rest mass equal to zero. massiveness. Properties of quarks Quark supermultiplets (triad
When the Greek philosopher Democritus called the simplest, indivisible particles further atoms (the word atom, recall, means “indivisible”), then he probably didn’t think everything was very complicated in principle. Various objects, plants, animals are built from indivisible, unchanging particles. The transformations observed in the world are a simple permutation of atoms. Everything in the world flows, everything changes, except for the atoms themselves, which remain unchanged.
But at the end of the 19th century, the complex structure of atoms was discovered and the electron was isolated as an integral part of the atom. Then, already in the 20th century, the proton and neutron were discovered - particles that make up the atomic nucleus. At first, all these particles were looked at exactly the same way as Democritus looked at atoms: they were considered indivisible and unchanging original entities, the basic building blocks of the universe.
The situation of attractive clarity did not last long. Everything turned out to be much more complicated:
as it turned out, there are no constant particles at all. In the very word elementary has a double meaning.
On the one hand, elementary is self-evident, the simplest. On the other hand, elementary is understood as something fundamental, underlying things (it is in this sense that they are now called subatomic particles elementary).
The following simple fact prevents us from considering the elementary particles known now as similar to the unchanging atoms of Democritus. None of the particles are immortal. Most of the particles now called elementary cannot live for more than two millionths of a second, even in the absence of any outside influence. A free neutron (a neutron outside the atomic nucleus) lives an average of 15 minutes.
Only photon, electron, proton and neutrino would retain their invariance if each of them were alone in the whole world (the neutrino is devoid of electric charge and its rest mass, apparently, is equal to zero).
But electrons and protons have the most dangerous brothers - positrons and antiprotons, upon collision with which the mutual annihilation of these particles and the formation of new ones occur.
A photon emitted by a table lamp lives no more than 10~8 s. This is the time it takes for it to reach the page of the book and be swallowed up by the paper. Only neutrinos are almost immortal due to the fact that they interact extremely weakly with other particles. However, neutrinos also die in collisions with other particles, although such collisions are extremely rare.
All elementary particles transform into each other, and these mutual transformations are the main fact of their existence.
Scientists observed transformations of elementary particles during collisions of high-energy particles.
Ideas about the immutability of elementary particles turned out to be untenable. But the idea of their indecomposability persisted.
Elementary particles are further indivisible, but they are inexhaustible in their properties.
That's what makes me think so. Let us have a natural desire to investigate whether, for example, an electron consists of any other subelementary particles. What needs to be done in order to try to dismember the electron? You can think of only one way. This is the same way that a child uses when he wants to know what is inside a plastic toy - a hard blow.
According to modern concepts, elementary particles are primary, further indecomposable particles, from which all matter is built. However, the indivisibility of elementary particles does not mean that they do not have an internal structure.
In the 60s. doubts arose that all the particles now called elementary fully justify this name. The basis for doubt is simple: there are a lot of these particles.
The discovery of a new elementary particle has always been and is now an outstanding triumph of science. But for quite a long time, a share of anxiety began to be added to each successive triumph. Triumphs began to follow literally one after another.
A group of so-called "strange" particles: K-me- zones and hyperons with masses exceeding the mass of nucleons. In the 70s. to them was added a large group of particles with even greater masses, called "enchanted". In addition, short-lived particles with a lifetime on the order of 10~22 -10~23 s have been discovered. These particles were named resonances, and their number exceeded two hundred.
It was then (in 1964) that M. Gell-Mannon and J. Zweig proposed a model according to which all particles participating in strong (nuclear) interactions hadrons, built from more fundamental (or primary) particles - quarks.
Quarks have a fractional electric charge . Protons and neutrons are made up of three quarks.
At present, no one doubts the reality of quarks, although they have not been detected in a free state and, probably, will never be detected. The existence of quarks is proved by experiments on the scattering of electrons of very high energy on protons and neutrons. The number of different quarks is six. Quarks, as far as is now known, lack an internal structure and in this sense can be considered truly elementary.
Light particles that do not participate in strong interactions are called leptons. There are also six of them, as well as quarks (an electron, three types of neutrinos and two more particles - a muon and a tau-lepton with masses much larger than the mass of an electron).
The existence of a twin of an electron - a positron - was theoretically predicted by the English physicist P. Dirac in 1931. At the same time, Dirac predicted that when a positron meets an electron, both particles should disappear giving rise to high-energy photons. The reverse process may also take place. the birth of an electron-positron pair, for example, in the collision of a photon of sufficiently high energy (its mass must be greater than the sum of the rest masses of the generated particles) with a nucleus.
Two years later, the positron was discovered using a cloud chamber placed in a magnetic field. The direction of curvature of the particle track indicated the sign of its charge. The ratio of its charge to mass was determined from the radius of curvature and energy of the particle. It turned out to be the same modulo as that of an electron. In figure 190 you see the first photograph that proved the existence of the positron. The particle moved from bottom to top and, having passed the lead plate, lost some of its energy. Because of this, the curvature of the trajectory increased.
The process of creating an electron-positron pair by a y-quantum in a lead plate is visible in the photograph shown in Figure 191. In a cloud chamber, located in a magnetic field, the pair leaves a characteristic trace in the form of a two-horned fork.
disappearance (annihilation) some particles and the appearance of others in reactions between elementary
Rest energy is the most grandiose and concentrated reservoir of energy in the Universe. And only during annihilation is it completely released, turning into other types of energy. Therefore, antimatter is the most perfect source of energy, the most high-calorie “fuel”. Whether humanity will ever be able to use this "fuel" is difficult to say now.
any particle with the corresponding antiparticle is annihilated. Both particles disappear, turning into radiation quanta or other particles.
Discovered relatively recently antiproton and - antineutron. The electric charge of the antiproton is negative. It is now well known that the birth of couples particle - antiparticle and their annihilation do not constitute a monopoly of electrons and positrons.
Atoms whose nuclei consist of antinucleons and whose shell consists of positrons form antimatter. In 1969, for the first time in our country, antihelium.
The answer to the ongoing question: what is the smallest particle in the universe has evolved with humanity.
People once thought that grains of sand were the building blocks of what we see around us. Then the atom was discovered and it was considered indivisible until it was split to reveal the protons, neutrons and electrons within. They didn't turn out to be the smallest particles in the universe either, as scientists discovered that protons and neutrons are made up of three quarks each.
So far, scientists have not been able to see any evidence that there is something inside quarks and that the most fundamental layer of matter or the smallest particle in the universe has been reached.
And even if quarks and electrons are indivisible, scientists don't know if they are the smallest bits of matter in existence or if the universe contains objects that are even smaller.
The smallest particles in the universe
They come in different flavors and sizes, some have an amazing bond, others essentially vaporize each other, many of them have fantastic names: baryons and mesons quarks, neutrons and protons, nucleons, hyperons, mesons, baryons, nucleons, photons, etc. .d.
The Higgs boson is a particle so important to science that it is called the "God particle". It is believed that it determines the mass of all others. The element was first theorized in 1964 when scientists wondered why some particles are more massive than others.
The Higgs boson is associated with the so-called Higgs field which is believed to fill the universe. Two elements (the Higgs field quantum and the Higgs boson) are responsible for giving others mass. Named after the Scottish scientist Peter Higgs. On March 14, 2013, the confirmation of the existence of the Higgs Boson was officially announced.
Many scientists argue that the Higgs mechanism has solved the missing piece of the puzzle to complete the existing "standard model" of physics that describes known particles.
The Higgs boson fundamentally determined the mass of everything that exists in the universe.
Quarks
Quarks (translated as crazy) are the building blocks of protons and neutrons. They are never alone, existing only in groups. Apparently, the force that binds quarks together increases with distance, so the farther away, the harder it will be to separate them. Therefore, free quarks never exist in nature.
Quarks fundamental particles are structureless, dotted about 10-16 cm in size.
For example, protons and neutrons are made up of three quarks, with protons having two identical quarks while neutrons have two different ones.
Supersymmetry
It is known that the fundamental "bricks" of matter - fermions - are quarks and leptons, and the keepers of the force of bosons are photons, gluons. The theory of supersymmetry says that fermions and bosons can turn into each other.
The predictive theory says that for every particle known to us, there is a sister particle that we have not yet discovered. For example, for an electron it is a selekron, a quark is a squark, a photon is a photino, and a higgs is a higgsino.
Why don't we observe this supersymmetry in the Universe now? Scientists believe that they are much heavier than their conventional cousins, and the heavier they are, the shorter their lifespan. In fact, they begin to break down as soon as they arise. The creation of supersymmetry requires quite a lot of energy, which only existed shortly after the big bang and could possibly be created in large accelerators like the Large Hadron Collider.
As to why the symmetry arose, physicists speculate that the symmetry may have been broken in some hidden sector of the universe that we cannot see or touch, but can only feel gravitationally.
Neutrino
Neutrinos are light subatomic particles that whistle everywhere at the close speed of light. In fact, trillions of neutrinos are streaming through your body at any given moment, although they rarely interact with normal matter.
Some come from the sun, while others come from cosmic rays interacting with the Earth's atmosphere and astronomical sources such as exploding stars in the Milky Way and other distant galaxies.
Antimatter
It is believed that all normal particles have antimatter with the same mass but opposite charge. When matter and meet, they destroy each other. For example, the antimatter particle of a proton is an antiproton, while the antimatter partner of an electron is called a positron. Antimatter is one of the most expensive substances in the world that people have been able to identify.
Gravitons
In the field of quantum mechanics, all fundamental forces are transmitted by particles. For example, light is made up of massless particles called photons that carry electromagnetic force. Similarly, the graviton is a theoretical particle that carries the force of gravity. Scientists have yet to discover gravitons, which are hard to find because they interact so weakly with matter.
Threads of energy
In experiments, tiny particles such as quarks and electrons act as single points of matter with no spatial distribution. But point objects complicate the laws of physics. Since it is impossible to approach infinitely close to the point, since the acting forces can become infinitely large.
An idea called superstring theory can solve this problem. The theory states that all particles, instead of being pointlike, are actually small filaments of energy. That is, all objects of our world consist of vibrating threads and membranes of energy. 
Nothing can be infinitely close to the thread because one part will always be slightly closer than the other. This "loophole" seems to solve some of the problems of infinity, making the idea attractive to physicists. However, scientists still have no experimental evidence that string theory is correct.
Another way of solving the point problem is to say that space itself is not continuous and smooth, but is actually made up of discrete pixels or grains, sometimes called the spatiotemporal structure. In this case, two particles cannot approach each other indefinitely, because they must always be separated by the minimum grain size of space.
black hole point
Another contender for the title of the smallest particle in the universe is a singularity (a single point) at the center of a black hole. Black holes form when matter condenses in a small enough space that gravity grabs onto it, causing the matter to be drawn inward, eventually condensing into a single point of infinite density. At least according to the current laws of physics.
But most experts don't consider black holes to be truly infinitely dense. They believe that this infinity is the result of an internal conflict between two current theories - general relativity and quantum mechanics. They suggest that when the theory of quantum gravity can be formulated, the true nature of black holes will be revealed.
Planck length
Threads of energy and even the smallest particle in the universe can be the size of a “plank length”.
The length of the bar is 1.6 x 10 -35 meters (the number 16 preceded by 34 zeros and a decimal point) - an incomprehensibly small scale that is associated with various aspects of physics.
The Planck length is the "natural unit" for measuring length, which was proposed by the German physicist Max Planck.
The Planck length is too small for any instrument to measure, but beyond that, it is believed to represent the theoretical limit of the shortest measurable length. According to the uncertainty principle, no instrument should ever be able to measure anything less than this, because in this range the universe is probabilistic and uncertain.
This scale is also considered the dividing line between general relativity and quantum mechanics.
The Planck length corresponds to the distance where the gravitational field is so strong that it can start making black holes out of the field's energy.
Apparently now, the smallest particle in the universe is about the size of a plank length: 1.6 10 −35 meters
findings
From the school bench it was known that the smallest particle in the Universe, the electron, has a negative charge and a very small mass, equal to 9.109 x 10 - 31 kg, and the classical radius of the electron is 2.82 x 10 -15 m.
However, physicists are already working with the smallest particles in the universe, the Planck size, which is about 1.6 x 10 −35 meters.
