Intermediate vector bosons. intermediate boson

INTERMEDIATE VECTOR BOSONS

Physical Encyclopedic Dictionary. - M.: Soviet Encyclopedia. . 1983 .

INTERMEDIATE VECTOR BOSONS

- vector Particles, due to the exchange of which is carried out weak interaction. They are called "intermediate" in historical terms. reasons, since their existence was predicted theoretically long before their direct discovery as real particles (1983), namely, the local four-fermion charged currents and neutral ticks was presented as the result of an "intermediate" exchange of virtual particles [in Fig. in ca-

As an example, it is shown how the indicated exchange is carried out in scattering by an electron

]. These bosons are intermediate in the same sense as (g) in charge scattering. particles. Exchange of vector bosons (electric respectively + e and - e)(electric charge 0) and g provides a connection between currents in a unified theory electroweak interaction, based on the symmetry group SU(2) x U(l). In this theory, masses (masses

and equal) and -bosons are calculated theoretically and are expressed in terms of the Fermi constant and Weinberg angle:

where a=1/137 is the fine structure constant. Weinberg angle and masses are measured in independent

experiments, therefore, the validity of the above relations with a percentage error is a very important argument in favor of the theory of the electroweak interaction.

Mass () and width charge. The W bosons are 80.60.4 GeV and 2.250.14 GeV, respectively, and the neutral boson widths are 91.1610.031 GeV and 2.5340.027 GeV. Charge The W boson decays into hadronic states in 70% of cases, and into lepton states in 30% of cases, and (the relative probability of each leptonic state is 10%). The Z° boson decays into hadronic states in 71% of cases, its lepton decay modes and their relative ones are equal, respectively: (3.2%), (3.36%), (3.33%) and

(19,2%). M. V. Terentiev.

Physical encyclopedia. In 5 volumes. - M.: Soviet Encyclopedia. Editor-in-Chief A. M. Prokhorov. 1988 .

See what "INTERMEDIATE VECTOR BOSONS" is in other dictionaries:

Particles W, Z0 with masses on the order of 80 and 90 GeV are carriers of the weak interaction. Experimentally discovered in 1983 ... Big Encyclopedic Dictionary

Particles W±, Z0 with masses of the order of 80 and 90 GeV, due to the exchange of which weak interaction is carried out. Experimentally discovered in 1983. * * * INTERMEDIATE VECTOR BOSONS INTERMEDIATE VECTOR BOSONS, W, Z0 particles with masses of about 80 and … encyclopedic Dictionary

Particles W+, Z0 with masses of the order of 80 and 90 GeV, due to the exchange of which weak interaction is carried out. Experimentally discovered in 1983 ... Natural science. encyclopedic Dictionary

intermediate vector bosons- Particles with spin 1, carrying out weak interaction ... Polytechnic terminological explanatory dictionary

Introduction. E. parts in the exact meaning of this term are primary, further indecomposable parts, from which, by assumption, all matter consists. In modern physics the term "E. h." usually used not in its exact meaning, but less strictly for the name ... ... Physical Encyclopedia

The composition of matter is incredibly simple. All visible matter in the Universe on Earth and in space is made up of three different kinds of fundamental particles: electrons and two types of quarks. These three particles (as well as others described below) are mutually attracted and ... ... Collier Encyclopedia

General name class ext. symmetries of field theory equations (i.e., symmetries associated with the elements of the field theory, and not with the properties of space-time), characterized by parameters that depend on a point in space-time (r, t). In physics it is accepted ... ... Physical Encyclopedia

- (KFT), relativistic quantum. theory of physics. systems with an infinite number of degrees of freedom. An example of such an email system. magn. field, for a complete description of the horn at any time, the assignment of electric strengths is required. and magn. fields at each point ... Physical Encyclopedia

Unified Gauge Theory of Electron. magn. and weak impact. (see WEAK INTERACTION). Physical Encyclopedic Dictionary. Moscow: Soviet Encyclopedia. Editor-in-Chief A. M. Prokhorov. 1983... Physical Encyclopedia

- (Fermi-Bose symmetry), a symmetry that connects fields, quanta to ryh have an integer. spin (yavl. bosons), with fields, quanta to ryh have a half-integer spin (yavl. fermions). The fields that transform during S. transformations through each other form ... ... Physical Encyclopedia

Meaning of INTERMEDIATE VECTOR BOSONS in the Big Encyclopedic Dictionary

INTERMEDIATE VECTOR BOSONS

particles W, Z0 with masses on the order of 80 and 90 GeV are carriers of the weak interaction. Experimentally discovered in 1983.

Big encyclopedic dictionary. 2012

"INTERMEDIATE VECTOR BOSONS" in books

I. Intermediate steps

From the book You can believe in people ... Notebooks of a good person author Saint Exupery Antoine de

I. Intermediate Stages Many contemporaries spoke of this brief but eventful life. In the beginning there was Antoine de Saint-Exupery, a "strong, cheerful, open" boy, who at the age of twelve was already inventing an airplane bicycle and declared that it would take off into the sky under

Intermediate dishes

From the book The Best Dishes for the Holiday Table. Simple, cheap, beautiful, delicious author Zvonareva Agafya Tikhonovna

intermediate goals

From the book Goldratt's Theory of Constraints. A systematic approach to continuous improvement author Detmer William

Intermediate goals In the course of fulfilling the main task, we have to take a number of steps, go through several stages, and each of them is an intermediate

Year of birth and vector couples

From the book Astrology of Love and Relationships. Date of birth will tell you how to meet your half and create a strong family author Solyanik Katerina

Year of birth and vector pairs Of course, eastern astrology is much more complicated than those horoscopes according to the signs of the zodiac of the eastern calendar, which are widely known. However, even these twelve characteristics can at the first stage clarify the situation with the prospect of building

40. Intermediate chakras

From the book Pranayama. The path to the secrets of yoga author Lisbeth Andre van

Intermediate bodies

From the book Life of the Soul in the Body author Sheremeteva Galina Borisovna

Intermediate bodies Experience of travelers in past lives Disruption of unity with the world, loss of a number of qualities and deformation of the matrix can create conditions for the soul to spend an intermediate life in the body of a plant or animal. Very rarely she can get a body

Vector commandments

From the book Practical course of Grigory Kvasha. Structural horoscope author Kvasha Grigory Semenovich

Vector commandments 1. For some, a vector marriage is an obvious proof of divine intervention in our lives, for others it is an equally obvious consequence of the devil's machinations. Hence the main commandment: entering into a vector marriage, do not expect to remain in the shadows. Vector

5.6. Intermediate states

From the book of Kabbalah. Upper world. The beginning of the way author Laitman Michael

5.6. Intermediate States In the spiritual world, there are intermediate states between the four basic states (inanimate, vegetative, animal and human). There is a certain set of elements, the order of which determines the transfer of information. In animal nature, this

1. Scalar, vector and tensor fields

From the book Gravity [From crystal spheres to wormholes] author Petrov Alexander Nikolaevich

1. Scalar, vector and tensor fields In the main text and further in the Appendixes we use the concepts of scalar, vector and tensor fields. In order to avoid discomfort when meeting with these terms, we will give some explanations. It's better to start with a vector. In normal 3D

3. Fermions and bosons

From the book Five Unsolved Problems of Science author Wiggins Arthur

3. Fermions and bosons All particles that make up the Universe fall into two groups: fermions and bosons. A similar distinction was introduced by graduate students at the University of Leiden (Holland) Samuel Goudsmit and George Uhlenbeck. Goudsmit, more occupied with research, remarked

Intermediate conclusions

From the book of the Assassins of Stalin. The main secret of the XX century author Mukhin Yury Ignatievich

Intermediate conclusions What do we need to isolate and remember from here? firstly, some kind of conspiracy has matured among the elite of the CPSU (b), and not just “peaceful opposition” or people “dissatisfied with Stalin’s policies”, but a conspiracy of vicious and decisive people capable of killing someone

Subtotals

From the book World War II author Utkin Anatoly Ivanovich

Intermediate results German troops approached less than a hundred kilometers from the capital of the Soviet Union. Under their dominion there was already a territory inhabited by 65 million inhabitants of the USSR. There were already three million Soviet prisoners in the German camps. Colonel

B.3. Vector read and write

From the book Programming for Linux. Professional approach author Mitchell Mark

4.6.5 Vector Parameters

From the C++ book by Hill Murray

4.6.5 Vector Parameters If a vector is used as a function parameter, then a pointer to its first element is passed. For example: int strlen(const char*);void f() (* char v = "a vector" strlen(v); strlen("Nicholas"); *); In other words, when passed as a parameter, the type parameter T is converted to T*.

6.1.10. Creating vector images

From the book Macintosh Tutorial author Skrylina Sofya

6.1.10. We create vector images To complete the task, we need the material of section. 5.1.10 and 5.1.11. Task number 1 Draw a house using vector graphics tools, taking fig. 6.10. The task is located on the first page of the document in the file: /pages/tasks/6.

The rapid development of elementary particle physics in recent years has significantly changed our ideas not only about hadrons, but also about leptons, that is, particles that have only weak and electromagnetic (charged leptons) interactions. In addition to the two pairs of leptons previously known (electrons and electron neutrinos and muons and muon neutrinos - see §§ 231, 233, 234), another heavy charged lepton was discovered, called the tau lepton (). Along with the t-lepton, apparently, there should be another neutrino, the so-called tau-neutrino (). True, this latter has not yet been observed in direct experiments. Tau neutrinos can appear, for example, in the decay of tau leptons or fly out together with tau leptons in the decays of heavier particles.

Each lepton has a corresponding antiparticle - an antilepton. Numerous experiments have shown that up to distances of the order of the order, leptons and anti-leptons behave like elementary "point" objects. It is leptons, together with quarks, that are, as they think today, truly elementary, or fundamental particles (see Table 14).

All processes of formation and decay of leptons (some of which were discussed earlier - see § 233) can be explained if we consider that leptons also have certain conserved quantum numbers, called "lepton charges" and reminiscent of the baryon charge.

Three types of such lepton charges are now known - electronic (), muonic () and tau-lepton ():

1) for electrons and electron neutrinos, the electron lepton charge, for their antiparticles, for all other particles;

2) for muons and muon neutrinos, the muon lepton charge is , for the corresponding antileptons , for all other particles ;

3) for tau lepton and tau neutrino; at anti-tau leptons ; for all other particles.

In all the processes studied so far, all three lepton charges are conserved. As an exercise, readers are invited to show, using the concept of conserved lepton charges, that decays (233.1), (233.2) and reactions (233.3), (233.4) can occur in nature, and processes such as , turn out to be forbidden. Indeed, these and other transitions that violate the laws of conservation of lepton charges have never been observed in any of the numerous search experiments. Leptons have no baryon charges and quark flavors, i.e., the corresponding quantum numbers are equal to zero. This is due to the fact that leptons do not participate in strong interactions at all.

In table. 14 we have placed those particles which today are considered truly elementary. Hadrons are not included in it, since their complex internal structure has been established quite reliably, and it has been proved that it is quarks “glued together” by the exchange of gluons that are the structural elements that make up hadrons. However, this table must be supplemented with other elementary particles. First of all, these are photons - quanta of the electromagnetic field, which carry out electromagnetic interactions between charged particles. We also placed gluons here, which carry out interactions between quarks and, together with quarks, are sentenced to “life imprisonment” inside hadrons.

Weak interactions also play a very important role in elementary particle physics. As already noted, this is the only interaction in nature that can change the individuality of fundamental particles - leptons and quarks - and cause mutual transformation between such particles (subjecting, however, to the laws of conservation of baryon and lepton charges). The question of what is the mechanism of action of weak forces has long been discussed. It has been suggested that these forces are due to the exchange of special quanta of the field of weak interactions, which are called intermediate bosons. Unlike gluons, intermediate bosons, like photons, must exist in a free state. The theory made it possible to predict the existence of three such intermediate bosons: - and -particles. And finally, in 1982-1983. intermediate bosons were discovered, and this discovery was a real sensation.

Intermediate bosons were registered in the most complex experiments at a storage accelerator with colliding proton-antiproton beams, at the energy of each of the colliding beams (now this energy has already been increased to ). This is the highest energy obtained artificially. A general view of one of the two huge installations on which this remarkable discovery was made is shown in Fig. 422, and in fig. 425 shows a snapshot from the computer display, on which the event of the formation and decay of an intermediate boson is registered.

The masses of intermediate bosons turned out to be very large - they are almost 100 times greater than the masses of nucleons (see Table 14). These are the heaviest particles created in the laboratory.

The discovery of intermediate bosons completed a very important cycle of research, which showed that the weak and electromagnetic forces, despite their apparent difference, are closely related to each other and, in essence, turn out to be manifestations of the same interaction, called the electroweak one. At present, intensive attempts are being made to establish links between the electroweak interaction and the strong one, and in the future even try to understand the unified nature of all four types of forces that exist in nature - strong, electromagnetic, weak and gravitational.

Rice. 425. Formation and decay of intermediate bosons. A snapshot is shown from the display of the computer on which the events registered at the installation were processed (Fig. 422). Beams of protons and antiprotons are directed along the axis of the cylindrical gas-discharge chamber of the facility, which is schematically shown on the display. An interaction event is shown in which a heavy intermediate boson is produced. An event (other particles) is registered on the image. Decay is observed: the muon is almost a transverse track with high momentum. The neutrino flies out in the opposite direction. It cannot be observed directly, but is identified by the kinematics of the event, since it carries away a large momentum.

The idea of the unity of strong, electromagnetic, and weak interactions conflicts with the division of fundamental particles into quarks, which have strong interactions, and leptons, which do not have such interactions. Some commonality of quarks and leptons may be evidenced by their division into groups having a similar structure. As can be seen from Table. 14, we can talk about three such groups, or, as they are called, generations, of fundamental particles: light -, -quarks and light leptons, , form the first such generation; heavier and -quarks together with muons and muon neutrinos constitute the second generation; and, finally, the heaviest quarks ( and ) and leptons () are part of the third generation. Apparently, there must be some processes in which quarks are converted into leptons, and different types of leptons () also experience mutual transformations. The search for such phenomena in which, although with a very low probability, there is still nonconservation of the baryon and lepton charges, is of great interest to modern science. For example, now in many laboratories of the world intensive searches are being made for the decay of protons into lighter particles (etc.). Due to the large mass of the proton, significant energy must be released in such decays.

Searches for the decay of protons are carried out on complex installations with large "sensitive volumes" of matter. The term "sensitive volume" means that if any nucleon in this volume decays into light particles, then such a decay will be registered. Sensitive volumes of existing and currently under construction installations contain nucleons, and exposures at these installations last for years. To protect against cosmic radiation, the installations are located in underground laboratories at great depths. So far it has not been possible to reliably register the decay of the proton. Several events found - "candidates for proton decays" - can be explained by background processes. In these experiments, it was found that the proton, even if it is not absolutely stable, has a huge lifetime years. This means, for example, that not a single proton decays with a high probability in a person during his entire life. The life scale of a proton turns out to be huge even in comparison with the lifetime of the Universe (years).

Three types of such lepton charges are now known - electronic (), muonic () and tau-lepton ():

1) for electrons and electron neutrinos, the electron lepton charge, for their antiparticles, for all other particles;

2) for muons and muon neutrinos, the muon lepton charge is , for the corresponding antileptons , for all other particles ;

3) for tau lepton and tau neutrino; at anti-tau leptons ; for all other particles.

Portal for the student. Self-training

Intermediate vector bosons. intermediate boson

See what "INTERMEDIATE VECTOR BOSONS" is in other dictionaries:

Meaning of INTERMEDIATE VECTOR BOSONS in the Big Encyclopedic Dictionary

See also interpretations, synonyms, meanings of the word and what is INTERMEDIATE VECTOR BOSONS in Russian in dictionaries, encyclopedias and reference books: