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The Standard Model problems lead to the new theories of extra dimensions: Randall-Sundrum model, Arkani-Hamed-Dimopoulos-Dvali model, and

The problems with theoretical explanation of vacuum energy as well as dark energy, dark matter, and cosmological constant problems are only the tip of the iceberg of problems in the modern theoretical physics. Some of them are

ordinary matter accounting for about 5% of mass energy in the Universe and no dark matter candidate in the Standard Model (SM),

hierarchy problem,

fine tuning of SM Higgs mass,

no explanation for fermion masses and mixings and three family structures,

unification of strong, electroweak, and gravitational forces,

compositeness of leptons and quarks,

It is an experimental fact that there is something we cannot explain within the SM.

As is known, vacuum is produced in the processes of phase transitions in Early Universe and the space-time structure of the physical vacuum exhibits the connection to the structure formation in our Universe. So, the understanding of Universe formation is deeply connected with the conception of the space-time. According to hierarchy formula [

Historically, KK theory appeared as the unification of gravitational and electromagnetic interactions due to the proposition of a fifth dimension in addition to the usual four-dimensional space-time [

Today, the idea of additional space as the instrumentation of the unification of all four interactions is of interest not only in theoretical physics [

Our paper is devoted to the searches for KK particles in three models of extra dimensions: Arkani-Hamed-Dimopoulos-Dvali (ADD) model, [

the production cross section of KK modes of massive gravitons and gauge bosons at energies from 14 TeV to planned 100 TeV,

the graviton mass spectrum for three graviton, G, emission processes: (a)

the graviton mass spectrum at 14 TeV at the LHC for numbers of extra dimensions (

the production cross section of graviton,

In this section, we will observe three models of extra dimensions, ADD, RS, and

RS theory presented by the gravity and weak branes as the 4-dimensional boundaries of the extra dimension (from [

Masses of KK particles for RS model are given by

The advantage of the presented models of extra dimensions lies in the possibility of the observation of the physics of Planck scales,

ADD model:

RS model:

RS resonances, connected with production of KK graviton, G, are described in [

Processes for the graviton resonance production through (a) quark-quark and (b) gluon-gluon fusion.

The ADD graviton emission and virtual graviton exchange processes are described in [

With the help of computer program Pythia8.2 for three models of extra dimensions, we have calculated the production cross sections of KK particles at energies varying from 14 to 100 TeV. According to the latest experimental data presented in [

The production cross section at the center of mass energies varying from 14 to 100 TeV for (a) LED model: left panel, dijet final state; right panel, monojet final state; (b) left panel, RS model; right panel,

From Figure

Within

Production cross sections at 20 TeV, 60 TeV, and 100 TeV at the center of mass energies as a function of KK mass for

From Figure

We will apply large-extra-dimensional (ADD-type) models in production processes for virtual extra dimensional scalars of graviscalar type. With the help of Pythia8.2, it is possible to generate monojet events from scalar graviton emission as described in [

The group of lowest-order G jet emission processes within monojet model was considered with the following parameters: ExtraDimensionsLED:

Graviton mass spectrum within monojet LED model for three graviton, G, emission processes: (a)

From Figure

As LED model depends on the number of extra dimensions,

Graviton mass spectrum within monojet LED model for G jet emission process

From Figure

As is known, the discovery of a Higgs boson,

The expected and observed upper limit for

From [

Branching fractions of graviton, G (from [

We will consider three processes of graviton decay,

From Figure

The modern high energy physics is connected with experimental searches of new physics beyond the SM. These searches are connected not only with new possibilities of modern accelerating technics but also with problems of SM physics. The SM problems are not only of theoretical character but also of experimental one, which is confirmed by modern experiments on the Higgs boson. Our work is dedicated to the studying of the properties of the new particles predicted by the theories of extra dimensions. Within three models, ADD, RS, and

The authors declare that there are no conflicts of interest regarding the publication of this paper.