arXiv subjects

G. A. Kozlov

Publications and source records attributed to G. A. Kozlov.

At least 19 recordsLinked to original sources

arXiv2026

The formation of inhomogeneities in gravitational string like mode

The investigation of the inhomogeneities in modern inflationary Universe scenarios is related, in particular, with the study of the role played by scalar fields in cosmological evolution. We present the model described by one of the extensions of the Abelian-Higgs theory, where the scale-invariant approach to the Standard Model (SM) is achieved by introducing the complex scalar fields and the vector fields in the hidden (dark) sector, where the latter and the SM are minimally coupled to gravity. The formation of the cosmological compact objects intuitively is explained in terms of the topological line defects - the string like tubes. The strings can get an energetically preferable configuration corresponding to the magnetic flux quantum inside an area defined by the mass of dark vector field.

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arXiv2024

Random fluctuation walk in the boson star formation process

We construct the mechanism of formation of the scalar boson star (BS) having a hierarchy of self-similar "lumps" of dark matter (DM) built into the probability distribution function of allowed steps. It can ensure to study the dynamics of the BS formation through the "cross-over" between the free scalar DM and the compact condensate (CC) phase in one-dimensional model of the random fluctuation walk. The main inputs are the random fluctuating weight $λ< 1$, the fundamental fluctuating length $ξ(λ)$ and the parameter $a >1$ of the spatial separation between the DM "lumps" inside the BS. The solution to the functional equation for the characteristic probability to find the free scalar DM and the CC phase is obtained. The time evolution of the probability to form the DM "lump" (growth of the BS) is presented with the power-law cascades expression depending on $λ$ and $a$. The special cases for $λ$ in terms of the energy densities of the BS ($ρ_\star$) and the DM ($ρ_\odot$), as well as the Bose-Einstein correlation function for two scalar DM particles, are considered. The lower bounds on the critical temperature at the "cross-over" depending on $ρ_\odot$, $ρ_\star$, the average multiplicities of the scalar DM particles and the parameters related to the chaotically behaviour of the particles are obtained.

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arXiv2024

Scalar boson stars: (thermo)dynamics and gravitational equilibria

We analyse the (thermo)dynamics of the scalar degrees of freedom in the scalar boson stars through the dark matter density under extreme conditions. The boson stars are studied in terms of a dark scalar sector in such a way this sector couples to the standard model Higgs boson doublet plus gravity.The stability of the BS is investigated at the level of the interaction between the scalars with the scale invariance breaking triggered by the electroweak symmetry breaking plus gravity. Analytic methods have been applied to an effective version of the theory, the scalar "tower" approximation, which should preserve an exact scale invariance. The production of the scalar dark matter and its decay have been discussed.

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arXiv2024

Intuitive study to the scalar boson stars formation

We study the feebly interacting dark matter with the Standard Model fields, where the preceding and the latter ones are the constituents of the bosonic cosmological objects, the scalar boson stars (BS). The scalar dark matter (SDM) massive fields can form the macroscopic scalar bound state when minimally coupled to gravity (GR). The star may have approximately a stationary form with an asymptotically flat geometry, and the maximal mass of the BS is larger than the solar mass. We consider an effective description of a more complete model with the (thermo)dynamic potential of the BS at finite temperature. The formation of the BS may also be explained in terms of the electric fluxes of the hidden vector field under the influence of the SDM field as the cosmological dynamical quantity minimally coupled to GR. The SDM fields may fluctuate with the temperature and is established around the equilibrium state at some weak background scale.

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arXiv2022

Primary photons, boson star and phase transition

We analyse the possibility that the dark matter candidate is from the approximate scale symmetry theory of the hidden scalar sector. The study includes the warm dark matter scenario and the Bose-Einstein condensation which may lead to the scalar boson stars (BS) giving rise to direct detection through the observation of the primary (direct) photons. The dynamical system of the scalar particles, the dilatons, at finite temperature and chemical potential is considered. The fluctuation of the particle density increases sharply within the increasing of the temperature. When the phase transition approaches, the fluctuation of the particle density has the non-monotonous rising when the ground state of the relative chemical potential tends to the critical value equal to one accompanying by the infinite number of particles. Our results suggest that the phase transition in the BS may be identified through the fluctuation in yield of primary photons induced directly by the conformal anomaly. The fluctuation rate of the photons grows up intensively in the infra-red to become very large at the phase transition.

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arXiv2022

The scalar garlands in the boson star

In the paper, we introduce the formalism to examine the impact of the hidden scalar sector to the conformal and the electroweak symmetries breaking. The novel approach to the scalar boson star (BS) naturalness is considered. The BS is presented by the local scalar field containing the Higgs boson field and the garland-like scalar dilaton fields of the conformal field theory. We show that taking into account the repulsive self-interactions and the flatness degree in the dark scalar sector prevents instability of the BS related to the black hole formation. We study in details how electroweak symmetry breaking affects the hidden sector by breaking its conformal symmetry and generating a mass gap to avoid the infra-red divergence. We apply our formalism to determine the modification of the Higgs quartic coupling away from its standard model (SM) value within the influence of the hidden sector. We have estimated the rate of the deviation from the SM with production of leptonic pairs due to decay of the dilaton and the dark photon. The latter is the subject of the dilaton decay first. The effect of new physics should be visible at the maximal energies of the LHC and the FCC.

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arXiv2020

COMET Phase-I Technical Design Report

The Technical Design for the COMET Phase-I experiment is presented in this paper. COMET is an experiment at J-PARC, Japan, which will search for neutrinoless conversion of muons into electrons in the field of an aluminium nucleus ($μ-e$ conversion, $μ^- N \to e^- N$); a lepton flavor violating process. The experimental sensitivity goal for this process in the Phase-I experiment is $3.1\times10^{-15}$, or 90 % upper limit of branching ratio of $7\times 10^{-15}$, which is a factor of 100 improvement over the existing limit. The expected number of background events is 0.032. To achieve the target sensitivity and background level, the 3.2 kW 8 GeV proton beam from J-PARC will be used. Two types of detectors, CyDet and StrECAL, will be used for detecting the \mue conversion events, and for measuring the beam-related background events in view of the Phase-II experiment, respectively. Results from simulation on signal and background estimations are also described.

physics.ins-det↗

arXiv2019

Lesson from a soluble model of critical point and primary photons

The critical point in particle physics at high temperature is studied through the ideal gas of scalars, the dilatons, in the model that implies the spontaneous breaking of an approximate scale symmetry. We consider the dynamical system of identical particles weakly interacting to each other. The critical point with the temperature as a function of a dilaton mass is established. The fluctuation of particle density grows up very sharply at critical point. Our results also suggest that the critical point may be identified through the fluctuation in yield of primary photons induced by conformal anomaly of strong and electromagnetic sectors of matter.

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arXiv2016

Dark photons in the Dalitz-like decay of a scalar

The couplings of the Standard Model sector to the scale invariant degrees of freedom can open the possibility to study dark photons (DP). The Dalitz-like decay of the (Higgs-like) scalar boson into a single photon and DP is studied. The interaction between DP and quarks is mediated by the derivative of the scalar field - the dilaton, the virtual (fictitious) state. The mass of the dilaton does not enter the final solutions. Upper limits are set on the DP mass, the mixing strength between the standard photon and DP. The model does allow to estimate the DP mass with the value of 4.5 MeV.

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arXiv2015

Dark photons in the decay of Higgs-like boson

We study the dark matter particle, the dark photon (DP), in the decay of the Higgs-like boson. The nature of dark matter is maintained through the hidden sector including the effects of breaking of the scale invariance. The model is based on the additional $U^{\prime}(1)$ gauge group associated with light DP. The interaction between DP and quarks is mediated by the derivative of the scalar - the dilaton. The latter appears in the conformal sector which triggers the electroweak symmetry breaking. Upper limits are set on the DP mass, the mixing strength between the standard photon and DP. The model does allow to estimate the DP mass with the value of 4.5 MeV. The maximal value of the scale invariance breaking constant is also reported.

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arXiv2015

Critical point and conformal anomaly

We study the critical point (CP) phenomenon through the increase of fluctuations related to characteristic critical mode. CP would also be identified through the production of primary photons induced by conformal anomaly of strong and electromagnetic interactions. The novel approach to an approximate scale symmetry breaking is developed for this.

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arXiv2013

To what extent should we find the chiral end point?

We analyze the critical phenomena in the theory of strong interactions at high temperatures starting from first principles. The model is based on the dual Yang-Mills theory with scalar degrees of freedom - the dilatons. The latter are produced due to the spontaneous breaking of an approximate scale symmetry. The phase transitions are considered in systems where the field conjugate to the order parameter has the (critical) chiral end mode. The hiral end point (ChEP) is a distinct singular feature existence of which is dictated by the chiral dynamics. The physical approach the effective ChEP is studied via the influence fluctuations of two-body Bose-Einstein correlation function for observed particles to which the chiral end mode couples.

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arXiv2012

Towards the Bose symmetry violation issue

We study the Bose symmetry violation through the decays of heavy vector bosons at high energies. In particular, the decay of a Z'-boson into two photons where one of the photons is the vector unparticle in the scale invariant sector is considered as a sample. We find out that the Bose symmetry might be violated in the nearly conformal sector at high energy frontier. This may be useful in phenomenological application to the CERN LHC experiments for new physics searches.

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arXiv2011

On decays of Z' into unparticle stuff

We study the decay of a Z' - boson into U -unparticle and a photon. The extended Landau-Yang theorem is used. The clear photon signal would make the decay Z' \rightarrow γU as an additional contribution mode for study of unparticle physics.

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arXiv2011

What did we know from the "ridge" in BEC at the CMS

We look at the new two-particle Bose-Einstein correlation (BEC) function accompanied by the color-electric flux model which can explain the "ridge" behavior in enhanced angular correlation between two identical pions at very broad rapidity with high multiplicity. We argue that such an investigation could probe both the size and the temperature of the source of two pions emitted into a narrow range of azimuthal angles. We can confirm the ev- idence for quark-gluon phase due to interaction of outgoing pions (having high transverse momenta) with the medium in thermal bath in proton-proton collisions.

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arXiv2011

Dilaton decays into unparticles and a single photon

We study the production of the vector $U$ -unparticle stuff and a single photon in decays of a dilaton. The signals of an unparticle can be detected through the missing energy and momentum distribution carried away by $U$ once it was produced in radiative decay of a dilaton The continuous energy spectrum of the emitted photons encoding the recoil unparticle can be measured in precision studies of rare decays of the dilaton or Higgs-boson after their discoveres.

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arXiv2011

Correlations of two photons at hadron colliders

We study the Bose-Einstein correlations of two photons and their coherent properties that can provide the information about the space-time structure of the emitting source through the Higgs-boson decays into two photons. We argue that such an investigation could probe the Higgs-boson mass. The model is rather sensitive to the temperature of the environment and to the external distortion effect in medium.

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arXiv2010

Bose-Einstein correlations of two identical particles through their first measurements by CMS at the LHC

We look at the new two-particle correlation function that can provide the space-time information about the source of two charged pions. This function clearly reflects the chaotic and incoherent nature of the particle emission source disturbed by external forces (fields). We argue that such an investiga- tion could probe the size and the temperature of the expanded source where two pions are emitted in thermal environment.

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