A5103192068- Particle physics theoretical and experimental studies
- Dark Matter and Cosmic Phenomena
- Cosmology and Gravitation Theories
- High-Energy Particle Collisions Research
- Distributed and Parallel Computing Systems
- Computational Physics and Python Applications
- Quantum Chromodynamics and Particle Interactions
- Advanced Data Storage Technologies
- Particle Detector Development and Performance
- Atomic and Subatomic Physics Research
- Sociopolitical Dynamics in Russia
- Scientific Research and Discoveries
- Astrophysics and Cosmic Phenomena
Lomonosov Moscow State University
1994-2024
University of Southampton
2022
A bstract The measured branching fractions of B -mesons into leptonic final states derived by the LHCb, Belle and BaBar collaborations hint towards breakdown lepton flavour universality. In this work we take at face value so-called $$ {R}_{D^{\left(\ast \right)}} <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML"> <mml:msub> <mml:mi>R</mml:mi> <mml:msup> <mml:mi>D</mml:mi> <mml:mfenced> <mml:mo>∗</mml:mo> </mml:mfenced> </mml:msup> </mml:msub> </mml:math> observables that are defined...
We consider a multi-component dark matter model where the sector contains scalar doublet and complex singlet. impose discrete $Z_4$ symmetry to ensure such that lightest component of doublet, $\tilde{A}$, singlet, $\tilde{S}$, are both stable. Interactions between sectors impact significantly observables, they allow in particular relax direct detection constraints on model. To determine parameter space satisfies relic density, theoretical collider as well indirect limits, we perform two...
A bstract We investigate, for the first time, a scenario where dark matter consists of three complex scalar fields that are stabilized by single Z 7 symmetry. As an extension well-known Higgs-portal, this model is also subject to important restrictions arising from relic density constraint and direct detection experiments. Our goal in paper find characterize viable regions model, analyze its prospects future First, processes affect densities identified (they include semiannihilations...
A bstract We consider a simple extension of the standard model with fermionic dark matter (DM) and Z ′ gauge boson acting as mediator. also assume scenario where cosmic reheating occurs at low temperatures due to decay massive inflaton into states. To follow evolution background sector states, we implement required Boltzmann equations in code micrOMEGAs explore both freeze-out freeze-in mechanisms. determine parameter space that satisfies relic density constraint under different assumptions...
A bstract Scenarios for multi-component scalar dark matter based on a single Z N ( ≥ 4) symmetry are simple and well-motivated. In this paper we investigate, the first time, phenomenology of 5 model two-component matter. This model, which can be seen as an extension well-known singlet features two complex fields — particles that Standard Model singlets but have different charges under symmetry. The interactions allowed by give rise to novel processes between affect their relic densities...
In scenarios with very small dark matter (DM) couplings and mass splittings between the DM other sector particles, so-called "co-scattering" or "conversion-driven freeze-out" can be dominant mechanism for production. We present inclusion of this in micrOMEGAs together a case study phenomenological implications fermionic singlet-triplet model. For latter, we focus on transition co-annihilation co-scattering processes. observe that is needed to describe thermal behaviour couplings, opening up...
We study the dark matter from an inert doublet and a complex scalar singlet stabilized by N symmetries. This field content is minimal one that allows dimensionless semi-annihilation couplings for > 2. consider explicitly 3 4 cases take into account constraints perturbativity, unitarity, vacuum stability, necessity electroweak preserving to be global minimum, precision tests, upper limits direct detection properties of Higgs boson. Co-annihilation sector particles as well conversion...
We study a simple model that can give rise to isospin-violating interactions of Dirac fermion asymmetric dark matter protons and neutrons through the interference scalar U(1)' gauge boson contribution. The yield large suppression elastic scattering cross section off Xenon relative Silicon thus reconciling CDMS-Si LUX results while being compatible with LHC findings on 126 GeV Higgs, electroweak precision tests flavour constraints.
We present a thorough analysis of the sequential freeze-in mechanism for dark matter production in early universe. In this relic density results from pair annihilation mediator particles which are themselves produced by thermal collisions standard model particles. Below some critical value coupling to fields, channel dominates over usual where is directly collisions, even when not equilibrium. The latter case requires computing full non-thermal distribution mediators, finite temperature...
We consider multicomponent dark matter in a model where one component is feebly interacting (FIMP) while the second weakly (WIMP). The contains an inert scalar doublet and complex singlet features discrete ${Z}_{4}$ symmetry. Using new of micromegas that allow us to compute relic density for including WIMPs FIMPs, we determine parameter space satisfies theoretical constraints, collider as well direct indirect detection limits. discuss possibility probe through astrophysical searches. find it...
At present time when a new generation of TeV colliders are beginning to operate one needs calculate cross-sections for great number various reactions. Such calculations united in the framework collider physical program, providing definite predictions how detect signatures physics and separate them from background. The CompHEP package was created calculation decay high energy collision processes elementary particles lowest order (tree) approximation. main idea put into make available passing...
Review of Monte Carlo event generators for signals new particles at LEP2. The areas covered include SUSY, HIGGS and Leptoquarks.
The search for a Dark Matter particle is the new grail and hard-sought nirvana of physics community. From theoretical side, it main challenge to provide consistent model-independent tool comparing bounds reach diverse experiments. We propose first complete classification minimal models, which provides missing link between experiments top-down models. Consistency achieved by imposing renormalisability invariance under full Standard Model symmetries. apply this paradigm fermionic multiplets...
A bstract The present-day B -anomalies involving b → sμ + μ − or cτ $$ \overline{\nu} <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML"> <mml:mover> <mml:mi>ν</mml:mi> <mml:mo>¯</mml:mo> </mml:mover> </mml:math> transitions can all be explained with the addition of a vector U 1 leptoquark mass {M}_{U_1} <mml:msub> <mml:mi>M</mml:mi> <mml:mi>U</mml:mi> <mml:mn>1</mml:mn> </mml:msub> ≳ . 8 TeV. In scalar singlet dark matter model (SSDMM), DM is S that couples to Higgs via λ hS 2 |H| We...
We explore the potential of ${e}^{+}{e}^{\ensuremath{-}}$ colliders to discover dark matter and determine its properties such as mass spin. For this purpose we study spin zero one-half cases $D$, which belongs $SU(2)$ weak doublet therefore has charged partner ${D}^{+}$. case scalar chose inert model, while for fermion suggest new minimal model with only three parameters. choose two benchmarks models under study, provide correct amount observed (DM) relic density consistent current DM...