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I. F. Ginzburg

Publications and source records attributed to I. F. Ginzburg.

At least 19 recordsLinked to original sources
arXiv2019

Problems with variable Hilbert space in quantum mechanics

The general problem is studied on a simple example. A quantum particle in an infinite one-dimensional well potential is considered. Let the boundaries of well changes in a finite time $T$. The standard methods for calculating probability of transition from an initial to the final state are in general inapplicable since the states of different wells belong to different Hilbert spaces. If the final well covers only a part of the initial well (and, possibly, some outer part of the configuration space), the total probability of the transition from any stationary state of the initial well into {\bf all} possible states of the final well is less than 1 at $T\to 0$. If the problem is regularized with a finite-height potential well, this missing probability can be understood as a non-zero probability of transitions into the continuous spectrum, despite the fact that this spectrum disappears at the removal of regularization. This phenomenon ("transition to nowhere'') can result new phenomena in some fundamental problems, in particular at description of earlier Universe. We discuss also how to calculate the probabilities of discussed transitions at final $T$ for some ranges of parameters.

quant-ph↗
arXiv2017

Prospects for charged Higgs searches at the LHC

The goal of this report is to summarize the current situation and discuss possible search strategies for charged scalars, in non-supersymmetric extensions of the Standard Model at the LHC. Such scalars appear in Multi-Higgs-Doublet models (MHDM), in particular in the popular Two-Higgs-Doublet model (2HDM), allowing for charged and additional neutral Higgs bosons. These models have the attractive property that electroweak precision observables are automatically in agreement with the Standard Model at the tree level. For the most popular version of this framework, Model~II, a discovery of a charged Higgs boson remains challenging, since the parameter space is becoming very constrained, and the QCD background is very high. We also briefly comment on models with dark matter which constrain the corresponding charged scalars that occur in these models. The stakes of a possible discovery of an extended scalar sector are very high, and these searches should be pursued in all conceivable channels, at the LHC and at future colliders.

hep-ph↗
arXiv2017

Discrete and continuous description of physical phenomena

The values of many phenomena in the Nature $z$ are determined in some discrete set of times t_n, separated by a small interval $Δt$ (which may also represent a coordinate, etc.). Let the $z$ value in neighbour point $t_{n+1}=t_n+Δt$ be expressed by the evolution equation as $z(t_{n+1})= z(t_n+Δt)=f(z(t_n))$. This equation gives {\it\underline{a discrete description}} of phenomenon. Considering phenomena at $t\gg Δt$ this equation is transformed often into the differential equation allowing to determine $z(t)$ -- {\underline{\it continuous description}}. It is usually assumed that the continuous description describes correctly the main features of a phenomenon at values $t>> Δt$. In this paper I show that the real behavior of some physical systems can differ strongly from that given by the continuous description. The observation of such effects may lead to the desire to supplement the original evolutionary model by additional mechanisms, the origin of which require special explanation. We will show that such construction may not be necessary -- simple evolution model can describe different observable effects. This text contains no new calculations. Most of the discussed facts are well known. New is the treatment of the results.

physics.gen-ph↗
arXiv2016

A simple criterium for CP conservation in the most general 2HDM

We find set of necessary and sufficient conditions for CP conservation in the most general 2HDM in terms of observable quantities. This set contains two relatively easily testable simple conditions instead of usually discussed three more complex ones.

hep-ph↗
arXiv2016

What tell us LHC data about Higgs boson parity

Recently CMS and ATLAS announced that they had measured the Higgs boson parity. Here we note that their approach can determine this parity only under the additional assumption that this particle has a definite parity. If parity conservation is violated in the Higgs sector, the parity of observed "Higgs" boson does not exist. The approach used in the mentioned experiments does not allow to observe such opportunity. In this sense titles of mentioned CMS and ATLAS publications are misleading.

hep-ph↗
arXiv2015

2HDM in terms of observable quantities

We express explicitly all parameters of the most general Two-Higgs-Doublet Model (2HDM) scalar potential via measurable ({\it basic}) quantities plus additional parameters specifying the basis choice. The full set of basic parameters is partitioned into two groups: the first group can be obtained by measuring all the scalar boson masses and the couplings of two neutrals to gauge bosons.The second group, in contrast, does not affect the masses and Higgs-gauge couplings, and can only be determined from processes involving Higgs self-interactions. These basic quantities can be treated as free parameters of model limited by general enough conditions. Apart from this construction {\em per se}, we also obtain three by-products: new sum rules for relative couplings, a clear possibility of the coexistence of relatively light Higgses with the strong interaction in the Higgs sector, and a restriction on the triple-Higgs coupling in the SM-like regime (the latter - in a separate paper).

hep-ph↗
arXiv2015

Multi-Higgs models. Perspectives for identification of wide set of models in future experiments at colliders in the SM-like situation

Higgs mechanism of EWSB can be realized in both well known minimal model and with more complex non-minimal Higgs models. These non-minimal models contain new Higgs bosons -- neutral $h_a$ and charged $H_b^\pm$. Necessary step in the discovery of such model is observation of these additional Higgses. We discuss the potential of such researches at modern and future colliders in the light of recent LHC results, for wide set of models, including 2HDM as a simplest example. Our conclusion is rather pessimistic. Discovery of new neutral Higgs boson at LHC is a very difficult task. Some windows to find them appear at accidentally favorable parameters of the theory. The regular way in the detection of these models is the study of processes with production of charged Higgs bosons (better, at Linear Collider).

hep-ph↗
arXiv2014

Nonminimal Higgs Models, Dark Matter, and Evolution of the Universe

The set of sum rules for a wide class of nonminimal Higgs models has been obtained. Difficulties and ways for revealing the possibilities of studying extended Higgs models at colliders have been revealed with the use of these sum rules and recent LHC results. New methods of studying multidoublet Higgs models with various symmetry groups have been applied to solve problems of classification of these groups, breaking of symmetries in vacuum, etc. A method for the determination of masses and spins of dark matter particles D and their partners via the energy spectrum of a lepton in the $e^+e^-\to DDW^+W^-$ process has been proposed. The possibility of the existence of strongly interacting dark matter has been revealed. Variants of the evolution of the phase states of the Universe have been analyzed within the inert doublet model.

hep-ph↗
arXiv2014

Measuring mass and spin of Dark Matter particles with the aid energy spectra of single lepton and dijet at the $e^+e^-$ Linear Collider

In many models stability of Dark Matter particles $D$ is ensured by conservation of a new quantum number referred to as $D$-parity. Our models also contain charged $D$-odd particles $D^\pm$ with the same spin as $D$. Here we propose a method to precisely measure the masses and spins of $D$-particles in the process $\epe\to D^+D^-\to DDW^+W^-\to DD (q\bar{q})(\ellν)$ with a signature {\it dijet + $μ$ (or $e$) + nothing}. It is shown that the energy distribution of the lepton has singular points (upper edge and kinks or a peak) whose positions are kinematically determined. For precise determination of $D$ and $D^\pm$ masses, it is sufficient to measure these singular points and upper edge of dijet energy spectrum. After this procedure, even an approximate measurement of the corresponding cross section allows a determination of the spin of $D$ particles to be performed. New points of this work are: 1) We propose to use only the well measurable energy spectra of {\bf individual leptons} and the upper edge of the dijet energy spectrum. 2) We propose to identify the spin of $D$-particles via value of the cross section for the discussed process.

hep-ph↗
arXiv2014

Beam Dump problem and Neutrino Factory Based on a $e^+e^-$ Linear Collider

The beam of an $e^+e^-$ Linear Collider after a collision at the main interaction point can be utilized to construct the neutrino factory with exceptional parameters. We also discuss briefly possible applications of some elements of the proposed scheme to standard fixed target experiments and new experiments with $ν_μN$ interactions.

physics.acc-ph↗
arXiv2012

Light charged Higgs at LHC

The LHC program for discovery of light charged Higgs with mass 135-180 GeV has to take into account decay $H^+\to \bar{b}\,t^*\to W^+b\bar{b}$. The distribution of decay products in effective mass of $t^*=Wb$ is obtained.

hep-ph↗
arXiv2012

Regge trajectories in QCD

We discuss some problems concerning the application of perturbative QCD to high energy soft processes. We show that summing the contributions of the lowest twist operators for non-singlet $t$-channel leads to a Regge-like amplitude. Singlet case is also discussed.

hep-ph↗
arXiv2010

Evolution of Universe to the present inert phase

We assume that current state of the Universe can be described by the Inert Doublet Model, containing two scalar doublets, one of which is responsible for EWSB and masses of particles and the second one having no couplings to fermions and being responsible for dark matter. We consider possible evolutions of the Universe to this state during cooling down of the Universe after inflation. We found that in the past Universe could pass through phase states having no DM candidate. In the evolution via such states in addition to a possible EWSB phase transition (2-nd order) the Universe sustained one 1-st order phase transition or two phase transitions of the 2-nd order.

hep-ph↗
arXiv2009

Physical problems for future Photon Colliders

In this report I discuss physical problems for future Photon Colliders (PLC), which can be stated AFTER 10 years of work of LHC and few years of work of e^+e^- ILC. I discuss mainly the unfavorable case when these colliders will give us only Higgs boson(s) and perhaps some charged particles of unclear nature. I focus my attention for the case of PLC based on the second stage of ILC (about 1 TeV) or CLIC (1-3 TeV). It offers opportunity to study new series of fundamental physical problems. Among them - multiple production of gauge bosons, hunt for strong interaction in Higgs sector, search of exotic interactions in the process $γγ\toγγ$ with final photons having transverse momenta (0.5 - 0.7)E_e.

hep-ph↗
arXiv2009

The evolution of vacuum states and phase transitions in 2HDM during cooling of Universe

We consider the evolution of the ground state in the Two Higgs Doublet Model during cooling down of the Universe after the Big Bang. Different regions in the space of free parameters of this model correspond to different sequences of thermal phase transitions. We discuss different paths of thermal evolution and corresponding evolution of physical properties of the system for different modern values of the parameters.

hep-ph↗
arXiv2009

Lessons from All Logs Summation in Yukawa Theories

Some features of old results in the total summation of all logarithmic contributions of all diagrams in Yukawa theory are presented. We discuss some lessons from this picture for the description of Pomeron, odderon, etc. in QCD.

hep-th↗