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M. I. Vysotsky

Publications and source records attributed to M. I. Vysotsky.

At least 37 records · Page 2Linked to original sources

New Physics at 1 TeV?

If decays of a heavy particle S are responsible for the diphoton excess with invariant mass 750 GeV observed at the 13 TeV LHC run, it can be easily accomodated in the Standard Model. Two scenarios are considered: production in gluon fusion through a loop of heavy isosinglet quark(s) and production in photon fusion through a loop of heavy isosinglet leptons. In the second case many heavy leptons are needed or/and they should have large electric charges in order to reproduce experimental data on $σ(pp \to SX) \cdot \mathrm{Br}(S \to γγ)$.

hep-ph↗

Suppression of $H\to VV$ decay channels in the Georgi-Machacek model

The $H\to ZZ$ decay mode is usually considered as one of the most promising ways to discover new heavy neutral scalar $H$. We show that in the Georgi-Machacek model it is possible to get large enhancement of double SM-like Higgs boson production due to $H$ decays while $ZZ$ and $WW$ decay channels could be highly suppressed.

hep-ph↗

Extending the Higgs sector: an extra singlet

An extension of the Standard Model with an additional Higgs singlet is analyzed. Bounds on singlet admixture in 125 GeV h boson from electroweak radiative corrections and data on h production and decays are obtained. Possibility of double h production enhancement at 14 TeV LHC due to heavy higgs contribution is considered.

hep-ph↗

Double Higgs production at LHC, see-saw type II and Georgi-Machacek model

The double Higgs production in the models with isospin-triplet scalars is studied. It is shown that in the see-saw type II model the mode with an intermediate heavy scalar, $pp\to H+X\to 2h+X$, may have the cross section which is compatible with that in the Standard Model. In the Georgi-Machacek model this cross section could be much larger than in SM since the vacuum expectation value of the triplet can be large.

hep-ph↗

Modern elementary particle physics

The purpose of these lectures is to describe the state of affairs in modern particle physics to young physicists who do not specialize in this subject.

physics.gen-ph↗

The rise and fall of the fourth quark-lepton generation

The existence of the fourth quark-lepton generation is not excluded by the electroweak precision data. However, the recent results on the 126 GeV higgs boson production and decay do not allow an extra generation at least as far as the perturbation theory can be used.

hep-ph↗

How to see an antistar

Polarization of photons emitted in weak decays occuring at distant star allows to determine whether this star is made from antimatter. Even more promissing is the observation of neutrinos (antineutrinos) produced at neutronization (antineutronization) reactions at the beginning of SN ($\bar{SN}$) explosion.

hep-ph↗

Charmed penguin versus BAU

Since the Standard Model most probably cannot explain the large value of CP asymmetries recently observed in D-meson decays we propose the fourth quark-lepton generation explanation of it. As a byproduct weakly mixed leptons of the fourth generation make it possible to save the baryon number of the Universe from erasure by sphalerons. An impact of the 4th generation on BBN is briefly discussed.

hep-ph↗

(ΔA_{CP})_{LHCb} and the fourth generation

LHCb collaboration measured CPV at the level of one percent in the difference of assymetries in $D^0(\bar D^0)\to π^+ π^-, K^+ K^-$ decays. If confirmed on a larger statistics and final systematics this would mean New Physics manifestation. The fourth quark-lepton generation can be responsible for the observed effect.

hep-ph↗

Critical nucleus charge in a superstrong magnetic field: effect of screening

A superstrong magnetic field stimulates the spontaneous production of positrons by naked nuclei by diminishing the value of the critical charge Z_{cr} . The phenomenon of screening of the Coulomb potential by a superstrong magnetic field which has been discovered recently acts in the opposite direction and prevents the nuclei with Z<52 from becoming critical. For Z>52 for a nucleus to become critical stronger B are needed than without taking screening into account.

hep-ph↗

Modification of Coulomb law and energy levels of the hydrogen atom in a superstrong magnetic field

We obtain the following analytical formula which describes the dependence of the electric potential of a point-like charge on the distance away from it in the direction of an external magnetic field B: Φ(z) = e/|z| [ 1- exp(-\sqrt{6m_e^2}|z|) + exp(-\sqrt{(2/π) e^3 B + 6m_e^2} |z|) ]. The deviation from Coulomb's law becomes essential for B > 3πB_{cr}/α= 3 πm_e^2/e^3 \approx 6 10^{16} G. In such superstrong fields, electrons are ultra-relativistic except those which occupy the lowest Landau level (LLL) and which have the energy epsilon_0^2 = m_e^2 + p_z^2. The energy spectrum on which LLL splits in the presence of the atomic nucleus is found analytically. For B > 3 πB_{cr}/α, it substantially differs from the one obtained without accounting for the modification of the atomic potential.

hep-ph↗

Atomic levels in superstrong magnetic fields and D=2 QED of massive electrons: screening

The photon polarization operator in superstrong magnetic fields induces the dynamical photon "mass" which leads to screening of Coulomb potential at small distances $z\ll 1/m$, $m$ is the mass of an electron. We demonstrate that this behaviour is qualitatively different from the case of D=2 QED, where the same formula for a polarization operator leads to screening at large distances as well. Because of screening the ground state energy of the hydrogen atom at the magnetic fields $B \gg m^2/e^3$ has the finite value $E_0 = -me^4/2 \ln^2(1/e^6)$.

hep-ph↗