Suppression of H→VVH\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.Comment: 5 page

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 $\sigma(pp \to SX) \cdot \mathrm{Br}(S \to \gamma \gamma)$.Comment: 7 pages, 4 figures, 1 tabl

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.Comment: 18 pages, 7 figures. v2: one equation added; references received after the publication of v1 are adde

pppp scattering at the LHC with the lepton pair production and one proton tagging

Analytical formulas for the cross section of the reaction $pp \to p + \ell^+ \ell^- + X$ are presented. Fiducial cross sections are compared with those measured recently by the ATLAS collaboration.Comment: 12 pages, 1 figur

Weak interaction corrections to muon pair production via the photon fusion at the LHC

Analytical formulas describing the correction due to the $Z$ boson exchange to the cross section of the reaction $pp\rightarrow p\mu^+\mu^- X$ are presented. When the invariant mass of the produced muon pair $W\gtrsim 150~\text{GeV}$ and its total transverse momentum is large, the correction is of the order of 20%.Comment: 17 pages, 5 figure

On production of heavy charged particles in γγ\gamma\gamma fusion at planned pppp colliders

Production of heavy fermions in ultraperipheral collisions ($pp\to p+\gamma\gamma+p\to p+\chi^{+}\chi^{-}+p$) and the semiexclusive reaction ($pp \to p+\gamma\gamma^{*}+X \to p+\chi^{+}\chi^{-}+X$) is considered. Differential and total cross sections for the energies of the planned $pp$ colliders are presented.Comment: 8 pages, 4 figures, 2 table