arXiv subjects

Lukas Pritchett

Publications and source records attributed to Lukas Pritchett.

3 recordsLinked to original sources

arXiv2017

The Light Composite Higgs in Strong Extended Technicolor

This paper extends an earlier one describing the Higgs boson $H$ as a light composite scalar in a strong extended technicolor model of electroweak symmetry breaking. The Higgs mass $M_H$ is made much smaller than $Λ_{ETC}$ by tuning the ETC coupling very close to the critical value for electroweak symmetry breaking. The technicolor interaction, neglected in the earlier paper, is considered here. Its weakness relative to extended technicolor is essential to understanding the lightness of $H$ compared to the low-lying spin-one technihadrons. Technicolor cannot be completely ignored, but implementing technigluon exchange together with strong extended technicolor appears difficult. We propose a solution that turns out to leave the results of the earlier paper essentially unchanged. An argument is then presented that masses of the spin-one technifermion bound states, $ρ_H$ and $a_H$, are much larger than $M_H$ and, plausibly, controlled by technicolor. Assuming $M_{ρ_H}$ and $M_{a_H}$ are in the TeV-energy region, we identify $ρ_H$ and $a_H$ with the diboson excesses observed near $2\,{\rm TeV}$ by ATLAS and CMS in LHC Run 1 data, and we discuss their phenomenology for Runs 2 and 3.

hep-ph↗

arXiv2017

The 30 GeV Dimuon Excess at ALEPH

A simple variation of a two-Higgs-doublet model is proposed to describe the $30\,{\rm GeV}$ dimuon excess reported by Heister in his reanalysis of $Z \to \bar bb$ events in ALEPH data taken in 1992-95. The heavier CP-even Higgs $H$ is the $125\,{\rm GeV}$ Higgs boson discovered at the LHC. The model admits two options for describing the dimuon excess: (1) The lighter CP-even Higgs $h$ and the CP-odd state $η_A$ are approximately degenerate and contribute to the $30\,{\rm GeV}$ excess. (2) Only the $h$ is at $30\,{\rm GeV}$ while the $η_A$ and $H$ are approximately degenerate at $125\,{\rm GeV}$. The ALEPH data favor option 1. Testable predictions are presented for LHC as well as LEP experiments. A potential no-go theorem for models of this type is also discussed.

hep-ph↗

arXiv2015

Heavy Vector Partners of the Light Composite Higgs

If the Higgs boson $H(125)$ is a composite due to new strong interactions at high energy, it has spin-one partners, $ρ_H$ and $a_H$, analogous to the $ρ$ and $a_1$ mesons of QCD. These bosons are heavy, their mass determined by the strong interaction scale. The strongly interacting particles light enough for $ρ_H$ and $a_H$ to decay to are the longitudinal weak bosons $V_L = W_L,\, Z_L$ and the Higgs boson $H$. These decay signatures are consistent with resonant diboson excesses recently reported near 2 TeV by ATLAS and CMS. We calculate $σ\times BR(ρ_H \to VV) =$ few fb and $σ\times BR(a_H \to VH) =$ 0.5-1 fb at $\sqrt{s} =$ 8 TeV, increasing by a factor of 5-7 at 13 TeV. Other tests of the hypothesis of the strong-interaction nature of the diboson resonances are suggested.

hep-ph↗