119239555
Higgsphobic and fermiophobic Z’ as a single dark matter candidate
A bstractA spin-1 Z’ particle as a single dark matter candidate is investigated by assuming that it does not directly couple to the Higgs boson and standard model fermions and does not mix with the photon and Z boson. The remaining dominant vertices are quartic Z′Z′ZZ and Z′Z′W+W−, which can induce effective $ {Z^{\prime }}{Z^{\prime }}q\overline{q} $ couplings through standard-model gauge-boson loops. We discuss constraints from the cosmological thermal relic density, and direct and indirect-detection experiments, and find that a dark Z’ can only exist above the W boson mass threshold, and the effective quartic coupling of Z′Z′VV is bounded in the region of 10−3~10−2.
118857534
Exothermic isospin-violating dark matter after SuperCDMS and CDEX
Abstract We show that exothermic isospin-violating dark matter (IVDM) can make the results of the latest CDMS-Si experiment consistent with recent null experiments, such as XENON10, XENON100, LUX, CDEX, and SuperCDMS, whereas for the CoGeNT experiment, a strong tension still persists. For CDMS-Si, separate exothermic dark matter or isospin-violating dark matter cannot fully ameliorate the tensions among these experiments; the tension disappears only if exothermic scattering is combined with an isospin-violating effect of f n / f p = − 0.7 . For such exothermic IVDM to exist, at least a new vector gauge boson (dark photon or dark Z') that connects SM quarks to Majorana-type DM particles is required.
119119738
searches for the heavy Higgs boson via two b jets plus diphoton
Extra scalar fields are common in beyond Standard Model (SM) new physics, and they may mix with the 125 GeV SM-like Higgs boson discovered at the LHC. This fact suggests possible discovery channels for these new scalar fields with their decay modes involving the 125 GeV Higgs boson. In this work, we explore the LHC search potential of the heavy CP-even Higgs boson H in the two-Higgs-doublet model. We focus on the channel of H decaying to a pair of light CP-even Higgs bosons h, with two h's decaying to two b jets and diphoton sequentially. This channel is particularly involved when the relevant cubic coupling is enhanced. We find such enhancement to be possible when taking a large CP-odd Higgs mass input for the two-Higgs-doublet model spectrum. Analogous to the SM Higgs self-coupling measurement, the two b jets plus diphoton final states are of particular interest due to the manageable SM background. After performing a cut-based analysis of both signal and background processes, we demonstrate the LHC search sensitivities for the heavy CP-even Higgs boson in a broad mass range via the two b jets plus diphoton final states.
119177190
Probing LHC Higgs Signals from Extended Electroweak Gauge Group
We study the effects of the extended electroweak gauge sector on the signal strengths of the Higgs boson at the LHC. Extension of the Higgs sector associate with the extension of the electroweak gauge symmetry. In our setup, there are two neutral Higgs states ($h$, $H$) and three new gauge bosons ($W'^{\pm}$, $Z'$). We assume the lightest scalar, $h$, is what LHC found and its mass is 125 GeV. We find the enhancement of $\mu(gg \to h \to \gamma \gamma)$. On the other hand, other decay processes are same as or smaller than the SM expectation.