Higgs couplings and Naturalness in the littlest Higgs model with T-parity at the LHC and TLEP

Abstract

Motivated by the recent LHC Higgs data and null results in searches for any new physics, we investigate the Higgs couplings and naturalness in the littlest Higgs model with T-parity. By performing the global fit of the latest Higgs data, electroweak precise observables and R b measurements, we find that the scale f can be excluded up to 600 GeV at 2σ confidence level. The expected Higgs coupling measurements at the future collider TLEP will improve this lower limit to above 3 TeV. Besides, the top parnter mass m T + can be excluded up to 880 GeV at 2σ confidence level. The future HL-LHC can constrain this mass in the region m T + < 2.2 TeV corresponding to the fine-tuning being lager than 1%.

Associated production of single top and Higgs at the LHC in the littlest Higgs model with T-parity

“…Combined with the global fit of the current Higgs data and the electroweak precision observables (EWPO) in ref. [49], the confidence regions (corresponding to 1σ, 2σ and 3σ ranges for case A) are provided in figures 2, 3. Furthermore, according to refs.…”

Little Higgs dark matter after PandaX-II/LUX-2016 and LHC Run-1

“…One is that two A H dark matter annihilate into SM particles, which is mainly through the schannel via exchanging the Higgs boson. However, due to the constraints of Higgs data and EWPOs, the mass of heavy photon is heavier than m h /2 [43][44][45][46][47]. Thus, without resonant enhancement, the pair annihilation cross section of A H is usually too small to satisfy the observed dark matter relic density.…”

“…Besides, we decouple the T -odd top quark t − by setting m t − = 3 TeV in order to JHEP12(2016)152 avoid the bound of LHC searches for long-lived charged particles. We adopt our previous scan method [45,46] by constructing the likelihood L ≡exp[− χ 2 i ] for each point, where index i denotes the following constraint:…”

Top Partner Production at e+e- Collider in the Littlest Higgs Model with T-Parity

“…Apart from direct searches, the indirect searches for the top partners through their contributions to the electroweak precision observables (EWPOs) [12,13], -pole observables [14][15][16], and the flavor physics [17][18][19][20][21][22][23][24] have been extensively investigated. The null results of the top partners, in conjunction with the EWPOs and the recent Higgs data, have tightly constrained the parameter space of the LHT model [25][26][27][28][29][30].…”