Discrimination of new physics models with the International Linear Collider

Abstract

The large hadron collider (LHC) is anticipated to provide signals of new physics at the TeV scale, which are likely to involve production of a WIMP dark matter candidate. The international linear collider (ILC) is to sort out these signals and lead us to some viable model of the new physics at the TeV scale. In this article, we discuss how the ILC can discriminate new physics models, taking the following three examples: the inert Higgs model, the supersymmetric model, and the littlest Higgs model with T-parity. These models predict dark matter particles with different spins, 0, 1/2, and 1, respectively, and hence comprise representative scenarios. Specifically, we focus on the pair production process, e + e − → χ + χ − → χ 0 χ 0 W + W − , where χ 0 and χ ± are the WIMP dark matter and a new charged particle predicted in each of these models. We then evaluate how accurately the properties of these new particles can be determined at the ILC and demonstrate that the ILC is capable of identifying the spin of the new charged particle and discriminating these models.2

WIMP physics with ensembles of direct-detection experiments

“…(14) with Wilson-coefficient values given by normalizations times the fiducial values listed in Table 6. The number of expected events for these benchmarks and these experiments is given in Table 7.…”

Compressing the inert doublet model

“…For larger mass splittings ∆ ± 10 GeV, the mono-photon requirement can be dropped and searches can be performed for leptons (or jets) and missing energy as described in Refs. [119,120].…”

Measuring Mass and Spin of Dark Matter Particles with the Aid Energy Spectra of Single Lepton and Dijet at the e<sup>+</sup>e<sup>-</sup> Linear Collider

“…This work and the estimates of the range where masses and spins can be determined with reasonable accuracy will be the subject of the forthcoming paper. [5] [6]. However, the individual jet energies and consequently, effective masses of dijets cannot be measured with a high precision.…”

“…Measuring positions of these singularities will allow, in principle, to determine masses D M and M + with good precision (Sections 2.3 and 2.4). In contrast to [5]- [6] [11]- [13], our description is suitable for different models.…”