Scalar Dark Matter in light of LEP and ILC Experiments

Abstract

In this work we study a scalar field dark matter model with mass of the order of 100 MeV. We assume dark matter is produced in the process $e^{-}+e^{+}\to \ddot{I}•+\ddot{I}{•}^{\ast }+{\hat{I}}^3$, that, in fact, could be a background for the standard process $e^{-}+e^{+}\to \hat{I}½+\bar{\hat{I}}½+{\hat{I}}^3$ extensively studied at LEP. We constrain the chiral couplings, $C_L$ and $C_R$, of the dark matter with electrons through an intermediate fermion of mass $m_F=100$ GeV and obtain $C_L=0.1(0.25)$ and $C_R=0.25(0.1)$ for the best fit point of our $\ddot{I}{‡}^2$ analysis. We also analyze the potential of ILC to detect this scalar dark matter for two configurations: (i) center of mass energy $\sqrt{s}=500$ GeV and luminosity $\mathcal{L}=250$ fb${}^{-1}$, and (ii) center of mass energy $\sqrt{s}=1$ TeV and luminosity $\mathcal{L}=500$ fb${}^{-1}$. The differences of polarized beams are also explored to better study the chiral couplings.

15 pages, 6 figures and 1 table. New references added and improvements in the text. Conclusions unchanged