$Υ$ Decays into Light Scalar Dark Matter

Abstract

We examine decays of a spin-1 bottomonium into a pair of light scalar Dark Matter (DM) particles, assuming that Dark Matter is produced due to exchange of heavy degrees of freedom. We perform a model-independent analysis and derive formulae for the branching ratios of these decays. We confront our calculation results with the experimental data. We show that the considered branching ratios are within the reach of the present BaBaR experimental sensitivity. Thus, Dark Matter production in Upsilon decays leads to constraints on parameters of various models containing a light spin-0 DM particle. We illustrate this for the models with a "WIMPless miracle", in particular for a Gauge Mediated SUSY breaking scenario, with a spin-0 DM particle in the hidden sector. Another example considered is the type II 2HDM with a scalar DM particle.

Figures (10)

• Figure 1: Diagrams for $\Upsilon(3S) \to \Phi \Phi^* \gamma$ transition: a), b) transition is generated by a bi-local interaction c) transition is generated by an effective local interaction.
• Figure 2: Upper bound on $|C_3|$ a) as a function of $m_\Phi$, for $\Lambda_H = 100~GeV$, b) as a function of $\Lambda_H$, for $m_\Phi = 1~GeV$.
• Figure 3: The differential branching ratio $dB(\Upsilon(3S) \to \Phi \Phi \gamma)/d\hat{s}$ versus the missing mass $\sqrt{s}$ within a self-conjugate DM scenario for $m_\Phi = 1~MeV$ (line 1), $m_\Phi = 1~GeV$ (line 2), $m_\Phi = 2~GeV$ (line 3) and $m_\Phi = 3~GeV$ (line 4).
• Figure 4: Partially integrated and total integrated branching ratios for $\Upsilon(3S) \to \Phi \Phi \gamma$ decay (lines 1 and 2 respectively), as functions of DM particle mass $m_\Phi$. The dashed line is the experimental bound (\ref{['i13']}).
• Figure 5: Upper bound on $\sqrt{C_1^2 + C_2^2}$ as a function of $m_\Phi$, for $\Lambda_H = 100~GeV$.