Non-perturbative QCD effects in ${\eta }_c$ and ${\eta }_b$ decays into baryons and WIMP scattering off nuclei

Abstract

In this work we estimate the helicity suppressed decay rates of ${\eta }_b$ resonances into baryon pairs due to instanton-induced effects by rescaling the corresponding partial widths of the experimentally measured branching ratios for the ${\eta }_c(1S)\to p\bar{p}$ and ${\eta }_c(1S)\to \Lambda \overline{(}\Lambda )$ decay modes. Thus we point out that both ${\eta }_b(1S)\to p\bar{p}$ and ${\eta }_b(1S)\to \Lambda \overline{(}\Lambda )$ channels could be detected at a Super B factory and LHC experiments. Furthermore, we examine related instanton-induced effects on WIMP scattering off nuclei concluding, albeit with large uncertainties, that they might enhance the spin-dependent cross section for a light pseudoscalar Higgs boson mediator, thereby inducing a dependence on the momentum transfer to the recoling nucleus.

Comments: Presented at Xth Quark Confinement and the Hadron Spectrum Conference, Garching, Munich, October 2012. 8 pages with 4 figures