Search for the production of dark matter in the framework of a mono- Z′ portal at the ILC with simulated electron-positron collisions at s=500 </mml:mtext…

In the present work, we study the possible production of the light neutral gauge boson (<a:math xmlns:a="http://www.w3.org/1998/Math/MathML" display="inline"><a:mrow><a:msup><a:mi mathvariant="normal">Z</a:mi><a:mo>′</a:mo></a:msup></a:mrow></a:math>) candidates, which originated from a simplified-model scenario based on the mono-<d:math xmlns:d="http://www.w3.org/1998/Math/MathML" display="inline"><d:msup><d:mi mathvariant="normal">Z</d:mi><d:mo>′</d:mo></d:msup></d:math> model, in association with dark matter. This study has been performed by studying events with dimuon plus missing transverse energy produced in the simulated electron-positron collisions at the foreseen International Linear Collider (ILC), operating at 500 GeV center of mass energy and integrated luminosity of <g:math xmlns:g="http://www.w3.org/1998/Math/MathML" display="inline"><g:mn>1000</g:mn><g:mtext> </g:mtext><g:mtext> </g:mtext><g:msup><g:mi>fb</g:mi><g:mrow><g:mo>−</g:mo><g:mn>1</g:mn></g:mrow></g:msup></g:math>. In case no new physics has been discovered, we set upper limits at 95% confidence level on the masses of various particles in the model as, spin-1 (<i:math xmlns:i="http://www.w3.org/1998/Math/MathML" display="inline"><i:mrow><i:msup><i:mi mathvariant="normal">Z</i:mi><i:mo>′</i:mo></i:msup></i:mrow></i:math>), as well as the fermionic dark matter.