Deep-Inelastic Scattering (DIS) 2022

Abstracts

Heavy Neutrinos at Future Linear e+e- Colliders

• Speaker: Krzysztof Mekala (University of Warsaw), Jürgen Reuter (DESY), Aleksander Filip Zarnecki (University of Warsaw)
• Status: submitted
• Abstract: Neutrinos are probably the most mysterious particles of the Standard Model. The mass hierarchy and oscillations, as well as the nature of their antiparticles, are currently being studied in experiments around the world. Moreover, in many models of New Physics, baryon asymmetry or dark matter density in the universe are explained by introducing new species of neutrinos. Among others, heavy neutrinos of the Dirac or Majorana nature were proposed to solve problems persistent in the Standard Model. Such neutrinos with masses above the EW scale could be produced at future linear e+e- colliders, like the Compact LInear Collider (CLIC) or the International Linear Collider (ILC). We studied the possibility of observing production and decays of heavy neutrinos in the qql final state at ILC running at 500 GeV and 1 TeV and CLIC running at 3 TeV. The analysis is based on the WHIZARD event generation and fast simulation of the detector response with DELPHES. Dirac and Majorana neutrinos with masses from 200 GeV to 3.2 TeV are considered. Estimated limits on the production cross sections and on the neutrino-lepton coupling are compared with the current limits coming from the LHC running at 13 TeV, as well as the expected future limits from hadron colliders. Obtained results are stricter than other limit estimates published so far.

Dark matter production with light mediator exchange at future e+e- colliders

• Speaker: Jan Kalinowski (University of Warsaw), Wojciech Kotlarski (TU - Dresden), Krzysztof Mekala (University of Warsaw), Aleksander Filip Zarnecki (University of Warsaw), Kamil Zembaczynski (University of Warsaw)
• Status: Submitted
• Abstract: One of the primary goals of the proposed future collider experiments is to search for dark matter (DM) particles using different experimental approaches. High energy e+e- colliders offer unique possibility for the most general search based on the mono-photon signature. As any e+e- scattering process can be accompanied by a hard photon emission from the initial state radiation, analysis of the energy spectrum and angular distributions of those photons can be used to search for hard processes with invisible final state production and to test the nature and interactions of the DM particles.Production of DM particles at the International Linear Collider (ILC) and Compact Linear Collider (CLIC) experiments was studied using dedicated simulation procedure developed for WHIZARD and the DELPHES fast simulation framework. Limits on the light DM production cross section in a generic model are set as a function of the mediator mass and width, and translated into the limits on the mediator coupling to electrons. If deviations from the Standard Model predictions are observed, mediator mass, width and coupling structure can be constrained from the reconstructed mono-photon event distributions.