Heavy Neutrinos at Future Linear e+e- Colliders

23 Sept 2021, 17:45
25m
Oral report Section 5. Neutrino physics and astrophysics. Section 5. Neutrino physics and astrophysics

Speaker

Mr Krzysztof Mekala (University of Warsaw)

Description

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 the 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 qql final state at the ILC running at 500 GeV and 1 TeV and the 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. Impact of the gamma-induced backgrounds on the experimental sensitivity is also discussed. According to our results, future linear colliders like ILC and CLIC have sensitivities to couplings orders of magnitude smaller than current and future limits from the LHC.

Primary authors

Aleksander Filip Zarnecki (University of Warsaw) Mr Krzysztof Mekala (University of Warsaw) Jürgen Reuter (DESY Hamburg, Germany) Simon Braß (DESY)

Presentation materials