Particle Physics Seminar: A search for displaced heavy neutral leptons in sqrt(s) = 13 TeV pp collisions collected with the ATLAS detector

Abstract:

The Standard Model (SM), while the best description we have of the laws of nature, is known to be incomplete. There are many SUSY and exotics models which seek to fill the gaps left by the SM. One intriguing set of models is that which includes a right handed, heavy neutrino, or heavy neutral lepton (HNL). This talk will describe the recent search for a long-lived such HNL that was performed at the ATLAS experiment (hot off the presses, public plots). This search used specialised reconstruction techniques to identify events with the displaced di-lepton vertices resulting from the displaced HNL decays. New limits were set for both single-flavour and multi-flavour mixing scenarios for HNLs of mass 3 GeV < mHNL < 15 GeV, in both normal and inverted neutrino-mass hierarchies.

Seminar Organizers: Dr. Michael Geller & Dr. Adi Ashkanzi