Long-lived heavy neutral leptons with a displaced shower signature at CMS

Giovanna Cottin, Juan Carlos Helo, Martin Hirsch, Cristián Peña, Christina Wang, Si Xie

Research output: Contribution to journalArticlepeer-review

2 Scopus citations


We study the LHC discovery potential in the search for heavy neutral leptons (HNL) with a new signature: a displaced shower in the CMS muon detector, giving rise to a large cluster of hits forming a displaced shower. A new Delphes module is used to model the CMS detector response for such displaced decays. We reinterpret a dedicated CMS search for neutral long-lived particles decaying in the CMS muon endcap detectors for the minimal HNL scenario. We demonstrate that this new strategy is particularly sensitive to active-sterile mixings with τ leptons, due to hadronic τ decays. HNL masses between ~ 1–6 GeV can be accessed for mixings as low as |VτN|2~10−7, probing unique regions of parameter space in the τ sector.

Original languageEnglish
Article number11
JournalJournal of High Energy Physics
Issue number2
StatePublished - Feb 2023
Externally publishedYes


  • New Light Particles
  • Sterile or Heavy Neutrinos


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