Search for light sterile neutrinos from $W^\pm$ decays at the LHC

Understand

We study the feasibility to observe sterile neutrinos with masses in the range 5 GeV $< m_N < 20$ GeV at the LHC, using exclusive semileptonic modes involving pions, $W\to \ell N \to \pi \ell\ell, 2\pi \ell\ell$ and $3\pi \ell\ell$.

• We thus cover a mass window that is between what can be studied in meson factories and high energy colliders.
• We run simulations for these exclusive events, where pions should be distinguished from the background provided the neutrino decay exhibits a vertex displacement from its production point.
• In a previous work we have estimated the theoretical rates and here we analyze the observability of the processes at the LHC, given the fact that exclusive hadronic states may be difficult to identify.