Speaker
Description
A search for long-lived particles decaying to an oppositely-charged lepton pair, $\mu\mu$, $ee$, or $e\mu$?, is presented
using 32.8 fb$^{-1}$ of $pp$ collision data collected at $\sqrt{s}$ = 13 TeV by the ATLAS detector at the LHC.
Candidate leptons are required to form a vertex, within the inner tracking volume of ATLAS, displaced
from the primary pp interaction region. No lepton pairs with an invariant mass greater than 12 GeV are
observed, consistent with the background expectations derived from data. The result is interpreted in
a supersymmetric model in which the lightest neutralino, produced via squark-antisquark production,
decays to $\ell^+\ell'^-\nu (\ell = e, \mu)$ with a finite lifetime due to the presence of R-parity violating couplings.
Cross section limits are presented for specific squark and neutralino masses. For a 700 GeV squark,
neutralinos with mass of 50–500 GeV and proper mean lifetimes corresponding to $c\tau$? of 1 mm to 6 m
are excluded. For a 1.6 TeV squark, 3 mm to 1 m are excluded for 1.3 TeV neutralinos.
