Search for long-lived particles decaying into displaced jets in proton-proton collisions at $\sqrt{s}=$ 13 TeV
Phys.Rev. D99 (2019) 032011
The collaboration

Abstract (data abstract)
A search for long-lived particles decaying into jets is presented. Data were collected with the CMS detector at the LHC from proton-proton collisionsat a center-of-mass energy of 13 $\mathrm{TeV}$ in 2016, corresponding to an integratedluminosity of 35.9 $\mathrm{fb}^{-1}$. The search examines the distinctive topology of displaced tracks and secondary vertices. The selected events are found to be consistent with standard model predictions.For a simplified model in which long-lived neutral particles are pair produced and decay to two jets, pair production cross sections largerthan 0.2 $\mathrm{fb}$ are excluded at $95 \%$ confidence level for a long-lived particle mass larger than 1000 $\mathrm{GeV}$ and proper decay lengths between 3 and 130 $\mathrm{mm}$.Several supersymmetry models with gauge-mediated supersymmetrybreaking or $R$-parity violation, where pair-produced long-lived gluinos or top squarks decay to several final-state topologiescontaining displaced jets, are also tested. For these models, in the mass ranges above 200 $\mathrm{GeV}$, gluino masses up to 2300--2400 $\mathrm{GeV}$ and top squark masses up to 1350--1600 $\mathrm{GeV}$ are excluded for proper decay lengths approximately between 10 and100 $\mathrm{mm}$. These are the most restrictive limits to date on these models.