Table 1.

Definition of the criteria used for the signal determination. Selections $\mathrm{S}e{l}_1$ and $\mathrm{B}k{g}_1$ are the baseline selections used in the fit, $\mathrm{S}e{l}_2$ and $\mathrm{B}k{g}_2$ are used for the determination of systematic effects. The material veto and the requirement $R_{\mathrm{xy}}>0.4$ $mm$ are applied to both LLP candidates. The last column gives the number of data events selected, for a di-LLP reconstructed mass above 19 $\mathrm{Ge}\mathrm{V}/c^2$

Selection	$N_{\min }^{\mathrm{track}}$	$m_{\min }^{\mathrm{LLP}}$ ($\mathrm{Ge}\mathrm{V}/c^2$)	${\mathit{\sigma }}_{\max }^{\mathrm{R}}$ ($mm$)	${\mathit{\sigma }}_{\max }^{\mathrm{Z}}$	$N_{\mathrm{d}}$ ($mm$)
$\mathrm{S}e{l}_1$	6	6	0.05	0.25	157
$\mathrm{S}e{l}_2$	5	5	0.05	0.25	387
$\mathrm{B}k{g}_1$	4	4	–	–	23.2k
$\mathrm{B}k{g}_2$	5	5	–	–	10.1k