Strategy and performance of the CMS long-lived particle trigger program in proton-proton collisions at $\sqrt{s}$ = 13.6 TeV

The CMS collaboration Hayrapetyan, Aram ; Makarenko, Vladimir ; Tumasyan, Armen ; et al.
CMS-EXO-23-016, 2026.
Inspire Record 3111434 DOI 10.17182/hepdata.165445

In the physics program of the CMS experiment during the CERN LHC Run 3, which started in 2022, the long-lived particle triggers have been improved and extended to expand the scope of the corresponding searches. These dedicated triggers and their performance are described in this paper, using several theoretical benchmark models that extend the standard model of particle physics. The results are based on proton-proton collision data collected with the CMS detector during 2022$-$2024 at a center-of-mass energy of 13.6 TeV, corresponding to integrated luminosities of up to 123 fb$^{-1}$.

119 data tables

Offline standard tracking efficiency during Run~3 for different tracking iterations, as a function of simulated radial position of the track production vertex. In the figure, $t\bar{t}$ simulation for 2025 conditions and an average PU of 62 is used, and the tracks are required to have $\mathrm{p_T}>0.9$ GeV and $|\eta|<2.5$. The tracking efficiency is defined as the ratio of the simulated tracks (with the aforementioned selection requirements) geometrically matched to a reconstructed track, divided by the total simulated tracks passing the selections.

Overall standard tracking efficiency at the HLT during Run~3, as a function of the simulated radial position of the track production vertex. In the figure, $t\bar{t}$ simulation for 2025 conditions and an average PU of 62 is used, and the tracks are required to have $\mathrm{p_T}>0.9$ GeV and $|\eta|<2.5$. The tracking efficiency is defined as the ratio of the simulated tracks (with the aforementioned selection requirements) geometrically matched to a reconstructed track, divided by the total simulated tracks passing the selections.

L1T+HLT efficiency of the MET+IsoTrk trigger as a function of the number of tracker layers with valid measurements of the track that pass the offline requirements, in $\tilde{\chi}_{1}^{\pm} \rightarrow \tilde{\chi}_{1}^{0}$+X simulated events for 2022 conditions, where $m_{\tilde{\chi}_{1}^{\pm}}=900$ GeV and $\tilde{\chi}_{1}^{0}$ is nearly mass-degenerate with $\tilde{\chi}_{1}^{\pm}$. The efficiency is shown for LLPs with $c\tau=$ 10, 100, and 1000 cm in black, blue, and red, respectively.

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