Boosted ggH(b bbar) Trigger Efficiency in 2018 Data ( CMS DP-2018/053)

This note shows the efficiency of an HLT trigger used in the gluon fusion Higgs decaying to a pair of b quarks analysis. This analysis searches for Higgs bosons in the “boosted” regime, so the 𝑝_𝑇 is required to be greater than 450 GeV and the entire H→𝑏𝑏 ̅ decay is reconstructed in a single jet. The efficiency measurements use the partial dataset collected by the CMS detector in 2018, corresponding to 24.3/fb.
The trigger requires the presence of one anti-𝑘_𝑡 jet with a cone size of ∆𝑅=0.8 (AK8) and a 𝑝_𝑇>330 GeV, the presence of an AK8 jet with a mass >30 GeV after soft and wide-angle radiation has been removed from the jet, and finally a “double-b” discriminator > −0.4 requirement is applied to jets that pass the 𝑝_𝑇 threshold. The “double-b” discriminator is a multivariate discriminator that holistically determines the likelihood that a jet contains two b quarks.
The offline analysis utilizes this “double-b” trigger, along with the combination of triggers that require a large amount of hadronic transverse energy in the event (𝐻_𝑇) and a jet with a 𝑝_𝑇 to be above a given threshold. This “double-b” trigger was introduced to gain trigger efficiency in the lower jet 𝑝_𝑇 region.

HLT_AK8PFJet330_TrimMass30_PFAK8BoostedDoubleB_np4: pT Double-b trigger efficiency measured in data as a function of 𝑝_𝑇 of the offline 𝑝_𝑇 leading AK8 jet. The efficiency is calculated for events that pass the HLT_IsoMu30 trigger and have a 𝑝_𝑇 leading AK8 jet with a double-b >0.9 and a soft-drop mass (𝑀_𝑆𝐷)>40 GeV. This preselection corresponds to the signal region in the offline analysis. [Get pdf version] Contact: Michael Krohn

HLT_AK8PFJet330_TrimMass30_PFAK8BoostedDoubleB_np4: pT Double-b trigger efficiency measured in data as a function of 𝑝_𝑇 of the offline 𝑝_𝑇 leading AK8 jet. The efficiency is calculated for events that pass the HLT_IsoMu30 trigger and have a 𝑝_𝑇 leading AK8 jet with a double-b >0.0 and a soft-drop mass (𝑀_𝑆𝐷)>40 GeV. This preselection corresponds to the control region used to estimate the multijet background in the offline analysis. [Get pdf version] Contact: Michael Krohn

HLT_AK8PFJet330_TrimMass30_PFAK8BoostedDoubleB_np4: eta Double-b trigger efficiency measured in data as a function of eta of the offline 𝑝_𝑇 leading AK8 jet. The efficiency is calculated for events that pass the HLT_IsoMu30 trigger and have a 𝑝_𝑇 leading AK8 jet with a 𝑝_𝑇>450 GeV, double-b >0.9, and soft-drop mass (𝑀_𝑆𝐷)>40 GeV. This preselection corresponds to the signal region in the offline analysis. [Get pdf version] Contact: Michael Krohn

HLT_AK8PFJet330_TrimMass30_PFAK8BoostedDoubleB_np4: double-b Double-b trigger efficiency measured in data as a function of the double-b discriminator of the offline 𝑝_𝑇 leading AK8 jet. The efficiency is calculated for events that pass the HLT_AK8PF400_TrimMass30 trigger and have a 𝑝_𝑇 leading AK8 jet with a 𝑝_𝑇 >450 GeV. The high efficiency at low double-b values is due to the offline and online double-b taggers not being fully correlated. The feature near 0 corresponds to a similar feature in the double-b discriminator distribution. [Get pdf version] Contact: Michael Krohn

-- ElisabettaGallo - 2018-09-18