Tau trigger commissioning on first 2017 data ( CMS DP-2017/035)

Triggers selecting events with hadronically-decaying tau leptons (tau_h) are used in a wide variety of CMS analysis, in particular those targeting processes with a H->tautau decay. The first weeks of the 2017 CMS data-taking have been dedicated to the commissioning of the new inner pixel layer installed during the winter shutdown. Optimal settings of the pixel detector were not available yet for the first weeks of datataking. This reflects on the performance of the tau triggers, which strongly rely on tracking for the reconstruction of the hadronic charged decay products of the tau. The performance of the tau triggers during this commissioning period is presented here. The trigger efficiency of the trigger paths used to select tau_h is computed per single-tau leg through the tag-and-probe method, as a function of the offline-reconstructed tau transverse momentum. μtau_h triggers are used for the efficiency measurement. Hadronically-decaying tau leptons from the Z-> tau_μtau_h process are selected in events that fired the single μ HLT and fulfill the baseline H->tautau requirements of well identified and isolated μtau_h pairs and MT(ETmiss, μ) < 30 GeV.

μ tauh trigger efficiency Combined L1 and High Level trigger efficiency of the tau-leg of the μtauh trigger (loose isolation, pT>27 GeV, seeded by μ+tau; Level-1) trigger for the H->tauμtauh analysis, measured using 5.8 fb-1 of 13 TeV data collected by CMS in 2017. Events used are those passing Z->tauμtauh tag-and-probe selections.The lines correspond to the result of an unbinned maximum likelihood fit with a Crystal-Ball integral function. Efficiency in data is shown split between data collected before and after 18/07/2017, when an improved tracking reconstruction at HLT has been deployed. [Get pdf version] Contact: Thomas Strebler

Jet HLT trigger commissioning on first 2017 data ()

Trigger efficiency for jets at High Level trigger (HLT) as a function of the offline jet transverse momentum. The events are triggered by a single muon. Both offline and online jets are reconstructed with the Particle Flow algorithm, using the anti-kT jet algorithm with the R parameter of 0.4. The trigger was re-run to reproduce the HLT jets in order to match them to the offline jets(dR<0.2). The jets are restricted to a pseudorapidity range |eta|<3.0. In each efficiency curve, the numerator is the number of offline jets which are matched to the online jets inside a dR<0.2 and of which the transverse momentum is larger than trigger threshold. The denominator is the number of offline jets. Offline jets are selected with pt>20 GeV and in a pseudorapidity range as indicated below.
Contact: Milos Dordevic

Jet trigger efficiency abs(eta(jet))<3.0	Jet trigger efficiency abs(eta(jet))<1.3	Jet trigger efficiency 1.3<abs(eta(jet))<3.0
[Get pdf version]	[Get pdf version]	[Get pdf version]

-- ElisabettaGallo - 2017-08-23