Performance of the CMS Barrel Muon Trigger Primitives in late 2016 pp collision runs

Abstract

This twiki page contains the plots presented in CMS DP-2016/074, which summarizes the performance of the CMS Barrel Muon Trigger primitives calculated by the TwinMux system using the first deployed version of an RPC-DT matching algorithm. For DT segments of low quality, this algorithm checks the presence of an RPC cluster matching in space the DT segment. The matching is based on the direction of the DT segment. If the RPC cluster is found, the RPC BX is assigned to the trigger primitive. The resulting trigger primitives are referred to as "Super-Primitives". Previous results on the TwinMux, making use of DT-only data were already published here.

DT Trigger Segment and DT+RPC SuperPrimitive Efficiency in TwinMux data

The efficiency of trigger primitives, both DT Trigger Segments and Super-Primitives, is defined and measured as the ratio between the number of observed and expected triggers.

The expected triggers are defined requiring the presence of a track segment in a chamber, reconstructed in both Theta and Phi views, belonging to a “Global Muon”, and having at least 4 associated hits in the Phi layers (minimum number of hits required to build a DT Track Segment).

The trigger primitive was then considered efficient if a trigger primitive was delivered at the correct bunch crossing (in-event BX=0 by definition) in the same chamber.

Notice that no efficiency can be computed if for no reconstructed segments are available.

Also, in order to avoid biases, a further event selection is used to ensure the chamber under study was not necessary to build a muon track in the Track Finder: at least two other stations are required to deliver trigger primitives in the event.

In the following plots we show the BX distributions and the efficiency of the DT Local Trigger alone and of the DT+RPC Super-Primitive:

• the two BX distributions are superimposed to appreciate the reduction of out of time triggers
• the two efficiencies are superimposed and shown as a function of the “Global Muon” pseudorapidity
• the ratios of DT+RPC Super-Primitive and DT-only Local Trigger efficiencies, for all chambers, are summarized in a set of four 2D maps

Figure

Caption

pdf version

DT Local Trigger and DT+RPC Super-Primitive BX The histograms show the bunch crossing distribution (BX) of the trigger primitives. The correct event bunch crossing is BX = 0. In open red circles, the DT-only Trigger Primitives. In solid black circles, the DT+RPC SuperPrimitives. The out of time DT-only Triggers are reduced using the better BX identification capability of the RPC clusters, with a corresponding increase in the number of DT+RPC SuperPrimitives in BX=0 (not visible in the plot due to the log scale).

pdf version

Super-primitive Local Trigger Efficiency vs muon η Trigger Primitive efficiency, for the MB1 station, versus the Global Muon eta. In red, open circles, the efficiency of DT-only Trigger Primitives. In blue, solid circles, the efficiency of DT+RPC SuperPrimitives. An average increase of the efficiency of about 1.4% is observed: from 94.1% (DT Local Trigger) to 95.5% (DT+RPC SuperPrimitives)

pdf version

*Ratio* The maps show the ratio of the efficiency of the DT+RPC SuperPrimitives and the DT-only Trigger Primitives for each DT chamber. The efficiency is improved in all chambers. An average increase of the efficiency of about 1.4% is observed: from 94.1% (DT-only Trigger Primitives) to 95.5% (DT+RPC SuperPrimitives)

pdf version

TwinMux Algorithm in 2016 TwinMux Algorithm in 2016.

Contacts

CMS DPG conveners of the Muon subdetectors

subdetector	email
Muon DPG Office	cms-muon-DPGO@cernNOSPAMPLEASE.ch
RPC	cms-dpg-conveners-rpc@cernNOSPAMPLEASE.ch
DT	cms-dpg-conveners-dt@cernNOSPAMPLEASE.ch
CSC	cms-dpg-conveners-csc@cernNOSPAMPLEASE.ch

-- IgnacioRedondo - 2016-11-23