ET 01.06.2002

CMS detector resolution

CMS Silicon Strip Tracker CMS Silicon Strip Detector Resolution HIP Silicon Beam Telescope

ET 01.06.2002

CMS Silicon Strip Tracker

Diameter 2.4 m, Length 5.6 m Tracker Inner Barrel (TIB), Tracker Inner Disks (TID),

Tracker Outer Barrel (TOB), Tracker End Caps (TEC) Temperature -10 C

0.1 1.5

2.520 cm

120 cm

0 2.8 m

ET 01.06.2002

CMS Silicon Strip Detectors

n-type <100> FZ Silicon wafers, p+ strips, AC coupled, single-sided Strip width: strip/pitch ~ 0.25, strip length typically 12.5 cm

Wafer thickness m

Resistivity kcm

Pitch @ barrel detectors m

Pitch @ disk detectors m

Inner Tracker 320 1.5–3.0 80 or 120 81-112 … 124-158

Outer Tracker 500 3.5–6.0 122 or 183 126-143 … 186-205

ET 01.06.2002

Needs for Detector Resolution

Objective of CMS and Tracker: to detect signatures of new physics at LHC Method: by identifying and precisely measuring leptons, photons and jets Tools: Tracking and Vertex reconstruction within a strong 4 T magnetic field

Tracker measurements are combined with track segments reconstructed in the outer muon system -> to further extend the region over which a precise MUON momentum measurement can be performed (-> alignment)

ET 01.06.2002

Requirements for the Detector Resolution

CMS Tracker is designed to ensure high quality momentum resolution: momentum resolution better than pT/pT = 0.15*pT (in TeV/c), all 2.5

Hit resolution requirements for successful track reconstruction: around 15 um @ Tracker inner radius around 40 um @ Tracker outer radius

This means: Pixel: barrel 10 –15 um

endcaps 15 –20 um TIB: better than 20 um for shorter pitches

approaching (pitch/neliojuuri12) for larger pitches TOB: pitch 140 um -> resolution better than 40 um

pitch 210 um -> resolution better than 60 um(for hight pT tracks)

ET 01.06.2002

Studies of Single Track Performance

Study of single hit quality for several pitch values Study of single muon tracks of several pT values in all silicon tracker -> evaluation of the precision of the track reconstruction performance Accumulation of 500 tracks for statistics CMSIM & GEANT

ET 01.06.2002

Test beam results of the Detector Resolution

Barrel strip detector: 50 um pitch, 12.5 cm length -> hit resolution 11 um Double-sided detectors: pitch 100 um, stereo angle 100 mrad -> resolution 34

um orthogonal to stereo strips and 320 um in the stereo coordinate Wedge detector: 6.25 cm strips, 38-50 um pitch -> resolution 7 um The dependence of the resolution on the signal-to-noise-ratio, bias voltage and

incidence angle is weak

ET 01.06.2002

HIP Silicon Beam Telescope

Our ”mini-Tracker” 8 layers of Silicon detectors & adequate read-out electronics and DAQ Pitch 55 um Spatial resolution obtained in summer 2001 beam tests: 10 m Summer 2002: our own rad-hard Cz detectors & stereo angle detector