1. 1 Goals -Short term: – Finish merging the L1 trigger configuration files with the HLT. – When this is done, hopefully I will see that the signal increase for a given fake rate. In this way, we can see that the pixel upgrade is a worthwhile project. - Longer term: – Integrate the Long Barrel Geometry and Phase II definitions. We will have tracking for level 1 taus for the first time. – Look at the HLT in the same manner as above.

2. 2 Tau Finding Algorithm Seed with a single tower: E.g. ET(1)>5 GeV Energy measurement in a 2x2 region (pick the one with highest sum ET): e.g. ET(2x2)>10 GeV Shape requirement in eta-direction: Has to be very local (or will blow up with PU): e.g. Max(ET(3x2)-ET(2x2))< 5

3. 3 Pixel Upgrade Opportunities for Upgrade Remove radiation damage Lower/move mass  Bpix Add 4 th layer Move layer 1 closer to IP Alter pitch  Fpix Add 3 rd disk Alter disk configuration Streamline sensor design Improved “3 out of 4” pixel seeding has implications for the HLT that are not well understood.

4. 4 HLT Predictions  Due to the new pixel tracks, we expect  Higher efficiency  We will find more tracks pointing to the calorimeter  Lower fake rate  With the more accurate tracks, we will be able to see if the track is really pointing to our cluster or rather in the isolation region.

5. 5 Requirements at L1 Level 1 – Cluster threshold 2 – Tauseedtower 10 – IsolationTauA 10000 – IsolationTauB 10000 – Isolation threshold tau 6

6. Requirements at L2 SLHChltL2TauJets – Unpacks list of taujet EtMin=15 – Iterative cone algorithm with Δr=0.2 SLHChltL2TauNarrowConeIsolationProducer – ECAL isolation, inner cone 0.15, outer cone 0.5 – ECAL clustering, cluster radius 0.08 – Tower Isolation, inner cone 0.2, outer cone 0.5 SLHChltL2TauRelaxingIsolationSelector – MinJetEt 15, isolation Still working through this calculation Jan 17. 2011

7. Requirements at L2.5 SLHChltL25TauConeIsolation - at least two pixel hits associated with the track conesize.5 - at least 5 hits in total (pixel plus strip) associated with the track - the transverse impact parameter does not exceed 300 μm - the minimum transverse momentum 1 GeV/c - the normalized chi-squared of the track fit below 100 - matching cone.2 - signal cone 0.15 - isolation cone 0.5 - minimum transverse momentum in isolation ring 1 GeV/c - maximum number of tracks in isolation ring 0 SLHChltL25TauLeadingTrackPtCutSelector - Min leading track pt > 5 SLHChltL25TauConeIsolation - at least two pixel hits associated with the track conesize.5 - at least 5 hits in total (pixel plus strip) associated with the track - the transverse impact parameter does not exceed 300 μm - the minimum transverse momentum 1 GeV/c - the normalized chi-squared of the track fit below 100 - uses a fixed cones size: signal cone 0.15, isolation cone 0.5 - min leading track pt 5.0 SLHChltL25TauConeIsolation - at least two pixel hits associated with the track conesize.5 - at least 5 hits in total (pixel plus strip) associated with the track - the transverse impact parameter does not exceed 300 μm - the minimum transverse momentum 1 GeV/c - the normalized chi-squared of the track fit below 100 - uses a fixed cones size: signal cone 0.15, isolation cone 0.5 - min leading track pt 5.0

8. Requirements at L3  SLHChltL3TauConeIsolation  At least 2 pixel hits associated with the track  At least five hits in total (pixel plus strip) associated with the track  The transverse impact parameter does not exceed 300μm  The pt must exceed 1 GeV/c  The normalized chi-squared of the track fit below 100  Matching cone 0.2, signal cone 0.15, isolation cone 0.5  0 tracks in isolation ring  Min pt in isolation ring 1 Gev/c  SLHChltL3TauIsolationSelector – Min pt leading track 5 GeV/c  SLHChltL1HLTSingleIsoTau30JetsMatch – Matches to a level 1 tau ΔR < 0.5