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Tau HLT +ZTT. Michail Bachtis University Of Wisconsin. Action items. Plots and talk for Tau ID Not this time either Finish Tau HLT Monitoring(push to include Tau HLT fixes early) This is done Gave DQM for CRAFT Some small modifications on offline DQM to be done by the end of the week
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Tau HLT +ZTT • Michail Bachtis • University Of Wisconsin
Action items Plots and talk for Tau ID Not this time either Finish Tau HLT Monitoring(push to include Tau HLT fixes early) This is done Gave DQM for CRAFT Some small modifications on offline DQM to be done by the end of the week Try flat isolation cut This has been done weeks ago and has been covered We converged to relative isolation + Maximum loose flta cut
Tau HLT at 310_preX A lot of work to show plots that unpacking is a problem in the current state Finally at 310_pre11 relvals we see that the efficiency is horrible due to the unpacking They asked me if unpacking at 20 is OK . ANSWER:IT is not! MY path threshold is 14 I want to unpack at 14 (end of story) In general : I want to unpack ECAL around tau jets for unpacking threshold = L1 Tau trigger threshold NOT MORE They asked if the timing is OK when lowering the threshold Timing is OK for GLOBAL unpacking so any threshold over 0 will work!!! Hope it is resolved in pre11!
More things that appeared I am making the poster for HEP2009/ Have to have it by Monday We had one for ICHEP so I am taking that as a ref since we did not approve new results The deadline for the trigger review note is on Friday!! I am making plots for that too
Tau ID No plots/ Implementing our new ideas Looking at MC data shows a lot of things Obviously a three prong background is a pion and a converted pair ! A lot of etas and phis in the region We need to reject electrons! Tail to the one prong Pi0 isolation: Comes from electron tracks in the region Tail to the three prong isolation Comes from brem photons when we associate the tracks Tail to the one prong isolation Comes from misidentification of a one prong +pi0 that converted
Solution1: Brem recovery Brem recovery Run on the track and pick the photons radiated tangentially It works !!!! <10% misassociation Custom code In 31X will use default(I needed a benchmark to evaluate it though) Calorimeter
Electron ID A very simplistic cut just to remove the electrons from the pion list If the track Brems it is an electron If the track does not brem E/P should be around 1 78% Efficiency 5% Fake Good for what I need now WILL Use default electron PreID in 31X but I have to evaluate it It is a booosted decision tree......
Conversions! Since we have electrons we can do conversions and improve pi0 resolution When you have two brem recovered electrons If the track inner points are near combine them and create converted photon If you have one electron Combine it with the photons (on the other side of the track opening) to get the brem photons from the not reconstructed track If you have no electron Search for photon pairs around pi0 mass If no photon pairs Use the highest photon as the pi0(Assume it is merged if the energy is over 20GeV)
Status Wrote everything Evaluating conversions Will try to have plots next week