Physics Studies Update FTK Meeting 02/23/06 Erik Brubaker U of Chicago

Feb 23, 2006FTK Meeting2 Overview Last meeting Update signal model Update bkgd model Update/improve LVL1 param’z’n Update to ATLAS release 11.0.X Document Results Add FTK performance information Tweak cuts, finalize study

Feb 23, 2006FTK Meeting3 H  hh  4b analysis Two algorithms for event selection in ATL- PHYS Algorithm AAlgorithm B NJETS >= 4 Consider leading 4 jets, pairing most consistent with 2 m h decays Consider any 4 jets most consistent with 2 m h decays Require b tag on all 4 jets Require both pairs have m bb = m h ± 25 GeV. Apply m h constraint, require m bbbb = m H ± 20 GeV.

Feb 23, 2006FTK Meeting4 Signal selection results L1Trig: 4 btags:  b = 0.6,  c = 0.1,  q = Still haven’t determined correct cross-section for this m h, m H. Trigger req makes Alg B strongly favored. Algorithm A StartL1Trig4 btagsm h cutm H cut # Events Cut eff. 6.6%0.3%36.6%44.1% Algorithm B StartL1Trig4 btagsm h cutm H cut # Events Cut eff. 6.6%1.4%84.9%67.6%  tot = 3.5e-5  tot = 5.4e-4

Feb 23, 2006FTK Meeting5 Background Selection Results SHERPA 2->2 + 2->3, ME/PS 25 GeV. Reported cross-section: 3.6e8 pb. Algorithm A StartL1Trig4 btagsm h cutm H cut # Events1.1602e e-068.2e-08 Cut eff. 0.0% 0.1%5.3% Algorithm B StartL1Trig4 btagsm h cutm H cut # Events1.1602e Cut eff. 0.0% 93.9%75.2%  tot = 7.1e-14  tot = 9.5e-11  L1 = 1.6e-4

Feb 23, 2006FTK Meeting6 Schedule Last meeting Update signal model Update bkgd model Update/improve LVL1 param’z’n Update to ATLAS release 11.0.X Document Results Add FTK performance information Tweak cuts, finalize study ~3 wks in parallel Finish Apr 7 Apr 7 – Apr 14 Apr 14 – Apr 28 Finish May 8